Searching the literature for proteins facilitates the identification of biological processes, if advanced methods of analysis are linked: a case study on microgravity-caused changes in cells.

PubMed

Bauer, Johann; Bussen, Markus; Wise, Petra; Wehland, Markus; Schneider, Sabine; Grimm, Daniela

2016-07-01

More than one hundred reports were published about the characterization of cells from malignant and healthy tissues, as well as of endothelial cells and stem cells exposed to microgravity conditions. We retrieved publications about microgravity related studies on each type of cells, extracted the proteins mentioned therein and analyzed them aiming to identify biological processes affected by microgravity culture conditions. The analysis revealed 66 different biological processes, 19 of them were always detected when papers about the four types of cells were analyzed. Since a response to the removal of gravity is common to the different cell types, some of the 19 biological processes could play a role in cellular adaption to microgravity. Applying computer programs, to extract and analyze proteins and genes mentioned in publications becomes essential for scientists interested to get an overview of the rapidly growing fields of gravitational biology and space medicine.

Intravital microscopy: a novel tool to study cell biology in living animals.

PubMed

Weigert, Roberto; Sramkova, Monika; Parente, Laura; Amornphimoltham, Panomwat; Masedunskas, Andrius

2010-05-01

Intravital microscopy encompasses various optical microscopy techniques aimed at visualizing biological processes in live animals. In the last decade, the development of non-linear optical microscopy resulted in an enormous increase of in vivo studies, which have addressed key biological questions in fields such as neurobiology, immunology and tumor biology. Recently, few studies have shown that subcellular processes can be imaged dynamically in the live animal at a resolution comparable to that achieved in cell cultures, providing new opportunities to study cell biology under physiological conditions. The overall aim of this review is to give the reader a general idea of the potential applications of intravital microscopy with a particular emphasis on subcellular imaging. An overview of some of the most exciting studies in this field will be presented using resolution as a main organizing criterion. Indeed, first we will focus on those studies in which organs were imaged at the tissue level, then on those focusing on single cells imaging, and finally on those imaging subcellular organelles and structures.

Chemical strategies for pancreatic β cell differentiation, reprogramming, and regeneration.

PubMed

Ma, Xiaojie; Zhu, Saiyong

2017-04-01

Generation of unlimited functional pancreatic β cells is critical for the study of pancreatic biology and treatment of diabetes mellitus. Recent advances have suggested several promising directions, including directed differentiation of pancreatic β cells from pluripotent stem cells, reprogramming of pancreatic β cells from other types of somatic cells, and stimulated proliferation and enhanced functions of existing pancreatic β cells. Small molecules are useful in generating unlimited numbers of functional pancreatic cells in vitro and could be further developed as drugs to stimulate endogenous pancreatic regeneration. Here, we provide an updated summary of recent major achievements in pancreatic β cell differentiation, reprogramming, proliferation, and function. These studies will eventually lead to significant advances in the field of pancreatic biology and regeneration. © The Author 2017. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Mast cells: potential positive and negative roles in tumor biology.

PubMed

Marichal, Thomas; Tsai, Mindy; Galli, Stephen J

2013-11-01

Mast cells are immune cells that reside in virtually all vascularized tissues. Upon activation by diverse mechanisms, mast cells can secrete a broad array of biologically active products that either are stored in the cytoplasmic granules of the cells (e.g., histamine, heparin, various proteases) or are produced de novo upon cell stimulation (e.g., prostaglandins, leukotrienes, cytokines, chemokines, and growth factors). Mast cells are best known for their effector functions during anaphylaxis and acute IgE-associated allergic reactions, but they also have been implicated in a wide variety of processes that maintain health or contribute to disease. There has been particular interest in the possible roles of mast cells in tumor biology. In vitro studies have shown that mast cells have the potential to influence many aspects of tumor biology, including tumor development, tumor-induced angiogenesis, and tissue remodeling, and the shaping of adaptive immune responses to tumors. Yet, the actual contributions of mast cells to tumor biology in vivo remain controversial. Here, we review some basic features of mast cell biology with a special emphasis on those relevant to their potential roles in tumors. We discuss how using in vivo tumor models in combination with models in which mast cell function can be modulated has implicated mast cells in the regulation of host responses to tumors. Finally, we summarize data from studies of human tumors that suggest either beneficial or detrimental roles for mast cells in tumors. ©2013 AACR.

Cell Biology and Microbiology: A Continuous Cross-Feeding.

PubMed

Pizarro-Cerdá, Javier; Cossart, Pascale

2016-07-01

Microbiology and cell biology both involve the study of cells, albeit at different levels of complexity and scale. Interactions between both fields during the past 25 years have led to major conceptual and technological advances that have reshaped the whole biology landscape and its biomedical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cell biology of the Koji mold Aspergillus oryzae.

PubMed

Kitamoto, Katsuhiko

2015-01-01

Koji mold, Aspergillus oryzae, has been used for the production of sake, miso, and soy sauce for more than one thousand years in Japan. Due to the importance, A. oryzae has been designated as the national micro-organism of Japan (Koku-kin). A. oryzae has been intensively studied in the past century, with most investigations focusing on breeding techniques and developing methods for Koji making for sake brewing. However, the understanding of fundamental biology of A. oryzae remains relatively limited compared with the yeast Saccharomyces cerevisiae. Therefore, we have focused on studying the cell biology including live cell imaging of organelles, protein vesicular trafficking, autophagy, and Woronin body functions using the available genomic information. In this review, I describe essential findings of cell biology of A. oryzae obtained in our study for a quarter of century. Understanding of the basic biology will be critical for not its biotechnological application, but also for an understanding of the fundamental biology of other filamentous fungi.

Molecular biology of mycoplasmas: from the minimum cell concept to the artificial cell.

PubMed

Cordova, Caio M M; Hoeltgebaum, Daniela L; Machado, Laís D P N; Santos, Larissa Dos

2016-01-01

Mycoplasmas are a large group of bacteria, sorted into different genera in the Mollicutes class, whose main characteristic in common, besides the small genome, is the absence of cell wall. They are considered cellular and molecular biology study models. We present an updated review of the molecular biology of these model microorganisms and the development of replicative vectors for the transformation of mycoplasmas. Synthetic biology studies inspired by these pioneering works became possible and won the attention of the mainstream media. For the first time, an artificial genome was synthesized (a minimal genome produced from consensus sequences obtained from mycoplasmas). For the first time, a functional artificial cell has been constructed by introducing a genome completely synthesized within a cell envelope of a mycoplasma obtained by transformation techniques. Therefore, this article offers an updated insight to the state of the art of these peculiar organisms' molecular biology.

Systems Biology Analysis of Heterocellular Signaling.

PubMed

Tape, Christopher J

2016-08-01

Tissues comprise multiple heterotypic cell types (e.g., epithelial, mesenchymal, and immune cells). Communication between heterotypic cell types is essential for biological cohesion and is frequently dysregulated in disease. Despite the importance of heterocellular communication, most systems biology techniques do not report cell-specific signaling data from mixtures of cells. As a result, our existing perspective of cellular behavior under-represents the influence of heterocellular signaling. Recent technical advances now permit the resolution of systems-level cell-specific signaling data. This review discusses how new physical, spatial, and isotopic resolving methods are facilitating unique systems biology studies of heterocellular communication. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolutionary cell biology: functional insight from "endless forms most beautiful".

PubMed

Richardson, Elisabeth; Zerr, Kelly; Tsaousis, Anastasios; Dorrell, Richard G; Dacks, Joel B

2015-12-15

In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking. © 2015 Richardson et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication 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).

Stem and progenitor cells: the premature desertion of rigorous definitions.

PubMed

Seaberg, Raewyn M; van der Kooy, Derek

2003-03-01

A current disturbing trend in stem cell biology is the abandonment of rigorous definitions of stem and progenitor cells in favor of more ambiguous, all-encompassing concepts. However, recent studies suggest that there are consistent, functional differences in the biology of these two cell types. Admittedly, it can be difficult to harmonize the in vivo and in vitro functional differences between stem and progenitor cells. Nonetheless, these distinctions between cell types should be emphasized rather than ignored, as they can be used to test specific hypotheses in neural stem cell biology.

Synthetic Biology Outside the Cell: Linking Computational Tools to Cell-Free Systems

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

Lewis, Daniel D.; Department of Biomedical Engineering, University of California Davis, Davis, CA; Villarreal, Fernando D.

As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with amore » special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems.« less

Synthetic Biology Outside the Cell: Linking Computational Tools to Cell-Free Systems

PubMed Central

Lewis, Daniel D.; Villarreal, Fernando D.; Wu, Fan; Tan, Cheemeng

2014-01-01

As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems. PMID:25538941

Synthetic biology outside the cell: linking computational tools to cell-free systems.

PubMed

Lewis, Daniel D; Villarreal, Fernando D; Wu, Fan; Tan, Cheemeng

2014-01-01

As mathematical models become more commonly integrated into the study of biology, a common language for describing biological processes is manifesting. Many tools have emerged for the simulation of in vivo synthetic biological systems, with only a few examples of prominent work done on predicting the dynamics of cell-free synthetic systems. At the same time, experimental biologists have begun to study dynamics of in vitro systems encapsulated by amphiphilic molecules, opening the door for the development of a new generation of biomimetic systems. In this review, we explore both in vivo and in vitro models of biochemical networks with a special focus on tools that could be applied to the construction of cell-free expression systems. We believe that quantitative studies of complex cellular mechanisms and pathways in synthetic systems can yield important insights into what makes cells different from conventional chemical systems.

Vision-guided micromanipulation system for biomedical application

NASA Astrophysics Data System (ADS)

Shim, Jae-Hong; Cho, Sung-Yong; Cha, Dong-Hyuk

2004-10-01

In these days, various researches for biomedical application of robots have been carried out. Particularly, robotic manipulation of the biological cells has been studied by many researchers. Usually, most of the biological cell's shape is sphere. Commercial biological manipulation systems have been utilized the 2-Dimensional images through the optical microscopes only. Moreover, manipulation of the biological cells mainly depends on the subjective viewpoint of an operator. Due to these reasons, there exist lots of problems such as slippery and destruction of the cell membrane and damage of the pipette tip etc. In order to overcome the problems, we have proposed a vision-guided biological cell manipulation system. The newly proposed manipulation system makes use of vision and graphic techniques. Through the proposed procedures, an operator can inject the biological cell scientifically and objectively. Also, the proposed manipulation system can measure the contact force occurred at injection of a biological cell. It can be transmitted a measured force to the operator by the proposed haptic device. Consequently, the proposed manipulation system could safely handle the biological cells without any damage. This paper presents the introduction of our vision-guided manipulation techniques and the concept of the contact force sensing. Through a series of experiments the proposed vision-guided manipulation system shows the possibility of application for precision manipulation of the biological cell such as DNA.

Insights into female germ cell biology: from in vivo development to in vitro derivations.

PubMed

Jung, Dajung; Kee, Kehkooi

2015-01-01

Understanding the mechanisms of human germ cell biology is important for developing infertility treatments. However, little is known about the mechanisms that regulate human gametogenesis due to the difficulties in collecting samples, especially germ cells during fetal development. In contrast to the mitotic arrest of spermatogonia stem cells in the fetal testis, female germ cells proceed into meiosis and began folliculogenesis in fetal ovaries. Regulations of these developmental events, including the initiation of meiosis and the endowment of primordial follicles, remain an enigma. Studying the molecular mechanisms of female germ cell biology in the human ovary has been mostly limited to spatiotemporal characterizations of genes or proteins. Recent efforts in utilizing in vitro differentiation system of stem cells to derive germ cells have allowed researchers to begin studying molecular mechanisms during human germ cell development. Meanwhile, the possibility of isolating female germline stem cells in adult ovaries also excites researchers and generates many debates. This review will mainly focus on presenting and discussing recent in vivo and in vitro studies on female germ cell biology in human. The topics will highlight the progress made in understanding the three main stages of germ cell developments: namely, primordial germ cell formation, meiotic initiation, and folliculogenesis.

Dynamic microenvironments: the fourth dimension.

PubMed

Tibbitt, Mark W; Anseth, Kristi S

2012-11-14

The extracellular space, or cell microenvironment, choreographs cell behavior through myriad controlled signals, and aberrant cues can result in dysfunction and disease. For functional studies of human cell biology or expansion and delivery of cells for therapeutic purposes, scientists must decipher this intricate map of microenvironment biology and develop ways to mimic these functions in vitro. In this Perspective, we describe technologies for four-dimensional (4D) biology: cell-laden matrices engineered to recapitulate tissue and organ function in 3D space and over time.

Quantitative biology of single neurons

PubMed Central

Eberwine, James; Lovatt, Ditte; Buckley, Peter; Dueck, Hannah; Francis, Chantal; Kim, Tae Kyung; Lee, Jaehee; Lee, Miler; Miyashiro, Kevin; Morris, Jacqueline; Peritz, Tiina; Schochet, Terri; Spaethling, Jennifer; Sul, Jai-Yoon; Kim, Junhyong

2012-01-01

The building blocks of complex biological systems are single cells. Fundamental insights gained from single-cell analysis promise to provide the framework for understanding normal biological systems development as well as the limits on systems/cellular ability to respond to disease. The interplay of cells to create functional systems is not well understood. Until recently, the study of single cells has concentrated primarily on morphological and physiological characterization. With the application of new highly sensitive molecular and genomic technologies, the quantitative biochemistry of single cells is now accessible. PMID:22915636

Micro/nano-fabrication technologies for cell biology.

PubMed

Qian, Tongcheng; Wang, Yingxiao

2010-10-01

Micro/nano-fabrication techniques, such as soft lithography and electrospinning, have been well-developed and widely applied in many research fields in the past decade. Due to the low costs and simple procedures, these techniques have become important and popular for biological studies. In this review, we focus on the studies integrating micro/nano-fabrication work to elucidate the molecular mechanism of signaling transduction in cell biology. We first describe different micro/nano-fabrication technologies, including techniques generating three-dimensional scaffolds for tissue engineering. We then introduce the application of these technologies in manipulating the physical or chemical micro/nano-environment to regulate the cellular behavior and response, such as cell life and death, differentiation, proliferation, and cell migration. Recent advancement in integrating the micro/nano-technologies and live cell imaging are also discussed. Finally, potential schemes in cell biology involving micro/nano-fabrication technologies are proposed to provide perspectives on the future research activities.

Micro/nano-fabrication technologies for cell biology

PubMed Central

Qian, Tongcheng

2012-01-01

Micro/nano-fabrication techniques, such as soft lithography and electrospinning, have been well-developed and widely applied in many research fields in the past decade. Due to the low costs and simple procedures, these techniques have become important and popular for biological studies. In this review, we focus on the studies integrating micro/nano-fabrication work to elucidate the molecular mechanism of signaling transduction in cell biology. We first describe different micro/nano-fabrication technologies, including techniques generating three-dimensional scaffolds for tissue engineering. We then introduce the application of these technologies in manipulating the physical or chemical micro/nano-environment to regulate the cellular behavior and response, such as cell life and death, differentiation, proliferation, and cell migration. Recent advancement in integrating the micro/nano-technologies and live cell imaging are also discussed. Finally, potential schemes in cell biology involving micro/nano-fabrication technologies are proposed to provide perspectives on the future research activities. PMID:20490938

Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands

PubMed Central

Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

2016-01-01

In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1+ pancreatic progenitors, much less is known about the transition toward Ngn3+ pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments. PMID:26834702

Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

PubMed

Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

2015-01-01

In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

Biological capacitance studies of anodes in microbial fuel cells using electrochemical impedance spectroscopy.

PubMed

Lu, Zhihao; Girguis, Peter; Liang, Peng; Shi, Haifeng; Huang, Guangtuan; Cai, Lankun; Zhang, Lehua

2015-07-01

It is known that cell potential increases while anode resistance decreases during the start-up of microbial fuel cells (MFCs). Biological capacitance, defined as the apparent capacitance attributed to biological activity including biofilm production, plays a role in this phenomenon. In this research, electrochemical impedance spectroscopy was employed to study anode capacitance and resistance during the start-up period of MFCs so that the role of biological capacitance was revealed in electricity generation by MFCs. It was observed that the anode capacitance ranged from 3.29 to 120 mF which increased by 16.8% to 18-20 times over 10-12 days. Notably, lowering the temperature and arresting biological activity via fixation by 4% para formaldehyde resulted in the decrease of biological capacitance by 16.9 and 62.6%, indicating a negative correlation between anode capacitance and anode resistance of MFCs. Thus, biological capacitance of anode should play an important role in power generation by MFCs. We suggest that MFCs are not only biological reactors and/or electrochemical cells, but also biological capacitors, extending the vision on mechanism exploration of electron transfer, reactor structure design and electrode materials development of MFCs.

Fluorescent probes for real-time measurement of nitric oxide in living cells.

PubMed

Li, Huili; Wan, Ajun

2015-11-07

Nitric oxide (NO) is an important signaling molecule in biology. Both NO excess and insufficiency have been implicated in numerous physiological and pathological conditions. In order to study the diverse biological roles of NO in cells and tissues, many techniques have been developed for assaying NO. Recently, new generations of fluorescent probes have become indispensible tools for the study of NO biology because of their sensitivity, selectivity, spatiotemporal resolution, and experimental feasibility. Rational application of these probes in the study requires the understanding of the molecular mechanism that the probes are involved in. In this review, we will present an arsenal of fluorescent probes used to detect NO in living cells and animal tissues. We will also discuss the molecular mechanisms, actualities and prospects of fluorescent probes in detecting NO in cell biology.

A brief history of the Japan Society for Cell Biology.

PubMed

Tashiro, Y; Okigaki, T

2001-02-01

The Japan Society for Cell Biology (JSCB) was first founded in 1950 as the Japan Society for Cellular Chemistry under the vigorous leadership of Seizo Katsunuma, in collaboration with Shigeyasu Amano and Satimaru Seno. The Society was provisionally named as above simply because cell biology had not yet been coined at that time in Japan, although in prospect and reality the Society was in fact for the purpose of pursuing cell biology. Later in 1964, the Society was properly renamed as the Japan Society for Cell Biology. After this renaming, the JSCB made great efforts to adapt itself to the rapid progress being made in cell biology. For this purpose the Society's constitution was created in 1966 and revised in 1969. According to the revised constitution, the President, Executive Committee and Councils were to be determined by ballot vote. The style of the annual meetings was gradually modified to incorporate general oral and poster presentations in addition to Symposia (1969-1974). The publication of annual periodicals in Japanese called Symposia of the Japan Society for Cellular Chemistry (1951-1967) and later Symposia of the Japan Society for Cell Biology (1968-1974) was replaced by a new international journal called Cell Structure and Function initiated in 1975. This reformation made it possible for the Society to participate in the Science Council of Japan in 1975 and finally in 1993 to acquire its own study section of Cell Biology with grants-in-aid from the Ministry of Education and Science, Japan. The JSCB hosted the 3rd International Congress on Cell Biology (ICCB) in 1984 and the 3rd Asian-Pacific Organization for Cell Biology (APOCB) Congress in 1998, thus contributing to the international advancement of cell biology. Now the membership of JSCB stands at approximately 1,800 and the number of presentations per meeting is 300 to 400 annually. Although a good number of interesting and important findings in cell biology have been reported from Japan, the general academic activity of the JSCB is far less than one might expect. This is simply due the fact that academic activity in the field of cell biology in Japan is divided among several other related societies such as the Japan Society for Molecular Biology and the Japan Society for Developmental Biology, among others.

Development and biological applications of optical tweezers and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Xie, Chang'an

Optical tweezers is a three-dimensional manipulation tool that employs a gradient force that originates from the single highly focused laser beam. Raman spectroscopy is a molecular analytical tool that can give a highly unique "fingerprint" for each substance by measuring the unique vibrations of its molecules. The combination of these two optical techniques offers a new tool for the manipulation and identification of single biological cells and microscopic particles. In this thesis, we designed and implemented a Laser-Tweezers-Raman-Spectroscopy (LTRS) system, also called the Raman-tweezers, for the simultaneous capture and analysis of both biological particles and non-biological particles. We show that microparticles can be conveniently captured at the focus of a laser beam and the Raman spectra of trapped particles can be acquired with high quality. The LTRS system overcomes the intrinsic Brownian motion and cell motility of microparticles in solution and provides a promising tool for in situ identifying suspicious agents. In order to increase the signal to noise ratio, several schemes were employed in LTRS system to reduce the blank noise and the fluorescence signal coming from analytes and the surrounding background. These techniques include near-infrared excitation, optical levitation, confocal microscopy, and frequency-shifted Raman difference. The LTRS system has been applied for the study in cell biology at the single cell level. With the built Raman-tweezers system, we studied the dynamic physiological processes of single living cells, including cell cycle, the transcription and translation of recombinant protein in transgenic yeast cells and the T cell activation. We also studied cell damage and associated biochemical processes in optical traps, UV radiations, and evaluated heating by near-infrared Raman spectroscopy. These studies show that the Raman-tweezers system is feasible to provide rapid and reliable diagnosis of cellular disorders and can be used as a valuable tool to study cellular processes within single living cells or intracellular organelles and may aid research in molecular and cellular biology.

Concise Review: Stem Cell Population Biology: Insights from Hematopoiesis.

PubMed

MacLean, Adam L; Lo Celso, Cristina; Stumpf, Michael P H

2017-01-01

Stem cells are fundamental to human life and offer great therapeutic potential, yet their biology remains incompletely-or in cases even poorly-understood. The field of stem cell biology has grown substantially in recent years due to a combination of experimental and theoretical contributions: the experimental branch of this work provides data in an ever-increasing number of dimensions, while the theoretical branch seeks to determine suitable models of the fundamental stem cell processes that these data describe. The application of population dynamics to biology is amongst the oldest applications of mathematics to biology, and the population dynamics perspective continues to offer much today. Here we describe the impact that such a perspective has made in the field of stem cell biology. Using hematopoietic stem cells as our model system, we discuss the approaches that have been used to study their key properties, such as capacity for self-renewal, differentiation, and cell fate lineage choice. We will also discuss the relevance of population dynamics in models of stem cells and cancer, where competition naturally emerges as an influential factor on the temporal evolution of cell populations. Stem Cells 2017;35:80-88. © 2016 AlphaMed Press.

Research on Bacteria in the Mainstream of Biology.

ERIC Educational Resources Information Center

Magasanik, Boris

1988-01-01

Stresses the importance of investigating bacterial mechanisms to discover clues for a greater understanding of cells. Cites examples of study areas of biological significance which may reveal information about the evolution of prokaryotes and eukaryotes and lead to a comprehensive theory of cell biology. (RT)

Engineering artificial cells by combining HeLa-based cell-free expression and ultra-thin double emulsion template

PubMed Central

Ho, Kwun Yin; Murray, Victoria L.; Liu, Allen P.

2015-01-01

Generation of artificial cells provides the bridge needed to cover the gap between studying the complexity of biological processes in whole cells and studying these same processes in an in vitro reconstituted system. Artificial cells are defined as the encapsulation of biologically active material in a biological or synthetic membrane. Here, we describe a robust and general method to produce artificial cells for the purpose of mimicking one or more behaviors of a cell. A microfluidic double emulsion system is used to encapsulate a mammalian cell free expression system that is able to express membrane proteins into the bilayer or soluble proteins inside the vesicles. The development of a robust platform that allows the assembly of artificial cells is valuable in understanding subcellular functions and emergent behaviors in a more cell-like environment as well as for creating novel signaling pathways to achieve specific cellular behaviors. PMID:25997354

Analysis of Cell Biomechanics Response to Gravity:A Fluids for Biology Study Utilizing NASA Glenns Zero Gravity Research Facility

NASA Technical Reports Server (NTRS)

Bomani, Bilal M. M.; Kassemi, Mohammad; Neumann, Eric S.

2016-01-01

It remains unclear how biological cells sense and respond to gravitational forces. Leading scientists state that a large gap exists in the understanding of physiological and molecular adaptation that occurs as biology enters the spaceflight realm. We are seeking a method to fully understand how cells sense microgravity/gravity and what triggers their response.

Emerging Importance of Phytochemicals in Regulation of Stem Cells Fate via Signaling Pathways.

PubMed

Dadashpour, Mehdi; Pilehvar-Soltanahmadi, Younes; Zarghami, Nosratollah; Firouzi-Amandi, Akram; Pourhassan-Moghaddam, Mohammad; Nouri, Mohammad

2017-11-01

To reach ideal therapeutic potential of stem cells for regenerative medicine purposes, it is essential to retain their self-renewal and differentiation capacities. Currently, biological factors are extensively used for stemness maintaining and differentiation induction of stem cells. However, low stability, high cost, complicated production process, and risks associated with viral/endotoxin infection hamper the widespread use of biological factors in the stem cell biology. Moreover, regarding the modulation of several signaling cascades, which lead to a distinct fate, phytochemicals are preferable in the stem cells biology because of their efficiency. Considering the issues related to the application of biological factors and potential advantages of phytochemicals in stem cell engineering, there is a considerable increasing trend in studies associated with the application of novel alternative molecules in the stem cell biology. In support of this statement, we aimed to highlight the various effects of phytochemicals on signaling cascades involved in commitment of stem cells. Hence, in this review, the current trends in the phytochemicals-based modulation of stem cell fate have been addressed. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Cell and molecular mechanics of biological materials

NASA Astrophysics Data System (ADS)

Bao, G.; Suresh, S.

2003-11-01

Living cells can sense mechanical forces and convert them into biological responses. Similarly, biological and biochemical signals are known to influence the abilities of cells to sense, generate and bear mechanical forces. Studies into the mechanics of single cells, subcellular components and biological molecules have rapidly evolved during the past decade with significant implications for biotechnology and human health. This progress has been facilitated by new capabilities for measuring forces and displacements with piconewton and nanometre resolutions, respectively, and by improvements in bio-imaging. Details of mechanical, chemical and biological interactions in cells remain elusive. However, the mechanical deformation of proteins and nucleic acids may provide key insights for understanding the changes in cellular structure, response and function under force, and offer new opportunities for the diagnosis and treatment of disease. This review discusses some basic features of the deformation of single cells and biomolecules, and examines opportunities for further research.

Teaching cell and molecular biology for gender equity.

PubMed

Sible, Jill C; Wilhelm, Dayna E; Lederman, Muriel

2006-01-01

Science, technology, engineering, and math (STEM) fields, including cell biology, are characterized by the "leaky pipeline" syndrome in which, over time, women leave the discipline. The pipeline itself and the pond into which it empties may not be neutral. Explicating invisible norms, attitudes, and practices by integrating social studies of science into science education may be the necessary first step in helping female students persist in STEM disciplines. In 2003 and 2004, a sophomore Cell and Molecular Biology course at Virginia Tech (Blacksburg, VA) was taught integrating social studies of science with standard material. The course was successfully implemented, teaching students factual content while increasing awareness of the cultures of science and their self-confidence in engaging with the subject. Course evaluation data indicated that females in particular perceived greater gains in logical thinking and problem-solving abilities than females in a traditional cell biology course. Consistent with K-12 studies, males in this class were likely to view scientists as male only, whereas females viewed scientists as male and female. This pilot project demonstrates that social studies can be integrated successfully in a cell biology course. Longitudinal studies of this cohort of students will indicate whether this approach contributes to the retention of women in the field.

Multispectral optical tweezers for molecular diagnostics of single biological cells

NASA Astrophysics Data System (ADS)

Butler, Corey; Fardad, Shima; Sincore, Alex; Vangheluwe, Marie; Baudelet, Matthieu; Richardson, Martin

2012-03-01

Optical trapping of single biological cells has become an established technique for controlling and studying fundamental behavior of single cells with their environment without having "many-body" interference. The development of such an instrument for optical diagnostics (including Raman and fluorescence for molecular diagnostics) via laser spectroscopy with either the "trapping" beam or secondary beams is still in progress. This paper shows the development of modular multi-spectral imaging optical tweezers combining Raman and Fluorescence diagnostics of biological cells.

Examining the Effect of Multiple Writing Tasks on Year 10 Biology Students' Understandings of Cell and Molecular Biology Concepts

ERIC Educational Resources Information Center

Hand, Brian; Hohenshell, Liesl; Prain, Vaughan

2007-01-01

This paper reports on a study that examined the cumulative effects on students' learning of science, and perceptions of the role of writing in learning, when the students engaged in multiple writing tasks with planning strategy support. The study was conducted with Year 10 biology students who completed two consecutive units on Cells and Molecular…

Cardiac c-Kit Biology Revealed by Inducible Transgenesis.

PubMed

Gude, Natalie A; Firouzi, Fareheh; Broughton, Kathleen M; Ilves, Kelli; Nguyen, Kristine P; Payne, Christina R; Sacchi, Veronica; Monsanto, Megan M; Casillas, Alexandria R; Khalafalla, Farid G; Wang, Bingyan J; Ebeid, David E; Alvarez, Roberto; Dembitsky, Walter P; Bailey, Barbara A; van Berlo, Jop; Sussman, Mark A

2018-06-22

Biological significance of c-Kit as a cardiac stem cell marker and role(s) of c-Kit+ cells in myocardial development or response to pathological injury remain unresolved because of varied and discrepant findings. Alternative experimental models are required to contextualize and reconcile discordant published observations of cardiac c-Kit myocardial biology and provide meaningful insights regarding clinical relevance of c-Kit signaling for translational cell therapy. The main objectives of this study are as follows: demonstrating c-Kit myocardial biology through combined studies of both human and murine cardiac cells; advancing understanding of c-Kit myocardial biology through creation and characterization of a novel, inducible transgenic c-Kit reporter mouse model that overcomes limitations inherent to knock-in reporter models; and providing perspective to reconcile disparate viewpoints on c-Kit biology in the myocardium. In vitro studies confirm a critical role for c-Kit signaling in both cardiomyocytes and cardiac stem cells. Activation of c-Kit receptor promotes cell survival and proliferation in stem cells and cardiomyocytes of either human or murine origin. For creation of the mouse model, the cloned mouse c-Kit promoter drives Histone2B-EGFP (enhanced green fluorescent protein; H2BEGFP) expression in a doxycycline-inducible transgenic reporter line. The combination of c-Kit transgenesis coupled to H2BEGFP readout provides sensitive, specific, inducible, and persistent tracking of c-Kit promoter activation. Tagging efficiency for EGFP+/c-Kit+ cells is similar between our transgenic versus a c-Kit knock-in mouse line, but frequency of c-Kit+ cells in cardiac tissue from the knock-in model is 55% lower than that from our transgenic line. The c-Kit transgenic reporter model reveals intimate association of c-Kit expression with adult myocardial biology. Both cardiac stem cells and a subpopulation of cardiomyocytes express c-Kit in uninjured adult heart, upregulating c-Kit expression in response to pathological stress. c-Kit myocardial biology is more complex and varied than previously appreciated or documented, demonstrating validity in multiple points of coexisting yet heretofore seemingly irreconcilable published findings. © 2018 American Heart Association, Inc.

Serotonin (5-HT) released by activated white blood cells in a biological fuel cell provide a potential energy source for electricity generation.

PubMed

Justin, Gusphyl A; Sun, Mingui; Zhang, Yingze; Cui, X Tracy; Sclabassi, Robert

2006-01-01

Previous studies by our group have demonstrated the ability of white blood cells to generate small electrical currents, on the order of 1-3 microA/cm(2), when placed at the anode compartment of a proton exchange membrane (PEM) biological fuel cell. In this research study, an electrochemical technique is used to further investigate the electron transfer ability of activated white blood cells at interfacing electrodes in an attempt to elucidate the mechanism of electron transfer in the original biological fuel cell experiments. Cyclic voltammograms were obtained for human white blood cells using a three-electrode system. The working and counter electrodes were made from carbon felt and platinum, respectively, while the reference was a saturated calomel electrode (SCE). Oxidation peaks were observed at an average potential of 363 mV vs. SCE for the PMA/ionomycin activated white blood cells in glucose solution. However a corresponding reduction peak was not observed, suggesting irreversibility of the redox reaction. The cyclic voltammograms recorded for the white blood cells bear very close similarities to those of the neurotransmitter serotonin (5-HT). Serotonin released by white blood cells into the extracellular environment may be irreversibly oxidized at the working electrode in the cyclic voltammetry experiments and at the PEM biological fuel cell anode in our earlier electrochemical cell studies.

A cell-based systems biology assessment of human blood to monitor immune responses after influenza vaccination.

PubMed

Hoek, Kristen L; Samir, Parimal; Howard, Leigh M; Niu, Xinnan; Prasad, Nripesh; Galassie, Allison; Liu, Qi; Allos, Tara M; Floyd, Kyle A; Guo, Yan; Shyr, Yu; Levy, Shawn E; Joyce, Sebastian; Edwards, Kathryn M; Link, Andrew J

2015-01-01

Systems biology is an approach to comprehensively study complex interactions within a biological system. Most published systems vaccinology studies have utilized whole blood or peripheral blood mononuclear cells (PBMC) to monitor the immune response after vaccination. Because human blood is comprised of multiple hematopoietic cell types, the potential for masking responses of under-represented cell populations is increased when analyzing whole blood or PBMC. To investigate the contribution of individual cell types to the immune response after vaccination, we established a rapid and efficient method to purify human T and B cells, natural killer (NK) cells, myeloid dendritic cells (mDC), monocytes, and neutrophils from fresh venous blood. Purified cells were fractionated and processed in a single day. RNA-Seq and quantitative shotgun proteomics were performed to determine expression profiles for each cell type prior to and after inactivated seasonal influenza vaccination. Our results show that transcriptomic and proteomic profiles generated from purified immune cells differ significantly from PBMC. Differential expression analysis for each immune cell type also shows unique transcriptomic and proteomic expression profiles as well as changing biological networks at early time points after vaccination. This cell type-specific information provides a more comprehensive approach to monitor vaccine responses.

The rise of developmental genetics - a historical account of the fusion of embryology and cell biology with human genetics and the emergence of the Stem Cell Initiative.

PubMed

Kidson, S H; Ballo, R; Greenberg, L J

2016-05-25

Genetics and cell biology are very prominent areas of biological research with rapid advances being driven by a flood of theoretical, technological and informational knowledge. Big biology and small biology continue to feed off each other. In this paper, we provide a brief overview of the productive interactions that have taken place between human geneticists and cell biologists at UCT, and credit is given to the enabling environment created led by Prof. Peter Beighton. The growth of new disciplines and disciplinary mergers that have swept away division of the past to make new exciting syntheses are discussed. We show how our joint research has benefitted from worldwide advances in developmental genetics, cloning and stem cell technologies, genomics, bioinformatics and imaging. We conclude by describing the role of the UCT Stem Cell Initiative and show how we are using induced pluripotent cells to carry out disease-in-the- dish studies on retinal degeneration and fibrosis.

Applications of CRISPR Genome Engineering in Cell Biology

PubMed Central

Wang, Fangyuan; Qi, Lei S.

2016-01-01

Recent advances in genome engineering are starting a revolution in biological research and translational applications. The CRISPR-associated RNA-guided endonuclease 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 genome and phenotype, thus promising a fuller understanding of cell biology. PMID:27599850

Phenformin inhibits cell proliferation and induces cell apoptosis and autophagy in cholangiocarcinoma.

PubMed

Hu, Shuyang; Ouyang, Qing; Cheng, Qingbao; Wang, Jinghan; Feng, Feiling; Qiao, Liang; Gan, Wei; Shi, Yang; Wu, Demin; Jiang, Xiaoqing

2018-04-01

Cholangiocarcinoma (CCA) is an aggressive malignant tumor and the prognosis of patients with advanced stage disease remains poor. Therefore, the identification of novel treatment agents for CCA is required. In the present study, the biological effects of the diabetes therapeutic agent, phenformin, in CCA cell lines was investigated. Cell Counting Kit‑8 cell viability, cellular clone formation and subcutaneous tumor formation assays were performed, which revealed that phenformin inhibited CCA cell proliferation and growth both in vitro and in vivo. In addition, phenformin induced CCA cell apoptosis and autophagy. Phenformin partly activated the liver kinase B1 (LKB1)/5' AMP‑activated protein kinase signaling pathway to exert its biological effects on CCA cell lines, as demonstrated by knockdown of LKB1, which reversed these effects. In conclusion, the present study demonstrated the biological effects of phenformin in CCA and suggested that phenformin may be a potential novel agent for CCA treatment.

The chromaffin cell: paradigm in cell, developmental and growth factor biology.

PubMed Central

Unsicker, K

1993-01-01

This article reviews the chromaffin cell in relation to studies that have elucidated fundamental phenomena in cell biology (the molecular anatomy of exocytosis) and developmental neuroscience (the principle of neuropoiesis in the development of the sympathoadrenal cell lineage). A final section addresses growth factor synthesis and storage in chromaffin cells and their implications for the treatment of neurological disorders, such as Parkinson's disease. Images Fig. 3 PMID:8300412

New developments in mast cell biology

PubMed Central

Kalesnikoff, Janet; Galli, Stephen J.

2010-01-01

Mast cells can function as effector and immunoregulatory cells in IgE-associated allergic disorders, as well as in certain innate and adaptive immune responses. This review will focus on exciting new developments in the field of mast cell biology published within the last year. It will highlight advances in the understanding of FcεRI-mediated signaling and mast cell activation events, as well as in the use of genetic models to study mast cell function in vivo. Finally, we will discuss newly identified roles of mast cells or individual mast cell products, such as proteases and IL-10, in host defense, cardiovascular disease and tumor biology, and in settings in which mast cells have anti-inflammatory or immunosuppressive functions. PMID:18936782

Analysis of undergraduate cell biology contents in Brazilian public universities.

PubMed

Mermelstein, Claudia; Costa, Manoel Luis

2017-04-01

The enormous amount of information available in cell biology has created a challenge in selecting the core concepts we should be teaching our undergraduates. One way to define a set of essential core ideas in cell biology is to analyze what a specific cell biology community is teaching their students. Our main objective was to analyze the cell biology content currently being taught in Brazilian universities. We collected the syllabi of cell biology courses from public universities in Brazil and analyzed the frequency of cell biology topics in each course. We also compared the Brazilian data with the contents of a major cell biology textbook. Our analysis showed that while some cell biology topics such as plasma membrane and cytoskeleton was present in ∼100% of the Brazilian curricula analyzed others such as cell signaling and cell differentiation were present in only ∼35%. The average cell biology content taught in the Brazilian universities is quite different from what is presented in the textbook. We discuss several possible explanations for these observations. We also suggest a list with essential cell biology topics for any biological or biomedical undergraduate course. The comparative discussion of cell biology topics presented here could be valuable in other educational contexts. © 2017 The Authors. Cell Biology International Published by John Wiley & Sons Ltd on behalf of International Federation of Cell Biology.

Noninvasive Assessment of Cell Fate and Biology in Transplanted Mesenchymal Stem Cells.

PubMed

Franchi, Federico; Rodriguez-Porcel, Martin

2017-01-01

Recently, molecular imaging has become a conditio sine qua non for cell-based regenerative medicine. Developments in molecular imaging techniques, such as reporter gene technology, have increasingly enabled the noninvasive assessment of the fate and biology of cells after cardiovascular applications. In this context, bioluminescence imaging is the most commonly used imaging modality in small animal models of preclinical studies. Here, we present a detailed protocol of a reporter gene imaging approach for monitoring the viability and biology of Mesenchymal Stem Cells transplanted in a mouse model of myocardial ischemia reperfusion injury.

Co-culture systems and technologies: taking synthetic biology to the next level.

PubMed

Goers, Lisa; Freemont, Paul; Polizzi, Karen M

2014-07-06

Co-culture techniques find myriad applications in biology for studying natural or synthetic interactions between cell populations. Such techniques are of great importance in synthetic biology, as multi-species cell consortia and other natural or synthetic ecology systems are widely seen to hold enormous potential for foundational research as well as novel industrial, medical and environmental applications with many proof-of-principle studies in recent years. What is needed for co-cultures to fulfil their potential? Cell-cell interactions in co-cultures are strongly influenced by the extracellular environment, which is determined by the experimental set-up, which therefore needs to be given careful consideration. An overview of existing experimental and theoretical co-culture set-ups in synthetic biology and adjacent fields is given here, and challenges and opportunities involved in such experiments are discussed. Greater focus on foundational technology developments for co-cultures is needed for many synthetic biology systems to realize their potential in both applications and answering biological questions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Prognostic Cell Biological Markers in Cervical Cancer Patients Primarily Treated With (Chemo)radiation: A Systematic Review

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

Noordhuis, Maartje G.; Eijsink, Jasper J.H.; Roossink, Frank

2011-02-01

The aim of this study was to systematically review the prognostic and predictive significance of cell biological markers in cervical cancer patients primarily treated with (chemo)radiation. A PubMed, Embase, and Cochrane literature search was performed. Studies describing a relation between a cell biological marker and survival in {>=}50 cervical cancer patients primarily treated with (chemo)radiation were selected. Study quality was assessed, and studies with a quality score of 4 or lower were excluded. Cell biological markers were clustered on biological function, and the prognostic and predictive significance of these markers was described. In total, 42 studies concerning 82 cell biologicalmore » markers were included in this systematic review. In addition to cyclooxygenase-2 (COX-2) and serum squamous cell carcinoma antigen (SCC-ag) levels, markers associated with poor prognosis were involved in epidermal growth factor receptor (EGFR) signaling (EGFR and C-erbB-2) and in angiogenesis and hypoxia (carbonic anhydrase 9 and hypoxia-inducible factor-1{alpha}). Epidermal growth factor receptor and C-erbB-2 were also associated with poor response to (chemo)radiation. In conclusion, EGFR signaling is associated with poor prognosis and response to therapy in cervical cancer patients primarily treated with (chemo)radiation, whereas markers involved in angiogenesis and hypoxia, COX-2, and serum SCC-ag levels are associated with a poor prognosis. Therefore, targeting these pathways in combination with chemoradiation may improve survival in advanced-stage cervical cancer patients.« less

Probing the biology of cell boundary conditions through confinement of Xenopus cell-free cytoplasmic extracts.

PubMed

Bermudez, Jessica G; Chen, Hui; Einstein, Lily C; Good, Matthew C

2017-01-01

Cell-free cytoplasmic extracts prepared from Xenopus eggs and embryos have for decades provided a biochemical system with which to interrogate complex cell biological processes in vitro. Recently, the application of microfabrication and microfluidic strategies in biology has narrowed the gap between in vitro and in vivo studies by enabling formation of cell-size compartments containing functional cytoplasm. These approaches provide numerous advantages over traditional biochemical experiments performed in a test tube. Most notably, the cell-free cytoplasm is confined using a two- or three-dimensional boundary, which mimics the natural configuration of a cell. This strategy enables characterization of the spatial organization of a cell, and the role that boundaries play in regulating intracellular assembly and function. In this review, we describe the marriage of Xenopus cell-free cytoplasm and confinement technologies to generate synthetic cell-like systems, the recent biological insights they have enabled, and the promise they hold for future scientific discovery. © 2017 Wiley Periodicals, Inc.

Basic techniques in mammalian cell tissue culture.

PubMed

Phelan, Katy; May, Kristin M

2015-03-02

Cultured mammalian cells are used extensively in cell biology studies. It requires a number of special skills in order to be able to preserve the structure, function, behavior, and biology of the cells in culture. This unit describes the basic skills required to maintain and preserve cell cultures: maintaining aseptic technique, preparing media with the appropriate characteristics, passaging, freezing and storage, recovering frozen stocks, and counting viable cells. Copyright © 2015 John Wiley & Sons, Inc.

The Future of Cell Biology: Emerging Model Organisms.

PubMed

Goldstein, Bob; King, Nicole

2016-11-01

Most current research in cell biology uses just a handful of model systems including yeast, Arabidopsis, Drosophila, Caenorhabditis elegans, zebrafish, mouse, and cultured mammalian cells. And for good reason - for many biological questions, the best system for the question is likely to be found among these models. However, in some cases, and particularly as the questions that engage scientists broaden, the best system for a question may be a little-studied organism. Modern research tools are facilitating a renaissance for unusual and interesting organisms as emerging model systems. As a result, we predict that an ever-expanding breadth of model systems may be a hallmark of future cell biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biology on a Chip: Microfabrication for Studying the Behavior of Cultured Cells

PubMed Central

Li, Nianzhen; Tourovskaia, Anna; Folch, Albert

2013-01-01

The ability to culture cells in vitro has revolutionized hypothesis testing in basic cell and molecular biology research and has become a standard methodology in drug screening and toxicology assays. However, the traditional cell culture methodology—consisting essentially of the immersion of a large population of cells in a homogeneous fluid medium—has become increasingly limiting, both from a fundamental point of view (cells in vivo are surrounded by complex spatiotemporal microenvironments) and from a practical perspective (scaling up the number of fluid handling steps and cell manipulations for high-throughput studies in vitro is prohibitively expensive). Micro fabrication technologies have enabled researchers to design, with micrometer control, the biochemical composition and topology of the substrate, the medium composition, as well as the type of neighboring cells surrounding the microenvironment of the cell. In addition, microtechnology is conceptually well suited for the development of fast, low-cost in vitro systems that allow for high-throughput culturing and analysis of cells under large numbers of conditions. Here we review a variety of applications of microfabrication in cell culture studies, with an emphasis on the biology of various cell types. PMID:15139302

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

PubMed

Quesenberry, P; Goldberg, L

2017-08-01

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

Macro- and microscale fluid flow systems for endothelial cell biology.

PubMed

Young, Edmond W K; Simmons, Craig A

2010-01-21

Recent advances in microfluidics have brought forth new tools for studying flow-induced effects on mammalian cells, with important applications in cardiovascular, bone and cancer biology. The plethora of microscale systems developed to date demonstrate the flexibility of microfluidic designs, and showcase advantages of the microscale that are simply not available at the macroscale. However, the majority of these systems will likely not achieve widespread use in the biological laboratory due to their complexity and lack of user-friendliness. To gain widespread acceptance in the biological research community, microfluidics engineers must understand the needs of cell biologists, while biologists must be made aware of available technology. This review provides a critical evaluation of cell culture flow (CCF) systems used to study the effects of mechanical forces on endothelial cells (ECs) in vitro. To help understand the need for various designs of CCF systems, we first briefly summarize main properties of ECs and their native environments. Basic principles of various macro- and microscale systems are described and evaluated. New opportunities are uncovered for developing technologies that have potential to both improve efficiency of experimentation as well as answer important biological questions that otherwise cannot be tackled with existing systems. Finally, we discuss some of the unresolved issues related to microfluidic cell culture, suggest possible avenues of investigation that could resolve these issues, and provide an outlook for the future of microfluidics in biological research.

Evaluation of the Redesign of an Undergraduate Cell Biology Course

ERIC Educational Resources Information Center

McEwen, Laura April; Harris, dik; Schmid, Richard F.; Vogel, Jackie; Western, Tamara; Harrison, Paul

2009-01-01

This article offers a case study of the evaluation of a redesigned and redeveloped laboratory-based cell biology course. The course was a compulsory element of the biology program, but the laboratory had become outdated and was inadequately equipped. With the support of a faculty-based teaching improvement project, the teaching team redesigned the…

Th1/Th2 Cytokines: An Easy Model to Study Gene Expression in Immune Cells

ERIC Educational Resources Information Center

Moran, Jose M.; Gonzalez-Polo, Rosa A.; Soler, German; Fuentes, Jose M.

2006-01-01

This report describes a laboratory exercise that was incorporated into a Cell Biology and Molecular Biology advanced course. The exercise was made for a class size with eight students and was designed to reinforce the understanding of basic molecular biology techniques. Students used the techniques of reverse transcription and arginase activity…

Femtosecond laser patterning of biological materials

NASA Astrophysics Data System (ADS)

Grigoropoulos, Costas P.; Jeon, Hojeong; Hidai, Hirofumi; Hwang, David J.

2011-03-01

This paper aims at presenting a review of work at the Laser Thermal Laboratory on the microscopic laser modification of biological materials using ultrafast laser pulses. We have devised a new method for fabricating high aspect ratio patterns of varying height by using two-photon polymerization process in order to study contact guidance and directed growth of biological cells. Studies using NIH-3T3 and MDCK cells indicate that cell morphology on fiber scaffolds is influenced by the pattern of actin microfilament bundles. Cells experienced different strength of contact guidance depending on the ridge height. Cell morphology and motility was investigated on micronscale anisotropic cross patterns and parallel line patterns having different aspect ratios. A significant effect on cell alignment and directionality of migration was observed. Cell morphology and motility were influenced by the aspect ratio of the cross pattern, the grid size, and the ridge height. Cell contractility was examined microscopically in order to measure contractile forces generated by individual cells on self-standing fiber scaffolds.

Radiosensitivity of cancer-initiating cells and normal stem cells (or what the Heisenberg uncertainly principle has to do with biology).

PubMed

Woodward, Wendy Ann; Bristow, Robert Glen

2009-04-01

Mounting evidence suggests that parallels between normal stem cell biology and cancer biology may provide new targets for cancer therapy. Prospective identification and isolation of cancer-initiating cells from solid tumors has promoted the descriptive and functional identification of these cells allowing for characterization of their response to contemporary cancer therapies, including chemotherapy and radiation. In clinical radiation therapy, the failure to clinically eradicate all tumor cells (eg, a lack of response, partial response, or nonpermanent complete response by imaging) is considered a treatment failure. As such, biologists have explored the characteristics of the small population of clonogenic cancer cells that can survive and are capable of repopulating the tumor after subcurative therapy. Herein, we discuss the convergence of these clonogenic studies with contemporary radiosensitivity studies that use cell surface markers to identify cancer-initiating cells. Implications for and uncertainties regarding incorporation of these concepts into the practice of modern radiation oncology are discussed.

Calculations of the Acceleration of Centrifugal Loading on Adherent Cells

NASA Astrophysics Data System (ADS)

Chen, Kang; Song, Yang; Liu, Qing; Zhang, Chunqiu

2017-07-01

Studies have shown that the morphology and function of living cells are greatly affected by the state of different high acceleration. Based on the centrifuge, we designed a centrifugal cell loading machine for the mechanical biology of cells under high acceleration loading. For the machine, the feasibility of the experiment was studied by means of constant acceleration or variable acceleration loading in the Petri dish fixture and/or culture flask. Here we analyzed the distribution of the acceleration of the cells with the change of position and size of the culturing device quantitatively. It is obtained that Petri dish fixture and/or culture flask can be used for constant acceleration loading by experiments; the centripetal acceleration of the adherent cells increases with the increase of the distance between the rotor center of the centrifuge and the fixture of the Petri dish and the size of the fixture. It achieves the idea that the general biology laboratory can conduct the study of mechanical biology at high acceleration. It also provides a basis for more accurate study of the law of high acceleration on mechanobiology of cells.

[Future directions of molecular bone cell biology].

PubMed

Yoneda, T

2001-01-01

Introduction of genetic approaches using knockout and/or transgenic mice has produced many pieces of information that can't be obtained by conventional cell biological studies and profoundly advanced our understanding of bone biology and metabolism. Here, the author will first briefly summarize the current findings in the recent bone research and subsequently attempt to predict future directions to which bone research is going to proceed with a special emphasis of osteoclast and osteoblast biology.

The planarian flatworm: an in vivo model for stem cell biology and nervous system regeneration

PubMed Central

Gentile, Luca; Cebrià, Francesc; Bartscherer, Kerstin

2011-01-01

Planarian flatworms are an exception among bilaterians in that they possess a large pool of adult stem cells that enables them to promptly regenerate any part of their body, including the brain. Although known for two centuries for their remarkable regenerative capabilities, planarians have only recently emerged as an attractive model for studying regeneration and stem cell biology. This revival is due in part to the availability of a sequenced genome and the development of new technologies, such as RNA interference and next-generation sequencing, which facilitate studies of planarian regeneration at the molecular level. Here, we highlight why planarians are an exciting tool in the study of regeneration and its underlying stem cell biology in vivo, and discuss the potential promises and current limitations of this model organism for stem cell research and regenerative medicine. PMID:21135057

Biological treatment strategies for disc degeneration: potentials and shortcomings

PubMed Central

Nerlich, Andreas G.; Boos, Norbert

2006-01-01

Recent advances in molecular biology, cell biology and material sciences have opened a new emerging field of techniques for the treatment of musculoskeletal disorders. These new treatment modalities aim for biological repair of the affected tissues by introducing cell-based tissue replacements, genetic modifications of resident cells or a combination thereof. So far, these techniques have been successfully applied to various tissues such as bone and cartilage. However, application of these treatment modalities to cure intervertebral disc degeneration is in its very early stages and mostly limited to experimental studies in vitro or in animal studies. We will discuss the potential and possible shortcomings of current approaches to biologically cure disc degeneration by gene therapy or tissue engineering. Despite the increasing number of studies examining the therapeutic potential of biological treatment strategies, a practicable solution to routinely cure disc degeneration might not be available in the near future. However, knowledge gained from these attempts might be applied in a foreseeable future to cure the low back pain that often accompanies disc degeneration and therefore be beneficial for the patient. PMID:16983559

Cell biology experiments conducted in space

NASA Technical Reports Server (NTRS)

Taylor, G. R.

1977-01-01

A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

Growth control of the eukaryote cell: a systems biology study in yeast.

PubMed

Castrillo, Juan I; Zeef, Leo A; Hoyle, David C; Zhang, Nianshu; Hayes, Andrew; Gardner, David Cj; Cornell, Michael J; Petty, June; Hakes, Luke; Wardleworth, Leanne; Rash, Bharat; Brown, Marie; Dunn, Warwick B; Broadhurst, David; O'Donoghue, Kerry; Hester, Svenja S; Dunkley, Tom Pj; Hart, Sarah R; Swainston, Neil; Li, Peter; Gaskell, Simon J; Paton, Norman W; Lilley, Kathryn S; Kell, Douglas B; Oliver, Stephen G

2007-01-01

Cell growth underlies many key cellular and developmental processes, yet a limited number of studies have been carried out on cell-growth regulation. Comprehensive studies at the transcriptional, proteomic and metabolic levels under defined controlled conditions are currently lacking. Metabolic control analysis is being exploited in a systems biology study of the eukaryotic cell. Using chemostat culture, we have measured the impact of changes in flux (growth rate) on the transcriptome, proteome, endometabolome and exometabolome of the yeast Saccharomyces cerevisiae. Each functional genomic level shows clear growth-rate-associated trends and discriminates between carbon-sufficient and carbon-limited conditions. Genes consistently and significantly upregulated with increasing growth rate are frequently essential and encode evolutionarily conserved proteins of known function that participate in many protein-protein interactions. In contrast, more unknown, and fewer essential, genes are downregulated with increasing growth rate; their protein products rarely interact with one another. A large proportion of yeast genes under positive growth-rate control share orthologs with other eukaryotes, including humans. Significantly, transcription of genes encoding components of the TOR complex (a major controller of eukaryotic cell growth) is not subject to growth-rate regulation. Moreover, integrative studies reveal the extent and importance of post-transcriptional control, patterns of control of metabolic fluxes at the level of enzyme synthesis, and the relevance of specific enzymatic reactions in the control of metabolic fluxes during cell growth. This work constitutes a first comprehensive systems biology study on growth-rate control in the eukaryotic cell. The results have direct implications for advanced studies on cell growth, in vivo regulation of metabolic fluxes for comprehensive metabolic engineering, and for the design of genome-scale systems biology models of the eukaryotic cell.

Growth control of the eukaryote cell: a systems biology study in yeast

PubMed Central

Castrillo, Juan I; Zeef, Leo A; Hoyle, David C; Zhang, Nianshu; Hayes, Andrew; Gardner, David CJ; Cornell, Michael J; Petty, June; Hakes, Luke; Wardleworth, Leanne; Rash, Bharat; Brown, Marie; Dunn, Warwick B; Broadhurst, David; O'Donoghue, Kerry; Hester, Svenja S; Dunkley, Tom PJ; Hart, Sarah R; Swainston, Neil; Li, Peter; Gaskell, Simon J; Paton, Norman W; Lilley, Kathryn S; Kell, Douglas B; Oliver, Stephen G

2007-01-01

Background Cell growth underlies many key cellular and developmental processes, yet a limited number of studies have been carried out on cell-growth regulation. Comprehensive studies at the transcriptional, proteomic and metabolic levels under defined controlled conditions are currently lacking. Results Metabolic control analysis is being exploited in a systems biology study of the eukaryotic cell. Using chemostat culture, we have measured the impact of changes in flux (growth rate) on the transcriptome, proteome, endometabolome and exometabolome of the yeast Saccharomyces cerevisiae. Each functional genomic level shows clear growth-rate-associated trends and discriminates between carbon-sufficient and carbon-limited conditions. Genes consistently and significantly upregulated with increasing growth rate are frequently essential and encode evolutionarily conserved proteins of known function that participate in many protein-protein interactions. In contrast, more unknown, and fewer essential, genes are downregulated with increasing growth rate; their protein products rarely interact with one another. A large proportion of yeast genes under positive growth-rate control share orthologs with other eukaryotes, including humans. Significantly, transcription of genes encoding components of the TOR complex (a major controller of eukaryotic cell growth) is not subject to growth-rate regulation. Moreover, integrative studies reveal the extent and importance of post-transcriptional control, patterns of control of metabolic fluxes at the level of enzyme synthesis, and the relevance of specific enzymatic reactions in the control of metabolic fluxes during cell growth. Conclusion This work constitutes a first comprehensive systems biology study on growth-rate control in the eukaryotic cell. The results have direct implications for advanced studies on cell growth, in vivo regulation of metabolic fluxes for comprehensive metabolic engineering, and for the design of genome-scale systems biology models of the eukaryotic cell. PMID:17439666

Prediction of lung cells oncogenic transformation for induced radon progeny alpha particles using sugarscape cellular automata.

PubMed

Baradaran, Samaneh; Maleknasr, Niaz; Setayeshi, Saeed; Akbari, Mohammad Esmaeil

2014-01-01

Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ.

Co-culture systems and technologies: taking synthetic biology to the next level

PubMed Central

Goers, Lisa; Freemont, Paul; Polizzi, Karen M.

2014-01-01

Co-culture techniques find myriad applications in biology for studying natural or synthetic interactions between cell populations. Such techniques are of great importance in synthetic biology, as multi-species cell consortia and other natural or synthetic ecology systems are widely seen to hold enormous potential for foundational research as well as novel industrial, medical and environmental applications with many proof-of-principle studies in recent years. What is needed for co-cultures to fulfil their potential? Cell–cell interactions in co-cultures are strongly influenced by the extracellular environment, which is determined by the experimental set-up, which therefore needs to be given careful consideration. An overview of existing experimental and theoretical co-culture set-ups in synthetic biology and adjacent fields is given here, and challenges and opportunities involved in such experiments are discussed. Greater focus on foundational technology developments for co-cultures is needed for many synthetic biology systems to realize their potential in both applications and answering biological questions. PMID:24829281

Cell and molecular biology of the spiny dogfish Squalus acanthias and little skate Leucoraja erinacea: insights from in vitro cultured cells.

PubMed

Barnes, D W

2012-04-01

Two of the most commonly used elasmobranch experimental model species are the spiny dogfish Squalus acanthias and the little skate Leucoraja erinacea. Comparative biology and genomics with these species have provided useful information in physiology, pharmacology, toxicology, immunology, evolutionary developmental biology and genetics. A wealth of information has been obtained using in vitro approaches to study isolated cells and tissues from these organisms under circumstances in which the extracellular environment can be controlled. In addition to classical work with primary cell cultures, continuously proliferating cell lines have been derived recently, representing the first cell lines from cartilaginous fishes. These lines have proved to be valuable tools with which to explore functional genomic and biological questions and to test hypotheses at the molecular level. In genomic experiments, complementary (c)DNA libraries have been constructed, and c. 8000 unique transcripts identified, with over 3000 representing previously unknown gene sequences. A sub-set of messenger (m)RNAs has been detected for which the 3' untranslated regions show elements that are remarkably well conserved evolutionarily, representing novel, potentially regulatory gene sequences. The cell culture systems provide physiologically valid tools to study functional roles of these sequences and other aspects of elasmobranch molecular cell biology and physiology. Information derived from the use of in vitro cell cultures is valuable in revealing gene diversity and information for genomic sequence assembly, as well as for identification of new genes and molecular markers, construction of gene-array probes and acquisition of full-length cDNA sequences. © 2012 The Author. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Racing of the biological pacemaker.

PubMed

Yu, Han-Gang

2009-01-01

Over the past decade, rapid progress in the molecular studies of cardiac ion channels and stem cells biology has led to efforts to create a biological pacemaker to supplement the widely-used electronic pacemaker. We will review the main concepts of cardiac pacemaker activities in different heart regions and the approaches to design a working biological pacemaker. We will focus on how to use the gene- and cell-based approaches to meet the requirements of a working biological pacemaker. Possible future development and precautions for creation of an effective biological pacemaker superior to the electronic counterpart are also discussed along with recent patents.

Of mice and women: a comparative tissue biology perspective of breast stem cells and differentiation.

PubMed

Dontu, Gabriela; Ince, Tan A

2015-06-01

Tissue based research requires a background in human and veterinary pathology, developmental biology, anatomy, as well as molecular and cellular biology. This type of comparative tissue biology (CTB) expertise is necessary to tackle some of the conceptual challenges in human breast stem cell research. It is our opinion that the scarcity of CTB expertise contributed to some erroneous interpretations in tissue based research, some of which are reviewed here in the context of breast stem cells. In this article we examine the dissimilarities between mouse and human mammary tissue and suggest how these may impact stem cell studies. In addition, we consider the differences between breast ducts vs. lobules and clarify how these affect the interpretation of results in stem cell research. Lastly, we introduce a new elaboration of normal epithelial cell types in human breast and discuss how this provides a clinically useful basis for breast cancer classification.

Imaging cell biology in live animals: ready for prime time.

PubMed

Weigert, Roberto; Porat-Shliom, Natalie; Amornphimoltham, Panomwat

2013-06-24

Time-lapse fluorescence microscopy is one of the main tools used to image subcellular structures in living cells. Yet for decades it has been applied primarily to in vitro model systems. Thanks to the most recent advancements in intravital microscopy, this approach has finally been extended to live rodents. This represents a major breakthrough that will provide unprecedented new opportunities to study mammalian cell biology in vivo and has already provided new insight in the fields of neurobiology, immunology, and cancer biology.

Researchers Study Strategies to Preserve Hearing | NIH MedlinePlus the Magazine

MedlinePlus

... L. Cunningham, PhD, Chief, Section on Sensory Cell Biology Photo Courtesy of: NIDCD An estimated half million ... Dr. Lisa Cunningham, Chief, Section on Sensory Cell Biology, spoke with NIH MedlinePlus magazine about the research. ...

Micro-behavior and Injury of Biological Cell during Thawing Process

NASA Astrophysics Data System (ADS)

Tada, Yukio; Momose, Noboru; Jiang, Rong; Hayashi, Yujiro

This study has been conducted to pursue the relation between microscale behavior and the injury of biological cell during freezing and thawing. As a sample of biological cells, protoplasts isolated from cultured wheat cells were selectively used. As the results of microscopic observation using a cold stage whose cooling and heating velocities were controlled, the recovery of cell by water influx due to osmotic pressure difference, and the fusion of intracellular ice were clarified with heating velocity. It was found that the osmotic stress acting on the ce11 membrane causes the thawing injuries connecting with swell and rupture of cell. The survival of cells was also inspected by dye-exclusion test using Evans Blue. The results suggested rapid temperature-rising is more harmful for slowly-frozen cell.

Echoes of the embryo: using the developmental biology toolkit to study cancer.

PubMed

Aiello, Nicole M; Stanger, Ben Z

2016-02-01

The hallmark of embryonic development is regulation - the tendency for cells to find their way into organized and 'well behaved' structures - whereas cancer is characterized by dysregulation and disorder. At face value, cancer biology and developmental biology would thus seem to have little to do with each other. But if one looks beneath the surface, embryos and cancers share a number of cellular and molecular features. Embryos arise from a single cell and undergo rapid growth involving cell migration and cell-cell interactions: features that are also seen in the context of cancer. Consequently, many of the experimental tools that have been used to study embryogenesis for over a century are well-suited to studying cancer. This article will review the similarities between embryogenesis and cancer progression and discuss how some of the concepts and techniques used to understand embryos are now being adapted to provide insight into tumorigenesis, from the origins of cancer cells to metastasis. © 2016. Published by The Company of Biologists Ltd.

Regenerative Chemical Biology: Current Challenges and Future Potential

PubMed Central

Ao, Ada; Hao, Jijun; Hong, Charles C.

2011-01-01

The enthusiasm surrounding the clinical potential of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) is tempered by the fact that key issues regarding their safety, efficacy, and long-term benefits have thus far been suboptimal. Small molecules can potentially relieve these problems at major junctions of stem cell biology and regenerative therapy. In this review, we will introduce recent advances in these important areas and the first-generation of small molecules used in the regenerative context. Current chemical biology studies will provide the archetype for future interdisciplinary collaborations, and improve clinical benefits of cell-based therapies. PMID:21513877

Cell biology solves mysteries of reproduction.

PubMed

Sutovsky, Peter

2012-09-01

Reproduction and fertility have been objects of keen inquiry since the dawn of humanity. Medieval anatomists provided the first accurate depictions of the female reproductive system, and early microscopists were fascinated by the magnified sight of sperm cells. Initial successes were achieved in the in vitro fertilization of frogs and the artificial insemination of dogs. Gamete and embryo research was in the cradle of modern cell biology, providing the first evidence of the multi-cellular composition of living beings and pointing out the importance of chromosomes for heredity. In the 20th century, reproductive research paved the way for the study of the cytoskeleton, cell signaling, and the cell cycle. In the last three decades, the advent of reproductive cell biology has brought us human in vitro fertilization, animal cloning, and human and animal embryonic stem cells. It has contributed to the development of transgenesis, proteomics, genomics, and epigenetics. This Special Issue represents a sample of the various areas of reproductive biology, with emphasis on molecular and cell biological aspects. Advances in spermatology, ovarian function, fertilization, and maternal-fetal interactions are discussed within the framework of fertility and diseases such as endometriosis and diabetes.

Biological characterization of metanephric mesenchymal stem cells from the Beijing duck.

PubMed

Chen, Jia; Pu, Yabin; Sun, Yujiao; Zhang, Ping; Li, Qian; Wang, Kunfu; Wang, Wenjie; Ma, Yuehui; Guan, Weijun

2016-02-01

Mesenchymal stem cells (MSCs) possess self-proliferation and multi-directional differentiation abilities. Previous studies on MSCs have mostly focused on the bone marrow, lungs, pancreas and umbilical cord blood, with few studies on metanephric tissues in ducks. For the present study, the Beijing duck was selected as an experimental animal. Duck embryo metanephric mesenchymal stem cells (MMSCs) were studied. MMSC isolation culture, analysis of biological characteristics, induced differentiation and identification were performed in preliminary experiments. In the current study, surface antigens and gene expression patterns were detected using immunofluorescence, reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. The induced cells, adipocytes, hepatocytes, epithelial cells and islet cells were identified by oil red O staining, periodic acid-Schiff staining, immunofluorescence and dithizone staining, respectively. RT-PCR was performed for detection of specific marker genes. The results suggested that the biological characteristics of MMSCs were similar to those of the MSCs previously analyzed. Primary MMSCs were sub-cultured to passage 21. The induced cells exhibit typical staining and immunofluorescence indicating the expression of specific genes. This demonstrates that MMSCs may be a novel alternative source of MSCs for experimental and clinical applications.

How a High-Gradient Magnetic Field Could Affect Cell Life

NASA Astrophysics Data System (ADS)

Zablotskii, Vitalii; Polyakova, Tatyana; Lunov, Oleg; Dejneka, Alexandr

2016-11-01

The biological effects of high-gradient magnetic fields (HGMFs) have steadily gained the increased attention of researchers from different disciplines, such as cell biology, cell therapy, targeted stem cell delivery and nanomedicine. We present a theoretical framework towards a fundamental understanding of the effects of HGMFs on intracellular processes, highlighting new directions for the study of living cell machinery: changing the probability of ion-channel on/off switching events by membrane magneto-mechanical stress, suppression of cell growth by magnetic pressure, magnetically induced cell division and cell reprograming, and forced migration of membrane receptor proteins. By deriving a generalized form for the Nernst equation, we find that a relatively small magnetic field (approximately 1 T) with a large gradient (up to 1 GT/m) can significantly change the membrane potential of the cell and thus have a significant impact on not only the properties and biological functionality of cells but also cell fate.

How a High-Gradient Magnetic Field Could Affect Cell Life

PubMed Central

Zablotskii, Vitalii; Polyakova, Tatyana; Lunov, Oleg; Dejneka, Alexandr

2016-01-01

The biological effects of high-gradient magnetic fields (HGMFs) have steadily gained the increased attention of researchers from different disciplines, such as cell biology, cell therapy, targeted stem cell delivery and nanomedicine. We present a theoretical framework towards a fundamental understanding of the effects of HGMFs on intracellular processes, highlighting new directions for the study of living cell machinery: changing the probability of ion-channel on/off switching events by membrane magneto-mechanical stress, suppression of cell growth by magnetic pressure, magnetically induced cell division and cell reprograming, and forced migration of membrane receptor proteins. By deriving a generalized form for the Nernst equation, we find that a relatively small magnetic field (approximately 1 T) with a large gradient (up to 1 GT/m) can significantly change the membrane potential of the cell and thus have a significant impact on not only the properties and biological functionality of cells but also cell fate. PMID:27857227

Cellular fluid mechanics.

PubMed

Kamm, Roger D

2002-01-01

The coupling of fluid dynamics and biology at the level of the cell is an intensive area of investigation because of its critical role in normal physiology and disease. Microcirculatory flow has been a focus for years, owing to the complexity of cell-cell or cell-glycocalyx interactions. Noncirculating cells, particularly those that comprise the walls of the circulatory system, experience and respond biologically to fluid dynamic stresses. In this article, we review the more recent studies of circulating cells, with an emphasis on the role of the glycocalyx on red-cell motion in small capillaries and on the deformation of leukocytes passing through the microcirculation. We also discuss flows in the vicinity of noncirculating cells, the influence of fluid dynamic shear stress on cell biology, and diffusion in the lipid bi-layer, all in the context of the important fluid-dynamic phenomena.

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

A Novel Strategy for Isolation, Molecular and Functional Characterization of Embryonic Mammary Stem Cells Using Molecular Genetics and Microfluidic Sorting

DTIC Science & Technology

2008-06-01

Geoffrey M. Wahl, Ph.D. CONTRACTING ORGANIZATION: The Salk Institute for Biological Studies La Jolla, CA 92037-1099...PERFORMING ORGANIZATION REPORT NUMBER The Salk Institute for Biological Studies La Jolla, CA 92037-1099 9. SPONSORING...validated the use of a micro- volume cell sorter ( Celula , Inc.). This instrument is capable of sorting as few as 150 GFP positive cells from a sample

Basic Techniques in Mammalian Cell Tissue Culture.

PubMed

Phelan, Katy; May, Kristin M

2016-11-01

Cultured mammalian cells are used extensively in cell biology studies. It requires a number of special skills in order to be able to preserve the structure, function, behavior, and biology of the cells in culture. This unit describes the basic skills required to maintain and preserve cell cultures: maintaining aseptic technique, preparing media with the appropriate characteristics, passaging, freezing and storage, recovering frozen stocks, and counting viable cells. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

[The application of stereology in radiology imaging and cell biology fields].

PubMed

Hu, Na; Wang, Yan; Feng, Yuanming; Lin, Wang

2012-08-01

Stereology is an interdisciplinary method for 3D morphological study developed from mathematics and morphology. It is widely used in medical image analysis and cell biology studies. Because of its unbiased, simple, fast, reliable and non-invasive characteristics, stereology has been widely used in biomedical areas for quantitative analysis and statistics, such as histology, pathology and medical imaging. Because the stereological parameters show distinct differences in different pathology, many scholars use stereological methods to do quantitative analysis in their studies in recent years, for example, in the areas of the condition of cancer cells, tumor grade, disease development and the patient's prognosis, etc. This paper describes the stereological concept and estimation methods, also illustrates the applications of stereology in the fields of CT images, MRI images and cell biology, and finally reflects the universality, the superiority and reliability of stereology.

Integrating interactive computational modeling in biology curricula.

PubMed

Helikar, Tomáš; Cutucache, Christine E; Dahlquist, Lauren M; Herek, Tyler A; Larson, Joshua J; Rogers, Jim A

2015-03-01

While the use of computer tools to simulate complex processes such as computer circuits is normal practice in fields like engineering, the majority of life sciences/biological sciences courses continue to rely on the traditional textbook and memorization approach. To address this issue, we explored the use of the Cell Collective platform as a novel, interactive, and evolving pedagogical tool to foster student engagement, creativity, and higher-level thinking. Cell Collective is a Web-based platform used to create and simulate dynamical models of various biological processes. Students can create models of cells, diseases, or pathways themselves or explore existing models. This technology was implemented in both undergraduate and graduate courses as a pilot study to determine the feasibility of such software at the university level. First, a new (In Silico Biology) class was developed to enable students to learn biology by "building and breaking it" via computer models and their simulations. This class and technology also provide a non-intimidating way to incorporate mathematical and computational concepts into a class with students who have a limited mathematical background. Second, we used the technology to mediate the use of simulations and modeling modules as a learning tool for traditional biological concepts, such as T cell differentiation or cell cycle regulation, in existing biology courses. Results of this pilot application suggest that there is promise in the use of computational modeling and software tools such as Cell Collective to provide new teaching methods in biology and contribute to the implementation of the "Vision and Change" call to action in undergraduate biology education by providing a hands-on approach to biology.

Electrophoresis of biological materials

NASA Technical Reports Server (NTRS)

1975-01-01

The selection of biological products was studied for electrophoresis in space. Free flow electrophoresis, isoelectric focusing, and isotachophoresis are described. The candidates discussed include: immunoglobulins and gamma globulins; isolated islet of langerhans from pancreas; bone marrow; tumor cells; kidney cells, cryoprecipitate; and column separated cultures.

Cell refractive index for cell biology and disease diagnosis: past, present and future.

PubMed

Liu, P Y; Chin, L K; Ser, W; Chen, H F; Hsieh, C-M; Lee, C-H; Sung, K-B; Ayi, T C; Yap, P H; Liedberg, B; Wang, K; Bourouina, T; Leprince-Wang, Y

2016-02-21

Cell refractive index is a key biophysical parameter, which has been extensively studied. It is correlated with other cell biophysical properties including mechanical, electrical and optical properties, and not only represents the intracellular mass and concentration of a cell, but also provides important insight for various biological models. Measurement techniques developed earlier only measure the effective refractive index of a cell or a cell suspension, providing only limited information on cell refractive index and hence hindering its in-depth analysis and correlation. Recently, the emergence of microfluidic, photonic and imaging technologies has enabled the manipulation of a single cell and the 3D refractive index of a single cell down to sub-micron resolution, providing powerful tools to study cells based on refractive index. In this review, we provide an overview of cell refractive index models and measurement techniques including microfluidic chip-based techniques for the last 50 years, present the applications and significance of cell refractive index in cell biology, hematology, and pathology, and discuss future research trends in the field, including 3D imaging methods, integration with microfluidics and potential applications in new and breakthrough research areas.

Multidisciplinary approaches to understanding collective cell migration in developmental biology.

PubMed

Schumacher, Linus J; Kulesa, Paul M; McLennan, Rebecca; Baker, Ruth E; Maini, Philip K

2016-06-01

Mathematical models are becoming increasingly integrated with experimental efforts in the study of biological systems. Collective cell migration in developmental biology is a particularly fruitful application area for the development of theoretical models to predict the behaviour of complex multicellular systems with many interacting parts. In this context, mathematical models provide a tool to assess the consistency of experimental observations with testable mechanistic hypotheses. In this review, we showcase examples from recent years of multidisciplinary investigations of neural crest cell migration. The neural crest model system has been used to study how collective migration of cell populations is shaped by cell-cell interactions, cell-environmental interactions and heterogeneity between cells. The wide range of emergent behaviours exhibited by neural crest cells in different embryonal locations and in different organisms helps us chart out the spectrum of collective cell migration. At the same time, this diversity in migratory characteristics highlights the need to reconcile or unify the array of currently hypothesized mechanisms through the next generation of experimental data and generalized theoretical descriptions. © 2016 The Authors.

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.

Knockdown of stem cell regulator Oct4A in ovarian cancer reveals cellular reprogramming associated with key regulators of cytoskeleton-extracellular matrix remodelling

PubMed Central

Samardzija, Chantel; Greening, David W.; Escalona, Ruth; Chen, Maoshan; Bilandzic, Maree; Luwor, Rodney; Kannourakis, George; Findlay, Jock K.; Ahmed, Nuzhat

2017-01-01

Oct4A is a master regulator of self-renewal and pluripotency in embryonic stem cells. It is a well-established marker for cancer stem cell (CSC) in malignancies. Recently, using a loss of function studies, we have demonstrated key roles for Oct4A in tumor cell survival, metastasis and chemoresistance in in vitro and in vivo models of ovarian cancer. In an effort to understand the regulatory role of Oct4A in tumor biology, we employed the use of an ovarian cancer shRNA Oct4A knockdown cell line (HEY Oct4A KD) and a global mass spectrometry (MS)-based proteomic analysis to investigate novel biological targets of Oct4A in HEY samples (cell lysates, secretomes and mouse tumor xenografts). Based on significant differential expression, pathway and protein network analyses, and comprehensive literature search we identified key proteins involved with biologically relevant functions of Oct4A in tumor biology. Across all preparations of HEY Oct4A KD samples significant alterations in protein networks associated with cytoskeleton, extracellular matrix (ECM), proliferation, adhesion, metabolism, epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs) and drug resistance was observed. This comprehensive proteomics study for the first time presents the Oct4A associated proteome and expands our understanding on the biological role of this stem cell regulator in carcinomas. PMID:28406185

N-Cadherin Maintains the Healthy Biology of Nucleus Pulposus Cells under High-Magnitude Compression.

PubMed

Wang, Zhenyu; Leng, Jiali; Zhao, Yuguang; Yu, Dehai; Xu, Feng; Song, Qingxu; Qu, Zhigang; Zhuang, Xinming; Liu, Yi

2017-01-01

Mechanical load can regulate disc nucleus pulposus (NP) biology in terms of cell viability, matrix homeostasis and cell phenotype. N-cadherin (N-CDH) is a molecular marker of NP cells. This study investigated the role of N-CDH in maintaining NP cell phenotype, NP matrix synthesis and NP cell viability under high-magnitude compression. Rat NP cells seeded on scaffolds were perfusion-cultured using a self-developed perfusion bioreactor for 5 days. NP cell biology in terms of cell apoptosis, matrix biosynthesis and cell phenotype was studied after the cells were subjected to different compressive magnitudes (low- and high-magnitudes: 2% and 20% compressive deformation, respectively). Non-loaded NP cells were used as controls. Lentivirus-mediated N-CDH overexpression was used to further investigate the role of N-CDH under high-magnitude compression. The 20% deformation compression condition significantly decreased N-CDH expression compared with the 2% deformation compression and control conditions. Meanwhile, 20% deformation compression increased the number of apoptotic NP cells, up-regulated the expression of Bax and cleaved-caspase-3 and down-regulated the expression of Bcl-2, matrix macromolecules (aggrecan and collagen II) and NP cell markers (glypican-3, CAXII and keratin-19) compared with 2% deformation compression. Additionally, N-CDH overexpression attenuated the effects of 20% deformation compression on NP cell biology in relation to the designated parameters. N-CDH helps to restore the cell viability, matrix biosynthesis and cellular phenotype of NP cells under high-magnitude compression. © 2017 The Author(s). Published by S. Karger AG, Basel.

Introduction to Single-Cell RNA Sequencing.

PubMed

Olsen, Thale Kristin; Baryawno, Ninib

2018-04-01

During the last decade, high-throughput sequencing methods have revolutionized the entire field of biology. The opportunity to study entire transcriptomes in great detail using RNA sequencing (RNA-seq) has fueled many important discoveries and is now a routine method in biomedical research. However, RNA-seq is typically performed in "bulk," and the data represent an average of gene expression patterns across thousands to millions of cells; this might obscure biologically relevant differences between cells. Single-cell RNA-seq (scRNA-seq) represents an approach to overcome this problem. By isolating single cells, capturing their transcripts, and generating sequencing libraries in which the transcripts are mapped to individual cells, scRNA-seq allows assessment of fundamental biological properties of cell populations and biological systems at unprecedented resolution. Here, we present the most common scRNA-seq protocols in use today and the basics of data analysis and discuss factors that are important to consider before planning and designing an scRNA-seq project. © 2018 by John Wiley & Sons, Inc. Copyright © 2018 John Wiley & Sons, Inc.

Mechanisms of bacterial morphogenesis: evolutionary cell biology approaches provide new insights.

PubMed

Jiang, Chao; Caccamo, Paul D; Brun, Yves V

2015-04-01

How Darwin's "endless forms most beautiful" have evolved remains one of the most exciting questions in biology. The significant variety of bacterial shapes is most likely due to the specific advantages they confer with respect to the diverse environments they occupy. While our understanding of the mechanisms generating relatively simple shapes has improved tremendously in the last few years, the molecular mechanisms underlying the generation of complex shapes and the evolution of shape diversity are largely unknown. The emerging field of bacterial evolutionary cell biology provides a novel strategy to answer this question in a comparative phylogenetic framework. This relatively novel approach provides hypotheses and insights into cell biological mechanisms, such as morphogenesis, and their evolution that would have been difficult to obtain by studying only model organisms. We discuss the necessary steps, challenges, and impact of integrating "evolutionary thinking" into bacterial cell biology in the genomic era. © 2015 WILEY Periodicals, Inc.

Using the mixed media according to internet-based on the instructional multimedia for developing students' learning achievements in biology course on foundational cell issue of secondary students at the 10th grade level in Rangsit University demonstration school

NASA Astrophysics Data System (ADS)

Kangloan, Pichet; Chayaburakul, Kanokporn; Santiboon, Toansakul

2018-01-01

The aims of this research study were 1) to develop students' learning achievements in biology course on foundational cell issue, 2) to examine students' satisfactions of their learning activities through the mixed media according to internet-based multi-instruction in biology on foundational cell issue at the 10th grade level were used in the first semester in the academic year 2014, which a sample size of 17 students in Rangsit University Demonstration School with cluster random sampling was selected. Students' learning administrations were instructed with the 3-instructional lesson plans according to the 5-Step Ladder Learning Management Plan (LLMP) namely; the maintaining lesson plan on the equilibrium of cell issue, a lesson plan for learning how to communicate between cell and cell division. Students' learning achievements were assessed with the 30-item Assessment of Learning Biology Test (ALBT), students' perceptions of their satisfactions were satisfied with the 20-item Questionnaire on Students Satisfaction (QSS), and students' learning activities were assessed with the Mixed Media Internet-Based Instruction (MMIBI) on foundational cell issue was designed. The results of this research study have found that: statistically significant of students' post-learning achievements were higher than their pre-learning outcomes and indicated that the differences were significant at the .05 level. Students' performances of their satisfaction to their perceptions toward biology class with the mixed media according to internet-based multi instruction in biology on foundational cell issue were the highest level and evidence of average mean score as 4.59.

Context clues: the importance of stem cell-material interactions

PubMed Central

Murphy, William L.

2014-01-01

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

Genomewide effects of peroxisome proliferator-activated receptor gamma in macrophages and dendritic cells--revealing complexity through systems biology.

PubMed

Cuaranta-Monroy, Ixchelt; Kiss, Mate; Simandi, Zoltan; Nagy, Laszlo

2015-09-01

Systems biology approaches have become indispensable tools in biomedical and basic research. These data integrating bioinformatic methods gained prominence after high-throughput technologies became available to investigate complex cellular processes, such as transcriptional regulation and protein-protein interactions, on a scale that had not been studied before. Immunology is one of the medical fields that systems biology impacted profoundly due to the plasticity of cell types involved and the accessibility of a wide range of experimental models. In this review, we summarize the most important recent genomewide studies exploring the function of peroxisome proliferator-activated receptor γ in macrophages and dendritic cells. PPARγ ChIP-seq experiments were performed in adipocytes derived from embryonic stem cells to complement the existing data sets and to provide comparators to macrophage data. Finally, lists of regulated genes generated from such experiments were analysed with bioinformatics and system biology approaches. We show that genomewide studies utilizing high-throughput data acquisition methods made it possible to gain deeper insights into the role of PPARγ in these immune cell types. We also demonstrate that analysis and visualization of data using network-based approaches can be used to identify novel genes and functions regulated by the receptor. The example of PPARγ in macrophages and dendritic cells highlights the crucial importance of systems biology approaches in establishing novel cellular functions for long-known signaling pathways. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

Intersections of lung progenitor cells, lung disease and lung cancer.

PubMed

Kim, Carla F

2017-06-30

The use of stem cell biology approaches to study adult lung progenitor cells and lung cancer has brought a variety of new techniques to the field of lung biology and has elucidated new pathways that may be therapeutic targets in lung cancer. Recent results have begun to identify the ways in which different cell populations interact to regulate progenitor activity, and this has implications for the interventions that are possible in cancer and in a variety of lung diseases. Today's better understanding of the mechanisms that regulate lung progenitor cell self-renewal and differentiation, including understanding how multiple epigenetic factors affect lung injury repair, holds the promise for future better treatments for lung cancer and for optimising the response to therapy in lung cancer. Working between platforms in sophisticated organoid culture techniques, genetically engineered mouse models of injury and cancer, and human cell lines and specimens, lung progenitor cell studies can begin with basic biology, progress to translational research and finally lead to the beginnings of clinical trials. Copyright ©ERS 2017.

New frontiers in human cell biology and medicine: can pluripotent stem cells deliver?

PubMed

Goldstein, Lawrence S B

2012-11-12

Human pluripotent stem cells provide enormous opportunities to treat disease using cell therapy. But human stem cells can also drive biomedical and cell biological discoveries in a human model system, which can be directly linked to understanding disease or developing new therapies. Finally, rigorous scientific studies of these cells can and should inform the many science and medical policy issues that confront the translation of these technologies to medicine. In this paper, I discuss these issues using amyotrophic lateral sclerosis as an example.

MATERIALS USED IN TEACHING AND EVALUATING THE CONCEPTS RELATED TO THE BIOLOGICAL CELL IN GRADES 2-6, PRACTICAL PAPER NO. 2.

ERIC Educational Resources Information Center

STAUSS, NYLES G.

INCLUDED ARE MATERIALS FOR USE IN TEACHING AND EVALUATING 11 SELECTED CONCEPTS RELATED TO THE BIOLOGICAL CELL IN GRADES 2 TO 6. THE CONCEPTS WERE SELECTED AND THEIR ORDER DETERMINED THROUGH AN ANALYSIS OF ELEMENTARY TEXTBOOK SERIES, HIGH SCHOOL AND COLLEGE BIOLOGY TEXTS, CYTOLOGY TEXTS, AND INFORMATION GATHERED THROUGH A PILOT STUDY. THE MATERIALS…

Factors Influencing Academic Performance of Students Enrolled in a Lower Division Cell Biology Core Course

ERIC Educational Resources Information Center

Soto, Julio G.; Anand, Sulekha

2009-01-01

Students' performance in two semesters of our Cell Biology course was examined for this study. Teaching strategies, behaviors, and pre-course variables were analyzed with respect to students' performance. Pre-semester and post-semester surveys were administered to ascertain students' perceptions about class difficulty, amount of study and effort…

Specificity and mechanism of action of alpha-helical membrane-active peptides interacting with model and biological membranes by single-molecule force spectroscopy.

PubMed

Sun, Shiyu; Zhao, Guangxu; Huang, Yibing; Cai, Mingjun; Shan, Yuping; Wang, Hongda; Chen, Yuxin

2016-07-01

In this study, to systematically investigate the targeting specificity of membrane-active peptides on different types of cell membranes, we evaluated the effects of peptides on different large unilamellar vesicles mimicking prokaryotic, normal eukaryotic, and cancer cell membranes by single-molecule force spectroscopy and spectrum technology. We revealed that cationic membrane-active peptides can exclusively target negatively charged prokaryotic and cancer cell model membranes rather than normal eukaryotic cell model membranes. Using Acholeplasma laidlawii, 3T3-L1, and HeLa cells to represent prokaryotic cells, normal eukaryotic cells, and cancer cells in atomic force microscopy experiments, respectively, we further studied that the single-molecule targeting interaction between peptides and biological membranes. Antimicrobial and anticancer activities of peptides exhibited strong correlations with the interaction probability determined by single-molecule force spectroscopy, which illustrates strong correlations of peptide biological activities and peptide hydrophobicity and charge. Peptide specificity significantly depends on the lipid compositions of different cell membranes, which validates the de novo design of peptide therapeutics against bacteria and cancers.

Multilayer network modeling of integrated biological systems. Comment on "Network science of biological systems at different scales: A review" by Gosak et al.

NASA Astrophysics Data System (ADS)

De Domenico, Manlio

2018-03-01

Biological systems, from a cell to the human brain, are inherently complex. A powerful representation of such systems, described by an intricate web of relationships across multiple scales, is provided by complex networks. Recently, several studies are highlighting how simple networks - obtained by aggregating or neglecting temporal or categorical description of biological data - are not able to account for the richness of information characterizing biological systems. More complex models, namely multilayer networks, are needed to account for interdependencies, often varying across time, of biological interacting units within a cell, a tissue or parts of an organism.

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.

Future perspective of induced pluripotent stem cells for diagnosis, drug screening and treatment of human diseases.

PubMed

Lian, Qizhou; Chow, Yenyen; Esteban, Miguel Angel; Pei, Duanqing; Tse, Hung-Fat

2010-07-01

Recent advances in stem cell biology have transformed the understanding of cell physiology and developmental biology such that it can now play a more prominent role in the clinical application of stem cell and regenerative medicine. Success in the generation of human induced pluripotent stem cells (iPS) as well as related emerging technology on the iPS platform provide great promise in the development of regenerative medicine. Human iPS cells show almost identical properties to human embryonic stem cells (ESC) in pluripotency, but avoid many of their limitations of use. In addition, investigations into reprogramming of somatic cells to pluripotent stem cells facilitate a deeper understanding of human stem cell biology. The iPS cell technology has offered a unique platform for studying the pathogenesis of human disease, pharmacological and toxicological testing, and cell-based therapy. Nevertheless, significant challenges remain to be overcome before the promise of human iPS cell technology can be realised.

Biological effects of radiation, metabolic and replication kinetics alterations

NASA Technical Reports Server (NTRS)

Post, J.

1972-01-01

The biological effects of radiation upon normal and cancerous tissues were studied. A macromolecular precursor of DNA, 3ETdR, was incorporated into the cell nucleus during synthesis and provided intranuclear beta radiation. Tritium labeled cells were studied with autoradiographic methods; cell cycle kinetics were determined and cell functions modified by radiation dosage or by drugs were also evaluated. The long term program has included; (1) effects of radiation on cell replication and the correlation with incorporated dose levels, (2) radiation induced changes in cell function, viz., the response of beta irradiated spleen lymphocytes to antigenic stimulation by sheep red blood cells (SRBC), (3) kinetics of tumor and normal cell replication; and (4) megakaryocyte formation and modification by radiomimetic drugs.

Wetting of silicone oil onto a cell-seeded substrate

NASA Astrophysics Data System (ADS)

Lu, Yongjie; Chan, Yau Kei; Chao, Youchuang; Shum, Ho Cheung

2017-11-01

Wetting behavior of solid substrates in three-phase systems containing two immiscible liquids are widely studied. There exist many three-phase systems in biological environments, such as droplet-based microfluidics or tamponade of silicone oil for eye surgery. However, few studies focus on wetting behavior of biological surfaces with cells. Here we investigate wetting of silicone oil onto cell-seeded PMMA sheet immersed in water. Using a simple parallel-plate cell, we show the effect of cell density, viscosity of silicone oil, morphology of silicone oil drops and interfacial tension on the wetting phenomenon. The dynamics of wetting is also observed by squeezing silicone oil drop using two parallel plates. Experimental results are explained based on disjoining pressure which is dependent on the interaction of biological surfaces and liquid used. These findings are useful for explaining emulsification of silicone oil in ophthalmological applications.

Ciona intestinalis notochord as a new model to investigate the cellular and molecular mechanisms of tubulogenesis.

PubMed

Denker, Elsa; Jiang, Di

2012-05-01

Biological tubes are a prevalent structural design across living organisms. They provide essential functions during the development and adult life of an organism. Increasing progress has been made recently in delineating the cellular and molecular mechanisms underlying tubulogenesis. This review aims to introduce ascidian notochord morphogenesis as an interesting model system to study the cell biology of tube formation, to a wider cell and developmental biology community. We present fundamental morphological and cellular events involved in notochord morphogenesis, compare and contrast them with other more established tubulogenesis model systems, and point out some unique features, including bipolarity of the notochord cells, and using cell shape changes and cell rearrangement to connect lumens. We highlight some initial findings in the molecular mechanisms of notochord morphogenesis. Based on these findings, we present intriguing problems and put forth hypotheses that can be addressed in future studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cell Line Modeling to Study Biomarker Panel in Prostate Cancer

PubMed Central

NickKholgh, Bita; Fang, Xiaolan; Winters, Shira M.; Raina, Anvi; Pandya, Komal S.; Gyabaah, Kenneth; Fino, Nora; Balaji, K.C.

2016-01-01

BACKGROUND African–American men with prostate cancer (PCa) present with higher-grade and -stage tumors compared to Caucasians. While the disparity may result from multiple factors, a biological basis is often strongly suspected. Currently, few well-characterized experimental model systems are available to study the biological basis of racial disparity in PCa. We report a validated in vitro cell line model system that could be used for the purpose. METHODS We assembled a PCa cell line model that included currently available African–American PCa cell lines and LNCaP (androgen-dependent) and C4-2 (castration-resistant) Caucasian PCa cells. The utility of the cell lines in studying the biological basis of variance in a malignant phenotype was explored using a multiplex biomarker panel consisting of proteins that have been proven to play a role in the progression of PCa. The panel expression was evaluated by Western blot and RT-PCR in cell lines and validated in human PCa tissues by RT-PCR. As proof-of-principle to demonstrate the utility of our model in functional studies, we performed MTS viability assays and molecular studies. RESULTS The dysregulation of the multiplex biomarker panel in primary African–American cell line (E006AA) was similar to metastatic Caucasian cell lines, which would suggest that the cell line model could be used to study an inherent aggressive phenotype in African–American men with PCa. We had previously demonstrated that Protein kinase D1 (PKD1) is a novel kinase that is down regulated in advanced prostate cancer. We established the functional relevance by over expressing PKD1, which resulted in decreased proliferation and epithelial mesenchymal transition (EMT) in PCa cells. Moreover, we established the feasibility of studying the expression of the multiplex biomarker panel in archived human PCa tissue from African–Americans and Caucasians as a prelude to future translational studies. CONCLUSION We have characterized a novel in vitro cell line model that could be used to study the biological basis of disparity in PCa between African–Americans and Caucasians. PMID:26764245

Cell junction dynamics in the testis: Sertoli-germ cell interactions and male contraceptive development.

PubMed

Cheng, C Yan; Mruk, Dolores D

2002-10-01

Spermatogenesis is an intriguing but complicated biological process. However, many studies since the 1960s have focused either on the hormonal events of the hypothalamus-pituitary-testicular axis or morphological events that take place in the seminiferous epithelium. Recent advances in biochemistry, cell biology, and molecular biology have shifted attention to understanding some of the key events that regulate spermatogenesis, such as germ cell apoptosis, cell cycle regulation, Sertoli-germ cell communication, and junction dynamics. In this review, we discuss the physiology and biology of junction dynamics in the testis, in particular how these events affect interactions of Sertoli and germ cells in the seminiferous epithelium behind the blood-testis barrier. We also discuss how these events regulate the opening and closing of the blood-testis barrier to permit the timely passage of preleptotene and leptotene spermatocytes across the blood-testis barrier. This is physiologically important since developing germ cells must translocate across the blood-testis barrier as well as traverse the seminiferous epithelium during their development. We also discuss several available in vitro and in vivo models that can be used to study Sertoli-germ cell anchoring junctions and Sertoli-Sertoli tight junctions. An in-depth survey in this subject has also identified several potential targets to be tackled to perturb spermatogenesis, which will likely lead to the development of novel male contraceptives.

Spermatogonial stem cell regulation and spermatogenesis

PubMed Central

Phillips, Bart T.; Gassei, Kathrin; Orwig, Kyle E.

2010-01-01

This article will provide an updated review of spermatogonial stem cells and their role in maintaining the spermatogenic lineage. Experimental tools used to study spermatogonial stem cells (SSCs) will be described, along with research using these tools to enhance our understanding of stem cell biology and spermatogenesis. Increased knowledge about the biology of SSCs improves our capacity to manipulate these cells for practical application. The chapter concludes with a discussion of future directions for fundamental investigation and practical applications of SSCs. PMID:20403877

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

Novel chlorinated dibenzofurans isolated from the cellular slime mold, Polysphondylium filamentosum, and their biological activities.

PubMed

Kikuchi, Haruhisa; Kubohara, Yuzuru; Nguyen, Van Hai; Katou, Yasuhiro; Oshima, Yoshiteru

2013-08-01

Cellular slime molds are expected to have the huge potential for producing secondary metabolites including polyketides, and we have studied the diversity of secondary metabolites of cellular slime molds for their potential utilization as new biological resources for natural product chemistry. From the methanol extract of fruiting bodies of Polysphondylium filamentosum, we obtained new chlorinated benzofurans Pf-1 (4) and Pf-2 (5) which display multiple biological activities; these include stalk cell differentiation-inducing activity in the well-studied cellular slime mold, Dictyostelium discoideum, and inhibitory activities on cell proliferation in mammalian cells and gene expression in Drosophila melanogaster. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Study of the Comparative Effectiveness of Zoology Prerequisites at Slippery Rock State College.

ERIC Educational Resources Information Center

Morrison, William Sechler

This study compared the effectiveness of three sequences of prerequisite courses required before taking zoology. Sequence 1 prerequisite courses consisted of general biology and human biology; Sequence 2 consisted of general biology; and Sequence 3 required cell biology. Zoology students in the spring of 1972 were pretest and a posttest. The mean…

Analysis of single mammalian cells on-chip.

PubMed

Sims, Christopher E; Allbritton, Nancy L

2007-04-01

A goal of modern biology is to understand the molecular mechanisms underlying cellular function. The ability to manipulate and analyze single cells is crucial for this task. The advent of microengineering is providing biologists with unprecedented opportunities for cell handling and investigation on a cell-by-cell basis. For this reason, lab-on-a-chip (LOC) technologies are emerging as the next revolution in tools for biological discovery. In the current discussion, we seek to summarize the state of the art for conventional technologies in use by biologists for the analysis of single, mammalian cells, and then compare LOC devices engineered for these same single-cell studies. While a review of the technical progress is included, a major goal is to present the view point of the practicing biologist and the advances that might increase adoption by these individuals. The LOC field is expanding rapidly, and we have focused on areas of broad interest to the biology community where the technology is sufficiently far advanced to contemplate near-term application in biological experimentation. Focus areas to be covered include flow cytometry, electrophoretic analysis of cell contents, fluorescent-indicator-based analyses, cells as small volume reactors, control of the cellular microenvironment, and single-cell PCR.

Defining Hepatocellular Carcinoma Subtypes and Treatment Responses in Patient-Derived Tumorgrafts

DTIC Science & Technology

2017-10-01

Our team will use human- mouse PDX models to uncover novel biology and establish a platform to study experimental therapeutics. 1. KEYWORDS: HCC...if early vs. advanced HCCs have distinct cell-intrinsic biology in PDX engraftment assays Major Task 1: Expand and characterize PDX models derived...have distinct cell-intrinsic biology in PDX engraftment assays Major Task 1: Expand and characterize PDX models derived from surgical and biopsy

Downregulation of the expression of HDGF attenuates malignant biological behaviors of hilar cholangiocarcinoma cells.

PubMed

Liu, Yanfeng; Sun, Jingxian; Yang, Guangyun; Liu, Zhaojian; Guo, Sen; Zhao, Rui; Xu, Kesen; Wu, Xiaopeng; Zhang, Zhaoyang

2015-09-01

Hepatoma-derived growth factor (HDGF) has been reported to be a potential predictive and prognostic marker for several types of cancer and important in malignant biological behaviors. However, its role in human hilar cholangiocarcinoma remains to be elucidated. Our previous study demonstrated that high expression levels of HDGF in hilar cholangiocarcinoma tissues correlates with tumor progression and patient outcome. The present study aimed to elucidate the detailed functions of the HDGF protein. This was performed by downregulating the protein expression of HDGF in the FRH0201 hilar cholangiocarcinoma cell line by RNA interference (RNAi) in vitro, and revealed that downregulation of the HDGF protein significantly inhibited the malignant biological behavior of the FRH0201 cells. In addition, further investigation revealed that downregulation of the protein expression of HDGF significantly decreased the secretion of vascular endothelial growth factor, which may be the mechanism partially responsible for the inhibition of malignant biological behaviors. These findings demonstrated that HDGF is important in promoting malignant biological behaviors, including proliferation, migration and invasion of hilar cholangiocarcinoma FRH0201 cells. Inhibition of the expression of HDGF downregulated the malignant biological behaviors, suggesting that downregulation of the protein expression of HDGF by RNAi may be a novel therapeutic approach to inhibit the progression of hilar cholangiocarcinoma.

Integrated micro/nanoengineered functional biomaterials for cell mechanics and mechanobiology: a materials perspective.

PubMed

Shao, Yue; Fu, Jianping

2014-03-12

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, an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions is presented and they are highlighted them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. 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 is also discussed. 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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Molecular biological features of male germ cell differentiation

PubMed Central

HIROSE, MIKA; TOKUHIRO, KEIZO; TAINAKA, HITOSHI; MIYAGAWA, YASUSHI; TSUJIMURA, AKIRA; OKUYAMA, AKIHIKO; NISHIMUNE, YOSHITAKE

2007-01-01

Somatic cell differentiation is required throughout the life of a multicellular organism to maintain homeostasis. In contrast, germ cells have only one specific function; to preserve the species by conveying the parental genes to the next generation. Recent studies of the development and molecular biology of the male germ cell have identified many genes, or isoforms, that are specifically expressed in the male germ cell. In the present review, we consider the unique features of male germ cell differentiation. (Reprod Med Biol 2007; 6: 1–9) PMID:29699260

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

PubMed Central

Wu, J.S.; Kim, A. M.; Bleher, R.; Myers, B.D.; Marvin, R. G.; Inada, H.; Nakamura, K.; Zhang, X.F.; Roth, E.; Li, S.Y.; Woodruff, T. K.; O'Halloran, T. V.; Dravid, Vinayak P.

2013-01-01

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room- and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. PMID:23500508

78 FR 64229 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-28

... Committee: AIDS and Related Research Integrated Review Group; AIDS Molecular and Cellular Biology Study...; Fellowships: Cell Biology, Developmental Biology and Bioengineering. Date: November 18-19, 2013. Time: 10:00 a...

Cell Based Therapeutic Approach in Vascular Surgery: Application and Review

PubMed Central

Rocca, Aldo; Tafuri, Domenico; Paccone, Marianna; Giuliani, Antonio; Zamboli, Anna Ginevra Immacolata; Surfaro, Giuseppe; Paccone, Andrea; Compagna, Rita; Amato, Maurizo; Serra, Raffaele; Amato, Bruno

2017-01-01

Abstract Multipotent stem cells - such as mesenchymal stem/stromal cells and stem cells derived from different sources like vascular wall are intensely studied to try to rapidly translate their discovered features from bench to bedside. Vascular wall resident stem cells recruitment, differentiation, survival, proliferation, growth factor production, and signaling pathways transduced were analyzed. We studied biological properties of vascular resident stem cells and explored the relationship from several factors as Matrix Metalloproteinases (MMPs) and regulations of biological, translational and clinical features of these cells. In this review we described a translational and clinical approach to Adult Vascular Wall Resident Multipotent Vascular Stem Cells (VW-SCs) and reported their involvement in alternative clinical approach as cells based therapy in vascular disease like arterial aneurysms or peripheral arterial obstructive disease. PMID:29071303

Toxicity Assessment of 17 alpha-ethinylestradiol by Cell-Culture Based NMR Metabolomics

EPA Science Inventory

A zebrafish liver cell line (ZFL) established from adult zebrafish has been used in a variety of biological research, including toxicology, pharmacology, developmental biology and molecular genetics. The goal of this study is to develop an in vitro approach to identify the respo...

Do lipids shape the eukaryotic cell cycle?

PubMed

Furse, Samuel; Shearman, Gemma C

2018-01-01

Successful passage through the cell cycle presents a number of structural challenges to the cell. Inceptive studies carried out in the last five years have produced clear evidence of modulations in the lipid profile (sometimes referred to as the lipidome) of eukaryotes as a function of the cell cycle. This mounting body of evidence indicates that lipids play key roles in the structural transformations seen across the cycle. The accumulation of this evidence coincides with a revolution in our understanding of how lipid composition regulates a plethora of biological processes ranging from protein activity through to cellular signalling and membrane compartmentalisation. In this review, we discuss evidence from biological, chemical and physical studies of the lipid fraction across the cell cycle that demonstrate that lipids are well-developed cellular components at the heart of the biological machinery responsible for managing progress through the cell cycle. Furthermore, we discuss the mechanisms by which this careful control is exercised. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Discovery of HeLa Cell Contamination in HES Cells: Call for Cell Line Authentication in Reproductive Biology Research.

PubMed

Kniss, Douglas A; Summerfield, Taryn L

2014-08-01

Continuous cell lines are used frequently in reproductive biology research to study problems in early pregnancy events and parturition. It has been recognized for 50 years that many mammalian cell lines contain inter- or intraspecies contaminations with other cells. However, most investigators do not routinely test their culture systems for cross-contamination. The most frequent contributor to cross-contamination of cell lines is the HeLa cell isolated from an aggressive cervical adenocarcinoma. We report on the discovery of HeLa cell contamination of the human endometrial epithelial cell line HES isolated in our laboratory. Short tandem repeat analysis of 9 unique genetic loci demonstrated molecular identity between HES and HeLa cells. In addition, we verified that WISH cells, isolated originally from human amnion epithelium, were also contaminated with HeLa cells. Inasmuch as our laboratory did not culture HeLa cells at the time of HES cell derivations, the source of contamination was the WISH cell line. These data highlight the need for continued diligence in authenticating cell lines used in reproductive biology research. © The Author(s) 2014.

A Comparison of CAL with a Conventional Method of Delivery of Cell Biology to Undergraduate Nursing Students Using an Experimental Design.

ERIC Educational Resources Information Center

Wharrad, Heather J.; Kent, Christine; Allcock, Nick; Wood, Barry

2001-01-01

In study 1, 12 nursing students attended slide lectures on cell biology; 13 used interactive computer-assisted learning (CAL). Study 2 surveyed 38 students who used CAL to study immunology. Students preferred CAL and felt confident in their grasp of the material, even without the presence of lecturers to answer questions. (Contains 16 references.)…

Primary culture of glial cells from mouse sympathetic cervical ganglion: a valuable tool for studying glial cell biology.

PubMed

de Almeida-Leite, Camila Megale; Arantes, Rosa Maria Esteves

2010-12-15

Central nervous system glial cells as astrocytes and microglia have been investigated in vitro and many intracellular pathways have been clarified upon various stimuli. Peripheral glial cells, however, are not as deeply investigated in vitro despite its importance role in inflammatory and neurodegenerative diseases. Based on our previous experience of culturing neuronal cells, our objective was to standardize and morphologically characterize a primary culture of mouse superior cervical ganglion glial cells in order to obtain a useful tool to study peripheral glial cell biology. Superior cervical ganglia from neonatal C57BL6 mice were enzymatically and mechanically dissociated and cells were plated on diluted Matrigel coated wells in a final concentration of 10,000cells/well. Five to 8 days post plating, glial cell cultures were fixed for morphological and immunocytochemical characterization. Glial cells showed a flat and irregular shape, two or three long cytoplasm processes, and round, oval or long shaped nuclei, with regular outline. Cell proliferation and mitosis were detected both qualitative and quantitatively. Glial cells were able to maintain their phenotype in our culture model including immunoreactivity against glial cell marker GFAP. This is the first description of immunocytochemical characterization of mouse sympathetic cervical ganglion glial cells in primary culture. This work discusses the uses and limitations of our model as a tool to study many aspects of peripheral glial cell biology. Copyright © 2010 Elsevier B.V. All rights reserved.

Octamer-binding protein 4 affects the cell biology and phenotypic transition of lung cancer cells involving β-catenin/E-cadherin complex degradation.

PubMed

Chen, Zhong-Shu; Ling, Dong-Jin; Zhang, Yang-De; Feng, Jian-Xiong; Zhang, Xue-Yu; Shi, Tian-Sheng

2015-03-01

Clinical studies have reported evidence for the involvement of octamer‑binding protein 4 (Oct4) in the tumorigenicity and progression of lung cancer; however, the role of Oct4 in lung cancer cell biology in vitro and its mechanism of action remain to be elucidated. Mortality among lung cancer patients is more frequently due to metastasis rather than their primary tumors. Epithelial‑mesenchymal transition (EMT) is a prominent biological event for the induction of epithelial cancer metastasis. The aim of the present study was to investigate whether Oct4 had the capacity to induce lung cancer cell metastasis via the promoting the EMT in vitro. Moreover, the effect of Oct4 on the β‑catenin/E‑cadherin complex, associated with EMT, was examined using immunofluorescence and immunoprecipitation assays as well as western blot analysis. The results demonstrated that Oct4 enhanced cell invasion and adhesion accompanied by the downregulation of epithelial marker cytokeratin, and upregulation of the mesenchymal markers vimentin and N‑cadherin. Furthermore, Oct4 induced EMT of lung cancer cells by promoting β‑catenin/E‑cadherin complex degradation and regulating nuclear localization of β‑catenin. In conclusion, the present study indicated that Oct4 affected the cell biology of lung cancer cells in vitro through promoting lung cancer cell metastasis via EMT; in addition, the results suggested that the association and degradation of the β‑catenin/E‑cadherin complex was regulated by Oct4 during the process of EMT.

Digital biology and chemistry.

PubMed

Witters, Daan; Sun, Bing; Begolo, Stefano; Rodriguez-Manzano, Jesus; Robles, Whitney; Ismagilov, Rustem F

2014-09-07

This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and cellular analysis. Microfluidics will impact digital biology and chemistry and will also benefit from them if it becomes massively distributed.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications.

PubMed

Khalili, Amelia Ahmad; Ahmad, Mohd Ridzuan

2015-08-05

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications

PubMed Central

Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

2015-01-01

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events. PMID:26251901

Protein Delivery into Plant Cells: Toward In vivo Structural Biology

PubMed Central

Cedeño, Cesyen; Pauwels, Kris; Tompa, Peter

2017-01-01

Understanding the biologically relevant structural and functional behavior of proteins inside living plant cells is only possible through the combination of structural biology and cell biology. The state-of-the-art structural biology techniques are typically applied to molecules that are isolated from their native context. Although most experimental conditions can be easily controlled while dealing with an isolated, purified protein, a serious shortcoming of such in vitro work is that we cannot mimic the extremely complex intracellular environment in which the protein exists and functions. Therefore, it is highly desirable to investigate proteins in their natural habitat, i.e., within live cells. This is the major ambition of in-cell NMR, which aims to approach structure-function relationship under true in vivo conditions following delivery of labeled proteins into cells under physiological conditions. With a multidisciplinary approach that includes recombinant protein production, confocal fluorescence microscopy, nuclear magnetic resonance (NMR) spectroscopy and different intracellular protein delivery strategies, we explore the possibility to develop in-cell NMR studies in living plant cells. While we provide a comprehensive framework to set-up in-cell NMR, we identified the efficient intracellular introduction of isotope-labeled proteins as the major bottleneck. Based on experiments with the paradigmatic intrinsically disordered proteins (IDPs) Early Response to Dehydration protein 10 and 14, we also established the subcellular localization of ERD14 under abiotic stress. PMID:28469623

Stabilities and Biological Activities of Vanadium Drugs: What is the Nature of the Active Species?

PubMed

Levina, Aviva; Lay, Peter A

2017-07-18

Diverse biological activities of vanadium(V) drugs mainly arise from their abilities to inhibit phosphatase enzymes and to alter cell signaling. Initial interest focused on anti-diabetic activities but has shifted to anti-cancer and anti-parasitic drugs. V-based anti-diabetics are pro-drugs that release active components (e.g., H 2 VO 4 - ) in biological media. By contrast, V anti-cancer drugs are generally assumed to enter cells intact; however, speciation studies indicate that nearly all drugs are likely to react in cell culture media during in vitro assays and the same would apply in vivo. The biological activities are due to V V and/or V IV reaction products with cell culture media, or the release of ligands (e.g., aromatic diimines, 8-hydroxyquinolines or thiosemicarbazones) that bind to essential metal ions in the media. Careful consideration of the stability and speciation of V complexes in cell culture media and in biological fluids is essential to design targeted V-based anti-cancer therapies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bioprocessing in Space

NASA Technical Reports Server (NTRS)

Morrison, D. R. (Compiler)

1977-01-01

Proceedings are presented of the 1976 NASA Colloquium on bioprocessing in space. The program included general sessions and formal presentations on the following topics: NASA's Space Shuttle, Spacelab, and space-processing programs; the known unusual behavior of materials in space; space-processing experiment results; cell biology, gravity sensors in cells, space electrophoresis of living cells, new approaches to biosynthesis of biologicals from cell culture in space, and zero-g fermentation concepts; and upcoming flight opportunities and industrial application planning studies already underway.

Recent findings and technological advances in phosphoproteomics for cells and tissues.

PubMed

von Stechow, Louise; Francavilla, Chiara; Olsen, Jesper V

2015-01-01

Site-specific phosphorylation is a fast and reversible covalent post-translational modification that is tightly regulated in cells. The cellular machinery of enzymes that write, erase and read these modifications (kinases, phosphatases and phospho-binding proteins) is frequently deregulated in different diseases, including cancer. Large-scale studies of phosphoproteins - termed phosphoproteomics - strongly rely on the use of high-performance mass spectrometric instrumentation. This powerful technology has been applied to study a great number of phosphorylation-based phenotypes. Nevertheless, many technical and biological challenges have to be overcome to identify biologically relevant phosphorylation sites in cells and tissues. This review describes different technological strategies to identify and quantify phosphorylation sites with high accuracy, without significant loss of analysis speed and reproducibility in tissues and cells. Moreover, computational tools for analysis, integration and biological interpretation of phosphorylation events are discussed.

Biofunctionalized 3-D Carbon Nano-Network Platform for Enhanced Fibroblast Cell Adhesion

NASA Astrophysics Data System (ADS)

Chowdhury, A. K. M. Rezaul Haque; Tavangar, Amirhossein; Tan, Bo; Venkatakrishnan, Krishnan

2017-03-01

Carbon nanomaterials have been investigated for various biomedical applications. In most cases, however, these nanomaterials must be functionalized biologically or chemically due to their biological inertness or possible cytotoxicity. Here, we report the development of a new carbon nanomaterial with a bioactive phase that significantly promotes cell adhesion. We synthesize the bioactive phase by introducing self-assembled nanotopography and altered nano-chemistry to graphite substrates using ultrafast laser. To the best of our knowledge, this is the first time that such a cytophilic bio-carbon is developed in a single step without requiring subsequent biological/chemical treatments. By controlling the nano-network concentration and chemistry, we develop platforms with different degrees of cell cytophilicity. We study quantitatively and qualitatively the cell response to nano-network platforms with NIH-3T3 fibroblasts. The findings from the in vitro study indicate that the platforms possess excellent biocompatibility and promote cell adhesion considerably. The study of the cell morphology shows a healthy attachment of cells with a well-spread shape, overextended actin filaments, and morphological symmetry, which is indicative of a high cellular interaction with the nano-network. The developed nanomaterial possesses great biocompatibility and considerably stimulates cell adhesion and subsequent cell proliferation, thus offering a promising path toward engineering various biomedical devices.

An Integrated Workflow To Assess Technical and Biological Variability of Cell Population Frequencies in Human Peripheral Blood by Flow Cytometry.

PubMed

Burel, Julie G; Qian, Yu; Lindestam Arlehamn, Cecilia; Weiskopf, Daniela; Zapardiel-Gonzalo, Jose; Taplitz, Randy; Gilman, Robert H; Saito, Mayuko; de Silva, Aruna D; Vijayanand, Pandurangan; Scheuermann, Richard H; Sette, Alessandro; Peters, Bjoern

2017-02-15

In the context of large-scale human system immunology studies, controlling for technical and biological variability is crucial to ensure that experimental data support research conclusions. In this study, we report on a universal workflow to evaluate both technical and biological variation in multiparameter flow cytometry, applied to the development of a 10-color panel to identify all major cell populations and T cell subsets in cryopreserved PBMC. Replicate runs from a control donation and comparison of different gating strategies assessed the technical variability associated with each cell population and permitted the calculation of a quality control score. Applying our panel to a large collection of PBMC samples, we found that most cell populations showed low intraindividual variability over time. In contrast, certain subpopulations such as CD56 T cells and Temra CD4 T cells were associated with high interindividual variability. Age but not gender had a significant effect on the frequency of several populations, with a drastic decrease in naive T cells observed in older donors. Ethnicity also influenced a significant proportion of immune cell population frequencies, emphasizing the need to account for these covariates in immune profiling studies. We also exemplify the usefulness of our workflow by identifying a novel cell-subset signature of latent tuberculosis infection. Thus, our study provides a universal workflow to establish and evaluate any flow cytometry panel in systems immunology studies. Copyright © 2017 by The American Association of Immunologists, Inc.

Human Embryonic Kidney 293 Cells: A Vehicle for Biopharmaceutical Manufacturing, Structural Biology, and Electrophysiology.

PubMed

Hu, Jianwen; Han, Jizhong; Li, Haoran; Zhang, Xian; Liu, Lan Lan; Chen, Fei; Zeng, Bin

2018-01-01

Mammalian cells, e.g., CHO, BHK, HEK293, HT-1080, and NS0 cells, represent important manufacturing platforms in bioengineering. They are widely used for the production of recombinant therapeutic proteins, vaccines, anticancer agents, and other clinically relevant drugs. HEK293 (human embryonic kidney 293) cells and their derived cell lines provide an attractive heterologous system for the development of recombinant proteins or adenovirus productions, not least due to their human-like posttranslational modification of protein molecules to provide the desired biological activity. Secondly, they also exhibit high transfection efficiency yielding high-quality recombinant proteins. They are easy to maintain and express with high fidelity membrane proteins, such as ion channels and transporters, and thus are attractive for structural biology and electrophysiology studies. In this article, we review the literature on HEK293 cells regarding their origins but also stress their advancements into the different cell lines engineered and discuss some significant aspects which make them versatile systems for biopharmaceutical manufacturing, drug screening, structural biology research, and electrophysiology applications. © 2018 S. Karger AG, Basel.

Cells from icons to symbols: molecularizing cell biology in the 1980s.

PubMed

Serpente, Norberto

2011-12-01

Over centuries cells have been the target of optical and electronic microscopes as well as others technologies, with distinctive types of visual output. Whilst optical technologies produce images 'evident to the eye', the electronic and especially the molecular create images that are more elusive to conceptualization and assessment. My study applies the semiotic approach to the production of images in cell biology to capture the shift from microscopic images to non-traditional visual technologies around 1980. Here I argue that the visual shift that coincides with the growing dominance of molecular biology involves a change from iconic to symbolic forms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Single-cell metabolomics: analytical and biological perspectives.

PubMed

Zenobi, R

2013-12-06

There is currently much interest in broad molecular profiling of single cells; a cell's metabolome-its full complement of small-molecule metabolites-is a direct indicator of phenotypic diversity of single cells and a nearly immediate readout of how cells react to environmental influences. However, the metabolome is very difficult to measure at the single-cell level because of rapid metabolic dynamics, the structural diversity of the molecules, and the inability to amplify or tag small-molecule metabolites. Measurement techniques including mass spectrometry, capillary electrophoresis, and, to a lesser extent, optical spectroscopy and fluorescence detection have led to impressive advances in single-cell metabolomics. Even though none of these methodologies can currently measure the metabolome of a single cell completely, rapidly, and nondestructively, progress has been sufficient such that the field is witnessing a shift from feasibility studies to investigations that yield new biological insight. Particularly interesting fields of application are cancer biology, stem cell research, and monitoring of xenobiotics and drugs in tissue sections at the single-cell level.

Nanoscale hybrid systems based on carbon nanotubes for biological sensing and control

PubMed Central

Cho, Youngtak; Shin, Narae; Kim, Daesan; Park, Jae Yeol

2017-01-01

This paper provides a concise review on the recent development of nanoscale hybrid systems based on carbon nanotubes (CNTs) for biological sensing and control. CNT-based hybrid systems have been intensively studied for versatile applications of biological interfaces such as sensing, cell therapy and tissue regeneration. Recent advances in nanobiotechnology not only enable the fabrication of highly sensitive biosensors at nanoscale but also allow the applications in the controls of cell growth and differentiation. This review describes the fabrication methods of such CNT-based hybrid systems and their applications in biosensing and cell controls. PMID:28188158

Mixing enhancement by biologically inspired convection in a micro-chamber using alternating current galvanotactic control of the Tetrahymena pyriformis

NASA Astrophysics Data System (ADS)

Kim, Jihoon; Jang, Yonghee; Byun, Doyoung; Hyung Kim, Dal; Jun Kim, Min

2013-09-01

Recently, there has been increasing interest in the swimming behavior of microorganisms and biologically inspired micro-robots. In this study, we investigated biologically induced convection flow with living microorganism using galvanotaxis. We fabricated and evaluated our micro-mixer with motile cells. For the cell based active micro-mixers, two miscible fluids were used to measure the mixing index. Under alternating current (AC) electric fields with varying frequency, a group of motile Tetrahymena pyriformis cells generated reciprocal motion with circulating flows around their pathline, enhancing the mixing ratio.

Cell biology, biophysics, and mechanobiology: From the basics to Clinics.

PubMed

Zeng, Y

2017-04-29

Cell biology, biomechanics and biophysics are the key subjects that guide our understanding in diverse areas of tissue growth, development, remodeling and homeostasis. Novel discoveries such as molecular mechanism, and mechanobiological mechanism in cell biology, biomechanics and biophysics play essential roles in our understanding of the pathogenesis of various human diseases, as well as in designing the treatment of these diseases. In addition, studies in these areas will also facilitate early diagnostics of human diseases, such as cardiovascular diseases and cancer. In this special issue, we collected 10 original research articles and 1 review...

MicroRNAs from the Planarian Schmidtea mediterranea: a model system for stem cell biology.

PubMed

Palakodeti, Dasaradhi; Smielewska, Magda; Graveley, Brenton R

2006-09-01

MicroRNAs (miRNAs) are approximately 22-nt RNA molecules that typically bind to the 3' untranslated regions of target mRNAs and function to either induce mRNA degradation or repress translation. miRNAs have been shown to play important roles in the function of stem cells and cell lineage decisions in a variety of organisms, including humans. Planarians are bilaterally symmetric metazoans that have the unique ability to completely regenerate lost tissues or organs. This regenerative capacity is facilitated by a population of stem cells known as neoblasts. Planarians are therefore an excellent model system for studying many aspects of stem cell biology. Here we report the cloning and initial characterization of 71 miRNAs from the planarian Schmidtea mediterranea. While several of the S. mediterranea miRNAs are members of miRNA families identified in other species, we also identified a number of planarian-specific miRNAs. This work lays the foundation for functional studies aimed at addressing the role of these miRNAs in regeneration, cell lineage decisions, and basic stem cell biology.

Computational studies of Ras and PI3K

NASA Technical Reports Server (NTRS)

Ren, Lei; Cucinotta, Francis A.

2004-01-01

Until recently, experimental techniques in molecular cell biology have been the primary means to investigate biological risk upon space radiation. However, computational modeling provides an alternative theoretical approach, which utilizes various computational tools to simulate proteins, nucleotides, and their interactions. In this study, we are focused on using molecular mechanics (MM) and molecular dynamics (MD) to study the mechanism of protein-protein binding and to estimate the binding free energy between proteins. Ras is a key element in a variety of cell processes, and its activation of phosphoinositide 3-kinase (PI3K) is important for survival of transformed cells. Different computational approaches for this particular study are presented to calculate the solvation energies and binding free energies of H-Ras and PI3K. The goal of this study is to establish computational methods to investigate the roles of different proteins played in the cellular responses to space radiation, including modification of protein function through gene mutation, and to support the studies in molecular cell biology and theoretical kinetics models for our risk assessment project.

Evolutionary cell biology: two origins, one objective.

PubMed

Lynch, Michael; Field, Mark C; Goodson, Holly V; Malik, Harmit S; Pereira-Leal, José B; Roos, David S; Turkewitz, Aaron P; Sazer, Shelley

2014-12-02

All aspects of biological diversification ultimately trace to evolutionary modifications at the cellular level. This central role of cells frames the basic questions as to how cells work and how cells come to be the way they are. Although these two lines of inquiry lie respectively within the traditional provenance of cell biology and evolutionary biology, a comprehensive synthesis of evolutionary and cell-biological thinking is lacking. We define evolutionary cell biology as the fusion of these two eponymous fields with the theoretical and quantitative branches of biochemistry, biophysics, and population genetics. The key goals are to develop a mechanistic understanding of general evolutionary processes, while specifically infusing cell biology with an evolutionary perspective. The full development of this interdisciplinary field has the potential to solve numerous problems in diverse areas of biology, including the degree to which selection, effectively neutral processes, historical contingencies, and/or constraints at the chemical and biophysical levels dictate patterns of variation for intracellular features. These problems can now be examined at both the within- and among-species levels, with single-cell methodologies even allowing quantification of variation within genotypes. Some results from this emerging field have already had a substantial impact on cell biology, and future findings will significantly influence applications in agriculture, medicine, environmental science, and synthetic biology.

Evolutionary cell biology: Two origins, one objective

PubMed Central

Lynch, Michael; Field, Mark C.; Goodson, Holly V.; Malik, Harmit S.; Pereira-Leal, José B.; Roos, David S.; Turkewitz, Aaron P.; Sazer, Shelley

2014-01-01

All aspects of biological diversification ultimately trace to evolutionary modifications at the cellular level. This central role of cells frames the basic questions as to how cells work and how cells come to be the way they are. Although these two lines of inquiry lie respectively within the traditional provenance of cell biology and evolutionary biology, a comprehensive synthesis of evolutionary and cell-biological thinking is lacking. We define evolutionary cell biology as the fusion of these two eponymous fields with the theoretical and quantitative branches of biochemistry, biophysics, and population genetics. The key goals are to develop a mechanistic understanding of general evolutionary processes, while specifically infusing cell biology with an evolutionary perspective. The full development of this interdisciplinary field has the potential to solve numerous problems in diverse areas of biology, including the degree to which selection, effectively neutral processes, historical contingencies, and/or constraints at the chemical and biophysical levels dictate patterns of variation for intracellular features. These problems can now be examined at both the within- and among-species levels, with single-cell methodologies even allowing quantification of variation within genotypes. Some results from this emerging field have already had a substantial impact on cell biology, and future findings will significantly influence applications in agriculture, medicine, environmental science, and synthetic biology. PMID:25404324

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

PubMed Central

Chen, Hao; Biela, Sarah A; Kaufmann, Dieter

2016-01-01

The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies. PMID:28144512

Promoting inquiry-based teaching in laboratory courses: are we meeting the grade?

PubMed

Beck, Christopher; Butler, Amy; da Silva, Karen Burke

2014-01-01

Over the past decade, repeated calls have been made to incorporate more active teaching and learning in undergraduate biology courses. The emphasis on inquiry-based teaching is especially important in laboratory courses, as these are the courses in which students are applying the process of science. To determine the current state of research on inquiry-based teaching in undergraduate biology laboratory courses, we reviewed the recent published literature on inquiry-based exercises. The majority of studies in our data set were in the subdisciplines of biochemistry, cell biology, developmental biology, genetics, and molecular biology. In addition, most exercises were guided inquiry, rather than open ended or research based. Almost 75% of the studies included assessment data, with two-thirds of these studies including multiple types of assessment data. However, few exercises were assessed in multiple courses or at multiple institutions. Furthermore, assessments were rarely based on published instruments. Although the results of the studies in our data set show a positive effect of inquiry-based teaching in biology laboratory courses on student learning gains, research that uses the same instrument across a range of courses and institutions is needed to determine whether these results can be generalized. © 2014 C. Beck et al. CBE—Life Sciences Education © 2014 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).

Microarray profiling analysis uncovers common molecular mechanisms of rubella virus, human cytomegalovirus, and herpes simplex virus type 2 infections in ECV304 cells.

PubMed

Mo, X; Xu, L; Yang, Q; Feng, H; Peng, J; Zhang, Y; Yuan, W; Wang, Y; Li, Y; Deng, Y; Wan, Y; Chen, Z; Li, F; Wu, X

2011-08-01

To study the common molecular mechanisms of various viruses infections that might result in congential cardiovascular diseases in perinatal period, changes in mRNA expression levels of ECV304 cells infected by rubella virus (RUBV), human cytomegalovirus (HCMV), and herpes simplex virus type 2 (HSV-2) were analyzed using a microarray system representing 18,716 human genes. 99 genes were found to exhibit differential expression (80 up-regulated and 19 down-regulated). Biological process analysis showed that 33 signaling pathways including 22 genes were relevant significantly to RV, HCMV and HSV-II infections. Of these 33 biological processes, 28 belong to one-gene biological processes and 5 belong to multiple-gene biological processes. Gene annotation indicated that the 5 multiple-gene biological processes including regulation of cell growth, collagen fibril organization, mRNA transport, cell adhesion and regulation of cell shape, and seven down- or up-regulated genes [CRIM1 (cysteine rich transmembrane BMP regulator 1), WISP2 (WNT1 inducible signaling pathway protein 2), COL12A1 (collagen, type XII, alpha 1), COL11A2 (collagen, type XI, alpha 2), CNTN5 (contactin 5), DDR1 (discoidin domain receptor tyrosine kinase 1), VEGF (vascular endothelial growth factor precursor)], are significantly correlated to RUBV, HCMV and HSV-2 infections in ECV304 cells. The results obtained in this study suggested the common molecular mechanisms of viruses infections that might result in congential cardiovascular diseases.

Enhanced relative biological effectiveness of proton radiotherapy in tumor cells with internalized gold nanoparticles

PubMed Central

Polf, Jerimy C.; Bronk, Lawrence F.; Driessen, Wouter H. P.; Arap, Wadih; Pasqualini, Renata; Gillin, Michael

2011-01-01

The development and use of sensitizing agents to improve the effectiveness of radiotherapy have long been sought to improve our ability to treat cancer. In this letter, we have studied the relative biological effectiveness of proton beam radiotherapy on prostate tumor cells with and without internalized gold nanoparticles. The effectiveness of proton radiotherapy for the killing of prostate tumor cells was increased by approximately 15%–20% for those cells containing internalized gold nanoparticles. PMID:21915155

Nanopipettes as Monitoring Probes for the Single Living Cell: State of the Art and Future Directions in Molecular Biology.

PubMed

Bulbul, Gonca; Chaves, Gepoliano; Olivier, Joseph; Ozel, Rifat Emrah; Pourmand, Nader

2018-06-06

Examining the behavior of a single cell within its natural environment is valuable for understanding both the biological processes that control the function of cells and how injury or disease lead to pathological change of their function. Single-cell analysis can reveal information regarding the causes of genetic changes, and it can contribute to studies on the molecular basis of cell transformation and proliferation. By contrast, whole tissue biopsies can only yield information on a statistical average of several processes occurring in a population of different cells. Electrowetting within a nanopipette provides a nanobiopsy platform for the extraction of cellular material from single living cells. Additionally, functionalized nanopipette sensing probes can differentiate analytes based on their size, shape or charge density, making the technology uniquely suited to sensing changes in single-cell dynamics. In this review, we highlight the potential of nanopipette technology as a non-destructive analytical tool to monitor single living cells, with particular attention to integration into applications in molecular biology.

Confocal micro-Raman spectroscopy of single biological cells using optical trapping and shifted excitation difference techniques

NASA Astrophysics Data System (ADS)

Xie, Changan; Li, Yong-qing

2003-03-01

We report on the study of single biological cells with a confocal micro-Raman spectroscopy system that uses optical trapping and shifted excitation Raman difference technique. A tunable diode laser was used to capture a living cell in solution, confine it in the confocal excitation volume, and then excite the Raman scattering. The optical trapping allows us to lift the cell well off the cover plate so that the fluorescence interference from the plate can be effectively reduced. In order to further remove the interference of the fluorescence and stray light from the trapped cell, we employed a shifted excitation Raman difference technique with slightly tuned laser frequencies. With this system, high-quality Raman spectra were obtained from single optically trapped biological cells including E. coli bacteria, yeast cells, and red blood cells. A significant difference between control and heat-treated E. coli B cells was observed due to the denaturation of biomolecules.

Human pluripotent stem cells: an emerging model in developmental biology.

PubMed

Zhu, Zengrong; Huangfu, Danwei

2013-02-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

The emerging age of cell-free synthetic biology.

PubMed

Smith, Mark Thomas; Wilding, Kristen M; Hunt, Jeremy M; Bennett, Anthony M; Bundy, Bradley C

2014-08-25

The engineering of and mastery over biological parts has catalyzed the emergence of synthetic biology. This field has grown exponentially in the past decade. As increasingly more applications of synthetic biology are pursued, more challenges are encountered, such as delivering genetic material into cells and optimizing genetic circuits in vivo. An in vitro or cell-free approach to synthetic biology simplifies and avoids many of the pitfalls of in vivo synthetic biology. In this review, we describe some of the innate features that make cell-free systems compelling platforms for synthetic biology and discuss emerging improvements of cell-free technologies. We also select and highlight recent and emerging applications of cell-free synthetic biology. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Donor Polymorphisms in Genes Related to B-Cell Biology Associated With Antibody-Mediated Rejection After Heart Transplantation.

PubMed

Marrón-Liñares, Grecia M; Núñez, Lucía; Crespo-Leiro, María G; Álvarez-López, Eloy; Barge-Caballero, Eduardo; Barge-Caballero, Gonzalo; Couto-Mallón, David; Pradas-Irun, Concepción; Muñiz, Javier; Tan, Carmela; Rodríguez, E Rene; Vázquez-Rodríguez, José Manuel; Hermida-Prieto, Manuel

2018-04-25

Heart transplantation (HT) is a well-established lifesaving treatment for endstage cardiac failure. Antibody-mediated rejection (AMR) represents one of the main problems after HT because of its diagnostic complexity and the poor evidence for supporting treatments. Complement cascade and B-cells play a key role in AMR and contribute to graft damage. This study explored the importance of variants in genes related to complement pathway and B-cell biology in HT and AMR in donors and in donor-recipient pairs.Methods and Results:Genetic variants in 112 genes (51 complement and 61 B-cell biology genes) were analyzed on next-generation sequencing in 28 donor-recipient pairs, 14 recipients with and 14 recipients without AMR. Statistical analysis was performed with SNPStats, R, and EPIDAT3.1. We identified one single nucleotide polymorphism (SNP) in donors in genes related to B-cell biology,interleukin-4 receptor subunitα (p.Ile75Val-IL4Rα), which correlated with the development of AMR. Moreover, in the analysis of recipient-donor genotype discrepancies, we identified another SNP, in this case inadenosine deaminase(ADA; p.Val178(p=)), which was related to B-cell biology, associated with the absence of AMR. Donor polymorphisms and recipient-donor discrepancies in genes related to the biology of B-cells, could have an important role in the development of AMR. In contrast, no variants in donor or in donor-recipient pairs in complement pathways seem to have an impact on AMR.

Integrated experimental platforms to study blast injuries: a bottom-up approach

NASA Astrophysics Data System (ADS)

Bo, C.; Williams, A.; Rankin, S.; Proud, W. G.; Brown, K. A.

2014-05-01

We are developing experimental models of blast injury using data from live biological samples. An integrated research strategy is followed to study material and biological properties of cells, tissues and organs, that are subjected to dynamic and static pressures, relevant to those of battlefield blast. We have developed a confined Split Hopkinson Pressure Bar (SHPB) system, which allows cells, either in suspension or as a monolayer, to be subjected to compression waves with pressures on the order of a few MPa and durations of hundreds of microseconds. The chamber design enables recovery of biological samples for cellular and molecular analysis. The SHPB platform, coupled with Quasi-Static experiments, is used to determine stress-strain curves of soft biological tissues under compression at low, medium and high strain rates. Tissue samples are examined, using histological techniques, to study macro- and microscopic changes induced by compression waves. In addition, a shock tube enables application of single or multiple air blasts with pressures on the order of kPa and a few milliseconds duration; this platform was used for initial studies on mesenchymal stem cells responses to blast pressures.

Repeatability and reproducibility of intracellular molar concentration assessed by synchrotron-based x-ray fluorescence microscopy

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

Merolle, L., E-mail: lucia.merolle@elettra.eu; Gianoncelli, A.; Malucelli, E., E-mail: emil.malucelli@unibo.it

2016-01-28

Elemental analysis of biological sample can give information about content and distribution of elements essential for human life or trace elements whose absence is the cause of abnormal biological function or development. However, biological systems contain an ensemble of cells with heterogeneous chemistry and elemental content; therefore, accurate characterization of samples with high cellular heterogeneity may only be achieved by analyzing single cells. Powerful methods in molecular biology are abundant, among them X-Ray microscopy based on synchrotron light source has gaining increasing attention thanks to its extremely sensitivity. However, reproducibility and repeatability of these measurements is one of the majormore » obstacles in achieving a statistical significance in single cells population analysis. In this study, we compared the elemental content of human colon adenocarcinoma cells obtained by three distinct accesses to synchrotron radiation light.« less

Clinico-pathological and biological prognostic variables in squamous cell carcinoma of the vulva.

PubMed

Gadducci, Angiolo; Tana, Roberta; Barsotti, Cecilia; Guerrieri, Maria Elena; Genazzani, Andrea Riccardo

2012-07-01

Several clinical-pathological parameters have been related to survival of patients with invasive squamous cell carcinoma of the vulva, whereas few studies have investigated the ability of biological variables to predict the clinical outcome of these patients. The present paper reviews the literature data on the prognostic relevance of lymph node-related parameters, primary tumor-related parameters, FIGO stage, blood variables, and tissue biological variables. Regarding these latter, the paper takes into account the analysis of DNA content, cell cycle-regulatory proteins, apoptosis-related proteins, epidermal growth factor receptor [EGFR], and proteins that are involved in tumor invasiveness, metastasis and angiogenesis. At present, the lymph node status and FIGO stage according to the new 2009 classification system are the main predictors for vulvar squamous cell carcinoma, whereas biological variables do not have yet a clinical relevance and their role is still investigational. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

An integrated workflow to assess technical and biological variability of cell population frequencies in human peripheral blood by flow cytometry

PubMed Central

Burel, Julie G.; Qian, Yu; Arlehamn, Cecilia Lindestam; Weiskopf, Daniela; Zapardiel-Gonzalo, Jose; Taplitz, Randy; Gilman, Robert H.; Saito, Mayuko; de Silva, Aruna D.; Vijayanand, Pandurangan; Scheuermann, Richard H.; Sette, Alessandro; Peters, Bjoern

2016-01-01

In the context of large-scale human system immunology studies, controlling for technical and biological variability is crucial to ensure that experimental data support research conclusions. Here, we report on a universal workflow to evaluate both technical and biological variation in multiparameter flow cytometry, applied to the development of a 10-color panel to identify all major cell populations and T cell subsets in cryopreserved PBMC. Replicate runs from a control donation and comparison of different gating strategies assessed technical variability associated with each cell population and permitted the calculation of a quality control score. Applying our panel to a large collection of PBMC samples, we found that most cell populations showed low intra-individual variability over time. In contrast, certain subpopulations such as CD56 T cells and Temra CD4 T cells were associated with high inter-individual variability. Age but not gender had a significant effect on the frequency of several populations, with a drastic decrease in naïve T cells observed in older donors. Ethnicity also influenced a significant proportion of immune cell population frequencies, emphasizing the need to account for these co-variates in immune profiling studies. Finally, we exemplify the usefulness of our workflow by identifying a novel cell-subset signature of latent tuberculosis infection. Thus, our study provides a universal workflow to establish and evaluate any flow cytometry panel in systems immunology studies. PMID:28069807

Radiogenic cell transformation and carcinogenesis

NASA Technical Reports Server (NTRS)

Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

1995-01-01

Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic mechanism(s) of radiogenic transformation of human epithelial cells.

Fluorogenic RNA Mango aptamers for imaging small non-coding RNAs in mammalian cells.

PubMed

Autour, Alexis; C Y Jeng, Sunny; D Cawte, Adam; Abdolahzadeh, Amir; Galli, Angela; Panchapakesan, Shanker S S; Rueda, David; Ryckelynck, Michael; Unrau, Peter J

2018-02-13

Despite having many key roles in cellular biology, directly imaging biologically important RNAs has been hindered by a lack of fluorescent tools equivalent to the fluorescent proteins available to study cellular proteins. Ideal RNA labelling systems must preserve biological function, have photophysical properties similar to existing fluorescent proteins, and be compatible with established live and fixed cell protein labelling strategies. Here, we report a microfluidics-based selection of three new high-affinity RNA Mango fluorogenic aptamers. Two of these are as bright or brighter than enhanced GFP when bound to TO1-Biotin. Furthermore, we show that the new Mangos can accurately image the subcellular localization of three small non-coding RNAs (5S, U6, and a box C/D scaRNA) in fixed and live mammalian cells. These new aptamers have many potential applications to study RNA function and dynamics both in vitro and in mammalian cells.

A practical guide to single-cell RNA-sequencing for biomedical research and clinical applications.

PubMed

Haque, Ashraful; Engel, Jessica; Teichmann, Sarah A; Lönnberg, Tapio

2017-08-18

RNA sequencing (RNA-seq) is a genomic approach for the detection and quantitative analysis of messenger RNA molecules in a biological sample and is useful for studying cellular responses. RNA-seq has fueled much discovery and innovation in medicine over recent years. For practical reasons, the technique is usually conducted on samples comprising thousands to millions of cells. However, this has hindered direct assessment of the fundamental unit of biology-the cell. Since the first single-cell RNA-sequencing (scRNA-seq) study was published in 2009, many more have been conducted, mostly by specialist laboratories with unique skills in wet-lab single-cell genomics, bioinformatics, and computation. However, with the increasing commercial availability of scRNA-seq platforms, and the rapid ongoing maturation of bioinformatics approaches, a point has been reached where any biomedical researcher or clinician can use scRNA-seq to make exciting discoveries. In this review, we present a practical guide to help researchers design their first scRNA-seq studies, including introductory information on experimental hardware, protocol choice, quality control, data analysis and biological interpretation.

Advanced techniques in placental biology -- workshop report.

PubMed

Nelson, D M; Sadovsky, Y; Robinson, J M; Croy, B A; Rice, G; Kniss, D A

2006-04-01

Major advances in placental biology have been realized as new technologies have been developed and existing methods have been refined in many areas of biological research. Classical anatomy and whole-organ physiology tools once used to analyze placental structure and function have been supplanted by more sophisticated techniques adapted from molecular biology, proteomics, and computational biology and bioinformatics. In addition, significant refinements in morphological study of the placenta and its constituent cell types have improved our ability to assess form and function in highly integrated manner. To offer an overview of modern technologies used by investigators to study the placenta, this workshop: Advanced techniques in placental biology, assembled experts who discussed fundamental principles and real time examples of four separate methodologies. Y. Sadovsky presented the principles of microRNA function as an endogenous mechanism of gene regulation. J. Robinson demonstrated the utility of correlative microscopy in which light-level and transmission electron microscopy are combined to provide cellular and subcellular views of placental cells. A. Croy provided a lecture on the use of microdissection techniques which are invaluable for isolating very small subsets of cell types for molecular analysis. Finally, G. Rice presented an overview methods on profiling of complex protein mixtures within tissue and/or fluid samples that, when refined, will offer databases that will underpin a systems approach to modern trophoblast biology.

Characterizing Cancer Drug Response and Biological Correlates: A Geometric Network Approach.

PubMed

Pouryahya, Maryam; Oh, Jung Hun; Mathews, James C; Deasy, Joseph O; Tannenbaum, Allen R

2018-04-23

In the present work, we apply a geometric network approach to study common biological features of anticancer drug response. We use for this purpose the panel of 60 human cell lines (NCI-60) provided by the National Cancer Institute. Our study suggests that mathematical tools for network-based analysis can provide novel insights into drug response and cancer biology. We adopted a discrete notion of Ricci curvature to measure, via a link between Ricci curvature and network robustness established by the theory of optimal mass transport, the robustness of biological networks constructed with a pre-treatment gene expression dataset and coupled the results with the GI50 response of the cell lines to the drugs. Based on the resulting drug response ranking, we assessed the impact of genes that are likely associated with individual drug response. For genes identified as important, we performed a gene ontology enrichment analysis using a curated bioinformatics database which resulted in biological processes associated with drug response across cell lines and tissue types which are plausible from the point of view of the biological literature. These results demonstrate the potential of using the mathematical network analysis in assessing drug response and in identifying relevant genomic biomarkers and biological processes for precision medicine.

Separation and sorting of cells in microsystems using physical principles

NASA Astrophysics Data System (ADS)

Lee, Gi-Hun; Kim, Sung-Hwan; Ahn, Kihoon; Lee, Sang-Hoon; Park, Joong Yull

2016-01-01

In the last decade, microfabrication techniques have been combined with microfluidics and applied to cell biology. Utilizing such new techniques, various cell studies have been performed for the research of stem cells, immune cells, cancer, neurons, etc. Among the various biological applications of microtechnology-based platforms, cell separation technology has been highly regarded in biological and clinical fields for sorting different types of cells, finding circulating tumor cells (CTCs), and blood cell separation, amongst other things. Many cell separation methods have been created using various physical principles. Representatively, these include hydrodynamic, acoustic, dielectrophoretic, magnetic, optical, and filtering methods. In this review, each of these methods will be introduced, and their physical principles and sample applications described. Each physical principle has its own advantages and disadvantages. The engineers who design the systems and the biologists who use them should understand the pros and cons of each method or principle, to broaden the use of microsystems for cell separation. Continuous development of microsystems for cell separation will lead to new opportunities for diagnosing CTCs and cancer metastasis, as well as other elements in the bloodstream.

Recent developments in microfluidics for cell studies.

PubMed

Xiong, Bin; Ren, Kangning; Shu, Yiwei; Chen, Yin; Shen, Bo; Wu, Hongkai

2014-08-20

As a technique for precisely manipulating fluid at the micrometer scale, the field of microfluidics has experienced an explosive growth over the past two decades, particularly owing to the advances in device design and fabrication. With the inherent advantages associated with its scale of operation, and its flexibility in being incorporated with other microscale techniques for manipulation and detection, microfluidics has become a major enabling technology, which has introduced new paradigms in various fields involving biological cells. A microfluidic device is able to realize functions that are not easily imaginable in conventional biological analysis, such as highly parallel, sophisticated high-throughput analysis, single-cell analysis in a well-defined manner, and tissue engineering with the capability of manipulation at the single-cell level. Major advancements in microfluidic device fabrication and the growing trend of implementing microfluidics in cell studies are presented, with a focus on biological research and clinical diagnostics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Targeting Deacetylases to Improve Outcomes after Allogeneic Bone Marrow Transplantation

PubMed Central

Reddy, Pavan

2013-01-01

Graft-versus-host disease (GVHD) is the major complication of allogeneic bone marrow transplantation (BMT). GVHD is a complex immunologically mediated biological process. Recent data have shown that histone deacetylase inhibitors (HDACis) have potent anti-inflammatory effects. We have been studying the role of acetylation through inhibition of histone deacetylases (HDACs) in modulating immunity, specifically, GVHD. HDAC inhibition regulates GVHD, at least in part, through suppression of the function of host antigen presenting cells such as dendritic cells (DCs). HDACis reduce DC responses by enhancing the expression of indoleamine 2,3 dioxygenase (IDO) in a STAT-3–dependent manner. They also alter the function of other immune cells such as T regulatory cells and NK cells, which also play important roles in the biology of GVHD. Based on these observations, a clinical trial has been launched to evaluate its impact on clinical GVHD. The clinical features, biology of GVHD, the experimental studies with HDACis, and preliminary observations from humans are discussed. PMID:23874019

cellPACK: A Virtual Mesoscope to Model and Visualize Structural Systems Biology

PubMed Central

Johnson, Graham T.; Autin, Ludovic; Al-Alusi, Mostafa; Goodsell, David S.; Sanner, Michel F.; Olson, Arthur J.

2014-01-01

cellPACK assembles computational models of the biological mesoscale, an intermediate scale (10−7–10−8m) between molecular and cellular biology. cellPACK’s modular architecture unites existing and novel packing algorithms to generate, visualize and analyze comprehensive 3D models of complex biological environments that integrate data from multiple experimental systems biology and structural biology sources. cellPACK is currently available as open source code, with tools for validation of models and with recipes and models for five biological systems: blood plasma, cytoplasm, synaptic vesicles, HIV and a mycoplasma cell. We have applied cellPACK to model distributions of HIV envelope protein to test several hypotheses for consistency with experimental observations. Biologists, educators, and outreach specialists can interact with cellPACK models, develop new recipes and perform packing experiments through scripting and graphical user interfaces at http://cellPACK.org. PMID:25437435

The "sweet" side of the protein corona: effects of glycosylation on nanoparticle-cell interactions.

PubMed

Wan, Sha; Kelly, Philip M; Mahon, Eugene; Stöckmann, Henning; Rudd, Pauline M; Caruso, Frank; Dawson, Kenneth A; Yan, Yan; Monopoli, Marco P

2015-02-24

The significance of a protein corona on nanoparticles in modulating particle properties and their biological interactions has been widely acknowledged. The protein corona is derived from proteins in biological fluids, many of which are glycosylated. To date, the glycans on the proteins have been largely overlooked in studies of nanoparticle-cell interactions. In this study, we demonstrate that glycosylation of the protein corona plays an important role in maintaining the colloidal stability of nanoparticles and influences nanoparticle-cell interactions. The removal of glycans from the protein corona enhances cell membrane adhesion and cell uptake of nanoparticles in comparison with the fully glycosylated form, resulting in the generation of a pro-inflammatory milieu by macrophages. This study highlights that the post-translational modification of proteins can significantly impact nanoparticle-cell interactions by modulating the protein corona properties.

Ionized gas (plasma) delivery of reactive oxygen species (ROS) into artificial cells

NASA Astrophysics Data System (ADS)

Hong, Sung-Ha; Szili, Endre J.; Jenkins, A. Toby A.; Short, Robert D.

2014-09-01

This study was designed to enhance our understanding of how reactive oxygen species (ROS), generated ex situ by ionized gas (plasma), can affect the regulation of signalling processes within cells. A model system, comprising of a suspension of phospholipid vesicles (cell mimics) encapsulating a ROS reporter, was developed to study the plasma delivery of ROS into cells. For the first time it was shown that plasma unequivocally delivers ROS into cells over a sustained period and without compromising cell membrane integrity. An important consideration in cell and biological assays is the presence of serum, which significantly reduced the transfer efficiency of ROS into the vesicles. These results are key to understanding how plasma treatments can be tailored for specific medical or biotechnology applications. Further, the phospholipid vesicle ROS reporter system may find use in other studies involving the application of free radicals in biology and medicine.

Understanding pathogenetic aspects and clinical presentation of primary effusion lymphoma (PEL) through its derived cell lines

PubMed Central

Carbone, Antonino; Cesarman, Ethel; Gloghini, Annunziata; Drexler, Hans G.

2013-01-01

Primary effusion lymphoma (PEL) is a very rare subgroup of B-cell lymphomas presenting as pleural, peritoneal and pericardial neoplastic effusions in the absence of a solid tumor mass or recognizable nodal involvement. There is strong evidence that Kaposi’s sarcoma associated herpesvirus (KSHV) is a causal agent of PEL. PEL tumor cells are latently infected by KSHV with consistent expression of several viral proteins and microRNAs that can affect cellular proliferation, differentiation and survival. The most relevant data on pathogenesis and biology of KSHV have been provided by studies on PEL derived cell lines. Fourteen continuous cell lines have been established from the malignant effusions of patients with AIDS-and non-AIDS-associated PEL. These KSHV+ EBV+/− cell lines are wellcharacterized, authenticated and mostly available from public biological ressource centers. The PEL cell lines display unique features and are clearly distinct from other lymphoma cell lines. PEL cell lines represent an indispensable tool for the understanding of KSHV biology and its impact on the clinical manifestation of PEL. Studies on PEL cell lines have shown that a number of viral genes, expressed during latency or lytic life cycle, have effects on cell binding, proliferation, angiogenesis and inflammation. Also PEL cell lines are important model systems for the study of the pathology of PEL including the lack of invasive or destructive growth patterns and the peculiar propensity of PEL to involve body cavity surfaces. PMID:20051807

Mitigating the risk of Zika virus contamination of raw materials and cell lines in the manufacture of biologicals.

PubMed

Zmurko, Joanna; Vasey, Douglas B; Donald, Claire L; Armstrong, Alison A; McKee, Marian L; Kohl, Alain; Clayton, Reginald F

2018-02-01

Ensuring the virological safety of biologicals is challenging due to the risk of viral contamination of raw materials and cell banks, and exposure during in-process handling to known and/or emerging viral pathogens. Viruses may contaminate raw materials and biologicals intended for human or veterinary use and remain undetected until appropriate testing measures are employed. The outbreak and expansive spread of the mosquito-borne flavivirus Zika virus (ZIKV) poses challenges to screening human- and animal -derived products used in the manufacture of biologicals. Here, we report the results of an in vitro study where detector cell lines were challenged with African and Asian lineages of ZIKV. We demonstrate that this pathogen is robustly detectable by in vitro assay, thereby providing assurance of detection of ZIKV, and in turn underpinning the robustness of in vitro virology assays in safety testing of biologicals.

Living matter—nexus of physics and biology in the 21st century

PubMed Central

Gardel, Margaret L.

2012-01-01

Cells are made up of complex assemblies of cytoskeletal proteins that facilitate force transmission from the molecular to cellular scale to regulate cell shape and force generation. The “living matter” formed by the cytoskeleton facilitates versatile and robust behaviors of cells, including their migration, adhesion, division, and morphology, that ultimately determine tissue architecture and mechanics. Elucidating the underlying physical principles of such living matter provides great opportunities in both biology and physics. For physicists, the cytoskeleton provides an exceptional toolbox to study materials far from equilibrium. For biologists, these studies will provide new understanding of how molecular-scale processes determine cell morphological changes. PMID:23112229

The effects of dynamic loading on the intervertebral disc.

PubMed

Chan, Samantha C W; Ferguson, Stephen J; Gantenbein-Ritter, Benjamin

2011-11-01

Loading is important to maintain the balance of matrix turnover in the intervertebral disc (IVD). Daily cyclic diurnal assists in the transport of large soluble factors across the IVD and its surrounding circulation and applies direct and indirect stimulus to disc cells. Acute mechanical injury and accumulated overloading, however, could induce disc degeneration. Recently, there is more information available on how cyclic loading, especially axial compression and hydrostatic pressure, affects IVD cell biology. This review summarises recent studies on the response of the IVD and stem cells to applied cyclic compression and hydrostatic pressure. These studies investigate the possible role of loading in the initiation and progression of disc degeneration as well as quantifying a physiological loading condition for the study of disc degeneration biological therapy. Subsequently, a possible physiological/beneficial loading range is proposed. This physiological/beneficial loading could provide insight into how to design loading regimes in specific system for the testing of various biological therapies such as cell therapy, chemical therapy or tissue engineering constructs to achieve a better final outcome. In addition, the parameter space of 'physiological' loading may also be an important factor for the differentiation of stem cells towards most ideally 'discogenic' cells for tissue engineering purpose.

Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope.

PubMed

Wu, J S; Kim, A M; Bleher, R; Myers, B D; Marvin, R G; Inada, H; Nakamura, K; Zhang, X F; Roth, E; Li, S Y; Woodruff, T K; O'Halloran, T V; Dravid, Vinayak P

2013-05-01

A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. Copyright © 2013 Elsevier B.V. All rights reserved.

Improving Satellite Compatible Microdevices to Study Biology in Space

NASA Technical Reports Server (NTRS)

Kalkus, Trevor; Snyder, Jessica; Paulino-Lima, Ivan; Rothschild, Lynn

2017-01-01

The technology for biology in space lags far behind the gold standard for biological experiments on Earth. To remedy this disparity, the Rothschild lab works on proof of concept, prototyping, and developing of new sensors and devices to further the capabilities of biology research on satellites. One such device is the PowerCell Payload System. One goal for synthetic biology in aiding space travel and colonization is to genetically engineer living cells to produce biochemicals in space. However, such farming in space presupposes bacteria retain their functionality post-launch, bombarded by radiation, and without the 1G of Earth. Our questions is, does a co-culture of cyanobacteria and protein-synthesizing bacteria produce Earth-like yields of target proteins? Is the yield sensitive to variable gravitational forces? To answer these questions, a PowerCell Payload System will spend 1 year aboard the German Aerospace Center's Euglena and Combined Regenerative Organic-food Production In Space (Eu:CROPIS) mission satellite. The PowerCell system is a pair of two 48-well microfluidic cards, each well seeded with bacteria. The system integrates fluidic, thermal, optical, electronic, and control systems to germinate bacteria spores, then measure the protein synthesized for comparison to parallel experiments conducted on the Earth. In developing the PowerCell Payload, we gained insight into the shortcomings of biology experiments on satellites. To address these issues, we have started three new prototyping projects: 1) The development of an extremely stable and radiation resistant cell-free system, allowing for the construction of proteins utilizing only cell components instead of living cells. This can be lyophilized on a substrate, like paper. (2) Using paper as a microfluidic platform that is flexible, stable, cheap, and wicking. The capillary action eliminates the need for pumps, reducing volume, mass, and potential failing points. Electrodes can be printed on the paper to sense for biochemicals. (3) Developing a modular, semi-autonomous microfluidic device that can be easily adapted for a variety of common biological experiments. This versatility will allow for quicker and cheaper experimentation. These improvements to satellite experiment platforms have the potential to radically increase the return from NASA's biological and field studies with reduced development time, mass, and cost with increased robustness data and interpretation.

DNA asymmetry in stem cells - immortal or mortal?

PubMed

Yadlapalli, Swathi; Yamashita, Yukiko M

2013-09-15

The immortal strand hypothesis proposes that stem cells retain a template copy of genomic DNA (i.e. an 'immortal strand') to avoid replication-induced mutations. An alternative hypothesis suggests that certain cells segregate sister chromatids non-randomly to transmit distinct epigenetic information. However, this area of research has been highly controversial, with conflicting data even from the same cell types. Moreover, historically, the same term of 'non-random sister chromatid segregation' or 'biased sister chromatid segregation' has been used to indicate distinct biological processes, generating a confusion in the biological significance and potential mechanism of each phenomenon. Here, we discuss the models of non-random sister chromatid segregation, and we explore the strengths and limitations of the various techniques and experimental model systems used to study this question. We also describe our recent study on Drosophila male germline stem cells, where sister chromatids of X and Y chromosomes are segregated non-randomly during cell division. We aim to integrate the existing evidence to speculate on the underlying mechanisms and biological relevance of this long-standing observation on non-random sister chromatid segregation.

A systems biology approach to defining regulatory mechanisms for cartilage and tendon cell phenotypes.

PubMed

Mueller, A J; Tew, S R; Vasieva, O; Clegg, P D; Canty-Laird, E G

2016-09-27

Phenotypic plasticity of adult somatic cells has provided emerging avenues for the development of regenerative therapeutics. In musculoskeletal biology the mechanistic regulatory networks of genes governing the phenotypic plasticity of cartilage and tendon cells has not been considered systematically. Additionally, a lack of strategies to effectively reproduce in vitro functional models of cartilage and tendon is retarding progress in this field. De- and redifferentiation represent phenotypic transitions that may contribute to loss of function in ageing musculoskeletal tissues. Applying a systems biology network analysis approach to global gene expression profiles derived from common in vitro culture systems (monolayer and three-dimensional cultures) this study demonstrates common regulatory mechanisms governing de- and redifferentiation transitions in cartilage and tendon cells. Furthermore, evidence of convergence of gene expression profiles during monolayer expansion of cartilage and tendon cells, and the expression of key developmental markers, challenges the physiological relevance of this culture system. The study also suggests that oxidative stress and PI3K signalling pathways are key modulators of in vitro phenotypes for cells of musculoskeletal origin.

DNA asymmetry in stem cells – immortal or mortal?

PubMed Central

Yadlapalli, Swathi; Yamashita, Yukiko M.

2013-01-01

Summary The immortal strand hypothesis proposes that stem cells retain a template copy of genomic DNA (i.e. an ‘immortal strand’) to avoid replication-induced mutations. An alternative hypothesis suggests that certain cells segregate sister chromatids non-randomly to transmit distinct epigenetic information. However, this area of research has been highly controversial, with conflicting data even from the same cell types. Moreover, historically, the same term of ‘non-random sister chromatid segregation’ or ‘biased sister chromatid segregation’ has been used to indicate distinct biological processes, generating a confusion in the biological significance and potential mechanism of each phenomenon. Here, we discuss the models of non-random sister chromatid segregation, and we explore the strengths and limitations of the various techniques and experimental model systems used to study this question. We also describe our recent study on Drosophila male germline stem cells, where sister chromatids of X and Y chromosomes are segregated non-randomly during cell division. We aim to integrate the existing evidence to speculate on the underlying mechanisms and biological relevance of this long-standing observation on non-random sister chromatid segregation. PMID:23970416

Black pepper (Piper nigrum) essential oil demonstrates tissue remodeling and metabolism modulating potential in human cells.

PubMed

Han, Xuesheng; Beaumont, Cody; Rodriguez, Damian; Bahr, Tyler

2018-05-17

Very few studies have investigated the biological activities of black pepper essential oil (BPEO) in human cells. Therefore, in the current study, we examined the biological activities of BPEO in cytokine-stimulated human dermal fibroblasts by analyzing the levels of 17 important protein biomarkers pertinent to inflammation and tissue remodeling. BPEO exhibited significant antiproliferative activity in these skin cells and significantly inhibited the production of Collagen I, Collagen III, and plasminogen activator inhibitor 1. In addition, we studied the effect of BPEO on the regulation of genome-wide expression and found that BPEO diversely modulated global gene expression. Further analysis showed that BPEO affected many important genes and signaling pathways closely related to metabolism, inflammation, tissue remodeling, and cancer signaling. This study is the first to provide evidence of the biological activities of BPEO in human dermal fibroblasts. The data suggest that BPEO possesses promising potential to modulate the biological processes of tissue remodeling, wound healing, and metabolism. Although further research is required, BPEO appears to be a good therapeutic candidate for a variety of health conditions including wound care and metabolic diseases. Research into the biological and pharmacological mechanisms of action of BPEO and its major active constituents is recommended. Copyright © 2018 John Wiley & Sons, Ltd.

Biological characteristics of human-urine-derived stem cells: potential for cell-based therapy in neurology.

PubMed

Guan, Jun-Jie; Niu, Xin; Gong, Fei-Xiang; Hu, Bin; Guo, Shang-Chun; Lou, Yuan-Lei; Zhang, Chang-Qing; Deng, Zhi-Feng; Wang, Yang

2014-07-01

Stem cells in human urine have gained attention in recent years; however, urine-derived stem cells (USCs) are far from being well elucidated. In this study, we compared the biological characteristics of USCs with adipose-derived stem cells (ASCs) and investigated whether USCs could serve as a potential cell source for neural tissue engineering. USCs were isolated from voided urine with a modified culture medium. Through a series of experiments, we examined the growth rate, surface antigens, and differentiation potential of USCs, and compared them with ASCs. USCs showed robust proliferation ability. After serial propagation, USCs retained normal karyotypes. Cell surface antigen expression of USCs was similar to ASCs. With lineage-specific induction factors, USCs could differentiate toward the osteogenic, chondrogenic, adipogenic, and neurogenic lineages. To assess the ability of USCs to survive, differentiate, and migrate, they were seeded onto hydrogel scaffold and transplanted into rat brain. The results showed that USCs were able to survive in the lesion site, migrate to other areas, and express proteins that were associated with neural phenotypes. The results of our study demonstrate that USCs possess similar biological characteristics with ASCs and have multilineage differentiation potential. Moreover USCs can differentiate to neuron-like cells in rat brain. The present study shows that USCs are a promising cell source for tissue engineering and regenerative medicine.

Cell biology: at the center of modern biomedicine.

PubMed

Budde, Priya Prakash; Williams, Elizabeth H; Misteli, Tom

2012-10-01

How does basic cell biology contribute to biomedicine? A new series of Features in JCB provides a cross section of compelling examples of how basic cell biology findings can lead to therapeutics. These articles highlight the fruitful, essential, and increasingly prominent bridge that exists between cell biology and the clinic.

Designer proteins: applications of genetic code expansion in cell biology.

PubMed

Davis, Lloyd; Chin, Jason W

2012-02-15

Designer amino acids, beyond the canonical 20 that are normally used by cells, can now be site-specifically encoded into proteins in cells and organisms. This is achieved using 'orthogonal' aminoacyl-tRNA synthetase-tRNA pairs that direct amino acid incorporation in response to an amber stop codon (UAG) placed in a gene of interest. Using this approach, it is now possible to study biology in vitro and in vivo with an increased level of molecular precision. This has allowed new biological insights into protein conformational changes, protein interactions, elementary processes in signal transduction and the role of post-translational modifications.

Thin film bioreactors in space

NASA Technical Reports Server (NTRS)

Hughes-Fulford, M.; Scheld, H. W.

1989-01-01

Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization, and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers an opportunity to learn more about basic biological systems with one inmportant variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would make it possible to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

The Biology of Cancer Exosomes: Insights and New Perspectives.

PubMed

Ruivo, Carolina F; Adem, Bárbara; Silva, Miguel; Melo, Sónia A

2017-12-01

Exosomes are a subclass of extracellular vesicles involved in intercellular communication that are released by all cell types, including cancer cells. Cancer exosomes carry malignant information in the form of proteins, lipids, and nucleic acids that can reprogram recipient cells. Exosomes have emerged as putative biological mediators in cancer contributing to major steps of disease progression. A leading role exists for cancer exosomes in specific aspects of tumor progression: modulation of immune response, tumor microenvironment reprogramming, and metastasis. This review will address the functions attributed to cancer exosomes in these three aspects of cancer biology, highlighting recent advances and potential limitations. Finally, we explore alternative strategies to develop better models to study cancer exosomes biology. Cancer Res; 77(23); 6480-8. ©2017 AACR . ©2017 American Association for Cancer Research.

A biotherapy based on PSCs-in-3D spheroid-ameliorated biologics depletes in vivo cancer-sustaining stem cells

PubMed Central

Zhou, Tianlin; Li, Meng; Wen, Yanjun; Lin, Xiaojuan; Xiang, Rong; Chen, Xiancheng

2015-01-01

CSCs are able to survive routine anticancer procedures and peripheral-immune attack. Here we develop and detail a framework of CSC elimination governed by 3D-biologics. Pluripotent cells-engineered 3D-biologics (PMSB) and control non-3D-biologics were prepared from placenta-based somatic stem cells (PSCs) and inoculated respectively into senile hosts bearing progressive mammary, lung, colon carcinomas and melanoma. We demonstrate that PMSB evokes in vivo central-immune microenvironment with subsequent re-expression of thymosin-α1 ~ β4 in thymic cortex-medulla borderline for rapid MHC-unrestricted renewal of γδT-dominated immunocompetence. The post-renewal γδT-subsets could accurately bind and drive CSCs into apoptosis. Finally, with central/peripheral integral microenvironment renewal and TERT/Wnt/β-catenin pathway blockade, the CSC-subsets are fully depleted, leading to substantial cure of diverse tumors by PMSB inoculation (P < 0.01), yet not by non-3D-biologics. Thus, our study may contribute to open up a new avenue for tumor remission via pluripotent cells-engineered 3D-biologics addressing quick renewal of central-thymus and peripheral immune-microenvironment. PMID:26512920

Bioelectrical Impedance and The Frequency Dependent Current Conduction Through Biological Tissues: A Short Review

NASA Astrophysics Data System (ADS)

Kanti Bera, Tushar

2018-03-01

Biological tissues are developed with biological cells which exhibit complex electrical impedance called electrical bioimpedance. Under an alternating electrical excitation the bioimpedance varies with the tissue anatomy, composition and the signal frequency. The current penetration and conduction paths vary with frequency of the applied signal. Bioimpedance spectroscopy is used to study the frequency response of the electrical impedance of biological materials noninvasively. In bioimpedance spectroscopy, a low amplitude electrical signal is injected to the tissue sample or body parts to characterization the sample in terms of its bioimpedance. The electrical current conduction phenomena, which is highly influenced by the tissue impedance and the signal frequency, is an important phenomena which should be studied to understand the bioimpedance techniques like bioelectrical impedance analysis (BIA), EIS, or else. In this paper the origin of bioelectrical impedance and current conduction phenomena has been reviewed to present a brief summary of bioelectrical impedance and the frequency dependent current conduction through biological tissues. Simulation studies are conducted with alternation current injection through a two dimensional model of biological tissues containing finite number of biological cells suspended in extracellular fluid. The paper demonstrates the simulation of alternating current conduction through biological tissues conducted by COMSOL Multiphysics. Simulation studies also show the frequency response of the tissue impedance for different tissue compositions.

Biologic agents for anterior cruciate ligament healing: A systematic review

PubMed Central

Di Matteo, Berardo; Loibl, Markus; Andriolo, Luca; Filardo, Giuseppe; Zellner, Johannes; Koch, Matthias; Angele, Peter

2016-01-01

AIM To systematically review the currently available literature concerning the application of biologic agents such as platelet-rich plasma (PRP) and stem cells to promote anterior cruciate ligament (ACL) healing. METHODS A systematic review of the literature was performed on the use of biologic agents (i.e., PRP or stem cells) to favor ACL healing during reconstruction or repair. The following inclusion criteria for relevant articles were used: Clinical reports of any level of evidence, written in English language, on the use of PRP or stem cells during ACL reconstruction/repair. Exclusion criteria were articles written in other languages, reviews, or studies analyzing other applications of PRP/stem cells in knee surgery not related to promoting ACL healing. RESULTS The database search identified 394 records that were screened. A total of 23 studies were included in the final analysis: In one paper stem cells were applied for ACL healing, in one paper there was a concomitant application of PRP and stem cells, whereas in the remaining 21 papers PRP was used. Based on the ACL injury pattern, two papers investigated biologic agents in ACL partial tears whereas 21 papers in ACL reconstruction. Looking at the quality of the available literature, 17 out of 21 studies dealing with ACL reconstruction were randomized controlled trials. Both studies on ACL repair were case series. CONCLUSION There is a paucity of clinical trials investigating the role of stem cells in promoting ACL healing both in case of partial and complete tears. The role of PRP is still controversial and the only advantage emerging from the literature is related to a better graft maturation over time, without documenting beneficial effects in terms of clinical outcome, bone-graft integration and prevention of bony tunnel enlargement. PMID:27672573

Near-infrared Raman spectroscopy of single optically trapped biological cells

NASA Astrophysics Data System (ADS)

Xie, Changan; Dinno, Mumtaz A.; Li, Yong-Qing

2002-02-01

We report on the development and testing of a compact laser tweezers Raman spectroscopy (LTRS) system. The system combines optical trapping and near-infrared Raman spectroscopy for manipulation and identification of single biological cells in solution. A low-power diode laser at 785 nm was used for both trapping and excitation for Raman spectroscopy of the suspended microscopic particles. The design of the LTRS system provides high sensitivity and permits real-time spectroscopic measurements of the biological sample. The system was calibrated by use of polystyrene microbeads and tested on living blood cells and on both living and dead yeast cells. As expected, different images and Raman spectra were observed for the different cells. The LTRS system may provide a valuable tool for the study of fundamental cellular processes and the diagnosis of cellular disorders.

Focus issue: series on computational and systems biology.

PubMed

Gough, Nancy R

2011-09-06

The application of computational biology and systems biology is yielding quantitative insight into cellular regulatory phenomena. For the month of September, Science Signaling highlights research featuring computational approaches to understanding cell signaling and investigation of signaling networks, a series of Teaching Resources from a course in systems biology, and various other articles and resources relevant to the application of computational biology and systems biology to the study of signal transduction.

Green synthesis, characterization and evaluation of biocompatibility of silver nanoparticles

NASA Astrophysics Data System (ADS)

Ahamed, Maqusood; Majeed Khan, M. A.; Siddiqui, M. K. J.; AlSalhi, Mohamad S.; Alrokayan, Salman A.

2011-04-01

Although green synthesis of silver nanoparticles (Ag NPs) by various plants and microorganisms has been reported, the potential of plants as biological materials for the synthesis of nanoparticles and their compatibility to biological systems is yet to be fully explored. In this study, we report a simple green method for the synthesis of Ag NPs using garlic clove extract as a reducing and stabilizing agent. In addition to green synthesis, biological response of Ag NPs in human lung epithelial A549 cells was also assessed. Ag NPs were rapidly synthesized using garlic clove extract and the formation of nanoparticles was observed within 30 min. The green synthesized Ag NPs were characterized using UV-vis spectrum, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), X-ray energy-dispersive spectroscopy (EDX) and dynamic light scattering (DLS). Characterization data demonstrated that the particles were crystalline in nature and spherical shaped with an average diameter of 12 nm. Measurements of cell viability, cell membrane integrity and intracellular production of reactive oxygen species have shown that the green synthesized Ag NPs were nontoxic to human lung epithelial A549 cells. This study demonstrated a simple, cost-effective and environmentally benign synthesis of Ag NPs with excellent biocompatibility to human lung epithelial A549 cells. This preliminary in vitro investigation needs to be followed up by future studies with various biological systems.

Developmental biology, the stem cell of biological disciplines.

PubMed

Gilbert, Scott F

2017-12-01

Developmental biology (including embryology) is proposed as "the stem cell of biological disciplines." Genetics, cell biology, oncology, immunology, evolutionary mechanisms, neurobiology, and systems biology each has its ancestry in developmental biology. Moreover, developmental biology continues to roll on, budding off more disciplines, while retaining its own identity. While its descendant disciplines differentiate into sciences with a restricted set of paradigms, examples, and techniques, developmental biology remains vigorous, pluripotent, and relatively undifferentiated. In many disciplines, especially in evolutionary biology and oncology, the developmental perspective is being reasserted as an important research program.

Relative biological effectiveness of light ions in human tumoural cell lines: role of protein p53

NASA Technical Reports Server (NTRS)

Baggio, L.; Cavinato, M.; Cherubini, R.; Conzato, M.; Cucinotta, F.; Favaretto, S.; Gerardi, S.; Lora, S.; Stoppa, P.; Williams, J. R.

2002-01-01

Protons and alpha particles of high linear energy transfer (LET) have shown an increased relative biological effectiveness (RBE) with respect to X/gamma rays for several cellular and molecular endpoints in different in vitro cell systems. To contribute to understanding the biochemical mechanisms involved in the increased effectiveness of high LET radiation, an extensive study has been designed. The present work reports the preliminary result of this study on two human tumoural cell lines, DLD1 and HCT116, (with different p53 status), which indicate that for these cell lines, p53 does not appear to take a part in the response to radiation induced DNA damage, suggesting an alternative p53-independent pathway and a cell biochemical mechanism dependent on the cell type.

A Statistical Analysis of Student Questions in a Cell Biology Laboratory

ERIC Educational Resources Information Center

Keeling, Elena L.; Polacek, Kelly M.; Ingram, Ella L.

2009-01-01

Asking questions is an essential component of the practice of science, but question-asking skills are often underemphasized in science education. In this study, we examined questions written by students as they prepared for laboratory exercises in a senior-level cell biology class. Our goals were to discover 1) what types of questions students…

Bioinformatics.

PubMed

Moore, Jason H

2007-11-01

Bioinformatics is an interdisciplinary field that blends computer science and biostatistics with biological and biomedical sciences such as biochemistry, cell biology, developmental biology, genetics, genomics, and physiology. An important goal of bioinformatics is to facilitate the management, analysis, and interpretation of data from biological experiments and observational studies. The goal of this review is to introduce some of the important concepts in bioinformatics that must be considered when planning and executing a modern biological research study. We review database resources as well as data mining software tools.

History of the Department of Cell Biology at Yale School of Medicine, 1813-2010

PubMed Central

Lentz, Thomas L.

2011-01-01

The Department of Cell Biology at the Yale University School of Medicine was established in 1983. It was preceded by the Section of Cell Biology, which was formed in 1973 when George E. Palade and collaborators came to Yale from the Rockefeller University. Cell Biology at Yale had its origins in the Department of Anatomy that existed from the beginning of classes at the Medical Institution of Yale College in 1813. This article reviews the history of the Department of Anatomy at Yale and its evolution into Cell Biology that began with the introduction of histology into the curriculum in the 1860s. The formation and development of the Section and Department of Cell Biology in the second half of the 20th century to the present time are described. Biographies and research activities of the chairs and key faculty in anatomy and cell biology are provided. PMID:21698037

Patterning cellular compartments within TRACER cultures using sacrificial gelatin printing.

PubMed

Xu, Bin; Rodenhizer, Darren; Lakhani, Shakir; Zhang, Xiaoshu; Soleas, John P; Ailles, Laurie; McGuigan, Alison P

2016-09-15

In the past decade, it has been well recognised that the tumour microenvironment contains microenvironmental components such as hypoxia that significantly influence tumour cell behaviours such, invasiveness and therapy resistance, all of which provide new targets for studying cancer biology and developing anticancer therapeutics. In response, a large number of two-dimensional and three-dimensional (3D) in vitro tumour models have been developed to recapitulate different aspects of the tumour microenvironment and enable the study of related biological questions. While more complex models enable new biological insight, such models often involve time-consuming and complex fabrication or analysis processes, which limit their adoption by the broader cancer biology community. To address this, we recently reported the development of a new platform that enables easy assembly and analysis of 3D tumour cultures, the tissue roll for analysis of cellular environment response (TRACER). The TRACER platform enables recapitulation of many spatial aspects of the tumour microenvironment to ask a variety of questions, however its original design contains only one cell type. In contrast tumours in vivo often contain a neoplastic and stromal compartment. To expand the types of questions the TRACER system is useful for asking, here we present a strategy to pattern distinct cell type domains into TRACER layers using a custom-built gelatin-dispensing pen. The pen allows deposition of a temporary gelatin barrier into the TRACER scaffold to define domain boundaries between cell populations. The gelatin can be melted away after cell seeding to allow interaction of cell populations from adjacent domains. Our device offers a simple strategy to generate complex multi-cell type tumour cultures for analysis of fundamental biology and drug development applications.

Robustness of synthetic oscillators in growing and dividing cells

NASA Astrophysics Data System (ADS)

Paijmans, Joris; Lubensky, David K.; Rein ten Wolde, Pieter

2017-05-01

Synthetic biology sets out to implement new functions in cells, and to develop a deeper understanding of biological design principles. Elowitz and Leibler [Nature (London) 403, 335 (2000), 10.1038/35002125] showed that by rational design of the reaction network, and using existing biological components, they could create a network that exhibits periodic gene expression, dubbed the repressilator. More recently, Stricker et al. [Nature (London) 456, 516 (2008), 10.1038/nature07389] presented another synthetic oscillator, called the dual-feedback oscillator, which is more stable. Detailed studies have been carried out to determine how the stability of these oscillators is affected by the intrinsic noise of the interactions between the components and the stochastic expression of their genes. However, as all biological oscillators reside in growing and dividing cells, an important question is how these oscillators are perturbed by the cell cycle. In previous work we showed that the periodic doubling of the gene copy numbers due to DNA replication can couple not only natural, circadian oscillators to the cell cycle [Paijmans et al., Proc. Natl. Acad. Sci. (USA) 113, 4063 (2016), 10.1073/pnas.1507291113], but also these synthetic oscillators. Here we expand this study. We find that the strength of the locking between oscillators depends not only on the positions of the genes on the chromosome, but also on the noise in the timing of gene replication: noise tends to weaken the coupling. Yet, even in the limit of high levels of noise in the replication times of the genes, both synthetic oscillators show clear signatures of locking to the cell cycle. This work enhances our understanding of the design of robust biological oscillators inside growing and diving cells.

Human pluripotent stem cells: an emerging model in developmental biology

PubMed Central

Zhu, Zengrong; Huangfu, Danwei

2013-01-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development ‘in a dish’. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development. PMID:23362344

Choosing an Appropriate Modelling Framework for Analysing Multispecies Co-culture Cell Biology Experiments.

PubMed

Markham, Deborah C; Simpson, Matthew J; Baker, Ruth E

2015-04-01

In vitro cell biology assays play a crucial role in informing our understanding of the migratory, proliferative and invasive properties of many cell types in different biological contexts. While mono-culture assays involve the study of a population of cells composed of a single cell type, co-culture assays study a population of cells composed of multiple cell types (or subpopulations of cells). Such co-culture assays can provide more realistic insights into many biological processes including tissue repair, tissue regeneration and malignant spreading. Typically, system parameters, such as motility and proliferation rates, are estimated by calibrating a mathematical or computational model to the observed experimental data. However, parameter estimates can be highly sensitive to the choice of model and modelling framework. This observation motivates us to consider the fundamental question of how we can best choose a model to facilitate accurate parameter estimation for a particular assay. In this work we describe three mathematical models of mono-culture and co-culture assays that include different levels of spatial detail. We study various spatial summary statistics to explore if they can be used to distinguish between the suitability of each model over a range of parameter space. Our results for mono-culture experiments are promising, in that we suggest two spatial statistics that can be used to direct model choice. However, co-culture experiments are far more challenging: we show that these same spatial statistics which provide useful insight into mono-culture systems are insufficient for co-culture systems. Therefore, we conclude that great care ought to be exercised when estimating the parameters of co-culture assays.

New Horizons in Enhancing the Proliferation and Differentiation of Neural Stem Cells Using Stimulatory Effects of the Short Time Exposure to Radiofrequency Radiation

PubMed Central

Eghlidospour, M.; Mortazavi, S. M. J.; Yousefi, F.; Mortazavi, S. A. R.

2015-01-01

Mobile phone use and wireless communication technology have grown explosively over the past decades. This rapid growth has caused widespread global concern about the potential detrimental effects of this technology on human health. Stem cells generate specialized cell types of the tissue in which they reside through normal differentiation pathways. Considering the undeniable importance of stem cells in modern medicine, numerous studies have been performed on the effects of ionizing and non-ionizing radiation on cellular processes such as: proliferation, differentiation, cell cycle and DNA repair processes. We have conducted extensive studies on beneficial (stimulatory) or detrimental biological effects of exposure to different sources of electromagnetic fields such as mobile phones, mobile phone base stations, mobile phone jammers, radar systems, magnetic resonance imaging (MRI) systems and dentistry cavitrons over the past years. In this article, recent studies on the biological effects of non-ionizing electromagnetic radiation in the range of radiofrequency (RF) on some important features of stem cells such as their proliferation and differentiation are reviewed. Studies reviewed in this paper indicate that the stimulatory or inhibitory effects of RF radiation on the proliferation and differentiation of stem cells depend on various factors such as the biological systems, experiment conditions, the frequency and intensity of RF and the duration of exposure. PMID:26396965

New Horizons in Enhancing the Proliferation and Differentiation of Neural Stem Cells Using Stimulatory Effects of the Short Time Exposure to Radiofrequency Radiation.

PubMed

Eghlidospour, M; Mortazavi, S M J; Yousefi, F; Mortazavi, S A R

2015-09-01

Mobile phone use and wireless communication technology have grown explosively over the past decades. This rapid growth has caused widespread global concern about the potential detrimental effects of this technology on human health. Stem cells generate specialized cell types of the tissue in which they reside through normal differentiation pathways. Considering the undeniable importance of stem cells in modern medicine, numerous studies have been performed on the effects of ionizing and non-ionizing radiation on cellular processes such as: proliferation, differentiation, cell cycle and DNA repair processes. We have conducted extensive studies on beneficial (stimulatory) or detrimental biological effects of exposure to different sources of electromagnetic fields such as mobile phones, mobile phone base stations, mobile phone jammers, radar systems, magnetic resonance imaging (MRI) systems and dentistry cavitrons over the past years. In this article, recent studies on the biological effects of non-ionizing electromagnetic radiation in the range of radiofrequency (RF) on some important features of stem cells such as their proliferation and differentiation are reviewed. Studies reviewed in this paper indicate that the stimulatory or inhibitory effects of RF radiation on the proliferation and differentiation of stem cells depend on various factors such as the biological systems, experiment conditions, the frequency and intensity of RF and the duration of exposure.

Epigenome overlap measure (EPOM) for comparing tissue/cell types based on chromatin states.

PubMed

Li, Wei Vivian; Razaee, Zahra S; Li, Jingyi Jessica

2016-01-11

The dynamics of epigenomic marks in their relevant chromatin states regulate distinct gene expression patterns, biological functions and phenotypic variations in biological processes. The availability of high-throughput epigenomic data generated by next-generation sequencing technologies allows a data-driven approach to evaluate the similarities and differences of diverse tissue and cell types in terms of epigenomic features. While ChromImpute has allowed for the imputation of large-scale epigenomic information to yield more robust data to capture meaningful relationships between biological samples, widely used methods such as hierarchical clustering and correlation analysis cannot adequately utilize epigenomic data to accurately reveal the distinction and grouping of different tissue and cell types. We utilize a three-step testing procedure-ANOVA, t test and overlap test to identify tissue/cell-type- associated enhancers and promoters and to calculate a newly defined Epigenomic Overlap Measure (EPOM). EPOM results in a clear correspondence map of biological samples from different tissue and cell types through comparison of epigenomic marks evaluated in their relevant chromatin states. Correspondence maps by EPOM show strong capability in distinguishing and grouping different tissue and cell types and reveal biologically meaningful similarities between Heart and Muscle, Blood & T-cell and HSC & B-cell, Brain and Neurosphere, etc. The gene ontology enrichment analysis both supports and explains the discoveries made by EPOM and suggests that the associated enhancers and promoters demonstrate distinguishable functions across tissue and cell types. Moreover, the tissue/cell-type-associated enhancers and promoters show enrichment in the disease-related SNPs that are also associated with the corresponding tissue or cell types. This agreement suggests the potential of identifying causal genetic variants relevant to cell-type-specific diseases from our identified associated enhancers and promoters. The proposed EPOM measure demonstrates superior capability in grouping and finding a clear correspondence map of biological samples from different tissue and cell types. The identified associated enhancers and promoters provide a comprehensive catalog to study distinct biological processes and disease variants in different tissue and cell types. Our results also find that the associated promoters exhibit more cell-type-specific functions than the associated enhancers do, suggesting that the non-associated promoters have more housekeeping functions than the non-associated enhancers.

Modeling the Soft Geometry of Biological Membranes

NASA Astrophysics Data System (ADS)

Daly, K.

This dissertation presents work done applying the techniques of physics to biological systems. The difference in length scales of the thickness of the phospolipid bilayer and overall size of a biological cell allows bilayer to be modeled elastically as a thin sheet. The Helfrich free energy is extended applied to models representing various biological systems, in order to find quasi-equilibrium states as well as transitions between states. Morphologies are approximated as axially sym-metric. Stable morphologies are de-termined analytically and through the use of computer simulation. The simple morphologies examined analytically give a model for the pearling transition seen in growing biological cells. An analytic model of celluar bulging in gram-negative bacteria predicts a critical pore radius for bulging of 20 nanometers. This model is extended to the membrane dynamics of human red blood cells, predicting three morphologic phases which are seen in vivo. A computer simulation was developed to study more complex morphologies with models representing different bilayer compositions. Single and multi-component bilayer models reproduce morphologies previously predicted by Seifert. A mean field model representing the intrinsic curvature of proteins coupling to membrane curvature is used to explore the stability of the particular morphology of rod outer segment cells. The process of pore formation and expansion in cell-cell fusion is not well understood. Simulation of the pore created in cell-cell fusion led to the finding of a minimal pore radius required for pore expansion, suggesting pores formed in nature are formed with a minimum size.

Emerging concepts and future challenges in innate lymphoid cell biology

PubMed Central

Artis, David

2016-01-01

Innate lymphoid cells (ILCs) are innate immune cells that are ubiquitously distributed in lymphoid and nonlymphoid tissues and enriched at mucosal and barrier surfaces. Three major ILC subsets are recognized in mice and humans. Each of these subsets interacts with innate and adaptive immune cells and integrates cues from the epithelium, the microbiota, and pathogens to regulate inflammation, immunity, tissue repair, and metabolic homeostasis. Although intense study has elucidated many aspects of ILC development, phenotype, and function, numerous challenges remain in the field of ILC biology. In particular, recent work has highlighted key new questions regarding how these cells communicate with their environment and other cell types during health and disease. This review summarizes new findings in this rapidly developing field that showcase the critical role ILCs play in directing immune responses through their ability to interact with a variety of hematopoietic and nonhematopoietic cells. In addition, we define remaining challenges and emerging questions facing the field. Finally, this review discusses the potential application of basic studies of ILC biology to the development of new treatments for human patients with inflammatory and infectious diseases in which ILCs play a role. PMID:27811053

In Vivo Imaging and Monitoring of Transplanted Stem Cells: Clinical Applications

PubMed Central

Rodriguez-Porcel, Martin

2010-01-01

Regenerative medicine using stem cells has appeared as a potential therapeutic alternative for coronary artery disease, and stem cell clinical studies are currently on their way. However, initial results of these studies have provided mixed information, in part because of the inability to correlate organ functional information with the presence/absence of transplanted stem cells. Recent advances in molecular biology and imaging have allowed the successful noninvasive monitoring of transplanted stem cells in the living subject. In this article, different imaging strategies (direct labeling, indirect labeling with reporter genes) to study the viability and biology of stem cells are discussed. In addition, the limitations of each approach and imaging modality (eg, single photon emission computed tomography, positron emission tomography, and MRI) and their requirements for clinical use are addressed. Use of these strategies will be critical as the different regenerative therapies are being tested for clinical use. PMID:20425184

How chemistry supports cell biology: the chemical toolbox at your service.

PubMed

Wijdeven, Ruud H; Neefjes, Jacques; Ovaa, Huib

2014-12-01

Chemical biology is a young and rapidly developing scientific field. In this field, chemistry is inspired by biology to create various tools to monitor and modulate biochemical and cell biological processes. Chemical contributions such as small-molecule inhibitors and activity-based probes (ABPs) can provide new and unique insights into previously unexplored cellular processes. This review provides an overview of recent breakthroughs in chemical biology that are likely to have a significant impact on cell biology. We also discuss the application of several chemical tools in cell biology research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Applications of cell-free protein synthesis in synthetic biology: Interfacing bio-machinery with synthetic environments.

PubMed

Lee, Kyung-Ho; Kim, Dong-Myung

2013-11-01

Synthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell-free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell-based systems, cell-free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell-free protein synthesis is virtually free from the intrinsic constraints of cell-based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell-free protein synthesis can be combined with various man-made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell-free protein synthesis with various reaction devices and analytical platforms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vascular Smooth Muscle Cells From Hypertensive Patient-Derived Induced Pluripotent Stem Cells to Advance Hypertension Pharmacogenomics.

PubMed

Biel, Nikolett M; Santostefano, Katherine E; DiVita, Bayli B; El Rouby, Nihal; Carrasquilla, Santiago D; Simmons, Chelsey; Nakanishi, Mahito; Cooper-DeHoff, Rhonda M; Johnson, Julie A; Terada, Naohiro

2015-12-01

Studies in hypertension (HTN) pharmacogenomics seek to identify genetic sources of variable antihypertensive drug response. Genetic association studies have detected single-nucleotide polymorphisms (SNPs) that link to drug responses; however, to understand mechanisms underlying how genetic traits alter drug responses, a biological interface is needed. Patient-derived induced pluripotent stem cells (iPSCs) provide a potential source for studying otherwise inaccessible tissues that may be important to antihypertensive drug response. The present study established multiple iPSC lines from an HTN pharmacogenomics cohort. We demonstrated that established HTN iPSCs can robustly and reproducibly differentiate into functional vascular smooth muscle cells (VSMCs), a cell type most relevant to vasculature tone control. Moreover, a sensitive traction force microscopy assay demonstrated that iPSC-derived VSMCs show a quantitative contractile response on physiological stimulus of endothelin-1. Furthermore, the inflammatory chemokine tumor necrosis factor α induced a typical VSMC response in iPSC-derived VSMCs. These studies pave the way for a large research initiative to decode biological significance of identified SNPs in hypertension pharmacogenomics. Treatment of hypertension remains suboptimal, and a pharmacogenomics approach seeks to identify genetic biomarkers that could be used to guide treatment decisions; however, it is important to understand the biological underpinnings of genetic associations. Mouse models do not accurately recapitulate individual patient responses based on their genetics, and hypertension-relevant cells are difficult to obtain from patients. Induced pluripotent stem cell (iPSC) technology provides a great interface to bring patient cells with their genomic data into the laboratory and to study hypertensive responses. As an initial step, the present study established an iPSC bank from patients with primary hypertension and demonstrated an effective and reproducible method of generating functional vascular smooth muscle cells. ©AlphaMed Press.

Physangulidine A, a withanolide from Physalis angulata, perturbs the cell cycle and induces cell death by apoptosis in prostate cancer cells.

PubMed

Reyes-Reyes, E Merit; Jin, Zhuang; Vaisberg, Abraham J; Hammond, Gerald B; Bates, Paula J

2013-01-25

Recently, our group reported the discovery of three new withanolides, physangulidines A-C, from Physalis angulata. In this study, the biological effects of physangulidine A (1), which was the most active and abundant of the three new constituents, are described. It was found that 1 significantly reduces survival in clonogenic assays for two hormone-independent prostate cancer cell lines. Flow cytometry and confocal microscopy studies in DU145 human prostate cancer cells indicated that 1 induces cell cycle arrest in the G(2)/M phase and causes defective mitosis. It was determined also that 1 produces programed cell death by apoptosis, as evidenced by biochemical markers and distinct changes in cell morphology. These results imply that the antimitotic and proapoptotic effects of 1 may contribute significantly to the biological activities and potential medicinal properties of its plant of origin.

Conceptual Challenges of the Systemic Approach in Understanding Cell Differentiation.

PubMed

Paldi, Andras

2018-01-01

The cells of a multicellular organism are derived from a single zygote and genetically identical. Yet, they are phenotypically very different. This difference is the result of a process commonly called cell differentiation. How the phenotypic diversity emerges during ontogenesis or regeneration is a central and intensely studied but still unresolved issue in biology. Cell biology is facing conceptual challenges that are frequently confused with methodological difficulties. How to define a cell type? What stability or change means in the context of cell differentiation and how to deal with the ubiquitous molecular variations seen in the living cells? What are the driving forces of the change? We propose to reframe the problem of cell differentiation in a systemic way by incorporating different theoretical approaches. The new conceptual framework is able to capture the insights made at different levels of cellular organization and considered previously as contradictory. It also provides a formal strategy for further experimental studies.

Low-concentration BPAF- and BPF-induced cell biological effects are mediated by ROS in MCF-7 breast cancer cells.

PubMed

Lei, Bingli; Sun, Su; Xu, Jie; Feng, Chenglian; Yu, Yingxin; Xu, Gang; Wu, Minghong; Peng, Wei

2018-02-01

Reactive oxygen species (ROS) induced by bisphenol A (BPA) have been implicated in cellular oxidative damage and carcinogenesis. It is not known whether the potential alternatives of BPA, bisphenol AF (BPAF), and bisphenol F (BPF) can also induce ROS involved in mediating biological responses. This study evaluated the toxicity of BPAF and BPF on cell proliferation, DNA damage, intracellular calcium homeostasis, and ROS generation in MCF-7 human breast cancer cells. The results showed that BPAF at 0.001-1 μM and BPF at 0.01-1 μM significantly increased cell viability and at 25 and 50 μM, both compounds decreased cell viability. At 0.01-10 μM, both BPAF and BPF increased DNA damage and significantly elevated ROS and intracellular Ca 2+ levels in MCF-7 cells. These biological effects were attenuated by the ROS scavenger N-acetylcysteine (NAC), indicating that ROS played a key role in the observed biological effects of BPAF and BPF on MCF-7 cells. These findings can deepen our understanding on the toxicity of BPAF and BPF, and provide basis data to further evaluate the potential health harm and establish environmental standard of BPAF and BPF.

Function and Biosynthesis of Cell Wall α-1,3-Glucan in Fungi.

PubMed

Yoshimi, Akira; Miyazawa, Ken; Abe, Keietsu

2017-11-18

Although α-1,3-glucan is a major cell wall polysaccharide in filamentous fungi, its biological functions remain unclear, except that it acts as a virulence factor in animal and plant pathogenic fungi: it conceals cell wall β-glucan on the fungal cell surface to circumvent recognition by hosts. However, cell wall α-1,3-glucan is also present in many of non-pathogenic fungi. Recently, the universal function of α-1,3-glucan as an aggregation factor has been demonstrated. Applications of fungi with modified cell wall α-1,3-glucan in the fermentation industry and of in vitro enzymatically-synthesized α-1,3-glucan in bio-plastics have been developed. This review focuses on the recent progress in our understanding of the biological functions and biosynthetic mechanism of cell wall α-1,3-glucan in fungi. We briefly consider the history of studies on α-1,3-glucan, overview its biological functions and biosynthesis, and finally consider the industrial applications of fungi deficient in α-1,3-glucan.

Wherever I may roam: protein and membrane trafficking in P. falciparum-infected red blood cells.

PubMed

Deponte, Marcel; Hoppe, Heinrich C; Lee, Marcus C S; Maier, Alexander G; Richard, Dave; Rug, Melanie; Spielmann, Tobias; Przyborski, Jude M

2012-12-01

Quite aside from its immense importance as a human pathogen, studies in recent years have brought to light the fact that the malaria parasite Plasmodium falciparum is an interesting eukaryotic model system to study protein trafficking. Studying parasite cell biology often reveals an overrepresentation of atypical cell biological features, possibly driven by the parasites' need to survive in an unusual biological niche. Malaria parasites possess uncommon cellular compartments to which protein traffic must be directed, including secretory organelles such as rhoptries and micronemes, a lysosome-like compartment referred to as the digestive vacuole and a complex (four membrane-bound) plastid, the apicoplast. In addition, the parasite must provide proteins to extracellular compartments and structures including the parasitophorous vacuole, the parasitophorous vacuolar membrane, the Maurer's clefts and both cytosol and plasma membrane of the host cell, the mature human red blood cell. Although some of these unusual destinations are possessed by other cell types, only Plasmodium parasites contain them all within one cell. Here we review what is known about protein and membrane transport in the P. falciparum-infected cell, highlighting novel features of these processes. A growing body of evidence suggests that this parasite is a real "box of tricks" with regards to protein traffic. Possibly, these tricks may be turned against the parasite by exploiting them as novel therapeutic targets. Copyright © 2012 Elsevier B.V. All rights reserved.

77 FR 54580 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-05

... . Name of Committee: Cell Biology Integrated Review Group, Membrane Biology and Protein Processing Study... Structure and Regeneration Study Section. Date: October 4-5, 2012. Time: 8 a.m. to 5 p.m. Agenda: To review...

76 FR 24897 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-03

..., Genomes, and Genetics Integrated Review Group, Prokaryotic Cell and Molecular Biology Study Section. Date..., Skeletal Biology Structure and Regeneration Study Section. Date: June 9-10, 2011. Time: 8 a.m. to 5:30 p.m...

Engineering three dimensional micro nerve tissue using postnatal stem cells from human dental apical papilla.

PubMed

Kim, Byung-Chul; Jun, Sung-Min; Kim, So Yeon; Kwon, Yong-Dae; Choe, Sung Chul; Kim, Eun-Chul; Lee, Jae-Hyung; Kim, Jinseok; Suh, Jun-Kyo Francis; Hwang, Yu-Shik

2017-04-01

The in vitro generation of cell-based three dimensional (3D) nerve tissue is an attractive subject to improve graft survival and integration into host tissue for neural tissue regeneration or to model biological events in stem cell differentiation. Although 3D organotypic culture strategies are well established for 3D nerve tissue formation of pluripotent stem cells to study underlying biology in nerve development, cell-based nerve tissues have not been developed using human postnatal stem cells with therapeutic potential. Here, we established a culture strategy for the generation of in vitro cell-based 3D nerve tissue from postnatal stem cells from apical papilla (SCAPs) of teeth, which originate from neural crest-derived ectomesenchyme cells. A stem cell population capable of differentiating into neural cell lineages was generated during the ex vivo expansion of SCAPs in the presence of EGF and bFGF, and SCAPs differentiated into neural cells, showing neural cell lineage-related molecular and gene expression profiles, morphological changes and electrophysical property under neural-inductive culture conditions. Moreover, we showed the first evidence that 3D cell-based nerve-like tissue with axons and myelin structures could be generated from SCAPs via 3D organotypic culture using an integrated bioprocess composed of polyethylene glycol (PEG) microwell-mediated cell spheroid formation and subsequent dynamic culture in a high aspect ratio vessel (HARV) bioreactor. In conclusion, the culture strategy in our study provides a novel approach to develop in vitro engineered nerve tissue using SCAPs and a foundation to study biological events in the neural differentiation of postnatal stem cells. Biotechnol. Bioeng. 2017;114: 903-914. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Geometric effects in microfluidics on heterogeneous cell stress using an Eulerian-Lagrangian approach.

PubMed

Warren, K M; Mpagazehe, J N; LeDuc, P R; Higgs, C F

2016-02-07

The response of individual cells at the micro-scale in cell mechanics is important in understanding how they are affected by changing environments. To control cell stresses, microfluidics can be implemented since there is tremendous control over the geometry of the devices. Designing microfluidic devices to induce and manipulate stress levels on biological cells can be aided by computational modeling approaches. Such approaches serve as an efficient precursor to fabricating various microfluidic geometries that induce predictable levels of stress on biological cells, based on their mechanical properties. Here, a three-dimensional, multiphase computational fluid dynamics (CFD) modeling approach was implemented for soft biological materials. The computational model incorporates the physics of the particle dynamics, fluid dynamics and solid mechanics, which allows us to study how stresses affect the cells. By using an Eulerian-Lagrangian approach to treat the fluid domain as a continuum in the microfluidics, we are conducting studies of the cells' movement and the stresses applied to the cell. As a result of our studies, we were able to determine that a channel with periodically alternating columns of obstacles was capable of stressing cells at the highest rate, and that microfluidic systems can be engineered to impose heterogenous cell stresses through geometric configuring. We found that when using controlled geometries of the microfluidics channels with staggered obstructions, we could increase the maximum cell stress by nearly 200 times over cells flowing through microfluidic channels with no obstructions. Incorporating computational modeling in the design of microfluidic configurations for controllable cell stressing could help in the design of microfludic devices for stressing cells such as cell homogenizers.

Simultaneously Synchrotron X-ray Fluorescence and Ptychographic Imaging of Frozen Biological Single Cells

DOE PAGES

Chen, S.; Deng, J.; Nashed, Y. S. G.; ...

2016-07-25

Bionanoprobe (BNP), a hard x-ray fluorescence sample-scanning nanoprobe at the Advanced Photon Source of Argonne National Laboratory, has been used to quantitatively study elemental distributions in biological cells with sub-100 nm spatial resolution and high sensitivity. Cryogenic conditions enable biological samples to be studied in their frozen-hydrated state with both ultrastructure and elemental distributions more faithfully preserved compared to conventional chemical fixation or dehydration methods. Furthermore, radiation damage is reduced in two ways: the diffusion rate of free radicals is decreased at low temperatures; and the sample is embedded in vitrified ice, which reduces mass loss.

Interaction between pancreatic β cell and electromagnetic fields: A systematic study toward finding the natural frequency spectrum of β cell system.

PubMed

Farashi, Sajjad

2017-01-01

Interaction between biological systems and environmental electric or magnetic fields has gained attention during the past few decades. Although there are a lot of studies that have been conducted for investigating such interaction, the reported results are considerably inconsistent. Besides the complexity of biological systems, the important reason for such inconsistent results may arise due to different excitation protocols that have been applied in different experiments. In order to investigate carefully the way that external electric or magnetic fields interact with a biological system, the parameters of excitation, such as intensity or frequency, should be selected purposefully due to the influence of these parameters on the system response. In this study, pancreatic β cell, the main player of blood glucose regulating system, is considered and the study is focused on finding the natural frequency spectrum of the system using modeling approach. Natural frequencies of a system are important characteristics of the system when external excitation is applied. The result of this study can help researchers to select proper frequency parameter for electrical excitation of β cell system. The results show that there are two distinct frequency ranges for natural frequency of β cell system, which consist of extremely low (or near zero) and 100-750 kHz frequency ranges. There are experimental works on β cell exposure to electromagnetic fields that support such finding.

Computer-aided design of biological circuits using TinkerCell

PubMed Central

Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. PMID:21327060

Chemotaxis in densely populated tissue determines germinal center anatomy and cell motility: a new paradigm for the development of complex tissues.

PubMed

Hawkins, Jared B; Jones, Mark T; Plassmann, Paul E; Thorley-Lawson, David A

2011-01-01

Germinal centers (GCs) are complex dynamic structures that form within lymph nodes as an essential process in the humoral immune response. They represent a paradigm for studying the regulation of cell movement in the development of complex anatomical structures. We have developed a simulation of a modified cyclic re-entry model of GC dynamics which successfully employs chemotaxis to recapitulate the anatomy of the primary follicle and the development of a mature GC, including correctly structured mantle, dark and light zones. We then show that correct single cell movement dynamics (including persistent random walk and inter-zonal crossing) arise from this simulation as purely emergent properties. The major insight of our study is that chemotaxis can only achieve this when constrained by the known biological properties that cells are incompressible, exist in a densely packed environment, and must therefore compete for space. It is this interplay of chemotaxis and competition for limited space that generates all the complex and biologically accurate behaviors described here. Thus, from a single simple mechanism that is well documented in the biological literature, we can explain both higher level structure and single cell movement behaviors. To our knowledge this is the first GC model that is able to recapitulate both correctly detailed anatomy and single cell movement. This mechanism may have wide application for modeling other biological systems where cells undergo complex patterns of movement to produce defined anatomical structures with sharp tissue boundaries.

A new biologic prognostic model based on immunohistochemistry predicts survival in patients with diffuse large B-cell lymphoma.

PubMed

Perry, Anamarija M; Cardesa-Salzmann, Teresa M; Meyer, Paul N; Colomo, Luis; Smith, Lynette M; Fu, Kai; Greiner, Timothy C; Delabie, Jan; Gascoyne, Randy D; Rimsza, Lisa; Jaffe, Elaine S; Ott, German; Rosenwald, Andreas; Braziel, Rita M; Tubbs, Raymond; Cook, James R; Staudt, Louis M; Connors, Joseph M; Sehn, Laurie H; Vose, Julie M; López-Guillermo, Armando; Campo, Elias; Chan, Wing C; Weisenburger, Dennis D

2012-09-13

Biologic factors that predict the survival of patients with a diffuse large B-cell lymphoma, such as cell of origin and stromal signatures, have been discovered by gene expression profiling. We attempted to simulate these gene expression profiling findings and create a new biologic prognostic model based on immunohistochemistry. We studied 199 patients (125 in the training set, 74 in the validation set) with de novo diffuse large B-cell lymphoma treated with rituximab and CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or CHOP-like therapies, and immunohistochemical stains were performed on paraffin-embedded tissue microarrays. In the model, 1 point was awarded for each adverse prognostic factor: nongerminal center B cell-like subtype, SPARC (secreted protein, acidic, and rich in cysteine) < 5%, and microvascular density quartile 4. The model using these 3 biologic markers was highly predictive of overall survival and event-free survival in multivariate analysis after adjusting for the International Prognostic Index in both the training and validation sets. This new model delineates 2 groups of patients, 1 with a low biologic score (0-1) and good survival and the other with a high score (2-3) and poor survival. This new biologic prognostic model could be used with the International Prognostic Index to stratify patients for novel or risk-adapted therapies.

Learning Cell Biology as a Team: A Project-Based Approach to Upper-Division Cell Biology

ERIC Educational Resources Information Center

Wright, Robin; Boggs, James

2002-01-01

To help students develop successful strategies for learning how to learn and communicate complex information in cell biology, we developed a quarter-long cell biology class based on team projects. Each team researches a particular human disease and presents information about the cellular structure or process affected by the disease, the cellular…

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.

Ultra-localized single cell electroporation using silicon nanowires.

PubMed

Jokilaakso, Nima; Salm, Eric; Chen, Aaron; Millet, Larry; Guevara, Carlos Duarte; Dorvel, Brian; Reddy, Bobby; Karlstrom, Amelie Eriksson; Chen, Yu; Ji, Hongmiao; Chen, Yu; Sooryakumar, Ratnasingham; Bashir, Rashid

2013-02-07

Analysis of cell-to-cell variation can further the understanding of intracellular processes and the role of individual cell function within a larger cell population. The ability to precisely lyse single cells can be used to release cellular components to resolve cellular heterogeneity that might be obscured when whole populations are examined. We report a method to position and lyse individual cells on silicon nanowire and nanoribbon biological field effect transistors. In this study, HT-29 cancer cells were positioned on top of transistors by manipulating magnetic beads using external magnetic fields. Ultra-rapid cell lysis was subsequently performed by applying 600-900 mV(pp) at 10 MHz for as little as 2 ms across the transistor channel and the bulk substrate. We show that the fringing electric field at the device surface disrupts the cell membrane, leading to lysis from irreversible electroporation. This methodology allows rapid and simple single cell lysis and analysis with potential applications in medical diagnostics, proteome analysis and developmental biology studies.

Programmable chemical reaction networks: emulating regulatory functions in living cells using a bottom-up approach.

PubMed

van Roekel, Hendrik W H; Rosier, Bas J H M; Meijer, Lenny H H; Hilbers, Peter A J; Markvoort, Albert J; Huck, Wilhelm T S; de Greef, Tom F A

2015-11-07

Living cells are able to produce a wide variety of biological responses when subjected to biochemical stimuli. It has become apparent that these biological responses are regulated by complex chemical reaction networks (CRNs). Unravelling the function of these circuits is a key topic of both systems biology and synthetic biology. Recent progress at the interface of chemistry and biology together with the realisation that current experimental tools are insufficient to quantitatively understand the molecular logic of pathways inside living cells has triggered renewed interest in the bottom-up development of CRNs. This builds upon earlier work of physical chemists who extensively studied inorganic CRNs and showed how a system of chemical reactions can give rise to complex spatiotemporal responses such as oscillations and pattern formation. Using purified biochemical components, in vitro synthetic biologists have started to engineer simplified model systems with the goal of mimicking biological responses of intracellular circuits. Emulation and reconstruction of system-level properties of intracellular networks using simplified circuits are able to reveal key design principles and molecular programs that underlie the biological function of interest. In this Tutorial Review, we present an accessible overview of this emerging field starting with key studies on inorganic CRNs followed by a discussion of recent work involving purified biochemical components. Finally, we review recent work showing the versatility of programmable biochemical reaction networks (BRNs) in analytical and diagnostic applications.

The relevance and implications of signet-ring cell adenocarcinoma of the oesophagus.

PubMed

Bleaney, Christopher William; Barrow, Mickhaiel; Hayes, Stephen; Ang, Yeng

2018-03-01

To review the current understanding of signet-ring type oesophageal adenocarcinoma including evidence for prognosis. We conducted a literature search of nine healthcare literature databases for articles detailing the biology and clinical outcomes of signet-ring cell adenocarcinoma of the oesophagus. The impact of signet-ring cell morphology was analysed and detailed in written text and tabular format. Current understanding of the biology of signet-ring cell adenocarcinoma of the oesophagus was summarised. Signet-ring cell carcinoma was represented in 7.61% of the 18 989 cases of oesophageal carcinoma reviewed in multiple studies. The presence of signet-ring cells conferred a worse prognosis and these tumours responded differently to conventional treatments as compared with typical adenocarcinoma. Little is known about the biological features of signet-ring cell adenocarcinoma of the oesophagus. Work in gastric lesions has identified potential targets for future treatments such as CDH1 and RHOA genes. Categorisation of signet-ring cell carcinomas by the proportion of signet-ring cells within tumours differs among clinicians despite WHO criteria for classification. The current UK guidelines for histopathological reporting of oesophageal tumours do not emphasise the importance of identifying signet-ring cells. The presence of signet-ring cells in oesophageal adenocarcinomas leads to poorer clinical outcomes. Current understanding of signet-ring cell biology in oesophageal cancer is limited. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Organ-On-A-Chip Platforms: A Convergence of Advanced Materials, Cells, and Microscale Technologies.

PubMed

Ahadian, Samad; Civitarese, Robert; Bannerman, Dawn; Mohammadi, Mohammad Hossein; Lu, Rick; Wang, Erika; Davenport-Huyer, Locke; Lai, Ben; Zhang, Boyang; Zhao, Yimu; Mandla, Serena; Korolj, Anastasia; Radisic, Milica

2018-01-01

Significant advances in biomaterials, stem cell biology, and microscale technologies have enabled the fabrication of biologically relevant tissues and organs. Such tissues and organs, referred to as organ-on-a-chip (OOC) platforms, have emerged as a powerful tool in tissue analysis and disease modeling for biological and pharmacological applications. A variety of biomaterials are used in tissue fabrication providing multiple biological, structural, and mechanical cues in the regulation of cell behavior and tissue morphogenesis. Cells derived from humans enable the fabrication of personalized OOC platforms. Microscale technologies are specifically helpful in providing physiological microenvironments for tissues and organs. In this review, biomaterials, cells, and microscale technologies are described as essential components to construct OOC platforms. The latest developments in OOC platforms (e.g., liver, skeletal muscle, cardiac, cancer, lung, skin, bone, and brain) are then discussed as functional tools in simulating human physiology and metabolism. Future perspectives and major challenges in the development of OOC platforms toward accelerating clinical studies of drug discovery are finally highlighted. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D molecular models of whole HIV-1 virions generated with cellPACK

PubMed Central

Goodsell, David S.; Autin, Ludovic; Forli, Stefano; Sanner, Michel F.; Olson, Arthur J.

2014-01-01

As knowledge of individual biological processes grows, it becomes increasingly useful to frame new findings within their larger biological contexts in order to generate new systems-scale hypotheses. This report highlights two major iterations of a whole virus model of HIV-1, generated with the cellPACK software. cellPACK integrates structural and systems biology data with packing algorithms to assemble comprehensive 3D models of cell-scale structures in molecular detail. This report describes the biological data, modeling parameters and cellPACK methods used to specify and construct editable models for HIV-1. Anticipating that cellPACK interfaces under development will enable researchers from diverse backgrounds to critique and improve the biological models, we discuss how cellPACK can be used as a framework to unify different types of data across all scales of biology. PMID:25253262

Evaluation of Formative Computer-Based Assessment by Cell Biology Students with Differing Entry Qualifications and Ethnicity

ERIC Educational Resources Information Center

Bax, Christopher; Baggott, Glenn; Howey, Ellen; Pellet-Many, Carolyn; Rayne, Richard; Neonaki, Maria; Bax, Bridget E.; White, Christopher Branford

2006-01-01

This study was carried out to examine students' responses to the use of on-line assessments that included feedback. First year BSc students taking a Cell Biology module undertook such an assessment and were then asked to evaluate the test by completing an anonymous questionnaire. Answers were analysed in light of the respondents' ethnicity and…

Cell biology: scaling and the emergence of evolutionary cell biology.

PubMed

Phillips, Patrick C; Bowerman, Bruce

2015-03-16

A new study investigating the origins of diversity in the structure of the mitotic spindle in nematode embryos, at timescales spanning a few generations to hundreds of millions of years, finds that most features of the spindle evolve via a scaling relationship generated by natural selection acting directly upon embryo size. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radiobiological effects of heavy ions and protons. [on cells of mammals, bacteria and viruses

NASA Technical Reports Server (NTRS)

Ryzhov, N. I.; Vorozhtsova, S. V.; Krasavin, Y. A.; Mashinskaya, T. Y.; Savchenko, N. Y.; Fedorov, B. S.; Khlaponina, V. F.; Shelegedin, V. N.; Gut, L.; Sabo, L.

1974-01-01

Radiobiological effects of heavy ions and protons are studied on cells of mammals, bacteria, viruses and DNA of bacteria. Results show that the dose effect dependence bears an exponential character; the reduction of RBE as LET of particle increases reflects the different character of microdistribution of absorbed energy in biological objects with different levels of biological organization.

Nano-textured fluidic biochip as biological filter for selective survival of neuronal cells.

PubMed

Han, Hsieh-Cheng; Lo, Hung-Chun; Wu, Chia-Yu; Chen, Kuei-Hsien; Chen, Li-Chyong; Ou, Keng-Liang; Hosseinkhani, Hossein

2015-06-01

This is an innovative study to engineer biological filter to evaluate the effect of template surface structure and physiochemical properties that can be used for wide variety of applications in biological, health care as well as environmental protection. Specifically, planar silicon (Si) wafer and arrayed Si nano-tips (SiNT) templates were fabricated and coated with gold for various lengths of time to study the effect of surface charge, surface roughness, and hydrophilicity on biological activity of rat pheochromocytoma cell lines PC12. The initial growth and proliferation of PC12 cells on Si and SiNT templates showed an antipathy for the ultra-sharp SiNTs templates. In contrast, the same cells demonstrated a preferable adherence to and proliferation on planar Si templates, resulting in higher cell densities by three orders of magnitude than those on SiNT templates. It is hypothesized that SiNTs array does generate nano-fluidic effect such that the effective contact region for aqueous solution on SiNTs is lower than that on planar Si templates, thus decreasing adsorbable area for cell viability and survival. Moreover, the effect of the gold coating on cell number density was analyzed in terms of the surface roughness, zeta potential and wetting properties of the templates. It was determined that surface charge, as measured by the zeta potential, strongly correlated with the trend observed in the surface cell density, whereas no such correlation was observed for surface roughness or wetting properties in the ranges of our experiment conditions. © 2014 Wiley Periodicals, Inc.

Is whole-culture synchronization biology's 'perpetual-motion machine'?

PubMed

Cooper, Stephen

2004-06-01

Whole-culture or batch synchronization cannot, in theory, produce a synchronized culture because it violates a fundamental law that proposes that no batch treatment can alter the cell-age order of a culture. In analogy with the history of perpetual-motion machines, it is suggested that the study of these whole-culture 'synchronization' methods might lead to an understanding of general biological principles even though these methods cannot be used to study the normal cell cycle.

Potential toxicity of graphene to cell functions via disrupting protein-protein interactions.

PubMed

Luan, Binquan; Huynh, Tien; Zhao, Lin; Zhou, Ruhong

2015-01-27

While carbon-based nanomaterials such as graphene and carbon nanotubes (CNTs) have become popular in state-of-the-art nanotechnology, their biological safety and underlying molecular mechanism is still largely unknown. Experimental studies have been focused at the cellular level and revealed good correlations between cell's death and the application of CNTs or graphene. Using large-scale all-atom molecular dynamics simulations, we theoretically investigate the potential toxicity of graphene to a biological cell at molecular level. Simulation results show that the hydrophobic protein-protein interaction (or recognition) that is essential to biological functions can be interrupted by a graphene nanosheet. Due to the hydrophobic nature of graphene, it is energetically favorable for a graphene nanosheet to enter the hydrophobic interface of two contacting proteins, such as a dimer. The forced separation of two functional proteins can disrupt the cell's metabolism and even lead to the cell's mortality.

Evaluation of the effects of a plasma activated medium on cancer cells

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

Mohades, S.; Laroussi, M., E-mail: mlarouss@odu.edu; Sears, J.

2015-12-15

The interaction of low temperature plasma with liquids is a relevant topic of study to the field of plasma medicine. This is because cells and tissues are normally surrounded or covered by biological fluids. Therefore, the chemistry induced by the plasma in the aqueous state becomes crucial and usually dictates the biological outcomes. This process became even more important after the discovery that plasma activated media can be useful in killing various cancer cell lines. Here, we report on the measurements of concentrations of hydrogen peroxide, a species known to have strong biological effects, produced by application of plasma tomore » a minimum essential culture medium. The activated medium is then used to treat SCaBER cancer cells. Results indicate that the plasma activated medium can kill the cancer cells in a dose dependent manner, retain its killing effect for several hours, and is as effective as apoptosis inducing drugs.« less

Purified high molecular weight synthetic Aβ(1-42) and biological Aβ oligomers are equipotent in rapidly inducing MTT formazan exocytosis.

PubMed

Weidner, Adam M; Housley, Molly; Murphy, M Paul; Levine, Harry

2011-06-15

Synthetic soluble Aβ oligomers are often used as a surrogate for biologic material in a number of model systems. We compared the activity of Aβ oligomers (synthetic and cell culture media derived) on the human SH-SY5Y neuroblastoma and C2C12 mouse myoblast cell lines in a novel, modified MTT assay. Separating oligomers from monomeric peptide by size exclusion chromatography produced effects at peptide concentrations approaching physiologic levels (10-100 nM). Purified oligomers, but not monomers or fibrils, elicited an increase of a detergent-insoluble form of MTT formazan within 2h as opposed to a control toxin (H(2)O(2)). This effect was comparable for biological and synthetic peptide in both cell types. Monomeric Aβ attenuated the effect of soluble oligomers. This study suggests that the activities of biological and synthetic oligomers are indistinguishable during early stages of Aβ oligomer-cell interaction. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Dendritic Cells Pulsed with Leukemia Cell-Derived Exosomes More Efficiently Induce Antileukemic Immunities

PubMed Central

Wei, Wei; Shen, Chang; Deng, Xiaohui; Chen, Linjun; Ma, Liyuan; Hao, Siguo

2014-01-01

Dendritic cells (DCs) and tumor cell-derived exosomes have been used to develop antitumor vaccines. However, the biological properties and antileukemic effects of leukemia cell-derived exosomes (LEXs) are not well described. In this study, the biological properties and induction of antileukemic immunity of LEXs were investigated using transmission electron microscopy, western blot analysis, cytotoxicity assays, and animal studies. Similar to other tumor cells, leukemia cells release exosomes. Exosomes derived from K562 leukemia cells (LEXK562) are membrane-bound vesicles with diameters of approximately 50–100 μm and harbor adhesion molecules (e.g., intercellular adhesion molecule-1) and immunologically associated molecules (e.g., heat shock protein 70). In cytotoxicity assays and animal studies, LEXs-pulsed DCs induced an antileukemic cytotoxic T-lymphocyte immune response and antileukemic immunity more effectively than did LEXs and non-pulsed DCs (P<0.05). Therefore, LEXs may harbor antigens and immunological molecules associated with leukemia cells. As such, LEX-based vaccines may be a promising strategy for prolonging disease-free survival in patients with leukemia after chemotherapy or hematopoietic stem cell transplantation. PMID:24622345

[Studies of the biological age in adult taiga ticks Ixodes persulcatus (Ixodinae)].

PubMed

Grigor'eva, L A

2013-01-01

The history of studies of the biological age in ixodid ticks is discussed. A method of estimation of the biological age in adult ticks of the genus Ixodes by the degree of fat inclusions in midgut cells and in the fat body is developed. An "age scale" for the determination of the calendar age was assumed.

Using the Concept Map Technique in Teaching Introductory Cell Biology to College Freshmen

ERIC Educational Resources Information Center

Yarden, Hagit; Marbach-Ad, Gili; Gershoni, Jonathan M.

2004-01-01

In our study, we focused on the conceptual understanding of the concepts and processes presented in the first lectures of an introductory course in cellular biology for biology majors. The study topic we considered was, "the structure of DNA and the functions of nucleotides". One hundred and eighteen students were asked to prepare concept maps…

Disease signatures for schizophrenia and bipolar disorder using patient-derived induced pluripotent stem cells.

PubMed

Watmuff, Bradley; Berkovitch, Shaunna S; Huang, Joanne H; Iaconelli, Jonathan; Toffel, Steven; Karmacharya, Rakesh

2016-06-01

Schizophrenia and bipolar disorder are complex psychiatric disorders that present unique challenges in the study of disease biology. There are no objective biological phenotypes for these disorders, which are characterized by complex genetics and prominent roles for gene-environment interactions. The study of the neurobiology underlying these severe psychiatric disorders has been hindered by the lack of access to the tissue of interest - neurons from patients. The advent of reprogramming methods that enable generation of induced pluripotent stem cells (iPSCs) from patient fibroblasts and peripheral blood mononuclear cells has opened possibilities for new approaches to study relevant disease biology using iPSC-derived neurons. While early studies with patient iPSCs have led to promising and intriguing leads, significant hurdles remain in our attempts to capture the complexity of these disorders in vitro. We present here an overview of studies to date of schizophrenia and bipolar disorder using iPSC-derived neuronal cells and discuss potential future directions that can result in the identification of robust and valid cellular phenotypes that in turn can lay the groundwork for meaningful clinical advances. Copyright © 2016 Elsevier Inc. All rights reserved.

Overexpression of miR-9 in mast cells is associated with invasive behavior and spontaneous metastasis

PubMed Central

2014-01-01

Background While microRNA (miRNA) expression is known to be altered in a variety of human malignancies contributing to cancer development and progression, the potential role of miRNA dysregulation in malignant mast cell disease has not been previously explored. The purpose of this study was to investigate the potential contribution of miRNA dysregulation to the biology of canine mast cell tumors (MCTs), a well-established spontaneous model of malignant mast cell disease. Methods We evaluated the miRNA expression profiles from biologically low-grade and biologically high-grade primary canine MCTs using real-time PCR-based TaqMan Low Density miRNA Arrays and performed real-time PCR to evaluate miR-9 expression in primary canine MCTs, malignant mast cell lines, and normal bone marrow-derived mast cells (BMMCs). Mouse mast cell lines and BMMCs were transduced with empty or pre-miR-9 expressing lentiviral constructs and cell proliferation, caspase 3/7 activity, and invasion were assessed. Transcriptional profiling of cells overexpressing miR-9 was performed using Affymetrix GeneChip Mouse Gene 2.0 ST arrays and real-time PCR was performed to validate changes in mRNA expression. Results Our data demonstrate that unique miRNA expression profiles correlate with the biological behavior of primary canine MCTs and that miR-9 expression is increased in biologically high grade canine MCTs and malignant cell lines compared to biologically low grade tumors and normal canine BMMCs. In transformed mouse malignant mast cell lines expressing either wild-type (C57) or activating (P815) KIT mutations and mouse BMMCs, miR-9 overexpression significantly enhanced invasion but had no effect on cell proliferation or apoptosis. Transcriptional profiling of normal mouse BMMCs and P815 cells possessing enforced miR-9 expression demonstrated dysregulation of several genes, including upregulation of CMA1, a protease involved in activation of matrix metalloproteases and extracellular matrix remodeling. Conclusions Our findings demonstrate that unique miRNA expression profiles correlate with the biological behavior of canine MCTs. Furthermore, dysregulation of miR-9 is associated with MCT metastasis potentially through the induction of an invasive phenotype, identifying a potentially novel pathway for therapeutic intervention. PMID:24517413

Neutron scattering to study membrane systems: from lipid vesicles to living cells.

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

Nickels, Jonathan D.; Chatterjee, Sneha; Stanley, Christopher B.

The existence and role of lateral lipid organization in biological membranes has been studied and contested for more than 30 years. Lipid domains, or rafts, are hypothesized as scalable compartments in biological membranes, providing appropriate physical environments to their resident membrane proteins. This implies that lateral lipid organization is associated with a range of biological functions, such as protein co-localization, membrane trafficking, and cell signaling, to name just a few. Neutron scattering techniques have proven to be an excellent tool to investigate these structural features in model lipids, and more recently, in living cells. I will discuss our recent workmore » using neutrons to probe the structure and mechanical properties in model lipid systems and our current efforts in using neutrons to probe the structure and organization of the bilayer in a living cell. These efforts in living cells have used genetic and biochemical strategies to generate a large neutron scattering contrast, making the membrane visible. I will present our results showing in vivo bilayer structure and discuss the outlook for this approach.« less

Carbon nanotubes reinforced chitosan films: mechanical properties and cell response of a novel biomaterial for cardiovascular tissue engineering.

PubMed

Kroustalli, A; Zisimopoulou, A E; Koch, S; Rongen, L; Deligianni, D; Diamantouros, S; Athanassiou, G; Kokozidou, M; Mavrilas, D; Jockenhoevel, S

2013-12-01

Carbon nanotubes have been proposed as fillers to reinforce polymeric biomaterials for the strengthening of their structural integrity to achieve better biomechanical properties. In this study, a new polymeric composite material was introduced by incorporating various low concentrations of multiwalled carbon nanotubes (MWCNTs) into chitosan (CS), aiming at achieving a novel composite biomaterial with superior mechanical and biological properties compared to neat CS, in order to be used in cardiovascular tissue engineering applications. Both mechanical and biological characteristics in contact with the two relevant cell types (endothelial cells and vascular myofibroblasts) were studied. Regarding the mechanical behavior of MWCNT reinforced CS (MWCNT/CS), 5 and 10 % concentrations of MWCNTs enhanced the mechanical behavior of CS, with that of 5 % exhibiting a superior mechanical strength compared to 10 % concentration and neat CS. Regarding biological properties, MWCNT/CS best supported proliferation of endothelial and myofibroblast cells, MWCNTs and MWCNT/CS caused no apoptosis and were not toxic of the examined cell types. Conclusively, the new material could be suitable for tissue engineering (TE) and particularly for cardiovascular TE applications.

The genetics and cell biology of fertilization.

PubMed

Geldziler, Brian D; Marcello, Matthew R; Shakes, Diane C; Singson, Andrew

2011-01-01

Although the general events surrounding fertilization in many species are well described, the molecular underpinnings of fertilization are still poorly understood. Caenorhabditis elegans has emerged as a powerful model system for addressing the molecular and cell biological mechanism of fertilization. A primary advantage is the ability to isolate and propagate mutants that effect gametes and no other cells. This chapter provides conceptual guidelines for the identification, maintenance, and experimental approaches for the study fertility mutants. Copyright © 2011 Elsevier Inc. All rights reserved.

Genome dynamics of the human embryonic kidney 293 lineage in response to cell biology manipulations.

PubMed

Lin, Yao-Cheng; Boone, Morgane; Meuris, Leander; Lemmens, Irma; Van Roy, Nadine; Soete, Arne; Reumers, Joke; Moisse, Matthieu; Plaisance, Stéphane; Drmanac, Radoje; Chen, Jason; Speleman, Frank; Lambrechts, Diether; Van de Peer, Yves; Tavernier, Jan; Callewaert, Nico

2014-09-03

The HEK293 human cell lineage is widely used in cell biology and biotechnology. Here we use whole-genome resequencing of six 293 cell lines to study the dynamics of this aneuploid genome in response to the manipulations used to generate common 293 cell derivatives, such as transformation and stable clone generation (293T); suspension growth adaptation (293S); and cytotoxic lectin selection (293SG). Remarkably, we observe that copy number alteration detection could identify the genomic region that enabled cell survival under selective conditions (i.c. ricin selection). Furthermore, we present methods to detect human/vector genome breakpoints and a user-friendly visualization tool for the 293 genome data. We also establish that the genome structure composition is in steady state for most of these cell lines when standard cell culturing conditions are used. This resource enables novel and more informed studies with 293 cells, and we will distribute the sequenced cell lines to this effect.

Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory.

PubMed

Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V McNeil; Segarra, Verónica A

2017-01-01

Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented-one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research.

Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory †

PubMed Central

Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K.; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V. McNeil; Segarra, Verónica A.

2017-01-01

Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented—one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research. PMID:28861134

Arginine-glycine-aspartic acid-polyethylene glycol-polyamidoamine dendrimer conjugate improves liver-cell aggregation and function in 3-D spheroid culture.

PubMed

Chen, Zhanfei; Lian, Fen; Wang, Xiaoqian; Chen, Yanling; Tang, Nanhong

The polyamidoamine (PAMAM) dendrimer, a type of macromolecule material, has been used in spheroidal cell culture and drug delivery in recent years. However, PAMAM is not involved in the study of hepatic cell-spheroid culture or its biological activity, particularly in detoxification function. Here, we constructed a PAMAM-dendrimer conjugate decorated by an integrin ligand: arginine-glycine-aspartic acid (RGD) peptide. Our studies demonstrate that RGD-polyethylene glycol (PEG)-PAMAM conjugates can promote singly floating hepatic cells to aggregate together in a sphere-like growth with a weak reactive oxygen species. Moreover, RGD-PEG-PAMAM conjugates can activate the AKT-MAPK pathway in hepatic cells to promote cell proliferation and improve basic function and ammonia metabolism. Together, our data support the hepatocyte sphere treated by RGD-PEG-PAMAM conjugates as a potential source of hepatic cells for a biological artificial liver system.

Hemoglobin Aggregation in Single Red Blood Cells of Sickle Cell Anemia

NASA Astrophysics Data System (ADS)

Nishio, Izumi; Tanaka, Toyoichi; Sun, Shao-Tang; Imanishi, Yuri; Tsuyoshi Ohnishi, S.

1983-06-01

A laser light scattering technique was used to observe the extent of hemoglobin aggregation in solitary red blood cells of sickle cell anemia. Hemoglobin aggregation was confirmed in deoxygenated cells. The light scattering technique can also be applied to cytoplasmic studies of any biological cell.

New ways of looking at very small holes - using optical nanoscopy to visualize liver sinusoidal endothelial cell fenestrations

NASA Astrophysics Data System (ADS)

Øie, Cristina I.; Mönkemöller, Viola; Hübner, Wolfgang; Schüttpelz, Mark; Mao, Hong; Ahluwalia, Balpreet S.; Huser, Thomas R.; McCourt, Peter

2018-02-01

Super-resolution fluorescence microscopy, also known as nanoscopy, has provided us with a glimpse of future impacts on cell biology. Far-field optical nanoscopy allows, for the first time, the study of sub-cellular nanoscale biological structures in living cells, which in the past was limited to electron microscopy (EM) (in fixed/dehydrated) cells or tissues. Nanoscopy has particular utility in the study of "fenestrations" - phospholipid transmembrane nanopores of 50-150 nm in diameter through liver sinusoidal endothelial cells (LSECs) that facilitate the passage of plasma, but (usually) not blood cells, to and from the surrounding hepatocytes. Previously, these fenestrations were only discernible with EM, but now they can be visualized in fixed and living cells using structured illumination microscopy (SIM) and in fixed cells using single molecule localization microscopy (SMLM) techniques such as direct stochastic optical reconstruction microscopy. Importantly, both methods use wet samples, avoiding dehydration artifacts. The use of nanoscopy can be extended to the in vitro study of fenestration dynamics, to address questions such as the following: are they actually dynamic structures, and how do they respond to endogenous and exogenous agents? A logical further extension of these methodologies to liver research (including the liver endothelium) will be their application to liver tissue sections from animal models with different pathological manifestations and ultimately to patient biopsies. This review will cover the current state of the art of the use of nanoscopy in the study of liver endothelium and the liver in general. Potential future applications in cell biology and the clinical implications will be discussed.

Open source bioimage informatics for cell biology.

PubMed

Swedlow, Jason R; Eliceiri, Kevin W

2009-11-01

Significant technical advances in imaging, molecular biology and genomics have fueled a revolution in cell biology, in that the molecular and structural processes of the cell are now visualized and measured routinely. Driving much of this recent development has been the advent of computational tools for the acquisition, visualization, analysis and dissemination of these datasets. These tools collectively make up a new subfield of computational biology called bioimage informatics, which is facilitated by open source approaches. We discuss why open source tools for image informatics in cell biology are needed, some of the key general attributes of what make an open source imaging application successful, and point to opportunities for further operability that should greatly accelerate future cell biology discovery.

Cerebrovascular accidents in sickle cell disease. Risk factors and blood transfusion influence. French Study Group on Sickle Cell Disease.

PubMed

de Montalembert, M; Beauvais, P; Bachir, D; Galacteros, F; Girot, R

1993-03-01

This study presents a series of 34 sickle cell patients with one or more cerebrovascular accidents (CVA). Risk factors were studied in a subgroup of 19 patients whose clinical and biological characteristics were compared to those of a group of 444 sickle cell patients without CVA. The only risk factor discovered was a past history of purulent meningitis, which was significantly more frequent in sickle cell patients than in those without CVA (P < 0.0001). No biological or radiological factor affecting the risk of recurrence was found. The risk of recurrence, neurological defects or death after subsequent CVA justify long-term transfusion treatment in patients presenting with a second CVA. However our study shows that 10 patients who were not transfused after their first CVA had no recurrences, (median follow up = 7.9 years; 2-18 years), providing a basis for discussion on the indications of long-term transfusion therapy for sickle cell patients presenting with their first CVA.

Fostering synergy between cell biology and systems biology.

PubMed

Eddy, James A; Funk, Cory C; Price, Nathan D

2015-08-01

In the shared pursuit of elucidating detailed mechanisms of cell function, systems biology presents a natural complement to ongoing efforts in cell biology. Systems biology aims to characterize biological systems through integrated and quantitative modeling of cellular information. The process of model building and analysis provides value through synthesizing and cataloging information about cells and molecules, predicting mechanisms and identifying generalizable themes, generating hypotheses and guiding experimental design, and highlighting knowledge gaps and refining understanding. In turn, incorporating domain expertise and experimental data is crucial for building towards whole cell models. An iterative cycle of interaction between cell and systems biologists advances the goals of both fields and establishes a framework for mechanistic understanding of the genome-to-phenome relationship. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Update and future perspectives of a thymic biological response modifier (Thymomodulin).

PubMed

Cazzola, P; Mazzanti, P; Kouttab, N M

1987-01-01

Thymomodulin (Ellem Industria Farmaceutica spa, Milan, Italy) is a calf thymus acid lysate with immunomodulating activities. It is composed of several peptides with a molecular weight range of 1-10kD. Extensive studies in animal systems showed that Thymomodulin exhibited no, or very little toxicity even when used at high doses. Studies done in vitro and in vivo demonstrated that Thymomodulin is a biologically active compound which regulates the maturation of human and murine pre T lymphocytes, as well as modulate the functions of apparently mature human and animal B and T lymphocytes. It was observed that Thymomodulin can promote myelopoiesis as demonstrated by an increase of granulocyte-macrophage colonies in agar. Although additional studies to examine its target cell lineage are required, it appears that Thymomodulin exhibits specificity toward T cells. Therefore, enhancement of other cell lineage functions by Thymomodulin may be indirect, and mainly due to its effect on T cells. Of major importance is to note that Thymomodulin is prepared in a manner which allows it to maintain its biological activity when administered orally.

Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

PubMed

Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

2015-02-01

During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

Sarcomatoid renal cell carcinoma: Biology and treatment advances.

PubMed

Mouallem, Nemer El; Smith, Steven C; Paul, Asit K

2018-06-01

Sarcomatoid transformation in renal cell carcinoma, so called sacromatoid RCC (sRCC), is associated with an aggressive behavior and a poor prognosis. Current therapeutic approaches are largely ineffective. Recent studies looking into the genomic and molecular characterization of sRCCs have provided insights into the biology and pathogenesis of this entity. These advances in molecular signatures may help development of effective treatment strategies. We herein present a review of recent developments in the pathology, biology, and treatment modalities in sRCC. Copyright © 2017 Elsevier Inc. All rights reserved.

Benefit evaluation of space processing of biological materials

NASA Technical Reports Server (NTRS)

1977-01-01

A rational analytical basis for the evaluation of potential benefits of space processing of biological materials is described. A preliminary evaluation of three candidate space processed biological materials was accomplished. Materials investigated were human lymphocytes, urokinase, and Beta cells. Separation of lymphocyte groups was considered in order to improve the matching of donors and recipients for kidney transplantation, while urokinase was examined in regard to treatment of thromboembolic diseases. Separation of Beta cells was studied since it could provide a highly effective means for the treatment of juvenile-onset diabetes.

The evolution of early cellular systems viewed through the lens of biological interactions.

PubMed

Poole, Anthony M; Lundin, Daniel; Rytkönen, Kalle T

2015-01-01

The minimal cell concept represents a pragmatic approach to the question of how few genes are required to run a cell. This is a helpful way to build a parts-list, and has been more successful than attempts to deduce a minimal gene set for life by inferring the gene repertoire of the last universal common ancestor, as few genes trace back to this hypothetical ancestral state. However, the study of minimal cellular systems is the study of biological outliers where, by practical necessity, coevolutionary interactions are minimized or ignored. In this paper, we consider the biological context from which minimal genomes have been removed. For instance, some of the most reduced genomes are from endosymbionts and are the result of coevolutionary interactions with a host; few such organisms are "free-living." As few, if any, biological systems exist in complete isolation, we expect that, as with modern life, early biological systems were part of an ecosystem, replete with organismal interactions. We favor refocusing discussions of the evolution of cellular systems on processes rather than gene counts. We therefore draw a distinction between a pragmatic minimal cell (an interesting engineering problem), a distributed genome (a system resulting from an evolutionary transition involving more than one cell) and the looser coevolutionary interactions that are ubiquitous in ecosystems. Finally, we consider the distributed genome and coevolutionary interactions between genomic entities in the context of early evolution.

Spectroscopic study of antileishmanial drug incubated in the promastigotes of Leishmania mexicana

NASA Astrophysics Data System (ADS)

Hung, J.; Castillo, J.; Jiménez, G.; Hasegawa, M.; Rodriguez, M.

2003-11-01

In this work we present spectroscopic study of Boldine (aporphine alkaloid) that possesses important biological activities, in particular, in interaction with the promastigotes of Leishmania mexicana. The results show the applicability of autofluorescence of this drug to determinate the possible mechanism of its biological action. The blue shift and hyperchromic effect in the emission spectrum of the drug in interaction with the parasite cells indicate an energy transference process between them. The morphological change of cell shape of the promastigotes treated with the drug is observed using confocal microscopy. This morphological cell-shape transformation evidences an important interaction between the drug studied and some protein of the parasite cell. Here we describe for the first time the fluorescence properties of the Boldine in the promastigotes of L. mexicana.

Cell-based composite materials with programmed structures and functions

DOEpatents

None

2016-03-01

The present invention is directed to the use of silicic acid to transform biological materials, including cellular architecture into inorganic materials to provide biocomposites (nanomaterials) with stabilized structure and function. In the present invention, there has been discovered a means to stabilize the structure and function of biological materials, including cells, biomolecules, peptides, proteins (especially including enzymes), lipids, lipid vesicles, polysaccharides, cytoskeletal filaments, tissue and organs with silicic acid such that these materials may be used as biocomposites. In many instances, these materials retain their original biological activity and may be used in harsh conditions which would otherwise destroy the integrity of the biological material. In certain instances, these biomaterials may be storage stable for long periods of time and reconstituted after storage to return the biological material back to its original form. In addition, by exposing an entire cell to form CSCs, the CSCs may function to provide a unique system to study enzymes or a cascade of enzymes which are otherwise unavailable.

Cell-based composite materials with programmed structures and functions

DOEpatents

Kaehr, Bryan J.; Brinker, C. Jeffrey; Townson, Jason L.

2018-05-15

The present invention is directed to the use of silicic acid to transform biological materials, including cellular architecture into inorganic materials to provide biocomposites (nanomaterials) with stabilized structure and function. In the present invention, there has been discovered a means to stabilize the structure and function of biological materials, including cells, biomolecules, peptides, proteins (especially including enzymes), lipids, lipid vesicles, polysaccharides, cytoskeletal filaments, tissue and organs with silicic acid such that these materials may be used as biocomposites. In many instances, these materials retain their original biological activity and may be used in harsh conditions which would otherwise destroy the integrity of the biological material. In certain instances, these biomaterials may be storage stable for long periods of time and reconstituted after storage to return the biological material back to its original form. In addition, by exposing an entire cell to form CSCs, the CSCs may function to provide a unique system to study enzymes or a cascade of enzymes which are otherwise unavailable.

The Reconstruction and Analysis of Gene Regulatory Networks.

PubMed

Zheng, Guangyong; Huang, Tao

2018-01-01

In post-genomic era, an important task is to explore the function of individual biological molecules (i.e., gene, noncoding RNA, protein, metabolite) and their organization in living cells. For this end, gene regulatory networks (GRNs) are constructed to show relationship between biological molecules, in which the vertices of network denote biological molecules and the edges of network present connection between nodes (Strogatz, Nature 410:268-276, 2001; Bray, Science 301:1864-1865, 2003). Biologists can understand not only the function of biological molecules but also the organization of components of living cells through interpreting the GRNs, since a gene regulatory network is a comprehensively physiological map of living cells and reflects influence of genetic and epigenetic factors (Strogatz, Nature 410:268-276, 2001; Bray, Science 301:1864-1865, 2003). In this paper, we will review the inference methods of GRN reconstruction and analysis approaches of network structure. As a powerful tool for studying complex diseases and biological processes, the applications of the network method in pathway analysis and disease gene identification will be introduced.

Entamoeba histolytica: a snapshot of current research and methods for genetic analysis

PubMed Central

Morf, Laura; Singh, Upinder

2012-01-01

Entamoeba histolytica represents one of the leading causes of parasitic death worldwide. Although identified as the causative agent of amebiasis since 1875, the molecular mechanisms by which the parasite causes disease are still not fully understood. Studying Entamoeba reveals insights into a eukaryotic cell that differs in many ways from better-studied model organisms. Thus, much can be learned from this protozoan parasite on evolution, cell biology and RNA biology. In this review we discuss selected research highlights in Entamoeba research and focus on the development of molecular biological techniques to study this pathogen. We end by highlighting some of the many questions that remain to be answered in order to fully understand this important human pathogen. PMID:22664276

Translational environmental biology: cell biology informing conservation.

PubMed

Traylor-Knowles, Nikki; Palumbi, Stephen R

2014-05-01

Typically, findings from cell biology have been beneficial for preventing human disease. However, translational applications from cell biology can also be applied to conservation efforts, such as protecting coral reefs. Recent efforts to understand the cell biological mechanisms maintaining coral health such as innate immunity and acclimatization have prompted new developments in conservation. Similar to biomedicine, we urge that future efforts should focus on better frameworks for biomarker development to protect coral reefs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biological restoration of central nervous system architecture and function: part 3-stem cell- and cell-based applications and realities in the biological management of central nervous system disorders: traumatic, vascular, and epilepsy disorders.

PubMed

Farin, Azadeh; Liu, Charles Y; Langmoen, Iver A; Apuzzo, Michael L J

2009-11-01

STEM CELL THERAPY has emerged as a promising novel therapeutic endeavor for traumatic brain injury, spinal cord injury, stroke, and epilepsy in experimental studies. A few preliminary clinical trials have further supported its safety and early efficacy after transplantation into humans. Although not yet clinically available for central nervous system disorders, stem cell technology is expected to evolve into one of the most powerful tools in the biological management of complex central nervous system disorders, many of which currently have limited treatment modalities. The identification of stem cells, discovery of neurogenesis, and application of stem cells to treat central nervous system disorders represent a dramatic evolution and expansion of the neurosurgeon's capabilities into the neurorestoration and neuroregeneration realms. In Part 3 of a 5-part series on stem cells, we discuss the theory, experimental evidence, and clinical data pertaining to the use of stem cells for the treatment of traumatic, vascular, and epileptic disorders.

Thin-film optoacoustic transducers for subcellular Brillouin oscillation imaging of individual biological cells.

PubMed

Pérez-Cota, Fernando; Smith, Richard J; Moradi, Emilia; Marques, Leonel; Webb, Kevin F; Clark, Matt

2015-10-01

At low frequencies ultrasound is a valuable tool to mechanically characterize and image biological tissues. There is much interest in using high-frequency ultrasound to investigate single cells. Mechanical characterization of vegetal and biological cells by measurement of Brillouin oscillations has been demonstrated using ultrasound in the GHz range. This paper presents a method to extend this technique from the previously reported single-point measurements and line scans into a high-resolution acoustic imaging tool. Our technique uses a three-layered metal-dielectric-metal film as a transducer to launch acoustic waves into the cell we want to study. The design of this transducer and measuring system is optimized to overcome the vulnerability of a cell to the exposure of laser light and heat without sacrificing the signal-to-noise ratio. The transducer substrate shields the cell from the laser radiation, efficiently generates acoustic waves, facilitates optical detection in transmission, and aids with heat dissipation away from the cell. This paper discusses the design of the transducers and instrumentation and presents Brillouin frequency images on phantom, fixed, and living cells.

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

Metabolic modelling in the development of cell factories by synthetic biology

PubMed Central

Jouhten, Paula

2012-01-01

Cell factories are commonly microbial organisms utilized for bioconversion of renewable resources to bulk or high value chemicals. Introduction of novel production pathways in chassis strains is the core of the development of cell factories by synthetic biology. Synthetic biology aims to create novel biological functions and systems not found in nature by combining biology with engineering. The workflow of the development of novel cell factories with synthetic biology is ideally linear which will be attainable with the quantitative engineering approach, high-quality predictive models, and libraries of well-characterized parts. Different types of metabolic models, mathematical representations of metabolism and its components, enzymes and metabolites, are useful in particular phases of the synthetic biology workflow. In this minireview, the role of metabolic modelling in synthetic biology will be discussed with a review of current status of compatible methods and models for the in silico design and quantitative evaluation of a cell factory. PMID:24688669

Cell interactions in bone tissue engineering.

PubMed

Pirraco, R P; Marques, A P; Reis, R L

2010-01-01

Bone fractures, where the innate regenerative bone response is compromised, represent between 4 and 8 hundred thousands of the total fracture cases, just in the United States. Bone tissue engineering (TE) brought the notion that, in cases such as those, it was preferable to boost the healing process of bone tissue instead of just adding artificial parts that could never properly replace the native tissue. However, despite the hype, bone TE so far could not live up to its promises and new bottom-up approaches are needed. The study of the cellular interactions between the cells relevant for bone biology can be of essential importance to that. In living bone, cells are in a context where communication with adjacent cells is almost permanent. Many fundamental works have been addressing these communications nonetheless, in a bone TE approach, the 3D perspective, being part of the microenvironment of a bone cell, is as crucial. Works combining the study of cell-to-cell interactions in a 3D environment are not as many as expected. Therefore, the bone TE field should not only gain knowledge from the field of fundamental Biology but also contribute for further understanding the biology of bone. In this review, a summary of the main works in the field of bone TE, aiming at studying cellular interactions in a 3D environment, and how they contributed towards the development of a functional engineered bone tissue, is presented.

Determination of Highly Sensitive Biological Cell Model Systems to Screen BPA-Related Health Hazards Using Pathway Studio.

PubMed

Ryu, Do-Yeal; Rahman, Md Saidur; Pang, Myung-Geol

2017-09-06

Bisphenol-A (BPA) is a ubiquitous endocrine-disrupting chemical. Recently, many issues have arisen surrounding the disease pathogenesis of BPA. Therefore, several studies have been conducted to investigate the proteomic biomarkers of BPA that are associated with disease processes. However, studies on identifying highly sensitive biological cell model systems in determining BPA health risk are lacking. Here, we determined suitable cell model systems and potential biomarkers for predicting BPA-mediated disease using the bioinformatics tool Pathway Studio. We compiled known BPA-mediated diseases in humans, which were categorized into five major types. Subsequently, we investigated the differentially expressed proteins following BPA exposure in several cell types, and analyzed the efficacy of altered proteins to investigate their associations with BPA-mediated diseases. Our results demonstrated that colon cancer cells (SW480), mammary gland, and Sertoli cells were highly sensitive biological model systems, because of the efficacy of predicting the majority of BPA-mediated diseases. We selected glucose-6-phosphate dehydrogenase (G6PD), cytochrome b-c1 complex subunit 1 (UQCRC1), and voltage-dependent anion-selective channel protein 2 (VDAC2) as highly sensitive biomarkers to predict BPA-mediated diseases. Furthermore, we summarized proteomic studies in spermatozoa following BPA exposure, which have recently been considered as another suitable cell type for predicting BPA-mediated diseases.

Determination of Highly Sensitive Biological Cell Model Systems to Screen BPA-Related Health Hazards Using Pathway Studio

PubMed Central

Ryu, Do-Yeal

2017-01-01

Bisphenol-A (BPA) is a ubiquitous endocrine-disrupting chemical. Recently, many issues have arisen surrounding the disease pathogenesis of BPA. Therefore, several studies have been conducted to investigate the proteomic biomarkers of BPA that are associated with disease processes. However, studies on identifying highly sensitive biological cell model systems in determining BPA health risk are lacking. Here, we determined suitable cell model systems and potential biomarkers for predicting BPA-mediated disease using the bioinformatics tool Pathway Studio. We compiled known BPA-mediated diseases in humans, which were categorized into five major types. Subsequently, we investigated the differentially expressed proteins following BPA exposure in several cell types, and analyzed the efficacy of altered proteins to investigate their associations with BPA-mediated diseases. Our results demonstrated that colon cancer cells (SW480), mammary gland, and Sertoli cells were highly sensitive biological model systems, because of the efficacy of predicting the majority of BPA-mediated diseases. We selected glucose-6-phosphate dehydrogenase (G6PD), cytochrome b-c1 complex subunit 1 (UQCRC1), and voltage-dependent anion-selective channel protein 2 (VDAC2) as highly sensitive biomarkers to predict BPA-mediated diseases. Furthermore, we summarized proteomic studies in spermatozoa following BPA exposure, which have recently been considered as another suitable cell type for predicting BPA-mediated diseases. PMID:28878155

The Effects of a Mathematical Approach to Teaching Two Topics in High School Biology on Student Achievement and Attitudes.

ERIC Educational Resources Information Center

Wixson, Eldwin Atwell, Jr.

Mathematical approaches to teaching cell structure and physiology and the probability aspects of genetics were used in each of two types of biology courses: one using the Biological Sciences Curriculum Study (BSCS) Yellow version and the other using Otto and Towle's "Modern Biology." Tests of lateral and vertical mathematics transfer, biology…

The cell's view of animal body-plan evolution.

PubMed

Lyons, Deirdre C; Martindale, Mark Q; Srivastava, Mansi

2014-10-01

An adult animal's form is shaped by the collective behavior of cells during embryonic development. To understand the forces that drove the divergence of animal body-plans, evolutionary developmental biology has focused largely on studying genetic networks operating during development. However, it is less well understood how these networks modulate characteristics at the cellular level, such as the shape, polarity, or migration of cells. We organized the "Cell's view of animal body plan evolution" symposium for the 2014 The Society for Integrative and Comparative Biology meeting with the explicit goal of bringing together researchers studying the cell biology of embryonic development in diverse animal taxa. Using a broad range of established and emerging technologies, including live imaging, single-cell analysis, and mathematical modeling, symposium participants revealed mechanisms underlying cells' behavior, a few of which we highlight here. Shape, adhesion, and movements of cells can be modulated over the course of evolution to alter adult body-plans and a major theme explored during the symposium was the role of actomyosin in coordinating diverse behaviors of cells underlying morphogenesis in a myriad of contexts. Uncovering whether conserved or divergent genetic mechanisms guide the contractility of actomyosin in these systems will be crucial to understanding the evolution of the body-plans of animals from a cellular perspective. Many speakers presented research describing developmental phenomena in which cell division and tissue growth can control the form of the adult, and other presenters shared work on studying cell-fate specification, an important source of novelty in animal body-plans. Participants also presented studies of regeneration in annelids, flatworms, acoels, and cnidarians, and provided a unifying view of the regulation of cellular behavior during different life-history stages. Additionally, several presentations highlighted technological advances that glean mechanistic insights from new and emerging model systems, thereby providing the phylogenetic breadth so essential for studying animal evolution. Thus, we propose that an explicit study of cellular phenomena is now possible for a wide range of taxa, and that it will be highly informative for understanding the evolution of animal body-plans. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Dispersion Behaviour of Silica Nanoparticles in Biological Media and Its Influence on Cellular Uptake.

PubMed

Halamoda-Kenzaoui, Blanka; Ceridono, Mara; Colpo, Pascal; Valsesia, Andrea; Urbán, Patricia; Ojea-Jiménez, Isaac; Gioria, Sabrina; Gilliland, Douglas; Rossi, François; Kinsner-Ovaskainen, Agnieszka

2015-01-01

Given the increasing variety of manufactured nanomaterials, suitable, robust, standardized in vitro screening methods are needed to study the mechanisms by which they can interact with biological systems. The in vitro evaluation of interactions of nanoparticles (NPs) with living cells is challenging due to the complex behaviour of NPs, which may involve dissolution, aggregation, sedimentation and formation of a protein corona. These variable parameters have an influence on the surface properties and the stability of NPs in the biological environment and therefore also on the interaction of NPs with cells. We present here a study using 30 nm and 80 nm fluorescently-labelled silicon dioxide NPs (Rubipy-SiO2 NPs) to evaluate the NPs dispersion behaviour up to 48 hours in two different cellular media either supplemented with 10% of serum or in serum-free conditions. Size-dependent differences in dispersion behaviour were observed and the influence of the living cells on NPs stability and deposition was determined. Using flow cytometry and fluorescence microscopy techniques we studied the kinetics of the cellular uptake of Rubipy-SiO2 NPs by A549 and CaCo-2 cells and we found a correlation between the NPs characteristics in cell media and the amount of cellular uptake. Our results emphasize how relevant and important it is to evaluate and to monitor the size and agglomeration state of nanoparticles in the biological medium, in order to interpret correctly the results of the in vitro toxicological assays.

Dispersion Behaviour of Silica Nanoparticles in Biological Media and Its Influence on Cellular Uptake

PubMed Central

Halamoda-Kenzaoui, Blanka; Ceridono, Mara; Colpo, Pascal; Valsesia, Andrea; Urbán, Patricia; Ojea-Jiménez, Isaac; Gioria, Sabrina; Gilliland, Douglas; Rossi, François; Kinsner-Ovaskainen, Agnieszka

2015-01-01

Given the increasing variety of manufactured nanomaterials, suitable, robust, standardized in vitro screening methods are needed to study the mechanisms by which they can interact with biological systems. The in vitro evaluation of interactions of nanoparticles (NPs) with living cells is challenging due to the complex behaviour of NPs, which may involve dissolution, aggregation, sedimentation and formation of a protein corona. These variable parameters have an influence on the surface properties and the stability of NPs in the biological environment and therefore also on the interaction of NPs with cells. We present here a study using 30 nm and 80 nm fluorescently-labelled silicon dioxide NPs (Rubipy-SiO2 NPs) to evaluate the NPs dispersion behaviour up to 48 hours in two different cellular media either supplemented with 10% of serum or in serum-free conditions. Size-dependent differences in dispersion behaviour were observed and the influence of the living cells on NPs stability and deposition was determined. Using flow cytometry and fluorescence microscopy techniques we studied the kinetics of the cellular uptake of Rubipy-SiO2 NPs by A549 and CaCo-2 cells and we found a correlation between the NPs characteristics in cell media and the amount of cellular uptake. Our results emphasize how relevant and important it is to evaluate and to monitor the size and agglomeration state of nanoparticles in the biological medium, in order to interpret correctly the results of the in vitro toxicological assays. PMID:26517371

A Study of Rubisco through Western Blotting and Tissue Printing Techniques

ERIC Educational Resources Information Center

Ma, Zhong; Cooper, Cynthia; Kim, Hyun-Joo; Janick-Buckner, Diane

2009-01-01

We describe a laboratory exercise developed for a cell biology course for second-year undergraduate biology majors. It was designed to introduce undergraduates to the basic molecular biology techniques of Western blotting and immunodetection coupled with the technique of tissue printing in detecting the presence, relative abundance, and…

Action Biology. Advanced Placement for the Second Year. First Edition.

ERIC Educational Resources Information Center

Davis, Mary Pitt

This document provides biology experiments designed for students who have completed a first year biology course. This self contained laboratory booklet contains four sections. In section 1, "Instrumentation in the Study of Cells," discussion sections and suggestions for teacher demonstrations are provided. It also includes some basic materials…

Nanocellulose reinforced gellan-gum hydrogels as potential biological substitutes for annulus fibrosus tissue regeneration.

PubMed

Pereira, Diana R; Silva-Correia, Joana; Oliveira, Joaquim M; Reis, Rui L; Pandit, Abhay; Biggs, Manus J

2018-04-01

Intervertebral disc (IVD) degeneration is associated with both structural damage and aging related degeneration. Annulus fibrosus (AF) defects such as annular tears, herniation and discectomy require novel tissue engineering strategies to functionally repair AF tissue. An ideal construct will repair the AF by providing physical and biological support, facilitating regeneration. The presented strategy herein proposes a gellan gum-based construct reinforced with cellulose nanocrystals (nCell) as a biological self-gelling AF substitute. Nanocomposite hydrogels were fabricated and characterized with respect to hydrogel swelling capacity, degradation rate in vitro and mechanical properties. Rheological evaluation on the nanocomposites demonstrated the GGMA reinforcement with nCell promoted matrix entanglement with higher scaffold stiffness observed upon ionic crosslinking. Compressive mechanical tests demonstrated compressive modulus values close to those of the human AF tissue. Furthermore, cell culture studies with encapsulated bovine AF cells indicated that nanocomposite constructs promoted cell viability and a physiologically relevant cell morphology for up to fourteen days in vitro. Copyright © 2017 Elsevier Inc. All rights reserved.

Real-time imaging of nitric oxide production in living cells with 1,3,5,7-tetramethyl-2,6-dicarbethoxy-8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacence by invert fluorescence microscope.

PubMed

Huang, Ke-Jing; Wang, Hong; Ma, Ming; Zhang, Xian; Zhang, Hua-Shan

2007-02-01

Although the importance of nitric oxide (NO) as a signalling molecule in many biological processes is becoming increasingly evident, many proposed and potential biological functions of NO still remain unclear. Bioimaging is a good technique to visualize observation of nitric oxide in biological samples. In this report, a fluorescent probe, 1,3,5,7-tetramethyl-2,6-dicarbethoxy-8-(3',4'-diaminophenyl)-difluoroboradiaza-s-indacence (TMDCDABODIPY), has been first applied to real-time image NO produced in PC12 cells, Sf9 cells and human vascular endothelial cells at the presence of l-arginine with inverted fluorescence microscope. NO production in the cells is successfully captured and imaged with fine temporal and spatial resolution. The results prove that the probe combined with inverted fluorescence microscope can be developed into a sensitive and selective method for further study of NO release from cells.

Computer-aided design of biological circuits using TinkerCell.

PubMed

Chandran, Deepak; Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze, and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. © 2010 Landes Bioscience

High-content adhesion assay to address limited cell samples†

PubMed Central

Warrick, Jay W.; Young, Edmond W. K.; Schmuck, Eric G.; Saupe, Kurt W.

2013-01-01

Cell adhesion is a broad topic in cell biology that involves physical interactions between cells and other cells or the surrounding extracellular matrix, and is implicated in major research areas including cancer, development, tissue engineering, and regenerative medicine. While current methods have contributed significantly to our understanding of cell adhesion, these methods are unsuitable for tackling many biological questions requiring intermediate numbers of cells (102–105), including small animal biopsies, clinical samples, and rare cell isolates. To overcome this fundamental limitation, we developed a new assay to quantify the adhesion of ~102–103 cells at a time on engineered substrates, and examined the adhesion strength and population heterogeneity via distribution-based modeling. We validated the platform by testing adhesion strength of cancer cells from three different cancer types (breast, prostate, and multiple myeloma) on both IL-1β activated and non-activated endothelial monolayers, and observed significantly increased adhesion for each cancer cell type upon endothelial activation, while identifying and quantifying distinct subpopulations of cell-substrate interactions. We then applied the assay to characterize adhesion of primary bone marrow stromal cells to different cardiac fibroblast-derived matrix substrates to demonstrate the ability to study limited cell populations in the context of cardiac cell-based therapies. Overall, these results demonstrate the sensitivity and robustness of the assay as well as its ability to enable extraction of high content, functional data from limited and potentially rare primary samples. We anticipate this method will enable a new class of biological studies with potential impact in basic and translational research. PMID:23426645

Comparative Phytochemical Analysis of Essential Oils from Different Biological Parts of Artemisia herba alba and Their Cytotoxic Effect on Cancer Cells.

PubMed

Tilaoui, Mounir; Ait Mouse, Hassan; Jaafari, Abdeslam; Zyad, Abdelmajid

2015-01-01

Carrying out the chemical composition and antiproliferative effects against cancer cells from different biological parts of Artemisia herba alba. Essential oils were studied by gas chromatography coupled to mass spectrometry (GC-MS) and their antitumoral activity was tested against P815 mastocytoma and BSR kidney carcinoma cell lines; also, in order to evaluate the effect on normal human cells, oils were tested against peripheral blood mononuclear cells PBMCs. Essential oils from leaves and aerial parts (mixture of capitulum and leaves) were mainly composed by oxygenated sesquiterpenes 39.89% and 46.15% respectively; capitulum oil contained essentially monoterpenes (22.86%) and monocyclic monoterpenes (21.48%); esters constituted the major fraction (62.8%) of stem oil. Essential oils of different biological parts studied demonstrated a differential antiproliferative activity against P815 and BSR cancer cells; P815 cells are the most sensitive to the cytotoxic effect. Leaves and capitulum essential oils are more active than aerial parts. Interestingly, no cytotoxic effect of these essential oils was observed on peripheral blood mononuclear cells. Our results showed that the chemical composition variability of essential oils depends on the nature of botanical parts of Artemisia herba alba. Furthermore, we have demonstrated that the differential cytotoxic effect depends not only on the essential oils concentration, but also on the target cells and the botanical parts of essential oils used.

Electromagnetic fields as structure-function zeitgebers in biological systems: environmental orchestrations of morphogenesis and consciousness.

PubMed

Rouleau, Nicolas; Dotta, Blake T

2014-01-01

Within a cell system structure dictates function. Any interaction between cells, or a cell and its environment, has the potential to have long term implications on the function of a given cell and emerging cell aggregates. The structure and function of cells are continuously subjected to modification by electrical and chemical stimuli. However, biological systems are also subjected to an ever-present influence: the electromagnetic (EM) environment. Biological systems have the potential to be influenced by subtle energies which are exchanged at atomic and subatomic scales as EM phenomena. These energy exchanges have the potential to manifest at higher orders of discourse and affect the output (behavior) of a biological system. Here we describe theoretical and experimental evidence of EM influence on cells and the integration of whole systems. Even weak interactions between EM energies and biological systems display the potential to affect a developing system. We suggest the growing literature of EM effects on biological systems has significant implications to the cell and its functional aggregates.

Tiny cells meet big questions: a closer look at bacterial cell biology.

PubMed

Goley, Erin D

2013-04-01

While studying actin assembly as a graduate student with Matt Welch at the University of California at Berkeley, my interest was piqued by reports of surprising observations in bacteria: the identification of numerous cytoskeletal proteins, actin homologues fulfilling spindle-like functions, and even the presence of membrane-bound organelles. Curiosity about these phenomena drew me to Lucy Shapiro's lab at Stanford University for my postdoctoral research. In the Shapiro lab, and now in my lab at Johns Hopkins, I have focused on investigating the mechanisms of bacterial cytokinesis. Spending time as both a eukaryotic cell biologist and a bacterial cell biologist has convinced me that bacterial cells present the same questions as eukaryotic cells: How are chromosomes organized and accurately segregated? How is force generated for cytokinesis? How is polarity established? How are signals transduced within and between cells? These problems are conceptually similar between eukaryotes and bacteria, although their solutions can differ significantly in specifics. In this Perspective, I provide a broad view of cell biological phenomena in bacteria, the technical challenges facing those of us who peer into bacterial cells, and areas of common ground as research in eukaryotic and bacterial cell biology moves forward.

Extending the knowledge in histochemistry and cell biology.

PubMed

Heupel, Wolfgang-Moritz; Drenckhahn, Detlev

2010-01-01

Central to modern Histochemistry and Cell Biology stands the need for visualization of cellular and molecular processes. In the past several years, a variety of techniques has been achieved bridging traditional light microscopy, fluorescence microscopy and electron microscopy with powerful software-based post-processing and computer modeling. Researchers now have various tools available to investigate problems of interest from bird's- up to worm's-eye of view, focusing on tissues, cells, proteins or finally single molecules. Applications of new approaches in combination with well-established traditional techniques of mRNA, DNA or protein analysis have led to enlightening and prudent studies which have paved the way toward a better understanding of not only physiological but also pathological processes in the field of cell biology. This review is intended to summarize articles standing for the progress made in "histo-biochemical" techniques and their manifold applications.

Interview: from Down's syndrome to basic epigenetics and back again.

PubMed

Lawrence, Jeanne; Telfer, Caroline

2013-12-01

Dr Jeanne Lawrence talks to Caroline Telfer, Commissioning Editor. Dr Jeanne Lawrence is an internationally recognized leader in the study of chromosome regulation by noncoding RNA and nuclear and genome organization. Her research bridges fundamental questions about genome regulation with clinical implications of recent advances in epigenetics. Her interest in chromosome structure and regulation has been a theme throughout her career and she has been honored for her work developing sensitive FISH technology for the detection of single copy genes, as well as RNAs. Her laboratory's publications include the initial demonstration of cell type-specific gene organization with nuclear subdomains; the novel biology of a noncoding RNA, XIST, which coats a whole X-chromosome to induce its silencing; and a new architectural role for a large noncoding RNA to scaffold a nuclear body. Her laboratory's work on epigenetic chromosome regulation in stem cells led to recent studies regarding unanticipated roles of repeat sequences in normal chromosome regulation and deregulation in cancer. Most recently, her laboratory has demonstrated a new approach to translate the basic mechanism of X-chromosome inactivation to correct a chromosomal dosage imbalance in patient-derived cells with trisomy 21 (Down's syndrome). Dr Lawrence has received awards from numerous agencies, including a Research Career Development Award from the National Center for Human Genome Research, career awards from the American Society of Cell Biology, the German Society for Biochemistry, the Muscular Dystrophy Association and a John Merck Fund Translational Research Award. She has served on the NIH National Advisory Council for Human Genome Research, numerous study sections and is currently a monitoring editor for the Journal of Cell Biology. Dr Lawrence has a BA in Biology and Music from Stephens College (MO, USA), a MS in Human Genetics and Genetic Counseling from Rutgers University (NJ, USA) and a PhD in Developmental Biology from Brown University (RI, USA). She is currently a Professor and Interim Chair of the Department of Cell and Developmental Biology at the University of Massachusetts Medical School (MA, USA).

Stem cells and reproduction.

PubMed

Du, Hongling; Taylor, Hugh S

2010-06-01

To review the latest developments in reproductive tract stem cell biology. In 2004, two studies indicated that ovaries contain stem cells which form oocytes in adults and that can be cultured in vitro into mature oocytes. A live birth after orthotopic transplantation of cryopreserved ovarian tissue in a woman whose ovaries were damaged by chemotherapy demonstrates the clinical potential of these cells. In the same year, another study provided novel evidence of endometrial regeneration by stem cells in women who received bone marrow transplants. This finding has potential for the use in treatment of uterine disorders. It also supports a new theory for the cause of endometriosis, which may have its origin in ectopic transdifferentiation of stem cells. Several recent studies have demonstrated that fetal cells enter the maternal circulation and generate microchimerism in the mother. The uterus is a dynamic organ permeable to fetal stem cells, capable of transdifferentiation and an end organ in which bone marrow stem cells may differentiate. Finally stem cell transformation can be an underlying cause of ovarian cancer. Whereas we are just beginning to understand stem cells, the potential implications of stem cells to reproductive biology and medicine are apparent.

Biological interaction of living cells with COSAN-based synthetic vesicles

PubMed Central

Tarrés, Màrius; Canetta, Elisabetta; Paul, Eleanor; Forbes, Jordan; Azzouni, Karima; Viñas, Clara; Teixidor, Francesc; Harwood, Adrian J.

2015-01-01

Cobaltabisdicarbollide (COSAN) [3,3′-Co(1,2-C2B9H11)2]−, is a complex boron-based anion that has the unusual property of self-assembly into membranes and vesicles. These membranes have similar dimensions to biological membranes found in cells, and previously COSAN has been shown to pass through synthetic lipid membranes and those of living cells without causing breakdown of membrane barrier properties. Here, we investigate the interaction of this inorganic membrane system with living cells. We show that COSAN has no immediate effect on cell viability, and cells fully recover when COSAN is removed following exposure for hours to days. COSAN elicits a range of cell biological effects, including altered cell morphology, inhibition of cell growth and, in some cases, apoptosis. These observations reveal a new biology at the interface between inorganic, synthetic COSAN membranes and naturally occurring biological membranes. PMID:25588708

Biological interaction of living cells with COSAN-based synthetic vesicles.

PubMed

Tarrés, Màrius; Canetta, Elisabetta; Paul, Eleanor; Forbes, Jordan; Azzouni, Karima; Viñas, Clara; Teixidor, Francesc; Harwood, Adrian J

2015-01-15

Cobaltabisdicarbollide (COSAN) [3,3'-Co(1,2-C2B9H11)2](-), is a complex boron-based anion that has the unusual property of self-assembly into membranes and vesicles. These membranes have similar dimensions to biological membranes found in cells, and previously COSAN has been shown to pass through synthetic lipid membranes and those of living cells without causing breakdown of membrane barrier properties. Here, we investigate the interaction of this inorganic membrane system with living cells. We show that COSAN has no immediate effect on cell viability, and cells fully recover when COSAN is removed following exposure for hours to days. COSAN elicits a range of cell biological effects, including altered cell morphology, inhibition of cell growth and, in some cases, apoptosis. These observations reveal a new biology at the interface between inorganic, synthetic COSAN membranes and naturally occurring biological membranes.

Summary of biological spaceflight experiments with cells.

PubMed

Dickson, K J

1991-07-01

Numerous biological experiments with cells have been conducted in space, and the importance of these experiments and this area of study is continually becoming evident. This contribution is a compilation of available information about spaceflight experiments with cells for the purpose of providing a single source of information for those interested in space gravitational cell biology. Experiments focused on a study of the effects of gravity and its absence on cells, cell function, and basic cellular processes have been included. Experiments include those involving viruses, bacteriophage, unicellular organisms, lower fungi, and animal and plant cell and tissue cultures, but exclude experiments with cells that were carried on a flight as part of a whole organism and later removed for study, and experiments with fertilized eggs. In addition, experiments in biotechnology, in which the microgravity environment is employed to study cell purification, cell fusion, protein crystallization, and similar processes, have not been included. Spaceflight experiments conducted by scientists from the U.S., U.S.S.R., and other countries and flown onboard sounding rockets (TEXUS, MAXUS, Consort), biosatellites (Biosatellite II, Cosmos), and various crewed spacecraft including the space shuttle (STS) and Soyuz, and space stations (Salyut, Mir) have been included, as well as high altitude balloon flights. Balloon flights are not spaceflights but can and are used as controls for the effects of space radiation, since organisms carried on balloons may be exposed to some of the same radiation as those taken into space, yet continue to be exposed to Earth's gravitational force. Parabolic flights on aircraft during which periods of microgravity of less than a minute are achieved have arbitrarily been excluded, because even though numerous experiments have been conducted, few results have been published.

Toxicity of silver nanoparticles in biological systems: Does the complexity of biological systems matter?

PubMed

Vazquez-Muñoz, Roberto; Borrego, Belen; Juárez-Moreno, Karla; García-García, Maritza; Mota Morales, Josué D; Bogdanchikova, Nina; Huerta-Saquero, Alejandro

2017-07-05

Currently, nanomaterials are more frequently in our daily life, specifically in biomedicine, electronics, food, textiles and catalysis just to name a few. Although nanomaterials provide many benefits, recently their toxicity profiles have begun to be explored. In this work, the toxic effects of silver nanoparticles (35nm-average diameter and Polyvinyl-Pyrrolidone-coated) on biological systems of different levels of complexity was assessed in a comprehensive and comparatively way, through a variety of viability and toxicological assays. The studied organisms included viruses, bacteria, microalgae, fungi, animal and human cells (including cancer cell lines). It was found that biological systems of different taxonomical groups are inhibited at concentrations of silver nanoparticles within the same order of magnitude. Thus, the toxicity of nanomaterials on biological/living systems, constrained by their complexity, e.g. taxonomic groups, resulted contrary to the expected. The fact that cells and virus are inhibited with a concentration of silver nanoparticles within the same order of magnitude could be explained considering that silver nanoparticles affects very primitive cellular mechanisms by interacting with fundamental structures for cells and virus alike. Copyright © 2017 Elsevier B.V. All rights reserved.

Open source bioimage informatics for cell biology

PubMed Central

Swedlow, Jason R.; Eliceiri, Kevin W.

2009-01-01

Significant technical advances in imaging, molecular biology and genomics have fueled a revolution in cell biology, in that the molecular and structural processes of the cell are now visualized and measured routinely. Driving much of this recent development has been the advent of computational tools for the acquisition, visualization, analysis and dissemination of these datasets. These tools collectively make up a new subfield of computational biology called bioimage informatics, which is facilitated by open source approaches. We discuss why open source tools for image informatics in cell biology are needed, some of the key general attributes of what make an open source imaging application successful, and point to opportunities for further operability that should greatly accelerate future cell biology discovery. PMID:19833518

Two dimensional electrophysiological characterization of human pluripotent stem cell-derived cardiomyocyte system

PubMed Central

Zhu, Huanqi; Scharnhorst, Kelsey S.; Stieg, Adam Z.; Gimzewski, James K.; Minami, Itsunari; Nakatsuji, Norio; Nakano, Haruko; Nakano, Atsushi

2017-01-01

Stem cell-derived cardiomyocytes provide a promising tool for human developmental biology, regenerative therapies, disease modeling, and drug discovery. As human pluripotent stem cell-derived cardiomyocytes remain functionally fetal-type, close monitoring of electrophysiological maturation is critical for their further application to biology and translation. However, to date, electrophysiological analyses of stem cell-derived cardiomyocytes has largely been limited by biologically undefined factors including 3D nature of embryoid body, sera from animals, and the feeder cells isolated from mouse. Large variability in the aforementioned systems leads to uncontrollable and irreproducible results, making conclusive studies difficult. In this report, a chemically-defined differentiation regimen and a monolayer cell culture technique was combined with multielectrode arrays for accurate, real-time, and flexible measurement of electrophysiological parameters in translation-ready human cardiomyocytes. Consistent with their natural counterpart, amplitude and dV/dtmax of field potential progressively increased during the course of maturation. Monolayer culture allowed for the identification of pacemaking cells using the multielectrode array platform and thereby the estimation of conduction velocity, which gradually increased during the differentiation of cardiomyocytes. Thus, the electrophysiological maturation of the human pluripotent stem cell-derived cardiomyocytes in our system recapitulates in vivo development. This system provides a versatile biological tool to analyze human heart development, disease mechanisms, and the efficacy/toxicity of chemicals. PMID:28266620

Understanding Super-Resolution Nanoscopy and Its Biological Applications in Cell Imaging

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

Hu, Dehong; Zhao, Baoming; Xie, Yumei

2013-01-01

Optical microscopy has been an ideal tool to study phenomena in live cells because visible light at reasonable intensity does not perturb much of the normal biological functions. However, optical resolution using visible light is significantly limited by the wavelength. Overcoming this diffraction-limit barrier will reveal biological mechanisms, cellular structures, and physiological processes at nanometer scale, orders of magnitude lower than current optical microscopy. Although this appears to be a daunting task, recently developed photoswitchable probes enable reconstruction of individual images into a super-resolution image, thus the emergence of nanoscopy. Harnessing the resolution power of nanoscopy, we report here nano-resolutionmore » fluorescence imaging of microtubules and their network structures in biological cells. The super-resolution nanoscopy successfully resolved nanostructures of microtubule network—a daunting task that cannot be completed using conventional wide-field microscopy.« less

Dynamics of intracellular processes in live-cell systems unveiled by fluorescence correlation microscopy.

PubMed

González Bardeci, Nicolás; Angiolini, Juan Francisco; De Rossi, María Cecilia; Bruno, Luciana; Levi, Valeria

2017-01-01

Fluorescence fluctuation-based methods are non-invasive microscopy tools especially suited for the study of dynamical aspects of biological processes. These methods examine spontaneous intensity fluctuations produced by fluorescent molecules moving through the small, femtoliter-sized observation volume defined in confocal and multiphoton microscopes. The quantitative analysis of the intensity trace provides information on the processes producing the fluctuations that include diffusion, binding interactions, chemical reactions and photophysical phenomena. In this review, we present the basic principles of the most widespread fluctuation-based methods, discuss their implementation in standard confocal microscopes and briefly revise some examples of their applications to address relevant questions in living cells. The ultimate goal of these methods in the Cell Biology field is to observe biomolecules as they move, interact with targets and perform their biological action in the natural context. © 2016 IUBMB Life, 69(1):8-15, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

The Biological Activities of Sesterterpenoid-Type Ophiobolins.

PubMed

Tian, Wei; Deng, Zixin; Hong, Kui

2017-07-18

Ophiobolins (Ophs) are a group of tricarbocyclic sesterterpenoids whose structures contain a tricyclic 5-8-5 carbotricyclic skeleton. Thus far, 49 natural Ophs have been reported and assigned into A-W subgroups in order of discovery. While these sesterterpenoids were first characterized as highly effective phytotoxins, later investigations demonstrated that they display a broad spectrum of biological and pharmacological characteristics such as phytotoxic, antimicrobial, nematocidal, cytotoxic, anti-influenza and inflammation-promoting activities. These bioactive molecules are promising drug candidates due to the developments of their anti-proliferative activities against a vast number of cancer cell lines, multidrug resistance (MDR) cells and cancer stem cells (CSCs). Despite numerous studies on the biological functions of Ophs, their pharmacological mechanism still requires further research. This review summarizes the chemical structures, sources, and biological activities of the oph family and discusses its mechanisms and structure-activity relationship to lay the foundation for the future developments and applications of these promising molecules.

From pericytes to perivascular tumours: correlation between pathology, stem cell biology, and tissue engineering.

PubMed

Mravic, Marco; Asatrian, Greg; Soo, Chia; Lugassy, Claire; Barnhill, Raymond L; Dry, Sarah M; Peault, Bruno; James, Aaron W

2014-09-01

Pericytes were once thought only to aid in angiogenesis and blood pressure control. Gradually, the known functions of pericytes and other perivascular stem cells (PSC) have broadly increased. The following review article will summarize the known functions and importance of pericytes across disciplines of pathology, stem cell biology, and tissue engineering. A literature review was performed for studies examining the importance of pericytes in pathology, stem cell biology, and tissue engineering. The importance of pericytes most prominently includes the identification of the perivascular identity of mesenchymal stem cells (or MSC). Now, pericytes and other PSC are known to display surface markers and multilineage differentiation potential of MSC. Accordingly, interest in the purification and use of PSC for mesenchymal tissue formation and regeneration has increased. Significant demonstration of in vivo efficacy in bone and muscle regeneration has been made in laboratory animals. Contemporaneously with the uncovering of an MSC identity for pericytes, investigators in tumour biology have found biologically relevant roles for pericytes in tumor formation, lymphovascular invasion, and perivascular tumor spread. As well, the contribution of pericytes to perivascular tumors has been examined (and debated), including glomus tumour, myopericytoma and solitary fibrous tumour/hemangiopericytoma. In addition, an expanding recognition of pericyte mimicry and perivascular tumour invasion has occurred, encompassing common malignancies of the brain and skin. In summary, pericytes have a wide range of roles in health and disease. Pericytes are being increasingly studied for their role in tumour formation, growth and invasion. Likewise, the application of pericytes/PSC for mesenchymal tissue engineering is an expanding field of interest.

Effects of intense magnetic fields on sedimentation pattern and gene expression profile in budding yeast

NASA Astrophysics Data System (ADS)

Ikehata, Masateru; Iwasaka, Masakazu; Miyakoshi, Junji; Ueno, Shoogo; Koana, Takao

2003-05-01

Effects of magnetic fields (MFs) on biological systems are usually investigated using biological indices such as gene expression profiles. However, to precisely evaluate the biological effects of MF, the effects of intense MFs on systematic material transport processes including experimental environment must be seriously taken into consideration. In this study, a culture of the budding yeast, Saccharomyces cerevisiae, was used as a model for an in vitro biological test system. After exposure to 5 T static vertical MF, we found a difference in the sedimentation pattern of cells depending on the location of the dish in the magnet bore. Sedimented cells were localized in the center of the dish when they were placed in the lower part of the magnet bore while the sedimentation of the cells was uniform in dishes placed in the upper part of the bore because of the diamagnetic force. Genome wide gene expression profile of the yeast cells after exposure to 5 T static MF for 2 h suggested that the MF did not affect the expression level of any gene in yeast cells although the sedimentation pattern was altered. In addition, exposure to 10 T for 1 h and 5 T for 24 h also did not affect the gene expression. On the other hand, a slight change in expressions of several genes which are related to respiration was observed by exposure to a 14 T static MF for 24 h. The necessity of estimating the indirect effects of MFs on a study of its biological effect of MF in vitro will be discussed.

Krüppel-like factors in mammalian stem cells and development

PubMed Central

Bialkowska, Agnieszka B.; Yang, Vincent W.

2017-01-01

Krüppel-like factors (KLFs) are a family of zinc-finger transcription factors that are found in many species. Recent studies have shown that KLFs play a fundamental role in regulating diverse biological processes such as cell proliferation, differentiation, development and regeneration. Of note, several KLFs are also crucial for maintaining pluripotency and, hence, have been linked to reprogramming and regenerative medicine approaches. Here, we review the crucial functions of KLFs in mammalian embryogenesis, stem cell biology and regeneration, as revealed by studies of animal models. We also highlight how KLFs have been implicated in human diseases and outline potential avenues for future research. PMID:28246209

Using space-based investigations to inform cancer research on Earth.

PubMed

Becker, Jeanne L; Souza, Glauco R

2013-05-01

Experiments conducted in the microgravity environment of space are not typically at the forefront of the mind of a cancer biologist. However, space provides physical conditions that are not achievable on Earth, as well as conditions that can be exploited to study mechanisms and pathways that control cell growth and function. Over the past four decades, studies have shown how exposure to microgravity alters biological processes that may be relevant to cancer. In this Review, we explore the influence of microgravity on cell biology, focusing on tumour cells grown in space together with work carried out using models in ground-based investigations.

Cell-size distribution in epithelial tissue formation and homeostasis

PubMed Central

Primo, Luca; Celani, Antonio

2017-01-01

How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. PMID:28330988

Cell-size distribution in epithelial tissue formation and homeostasis.

PubMed

Puliafito, Alberto; Primo, Luca; Celani, Antonio

2017-03-01

How cell growth and proliferation are orchestrated in living tissues to achieve a given biological function is a central problem in biology. During development, tissue regeneration and homeostasis, cell proliferation must be coordinated by spatial cues in order for cells to attain the correct size and shape. Biological tissues also feature a notable homogeneity of cell size, which, in specific cases, represents a physiological need. Here, we study the temporal evolution of the cell-size distribution by applying the theory of kinetic fragmentation to tissue development and homeostasis. Our theory predicts self-similar probability density function (PDF) of cell size and explains how division times and redistribution ensure cell size homogeneity across the tissue. Theoretical predictions and numerical simulations of confluent non-homeostatic tissue cultures show that cell size distribution is self-similar. Our experimental data confirm predictions and reveal that, as assumed in the theory, cell division times scale like a power-law of the cell size. We find that in homeostatic conditions there is a stationary distribution with lognormal tails, consistently with our experimental data. Our theoretical predictions and numerical simulations show that the shape of the PDF depends on how the space inherited by apoptotic cells is redistributed and that apoptotic cell rates might also depend on size. © 2017 The Author(s).

Constitutive expression of tdTomato protein as a cytotoxicity and proliferation marker for space radiation biology

NASA Astrophysics Data System (ADS)

Chishti, Arif A.; Hellweg, Christine E.; Berger, Thomas; Baumstark-Khan, Christa; Feles, Sebastian; Kätzel, Thorben; Reitz, Günther

2015-01-01

The radiation risk assessment for long-term space missions requires knowledge on the biological effectiveness of different space radiation components, e.g. heavy ions, on the interaction of radiation and other space environmental factors such as microgravity, and on the physical and biological dose distribution in the human body. Space experiments and ground-based experiments at heavy ion accelerators require fast and reliable test systems with an easy readout for different endpoints. In order to determine the effect of different radiation qualities on cellular proliferation and the biological depth dose distribution after heavy ion exposure, a stable human cell line expressing a novel fluorescent protein was established and characterized. tdTomato, a red fluorescent protein of the new generation with fast maturation and high fluorescence intensity, was selected as reporter of cell proliferation. Human embryonic kidney (HEK/293) cells were stably transfected with a plasmid encoding tdTomato under the control of the constitutively active cytomegalovirus (CMV) promoter (ptdTomato-N1). The stably transfected cell line was named HEK-ptdTomato-N1 8. This cytotoxicity biosensor was tested by ionizing radiation (X-rays and accelerated heavy ions) exposure. As biological endpoints, the proliferation kinetics and the cell density reached 100 h after irradiation reflected by constitutive expression of the tdTomato were investigated. Both were reduced dose-dependently after radiation exposure. Finally, the cell line was used for biological weighting of heavy ions of different linear energy transfer (LET) as space-relevant radiation quality. The relative biological effectiveness of accelerated heavy ions in reducing cellular proliferation peaked at an LET of 91 keV/μm. The results of this study demonstrate that the HEK-ptdTomato-N1 reporter cell line can be used as a fast and reliable biosensor system for detection of cytotoxic damage caused by ionizing radiation.

Discovery of Possible Gene Relationships through the Application of Self-Organizing Maps to DNA Microarray Databases

PubMed Central

Chavez-Alvarez, Rocio; Chavoya, Arturo; Mendez-Vazquez, Andres

2014-01-01

DNA microarrays and cell cycle synchronization experiments have made possible the study of the mechanisms of cell cycle regulation of Saccharomyces cerevisiae by simultaneously monitoring the expression levels of thousands of genes at specific time points. On the other hand, pattern recognition techniques can contribute to the analysis of such massive measurements, providing a model of gene expression level evolution through the cell cycle process. In this paper, we propose the use of one of such techniques –an unsupervised artificial neural network called a Self-Organizing Map (SOM)–which has been successfully applied to processes involving very noisy signals, classifying and organizing them, and assisting in the discovery of behavior patterns without requiring prior knowledge about the process under analysis. As a test bed for the use of SOMs in finding possible relationships among genes and their possible contribution in some biological processes, we selected 282 S. cerevisiae genes that have been shown through biological experiments to have an activity during the cell cycle. The expression level of these genes was analyzed in five of the most cited time series DNA microarray databases used in the study of the cell cycle of this organism. With the use of SOM, it was possible to find clusters of genes with similar behavior in the five databases along two cell cycles. This result suggested that some of these genes might be biologically related or might have a regulatory relationship, as was corroborated by comparing some of the clusters obtained with SOMs against a previously reported regulatory network that was generated using biological knowledge, such as protein-protein interactions, gene expression levels, metabolism dynamics, promoter binding, and modification, regulation and transport of proteins. The methodology described in this paper could be applied to the study of gene relationships of other biological processes in different organisms. PMID:24699245

Molecular Force Spectroscopy on Cells

NASA Astrophysics Data System (ADS)

Liu, Baoyu; Chen, Wei; Zhu, Cheng

2015-04-01

Molecular force spectroscopy has become a powerful tool to study how mechanics regulates biology, especially the mechanical regulation of molecular interactions and its impact on cellular functions. This force-driven methodology has uncovered a wealth of new information of the physical chemistry of molecular bonds for various biological systems. The new concepts, qualitative and quantitative measures describing bond behavior under force, and structural bases underlying these phenomena have substantially advanced our fundamental understanding of the inner workings of biological systems from the nanoscale (molecule) to the microscale (cell), elucidated basic molecular mechanisms of a wide range of important biological processes, and provided opportunities for engineering applications. Here, we review major force spectroscopic assays, conceptual developments of mechanically regulated kinetics of molecular interactions, and their biological relevance. We also present current challenges and highlight future directions.

Cellular Analysis of Adult Neural Stem Cells for Investigating Prion Biology.

PubMed

Haigh, Cathryn L

2017-01-01

Traditional primary and secondary cell cultures have been used for the investigation of prion biology and disease for many years. While both types of cultures produce highly valid and immensely valuable results, they also have their limitations; traditional cell lines are often derived from cancers, therefore subject to numerous DNA changes, and primary cultures are labor-intensive and expensive to produce requiring sacrifice of many animals. Neural stem cell (NSC) cultures are a relatively new technology to be used for the study of prion biology and disease. While NSCs are subject to their own limitations-they are generally cultured ex vivo in environments that artificially force their growth-they also have their own unique advantages. NSCs retain the ability for self-renewal and can therefore be propagated in culture similarly to secondary cultures without genetic manipulation. In addition, NSCs are multipotent; they can be induced to differentiate into mature cells of central nervous system (CNS) linage. The combination of self-renewal and multipotency allows NSCs to be used as a primary cell line over multiple generations saving time, costs, and animal harvests, thus providing a valuable addition to the existing cell culture repertoire used for investigation of prion biology and disease. Furthermore, NSC cultures can be generated from mice of any genotype, either by embryonic harvest or harvest from adult brain, allowing gene expression to be studied without further genetic manipulation. This chapter describes a standard method of culturing adult NSCs and assays for monitoring NSC growth, migration, and differentiation and revisits basic reactive oxygen species detection in the context of NSC cultures.

Three-dimensional printing of human skeletal muscle cells: An interdisciplinary approach for studying biological systems.

PubMed

Bagley, James R; Galpin, Andrew J

2015-01-01

Interdisciplinary exploration is vital to education in the 21st century. This manuscript outlines an innovative laboratory-based teaching method that combines elements of biochemistry/molecular biology, kinesiology/health science, computer science, and manufacturing engineering to give students the ability to better conceptualize complex biological systems. Here, we utilize technology available at most universities to print three-dimensional (3D) scale models of actual human muscle cells (myofibers) out of bioplastic materials. The same methodological approach could be applied to nearly any cell type or molecular structure. This advancement is significant because historically, two-dimensional (2D) myocellular images have proven insufficient for detailed analysis of organelle organization and morphology. 3D imaging fills this void by providing accurate and quantifiable myofiber structural data. Manipulating tangible 3D models combats 2D limitation and gives students new perspectives and alternative learning experiences that may assist their understanding. This approach also exposes learners to 1) human muscle cell extraction and isolation, 2) targeted fluorescence labeling, 3) confocal microscopy, 4) image processing (via open-source software), and 5) 3D printing bioplastic scale-models (×500 larger than the actual cells). Creating these physical models may further student's interest in the invisible world of molecular and cellular biology. Furthermore, this interdisciplinary laboratory project gives instructors of all biological disciplines a new teaching tool to foster integrative thinking. © 2015 The International Union of Biochemistry and Molecular Biology.

Agent-based modeling: case study in cleavage furrow models.

PubMed

Mogilner, Alex; Manhart, Angelika

2016-11-07

The number of studies in cell biology in which quantitative models accompany experiments has been growing steadily. Roughly, mathematical and computational techniques of these models can be classified as "differential equation based" (DE) or "agent based" (AB). Recently AB models have started to outnumber DE models, but understanding of AB philosophy and methodology is much less widespread than familiarity with DE techniques. Here we use the history of modeling a fundamental biological problem-positioning of the cleavage furrow in dividing cells-to explain how and why DE and AB models are used. We discuss differences, advantages, and shortcomings of these two approaches. © 2016 Mogilner and Manhart. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication 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).

Comparing the Impacts of Tutorial and Edutainment Software Programs on Students' Achievements, Misconceptions, and Attitudes towards Biology

NASA Astrophysics Data System (ADS)

Kara, Yılmaz; Yeşilyurt, Selami

2008-02-01

The purpose of this study was to investigate the effects of tutorial and edutainment design of instructional software programs related to the "cell division" topic on student achievements, misconceptions and attitudes. An experimental research design including the cell division achievement test (CAT), the cell division concept test (CCT) and biology attitude scale (BAS) was applied at the beginning and at the end of the research. After the treatment, general achievement in CAT increased in favor of experimental groups. Instructional software programs also had the positive effect to the awareness of students' understandings to the general functions of mitosis and meiosis. However, the current study revealed that there were still some misconceptions in the experimental groups even after the treatment. It was also noticed that only using edutainment software program significantly changed students' attitudes towards biology.

Fabrication of uniform multi-compartment particles using microfludic electrospray technology for cell co-culture studies.

PubMed

Liu, Zhou; Shum, Ho Cheung

2013-01-01

In this work, we demonstrate a robust and reliable approach to fabricate multi-compartment particles for cell co-culture studies. By taking advantage of the laminar flow within our microfluidic nozzle, multiple parallel streams of liquids flow towards the nozzle without significant mixing. Afterwards, the multiple parallel streams merge into a single stream, which is sprayed into air, forming monodisperse droplets under an electric field with a high field strength. The resultant multi-compartment droplets are subsequently cross-linked in a calcium chloride solution to form calcium alginate micro-particles with multiple compartments. Each compartment of the particles can be used for encapsulating different types of cells or biological cell factors. These hydrogel particles with cross-linked alginate chains show similarity in the physical and mechanical environment as the extracellular matrix of biological cells. Thus, the multi-compartment particles provide a promising platform for cell studies and co-culture of different cells. In our study, cells are encapsulated in the multi-compartment particles and the viability of cells is quantified using a fluorescence microscope after the cells are stained for a live/dead assay. The high cell viability after encapsulation indicates the cytocompatibility and feasibility of our technique. Our multi-compartment particles have great potential as a platform for studying cell-cell interactions as well as interactions of cells with extracellular factors.

Fabrication of uniform multi-compartment particles using microfludic electrospray technology for cell co-culture studies

PubMed Central

Liu, Zhou; Shum, Ho Cheung

2013-01-01

In this work, we demonstrate a robust and reliable approach to fabricate multi-compartment particles for cell co-culture studies. By taking advantage of the laminar flow within our microfluidic nozzle, multiple parallel streams of liquids flow towards the nozzle without significant mixing. Afterwards, the multiple parallel streams merge into a single stream, which is sprayed into air, forming monodisperse droplets under an electric field with a high field strength. The resultant multi-compartment droplets are subsequently cross-linked in a calcium chloride solution to form calcium alginate micro-particles with multiple compartments. Each compartment of the particles can be used for encapsulating different types of cells or biological cell factors. These hydrogel particles with cross-linked alginate chains show similarity in the physical and mechanical environment as the extracellular matrix of biological cells. Thus, the multi-compartment particles provide a promising platform for cell studies and co-culture of different cells. In our study, cells are encapsulated in the multi-compartment particles and the viability of cells is quantified using a fluorescence microscope after the cells are stained for a live/dead assay. The high cell viability after encapsulation indicates the cytocompatibility and feasibility of our technique. Our multi-compartment particles have great potential as a platform for studying cell-cell interactions as well as interactions of cells with extracellular factors. PMID:24404050

Comparative Study of the Physical, Topographical and Biological Properties of Electrospinning PCL, PLLA, their Blend and Copolymer Scaffolds

NASA Astrophysics Data System (ADS)

Bolbasov, E.; Goreninskii, S.; Tverdokhlebov, S.; Mishanin, A.; Viknianshchuk, A.; Bezuidenhout, D.; Golovkin, A.

2018-05-01

Biodegradable polymers (blends, copolymers) could be the ideal materials for manufacturing of scaffolds for small diameter vascular graft. Such material characteristics as mechanical properties, chemical structure, nano- and micro topography, surface charge, porosity, wettability etc. are becoming the most important aspects for effectiveness of prosthesis biofunctionalization because of their great impact on cell adhesion, spreading, cell proliferation, differentiation and cell function. The aim of the study is to compare physical, topographical and biological properties of polycaprolactone (PCL), poly-L-lactic acid (PLLA), polycaprolactone + poly-L-lactic acid blend (PCL PLLA), L-lactide/Caprolactone copolymer (PLC7015) scaffolds fabricated with the same fiber thickness using electrospun technology. PCL PLLA scaffolds had the highest average pore area (p<0.01) and the lowest strength (p<0.01). PLC7015 scaffolds had the significantly lower average pore area (p=0.03) but the highest elastic deformation (p<0.01). Biological testing with MMSC (multipotent mesenchyme stem cells) demonstrated that after 72 hours of co-cultivation only on PCL and PLLA scaffolds cells entered to the active phase of adhesion process. We propose that physical and topographical properties of PCL, PLLA, their blend and copolymer are of a great dependence of chemical structure but could be changed during the manufacturing process that will lead to changes in biological properties.

Stress stiffened silicon nitride micro bridges array as substrate with tunable stiffness for cell culture.

PubMed

Chen, Jianfeng; Liu, Guangli; Ma, Chengfu; Zhao, Gang; Du, Wenqiang; Zhu, Wulin; Chu, Jiaru

2017-06-01

Recently, interactions between one-dimensional structural stiffness of physical micro environments and cell biological process have been widely studied. However in previous studies, the influence of structural stiffness on biological process was coupled with the influence of micro fiber curvature. Therefore decoupling the influences of fiber curvature and structural stiffness on cell biological process is of prime importance. In this study, we proposed a novel cell culture substrate comprised of silicon nitride bridges whose structure stiffness can be regulated by altering the axial residual stress without changing material and geometry properties. Both theoretical calculations and finite element simulations were performed to study the influence of residual stress on structure stiffness of bridges. Then multi-positions AFM bending tests were implemented to measure local stiffness of a single micro bridge so as to verify our predictions. NIH/3T3 mouse fibroblast cells were cultured on our substrates to examine the feasibility of the substrate application for investigating cellular response to microenvironment with variable stiffness. The results showed that cells on the edge region near bridge ends were more spread, elongated and better aligned along the bridge axial direction than those on the bridge center region. The results suggest that cells can sense and respond to the differences of stiffness and stiffness gradient between the edge and the center region of the bridges, which makes this kind of substrates can be applied in some biomedical fields, such as cell migration and wound healing. Copyright © 2017 Elsevier B.V. All rights reserved.

Engineering cell-fluorescent ion track hybrid detectors.

PubMed

Niklas, Martin; Greilich, Steffen; Melzig, Claudius; Akselrod, Mark S; Debus, Jürgen; Jäkel, Oliver; Abdollahi, Amir

2013-06-11

The lack of sensitive biocompatible particle track detectors has so far limited parallel detection of physical energy deposition and biological response. Fluorescent nuclear track detectors (FNTDs) based on Al₂O₃:C,Mg single crystals combined with confocal laser scanning microscopy (CLSM) provide 3D information on ion tracks with a resolution limited by light diffraction. Here we report the development of next generation cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). The biocompatibility of FNTDs was tested using six different cell lines, i.e. human non-small cell lung carcinoma (A549), glioblastoma (U87), androgen independent prostate cancer (PC3), epidermoid cancer (A431) and murine (VmDk) glioma SMA-560. To evaluate cell adherence, viability and conformal coverage of the crystals different seeding densities and alternative coating with extracellular matrix (fibronectin) was tested. Carbon irradiation was performed in Bragg peak (initial 270.55 MeV u⁻¹). A series of cell compartment specific fluorescence stains including nuclear (HOECHST), membrane (Glut-1), cytoplasm (Calcein AM, CM-DiI) were tested on Cell-Fit-HDs and a single CLSM was employed to co-detect the physical (crystal) as well as the biological (cell layer) information. The FNTD provides a biocompatible surface. Among the cells tested, A549 cells formed the most uniform, viable, tightly packed epithelial like monolayer. The ion track information was not compromised in Cell-Fit-HD as compared to the FNTD alone. Neither cell coating and culturing, nor additional staining procedures affected the properties of the FNTD surface to detect ion tracks. Standard immunofluorescence and live staining procedures could be employed to co-register cell biology and ion track information. The Cell-Fit-Hybrid Detector system is a promising platform for a multitude of studies linking biological response to energy deposition at high level of optical microscopy resolution.

Interaction of Herbal Compounds with Biological Targets: A Case Study with Berberine

PubMed Central

Chen, Xiao-Wu; Di, Yuan Ming; Zhang, Jian; Zhou, Zhi-Wei; Li, Chun Guang; Zhou, Shu-Feng

2012-01-01

Berberine is one of the main alkaloids found in the Chinese herb Huang lian (Rhizoma Coptidis), which has been reported to have multiple pharmacological activities. This study aimed to analyze the molecular targets of berberine based on literature data followed by a pathway analysis using the PANTHER program. PANTHER analysis of berberine targets showed that the most classes of molecular functions include receptor binding, kinase activity, protein binding, transcription activity, DNA binding, and kinase regulator activity. Based on the biological process classification of in vitro berberine targets, those targets related to signal transduction, intracellular signalling cascade, cell surface receptor-linked signal transduction, cell motion, cell cycle control, immunity system process, and protein metabolic process are most frequently involved. In addition, berberine was found to interact with a mixture of biological pathways, such as Alzheimer's disease-presenilin and -secretase pathways, angiogenesis, apoptosis signalling pathway, FAS signalling pathway, Hungtington disease, inflammation mediated by chemokine and cytokine signalling pathways, interleukin signalling pathway, and p53 pathways. We also explored the possible mechanism of action for the anti-diabetic effect of berberine. Further studies are warranted to elucidate the mechanisms of action of berberine using systems biology approach. PMID:23213296

IL-7 and CD4 T Follicular Helper Cells in HIV-1 Infection.

PubMed

Chiodi, Francesca; Bekele, Yonas; Lantto Graham, Rebecka; Nasi, Aikaterini

2017-01-01

IL-7 was previously shown to upregulate the expression of molecules important for interaction of CD4+ T cells with B cells. It is poorly studied whether IL-7 has a role in the biology of T follicular helper (Tfh) cells and whether IL-7 dysregulates the expression of B-cell costimulatory molecules on Tfh cells. We review the literature and provide arguments in favor of IL-7 being involved in the biology of human Tfh cells. The CD127 IL-7 receptor is expressed on circulating Tfh and non-Tfh cells, and we show that IL-7, but not IL-6 or IL-21, upregulates the expression of CD70 and PD-1 on these cells. We conclude that IL-7, a cytokine whose level is elevated during HIV-1 infection, may have a role in increased expression of B cell costimulatory molecules on Tfh cells and lead to abnormal B cell differentiation.

Phenotype-Based Screening of Small Molecules to Modify Plant Cell Walls Using BY-2 Cells.

PubMed

Okubo-Kurihara, Emiko; Matsui, Minami

2018-01-01

The plant cell wall is an important and abundant biomass with great potential for use as a modern recyclable resource. For effective utilization of this cellulosic biomass, its ability to degrade efficiently is key point. With the aim of modifying the cell wall to allow easy decomposition, we used chemical biological technology to alter its structure. As a first step toward evaluating the chemicals in the cell wall we employed a phenotype-based approach using high-throughput screening. As the plant cell wall is essential in determining cell morphology, phenotype-based screening is particularly effective in identifying compounds that bring about alterations in the cell wall. For rapid and reproducible screening, tobacco BY-2 cell is an excellent system in which to observe cell morphology. In this chapter, we provide a detailed chemical biological methodology for studying cell morphology using tobacco BY-2 cells.

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.

SU-E-T-146: Effects of Uncertainties of Radiation Sensitivity of Biological Modelling for Treatment Planning

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

Oita, M; Department of Life System, Institute of Technology and Science, Graduate School, The Tokushima University; Uto, Y

Purpose: The aim of this study was to evaluate the distribution of uncertainty of cell survival by radiation, and assesses the usefulness of stochastic biological model applying for gaussian distribution. Methods: For single cell experiments, exponentially growing cells were harvested from the standard cell culture dishes by trypsinization, and suspended in test tubes containing 1 ml of MEM(2x10{sup 6} cells/ml). The hypoxic cultures were treated with 95% N{sub 2}−5% CO{sub 2} gas for 30 minutes. In vitro radiosensitization was also measured in EMT6/KU single cells to add radiosensitizer under hypoxic conditions. X-ray irradiation was carried out by using an Xraymore » unit (Hitachi X-ray unit, model MBR-1505R3) with 0.5 mm Al/1.0 mm Cu filter, 150 kV, 4 Gy/min). In vitro assay, cells on the dish were irradiated with 1 Gy to 24 Gy, respectively. After irradiation, colony formation assays were performed. Variations of biological parameters were investigated at standard cell culture(n=16), hypoxic cell culture(n=45) and hypoxic cell culture(n=21) with radiosensitizers, respectively. The data were obtained by separate schedule to take account for the variation of radiation sensitivity of cell cycle. Results: At standard cell culture, hypoxic cell culture and hypoxic cell culture with radiosensitizers, median and standard deviation of alpha/beta ratio were 37.1±73.4 Gy, 9.8±23.7 Gy, 20.7±21.9 Gy, respectively. Average and standard deviation of D{sub 50} were 2.5±2.5 Gy, 6.1±2.2 Gy, 3.6±1.3 Gy, respectively. Conclusion: In this study, we have challenged to apply these uncertainties of parameters for the biological model. The variation of alpha values, beta values, D{sub 50} as well as cell culture might have highly affected by probability of cell death. Further research is in progress for precise prediction of the cell death as well as tumor control probability for treatment planning.« less

Culture Models for Studying Thyroid Biology and Disorders

PubMed Central

Toda, Shuji; Aoki, Shigehisa; Uchihashi, Kazuyoshi; Matsunobu, Aki; Yamamoto, Mihoko; Ootani, Akifumi; Yamasaki, Fumio; Koike, Eisuke; Sugihara, Hajime

2011-01-01

The thyroid is composed of thyroid follicles supported by extracellular matrix, capillary network, and stromal cell types such as fibroblasts. The follicles consist of thyrocytes and C cells. In this microenvironment, thyrocytes are highly integrated in their specific structural and functional polarization, but monolayer and floating cultures cannot allow thyrocytes to organize the follicles with such polarity. In contrast, three-dimensional (3-D) collagen gel culture enables thyrocytes to form 3-D follicles with normal polarity. However, these systems never reconstruct the follicles consisting of both thyrocytes and C cells. Thyroid tissue-organotypic culture retains 3-D follicles with both thyrocytes and C cells. To create more appropriate experimental models, we here characterize four culture systems above and then introduce the models for studying thyroid biology and disorders. Finally, we propose a new approach to the cell type-specific culture systems on the basis of in vivo microenvironments of various cell types. PMID:22363871

Castles and cuitlacoche: the first international Ustilago conference.

PubMed

Kronstad, J W

2003-04-01

The first international Ustilago conference was held in Marburg, Germany from August 22 to 25, 2002. The meeting focused on molecular genetic and cell biology research with Ustilago maydis, the causative agent of common smut of maize. This fungus has emerged as a useful experimental organism for studying the biology of basidiomycete fungi, with a particular emphasis on the interaction of the fungus with the host plant. Thus presentations at the meeting covered the range of current research topics including DNA recombination and repair, mating and sexual development, phytopathology, cell biology, the cell cycle, signaling, and genomics. The meeting also highlighted historical aspects of U. maydis research with presentations by pioneers in the field including Robin Holiday (recombination), Yigal Koltin (killer phenomenon) and Peter Day (plant pathology).

The excitability of plant cells: with a special emphasis on characean internodal cells

NASA Technical Reports Server (NTRS)

Wayne, R.

1994-01-01

This review describes the basic principles of electrophysiology using the generation of an action potential in characean internodal cells as a pedagogical tool. Electrophysiology has proven to be a powerful tool in understanding animal physiology and development, yet it has been virtually neglected in the study of plant physiology and development. This review is, in essence, a written account of my personal journey over the past five years to understand the basic principles of electrophysiology so that I can apply them to the study of plant physiology and development. My formal background is in classical botany and cell biology. I have learned electrophysiology by reading many books on physics written for the lay person and by talking informally with many patient biophysicists. I have written this review for the botanist who is unfamiliar with the basics of membrane biology but would like to know that she or he can become familiar with the latest information without much effort. I also wrote it for the neurophysiologist who is proficient in membrane biology but knows little about plant biology (but may want to teach one lecture on "plant action potentials"). And lastly, I wrote this for people interested in the history of science and how the studies of electrical and chemical communication in physiology and development progressed in the botanical and zoological disciplines.

Genetically Encoded Photoactuators and Photosensors for Characterization and Manipulation of Pluripotent Stem Cells

PubMed Central

Pomeroy, Jordan E.; Nguyen, Hung X.; Hoffman, Brenton D.; Bursac, Nenad

2017-01-01

Our knowledge of pluripotent stem cell biology has advanced considerably in the past four decades, but it has yet to deliver on the great promise of regenerative medicine. The slow progress can be mainly attributed to our incomplete understanding of the complex biologic processes regulating the dynamic developmental pathways from pluripotency to fully-differentiated states of functional somatic cells. Much of the difficulty arises from our lack of specific tools to query, or manipulate, the molecular scale circuitry on both single-cell and organismal levels. Fortunately, the last two decades of progress in the field of optogenetics have produced a variety of genetically encoded, light-mediated tools that enable visualization and control of the spatiotemporal regulation of cellular function. The merging of optogenetics and pluripotent stem cell biology could thus be an important step toward realization of the clinical potential of pluripotent stem cells. In this review, we have surveyed available genetically encoded photoactuators and photosensors, a rapidly expanding toolbox, with particular attention to those with utility for studying pluripotent stem cells. PMID:28912894

Function and Biosynthesis of Cell Wall α-1,3-Glucan in Fungi

PubMed Central

Yoshimi, Akira; Miyazawa, Ken; Abe, Keietsu

2017-01-01

Although α-1,3-glucan is a major cell wall polysaccharide in filamentous fungi, its biological functions remain unclear, except that it acts as a virulence factor in animal and plant pathogenic fungi: it conceals cell wall β-glucan on the fungal cell surface to circumvent recognition by hosts. However, cell wall α-1,3-glucan is also present in many of non-pathogenic fungi. Recently, the universal function of α-1,3-glucan as an aggregation factor has been demonstrated. Applications of fungi with modified cell wall α-1,3-glucan in the fermentation industry and of in vitro enzymatically-synthesized α-1,3-glucan in bio-plastics have been developed. This review focuses on the recent progress in our understanding of the biological functions and biosynthetic mechanism of cell wall α-1,3-glucan in fungi. We briefly consider the history of studies on α-1,3-glucan, overview its biological functions and biosynthesis, and finally consider the industrial applications of fungi deficient in α-1,3-glucan. PMID:29371579

Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells

PubMed Central

Sato, Hiromi

2017-01-01

Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1) extracellular matrix, 2) intercellular adhesion molecules and cell surface receptors, 3) intracellular proteins, 4) cell-cell junction proteins, and 5) a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins) and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or pathways including endothelial barrier damage and inflammation, potentially leading to vascular hyperpermeability and severe illness in vivo. This work provides new insights into the pathophysiological mechanisms of Leptospira infection. PMID:28750011

Leptospira interrogans causes quantitative and morphological disturbances in adherens junctions and other biological groups of proteins in human endothelial cells.

PubMed

Sato, Hiromi; Coburn, Jenifer

2017-07-01

Pathogenic Leptospira transmits from animals to humans, causing the zoonotic life-threatening infection called leptospirosis. This infection is reported worldwide with higher risk in tropical regions. Symptoms of leptospirosis range from mild illness to severe illness such as liver damage, kidney failure, respiratory distress, meningitis, and fatal hemorrhagic disease. Invasive species of Leptospira rapidly disseminate to multiple tissues where this bacterium damages host endothelial cells, increasing vascular permeability. Despite the burden in humans and animals, the pathogenic mechanisms of Leptospira infection remain to be elucidated. The pathogenic leptospires adhere to endothelial cells and permeabilize endothelial barriers in vivo and in vitro. In this study, human endothelial cells were infected with the pathogenic L. interrogans serovar Copenhageni or the saprophyte L. biflexa serovar Patoc to investigate morphological changes and other distinctive phenotypes of host cell proteins by fluorescence microscopy. Among those analyzed, 17 proteins from five biological classes demonstrated distinctive phenotypes in morphology and/or signal intensity upon infection with Leptospira. The affected biological groups include: 1) extracellular matrix, 2) intercellular adhesion molecules and cell surface receptors, 3) intracellular proteins, 4) cell-cell junction proteins, and 5) a cytoskeletal protein. Infection with the pathogenic strain most profoundly disturbed the biological structures of adherens junctions (VE-cadherin and catenins) and actin filaments. Our data illuminate morphological disruptions and reduced signals of cell-cell junction proteins and filamentous actin in L. interrogans-infected endothelial cells. In addition, Leptospira infection, regardless of pathogenic status, influenced other host proteins belonging to multiple biological classes. Our data suggest that this zoonotic agent may damage endothelial cells via multiple cascades or pathways including endothelial barrier damage and inflammation, potentially leading to vascular hyperpermeability and severe illness in vivo. This work provides new insights into the pathophysiological mechanisms of Leptospira infection.

Microarray gene-expression study in fibroblast and lymphoblastoid cell lines from antipsychotic-naïve first-episode schizophrenia patients.

PubMed

Gassó, Patricia; Mas, Sergi; Rodríguez, Natalia; Boloc, Daniel; García-Cerro, Susana; Bernardo, Miquel; Lafuente, Amalia; Parellada, Eduard

2017-12-01

Schizophrenia (SZ) is a chronic psychiatric disorder whose onset of symptoms occurs in late adolescence and early adulthood. The etiology is complex and involves important gene-environment interactions. Microarray gene-expression studies on SZ have identified alterations in several biological processes. The heterogeneity in the results can be attributed to the use of different sample types and other important confounding factors including age, illness chronicity and antipsychotic exposure. The aim of the present microarray study was to analyze, for the first time to our knowledge, differences in gene expression profiles in 18 fibroblast (FCLs) and 14 lymphoblastoid cell lines (LCLs) from antipsychotic-naïve first-episode schizophrenia (FES) patients and healthy controls. We used an analytical approach based on protein-protein interaction network construction and functional annotation analysis to identify the biological processes that are altered in SZ. Significant differences in the expression of 32 genes were found when LCLs were assessed. The network and gene set enrichment approach revealed the involvement of similar biological processes in FCLs and LCLs, including apoptosis and related biological terms such as cell cycle, autophagy, cytoskeleton organization and response to stress and stimulus. Metabolism and other processes, including signal transduction, kinase activity and phosphorylation, were also identified. These results were replicated in two independent cohorts using the same analytical approach. This provides more evidence for altered apoptotic processes in antipsychotic-naïve FES patients and other important biological functions such as cytoskeleton organization and metabolism. The convergent results obtained in both peripheral cell models support their usefulness for transcriptome studies on SZ. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular biological and immunohistological characterization of canine dermal papilla cells and the evaluation of culture conditions.

PubMed

Kobayashi, Tetsuro; Fujisawa, Akiko; Amagai, Masayuki; Iwasaki, Toshiroh; Ohyama, Manabu

2011-10-01

The dermal papilla (DP) plays pivotal roles in hair follicle morphogenesis and cycling. However, our understanding of the biology of the canine DP is extremely limited. The aim of this study was to elucidate molecular biological and immunohistochemical characteristics of canine DP cells and determine appropriate conditions for in vitro expansion. Histological investigation revealed that the canine DP expressed biomarkers of human and rodent DP, including alkaline phosphatase (ALP) and versican. When microdissected, canine DP, but not fibroblasts, strongly expressed the DP-related genes for alkaline phosphatase, Wnt inhibitory factor 1 and lymphoid enhancer-binding factor 1, confirming successful isolation. The growth rate of isolated canine DP cells was moderate in conventional culture conditions for rodent and human DP; however, AmnioMAX-C100 complete medium allowed more efficient cultivation. Dermal papilla marker gene expression was maintained in early passage cultured DP cells, but gradually lost after the third passage. Approaches to mimic the in vivo DP environment in culture, such as supplementation of keratinocyte-conditioned medium or use of extracellular matrix-coated dishes, moderately ameliorated loss of DP gene expression in canine DP cells. It is possible that constituent factors in AmnioMAX may influence culture. These findings suggested that further refinements of culture conditions may enable DP cell expansion without impairing intrinsic properties and, importantly, demonstrated that AmnioMAX-cultured early passage canine DP cells partly maintained the biological characteristics of in vivo canine DP cells. This study provides crucial information necessary for further optimization of culture conditions of canine DP. © 2011 The Authors. Veterinary Dermatology. © 2011 ESVD and ACVD.

Tested Studies for Laboratory Teaching. Proceedings of the Workshop/Conference of the Association for Biology Laboratory Education (ABLE) (16th, Atlanta, Georgia, June 7-11, 1994). Volume 16.

ERIC Educational Resources Information Center

Goldman, Corey A., Ed.

The focus of the Association for Biology Laboratory Education (ABLE) is to improve the undergraduate biology laboratory experience by promoting the development and dissemination of interesting, innovative, and reliable laboratory exercises. This proceedings volume contains 17 papers on the topics of cell and molecular biology, genetics, and…

Biology of Leptoypha hospita (Hemiptera: Tingidae), a Potential Biological Control Agent of Chinese Privet

Treesearch

Yanzhuo Zhang; James L. Hanula; Scott Horn; Kristine Braman; Jianghua Sun

2011-01-01

The biology of Leptoypha hospita Drake et Poor (Hemiptera: Tingidae), a potential biological control agent from China for Chinese privet, Ligustrum sinense Lour., was studied in quarantine in the United States. Both nymphs and adults feed on Chinese privet mesophyll cells that lead to a bleached appearance of leaves and dieback of branch tips. L. hospita has five...

Human Organ Culture: Updating the Approach to Bridge the Gap from In Vitro to In Vivo in Inflammation, Cancer, and Stem Cell Biology.

PubMed

Al-Lamki, Rafia S; Bradley, John R; Pober, Jordan S

2017-01-01

Human studies, critical for developing new diagnostics and therapeutics, are limited by ethical and logistical issues, and preclinical animal studies are often poor predictors of human responses. Standard human cell cultures can address some of these concerns but the absence of the normal tissue microenvironment can alter cellular responses. Three-dimensional cultures that position cells on synthetic matrices, or organoid or organ-on-a-chip cultures, in which different cell spontaneously organize contacts with other cells and natural matrix only partly overcome this limitation. Here, we review how human organ cultures (HOCs) can more faithfully preserve in vivo tissue architecture and can better represent disease-associated changes. We will specifically describe how HOCs can be combined with both traditional and more modern morphological techniques to reveal how anatomic location can alter cellular responses at a molecular level and permit comparisons among different cells and different cell types within the same tissue. Examples are provided involving use of HOCs to study inflammation, cancer, and stem cell biology.

Human Organ Culture: Updating the Approach to Bridge the Gap from In Vitro to In Vivo in Inflammation, Cancer, and Stem Cell Biology

PubMed Central

Al-Lamki, Rafia S.; Bradley, John R.; Pober, Jordan S.

2017-01-01

Human studies, critical for developing new diagnostics and therapeutics, are limited by ethical and logistical issues, and preclinical animal studies are often poor predictors of human responses. Standard human cell cultures can address some of these concerns but the absence of the normal tissue microenvironment can alter cellular responses. Three-dimensional cultures that position cells on synthetic matrices, or organoid or organ-on-a-chip cultures, in which different cell spontaneously organize contacts with other cells and natural matrix only partly overcome this limitation. Here, we review how human organ cultures (HOCs) can more faithfully preserve in vivo tissue architecture and can better represent disease-associated changes. We will specifically describe how HOCs can be combined with both traditional and more modern morphological techniques to reveal how anatomic location can alter cellular responses at a molecular level and permit comparisons among different cells and different cell types within the same tissue. Examples are provided involving use of HOCs to study inflammation, cancer, and stem cell biology. PMID:28955710

Integrated Experimental Platforms to Study Blast Injuries: a Bottom-Up Approach

NASA Astrophysics Data System (ADS)

Bo, Chiara

2013-06-01

Developing a cellular and molecular understanding of the nature of traumatic and post-traumatic effects of blast events on live biological samples is critical for improving clinical outcomes.1 To investigate the consequences of pressure waves upon cellular structures and the underlying physiological and biochemical changes, we are using an integrated approach to study the material and biological properties of cells, tissues and organs when subjected to extreme conditions. In particular we have developed a confined Split Hopkinson Pressure Bar (SHPB) system, which allows us to subject cells in suspension or in a monolayer to compression waves of the order of few MPa and duration of hundreds of microseconds.2 The chamber design also enables recovery of the biological samples for cellular and molecular analysis. Specifically, cell survivability, viability, proliferation and morphological changes are investigated post compression for different cell populations. The SHPB platform, coupled with Quasi-Static experiments, is also used to determine stress-strain curves of soft biological tissues under compression at low, medium and high strain rates. Samples are also examined using histological techniques to study macro- and microscopical changes induced by compression waves. Finally, a shock tube has been developed to replicate primary blast damage on organs (i.e. mice lungs) and cell monolayers by generating single or multiple air blast of the order of kPa and few milliseconds duration. This platform allows us to visualize post-traumatic morphological changes at the cellular level as a function of the stimulus pressure and duration as well as biomarker signatures of blast injuries. Adapting and integrating a variety of approaches with different experimental platforms allows us to sample a vast pressure-time space in terms of biological and structural damage that mimic blast injuries and also to determine which physical parameters (peak pressure, stimulus duration, impulse) are contributing to the injury process. Moreover, understanding biological damage following blast events is crucial to developing novel clinical approaches to detect and treat traumatic injury pathologies. This work is supported by he Atomic Weapons Establishment, UK and The Royal British Legion Centre for Blast Injury Studies at Imperial College London, UK

Quantitative proteomics in biological research.

PubMed

Wilm, Matthias

2009-10-01

Proteomics has enabled the direct investigation of biological material, at first through the analysis of individual proteins, then of lysates from cell cultures, and finally of extracts from tissues and biopsies from entire organisms. Its latest manifestation - quantitative proteomics - allows deeper insight into biological systems. This article reviews the different methods used to extract quantitative information from mass spectra. It follows the technical developments aimed toward global proteomics, the attempt to characterize every expressed protein in a cell by at least one peptide. When applications of the technology are discussed, the focus is placed on yeast biology. In particular, differential quantitative proteomics, the comparison between an experiment and its control, is very discriminating for proteins involved in the process being studied. When trying to understand biological processes on a molecular level, differential quantitative proteomics tends to give a clearer picture than global transcription analyses. As a result, MS has become an even more indispensable tool for biochemically motivated biological research.

Synthetic Nanoelectronic Probes for Biological Cells and Tissue

PubMed Central

2013-01-01

Research at the interface between nanoscience and biology has the potential to produce breakthroughs in fundamental science and lead to revolutionary technologies. In this review, we focus on nanoelectronic/biological interfaces. First, we discuss nanoscale field effect transistors (nanoFETs) as probes to study cellular systems, including the realization of nanoFET comparable in size to biological nanostructures involved in communication using synthesized nanowires. Second, we overview current progress in multiplexed extracellular sensing using planar nanoFET arrays. Third, we describe the design and implementation of three distinct nanoFETs used to realize the first intracellular electrical recording from single cells. Fourth, we present recent progress in merging electronic and biological systems at the 3D tissue level by using macroporous nanoelectronic scaffolds. Finally, we discuss future development in this research area, the unique challenges and opportunities, and the tremendous impact these nanoFET based technologies might have in advancing biology and medical sciences. PMID:23451719

In Situ Tissue Engineering Using Magnetically Guided Three-Dimensional Cell Patterning

PubMed Central

Grogan, Shawn P.; Pauli, Chantal; Chen, Peter; Du, Jiang; Chung, Christine B.; Kong, Seong Deok; Colwell, Clifford W.; Lotz, Martin K.; Jin, Sungho

2012-01-01

Manipulation of cell patterns in three dimensions in a manner that mimics natural tissue organization and function is critical for cell biological studies and likely essential for successfully regenerating tissues—especially cells with high physiological demands, such as those of the heart, liver, lungs, and articular cartilage.1,2 In the present study, we report on the feasibility of arranging iron oxide-labeled cells in three-dimensional hydrogels using magnetic fields. By manipulating the strength, shape, and orientation of the magnetic field and using crosslinking gradients in hydrogels, multi-directional cell arrangements can be produced in vitro and even directly in situ. We show that these ferromagnetic particles are nontoxic between 0.1 and 10 mg/mL; certain species of particles can permit or even enhance tissue formation, and these particles can be tracked using magnetic resonance imaging. Taken together, this approach can be adapted for studying basic biological processes in vitro, for general tissue engineering approaches, and for producing organized repair tissues directly in situ. PMID:22224660

Novel optical methodologies in studying mechanical signal transduction in mammalian cells

NASA Technical Reports Server (NTRS)

Stamatas, G. N.; McIntire, L. V.

1999-01-01

For the last 3 decades evidence has been accumulating that some types of mammalian cells respond to their mechanically active environment by altering their morphology, growth rate, and metabolism. The study of such responses is very important in understanding, physiological and pathological conditions ranging from bone formation to atherosclerosis. Obtaining this knowledge has been the goal for an active research area in bioengineering termed cell mechanotransduction. The advancement of optical methodologies used in cell biology research has given the tools to elucidate cellular mechanisms that would otherwise be impossible to visualize. Combined with molecular biology techniques, they give engineers invaluable tools in understanding the chemical pathways involved in mechanotransduction. Herein we briefly review the current knowledge on mechanical signal transduction in mammalian cells, focusing on the application of novel optical techniques in the ongoing research.

New Materials for Biological Fuel Cells

DTIC Science & Technology

2012-04-01

polymer electrolyte membrane ( PEM ), to the membrane-less biological fuel cell (center figure) where the two electrodes are submerged in the same... PEM . MT15_4p166_173.indd 171 4/10/2012 3:46:31 PM REVIEW New materials for biological fuel cells APRIL 2012 | VOLUME 15 | NUMBER 4172 These...ISSN:1369 7021 © Elsevier Ltd 2012APRIL 2012 | VOLUME 15 | NUMBER 4166 New materials for biological fuel cells Over the last decade, there has

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

The Histochemistry and Cell Biology compendium: a review of 2012.

PubMed

Taatjes, Douglas J; Roth, Jürgen

2013-06-01

The year 2012 was another exciting year for Histochemistry and Cell Biology. Innovations in immunohistochemical techniques and microscopy-based imaging have provided the means for advances in the field of cell biology. Over 130 manuscripts were published in the journal during 2012, representing methodological advancements, pathobiology of disease, and cell and tissue biology. This annual review of the manuscripts published in the previous year in Histochemistry and Cell Biology serves as an abbreviated reference for the readership to quickly peruse and discern trends in the field over the past year. The review has been broadly divided into multiple sections encompassing topics such as method advancements, subcellular components, extracellular matrix, and organ systems. We hope that the creation of this subdivision will serve to guide the reader to a specific topic of interest, while simultaneously providing a concise and easily accessible encapsulation of other topics in the broad area of Histochemistry and Cell Biology.

Evaluation of the health impact of nanoparticles emitted from combustion sources: Comprehensive characterization of the physicochemical properties of nanoparticle emissions from wood combustion compliances, car- and ship diesel-engines as well as investigation of their toxicological effects on human lung cells and macrophages.

NASA Astrophysics Data System (ADS)

Zimmermann, R.; Dittmar, G.; Kanashova, T.; Buters, J.; Öder, S.; Paur, H. R.; Mülhopt, S.; Dilger, M.; Weiss, C.; Harndorf, H.; Stengel, B.; Hirvonen, M. R.; Jokiniemi, J.; Hiller, K.; Sapcariu, S.; Sippula, O.; Streibel, T.; Karg, E.; Weggler, B.; Schnelle-Kreis, J.; Lintelmann, J.; Sklorz, M.; Orasche, J.; Müller, L.; Passig, J.; Gröger, T.; BéruBé, K.; Krebs, T.

2016-12-01

Combustion emissions cause health effects. The HICE-Aerosol and Health project team studies the physicochemical properties as well as biological and toxicological effects on lung cells of combustion particle emissions. The chemical composition and physical parameters thoroughly characterized. Human lung cells are exposed to the diluted combustion exhaust fumes at the air-liquid interface (ALI), allowing a realistic lung-cell exposure by simulation of the lung situation. After exposure, cellular responses of the exposed lung cells are studied by multi-omics molecular biological analyses on transcriptomic, proteomic and metabolomic level. Emissions of wood combustion (log wood, pellet heater), ship diesel engines and car gasoline engines are addressed. Special field deployable ALI-exposition systems in a mobile S2-biological laboratory were set up and applied. Human alveolar epithelial cells (A549, BEAS2B and primary cells) as well as murine macrophages were ALI-exposed to diluted emissions. The cellular effects were then comprehensively characterized (viability, cyto-toxicology, multi-omics effects monitoring) and put in context with the chemical and physical aerosol data. The following order of overall cellular response-strength was observed: A relatively mild cellular effect is observed for the diluted wood combustion emissions. Interestingly the effects-strength for log-wood and pellet burner emissions are similar, although PM-concentrations are much higher for the log-wood heater. Similar mild biological effects are observed for the gasoline car emissions. The ship diesel engine emissions induced the most intense biological responses. A surprising result in this context is, that heavy fuel oil (HFO)-emissions showed lower biological effect strengths than the supposedly cleaner diesel fuel emissions (DF). The HFO-emission contain high concentrations of known toxicants (transition metals, polycyclic aromatics). This result was recently confirmed by experiments with murine RAW macrophages. Detailed analyses of the activated cellular response pathways, such as pro-inflammatory responses, xenobiotic metabolism, phagocytosis and oxidative stress were performed. The data is suggesting a large difference in relative toxicity for different combustion sources.

The species translation challenge—A systems biology perspective on human and rat bronchial epithelial cells

PubMed Central

Poussin, Carine; Mathis, Carole; Alexopoulos, Leonidas G; Messinis, Dimitris E; Dulize, Rémi H J; Belcastro, Vincenzo; Melas, Ioannis N; Sakellaropoulos, Theodore; Rhrissorrakrai, Kahn; Bilal, Erhan; Meyer, Pablo; Talikka, Marja; Boué, Stéphanie; Norel, Raquel; Rice, John J; Stolovitzky, Gustavo; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

2014-01-01

The biological responses to external cues such as drugs, chemicals, viruses and hormones, is an essential question in biomedicine and in the field of toxicology, and cannot be easily studied in humans. Thus, biomedical research has continuously relied on animal models for studying the impact of these compounds and attempted to ‘translate’ the results to humans. In this context, the SBV IMPROVER (Systems Biology Verification for Industrial Methodology for PROcess VErification in Research) collaborative initiative, which uses crowd-sourcing techniques to address fundamental questions in systems biology, invited scientists to deploy their own computational methodologies to make predictions on species translatability. A multi-layer systems biology dataset was generated that was comprised of phosphoproteomics, transcriptomics and cytokine data derived from normal human (NHBE) and rat (NRBE) bronchial epithelial cells exposed in parallel to more than 50 different stimuli under identical conditions. The present manuscript describes in detail the experimental settings, generation, processing and quality control analysis of the multi-layer omics dataset accessible in public repositories for further intra- and inter-species translation studies. PMID:25977767

The species translation challenge-a systems biology perspective on human and rat bronchial epithelial cells.

PubMed

Poussin, Carine; Mathis, Carole; Alexopoulos, Leonidas G; Messinis, Dimitris E; Dulize, Rémi H J; Belcastro, Vincenzo; Melas, Ioannis N; Sakellaropoulos, Theodore; Rhrissorrakrai, Kahn; Bilal, Erhan; Meyer, Pablo; Talikka, Marja; Boué, Stéphanie; Norel, Raquel; Rice, John J; Stolovitzky, Gustavo; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

2014-01-01

The biological responses to external cues such as drugs, chemicals, viruses and hormones, is an essential question in biomedicine and in the field of toxicology, and cannot be easily studied in humans. Thus, biomedical research has continuously relied on animal models for studying the impact of these compounds and attempted to 'translate' the results to humans. In this context, the SBV IMPROVER (Systems Biology Verification for Industrial Methodology for PROcess VErification in Research) collaborative initiative, which uses crowd-sourcing techniques to address fundamental questions in systems biology, invited scientists to deploy their own computational methodologies to make predictions on species translatability. A multi-layer systems biology dataset was generated that was comprised of phosphoproteomics, transcriptomics and cytokine data derived from normal human (NHBE) and rat (NRBE) bronchial epithelial cells exposed in parallel to more than 50 different stimuli under identical conditions. The present manuscript describes in detail the experimental settings, generation, processing and quality control analysis of the multi-layer omics dataset accessible in public repositories for further intra- and inter-species translation studies.

Concepts for the clinical use of stem cells in equine medicine

PubMed Central

Koch, Thomas G.; Berg, Lise C.; Betts, Dean H.

2008-01-01

Stem cells from various tissues hold great promise for their therapeutic use in horses, but so far efficacy or proof-of-principle has not been established. The basic characteristics and properties of various equine stem cells remain largely unknown, despite their increasingly widespread experimental and empirical commercial use. A better understanding of equine stem cell biology and concepts is needed in order to develop and evaluate rational clinical applications in the horse. Controlled, well-designed studies of the basic biologic characteristics and properties of these cells are needed to move this new equine research field forward. Stem cell research in the horse has exciting equine specific and comparative perspectives that will most likely benefit the health of horses and, potentially, humans. PMID:19119371

Exosomes as agents of change in the cardiovascular system.

PubMed

Poe, A J; Knowlton, A A

2017-10-01

Exosomes have an evolving role in paracrine and autocrine signaling, which is enhanced because these lipid vesicles are quite stable and can deliver miRNA, DNA, protein and other molecules to cells throughout the body. Most cell types release exosomes, and exosomes are found in all biological fluids, making them accessible biomarkers. Significantly, exosomes can carry a biologically potent cargo, which can alter the phenotype of recipient cells. In the cardiovascular system exosomes have been primarily studied for their role in mediating the beneficial effects of mesenchymal stem cells after myocardial injury. Exosomes released by cardiac cells in disease states, such as myocardial ischemia, can potentially have important pathophysiologic effects on other cardiac cells as well as on distant organs. Published by Elsevier Ltd.

Three-dimensional behavior of ice crystals and biological cells during freezing of cell suspensions.

PubMed

Ishiguro, H; Koike, K

1998-09-11

Behavior of ice crystals and human red blood cells during extracellular-freezing was investigated in three-dimensions using a confocal laser scanning microscope(CLSM), which noninvasively produces tomograms of biological materials. Physiological saline and physiological saline with 2.4 M glycerol were used for suspension. Various cooling rates for directional solidification were used for distinctive morphology of the ice crystals. Addition of acridine orange as a fluorescent dye into the cell suspension enabled ice crystal, cells and unfrozen solution to be distinguished by different colors. The results indicate that the microscopic structure is three-dimensional for flat, cellular, and dendritic solid-liquid interfaces and that a CLSM is very effective in studying three-dimensional structure during the freezing of cell suspensions.

SU-G-TeP3-07: On the Development of Mechano-Biological Assessment of Leukemia Cells Using Optical Tweezers

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

Brost, E; Brooks, J; Piepenburg, J

Purpose: Patients with BCR-ABL (Ph +ve) acute lymphoblastic leukemia are at very high risk of relapse and mortality. In line with the NIH mission to understand the physical and biological processes, we seek to report mechano-biological method to assessment and distinguish treated/untreated leukemia cells. Methods: BCR-ABL leukemia cell populations and silica microspheres were trapped in a 100x magnification optical trapping system (λ=660 nm, 70 mW). Light refracted through the trapped sample was collected in the back focal plane by a quadrant detector to measure the positions of individual cells. The sample was driven at a known frequency and amplitude withmore » a flexure translation stage, and the target’s response was recorded. The measured response was calibrated using the known driving parameters, and information about cell movements due to mechano-biological effects was extracted. Two leukemia cell populations were tested: a control group and a group treated with 2 Gy. Results: The mechano-biological movements of 10 microspheres, control cells, and treated cells were tracked over a ∼30 minute window at 1 minute intervals. The microsphere population did not see significant change in mechano-biological movements over the testing interval and remained constant. The control cell population saw a two-fold rise in activity that peaked around 1200 seconds, then dropped off sharply. The treated cell population saw a two-fold rise in activity that peaked at 400 seconds, and dropped off slowly. Conclusion: The investigated technique allows for direct measurement the movements of a trapped object due to mechano-biological effects such as thermal and extracellular motion. When testing microspheres, the mechano-biological activity remained constant over time due to the lack of biological factors. In both the control and treated cell populations, the mechano-biological activity was increased, possibly due to mitochondrial activation. This extra activity decreased over time, possibly due to cellular damage from trapping radiation.« less

MicroRNAs in Control of Stem Cells in Normal and Malignant Hematopoiesis

PubMed Central

Roden, Christine; Lu, Jun

2016-01-01

Studies on hematopoietic stem cells (HSCs) and leukemia stem cells (LSCs) have helped to establish the paradigms of normal and cancer stem cell concepts. For both HSCs and LSCs, specific gene expression programs endowed by their epigenome functionally distinguish them from their differentiated progenies. MicroRNAs (miRNAs), as a class of small non-coding RNAs, act to control post-transcriptional gene expression. Research in the past decade has yielded exciting findings elucidating the roles of miRNAs in control of multiple facets of HSC and LSC biology. Here we review recent progresses on the functions of miRNAs in HSC emergence during development, HSC switch from a fetal/neonatal program to an adult program, HSC self-renewal and quiescence, HSC aging, HSC niche, and malignant stem cells. While multiple different miRNAs regulate a diverse array of targets, two common themes emerge in HSC and LSC biology: miRNA mediated regulation of epigenetic machinery and cell signaling pathways. In addition, we propose that miRNAs themselves behave like epigenetic regulators, as they possess key biochemical and biological properties that can provide both stability and alterability to the epigenetic program. Overall, the studies of miRNAs in stem cells in the hematologic contexts not only provide key understandings to post-transcriptional gene regulation mechanisms in HSCs and LSCs, but also will lend key insights for other stem cell fields. PMID:27547713

Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: A contribution to the optimization of gene and drug delivery

NASA Astrophysics Data System (ADS)

Grimaldi, Paola; Di Giambattista, Lucia; Giordani, Serena; Udroiu, Ion; Pozzi, Deleana; Gaudenzi, Silvia; Bedini, Angelico; Giliberti, Claudia; Palomba, Raffaele; Congiu Castellano, Agostina

2011-12-01

Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound.

The quest for a new modelling framework in mathematical biology. Comment on "On the interplay between mathematics and biology: Hallmarks towards a new systems biology" by N. Bellomo et al.

NASA Astrophysics Data System (ADS)

Eftimie, Raluca

2015-03-01

One of the main unsolved problems of modern physics is finding a "theory of everything" - a theory that can explain, with the help of mathematics, all physical aspects of the universe. While the laws of physics could explain some aspects of the biology of living systems (e.g., the phenomenological interpretation of movement of cells and animals), there are other aspects specific to biology that cannot be captured by physics models. For example, it is generally accepted that the evolution of a cell-based system is influenced by the activation state of cells (e.g., only activated and functional immune cells can fight diseases); on the other hand, the evolution of an animal-based system can be influenced by the psychological state (e.g., distress) of animals. Therefore, the last 10-20 years have seen also a quest for a "theory of everything"-approach extended to biology, with researchers trying to propose mathematical modelling frameworks that can explain various biological phenomena ranging from ecology to developmental biology and medicine [1,2,6]. The basic idea behind this approach can be found in a few reviews on ecology and cell biology [6,7,9-11], where researchers suggested that due to the parallel between the micro-scale dynamics and the emerging macro-scale phenomena in both cell biology and in ecology, many mathematical methods used for ecological processes could be adapted to cancer modelling [7,9] or to modelling in immunology [11]. However, this approach generally involved the use of different models to describe different biological aspects (e.g., models for cell and animal movement, models for competition between cells or animals, etc.).

Apoptosis: a four-week laboratory investigation for advanced molecular and cellular biology students.

PubMed

DiBartolomeis, Susan M; Moné, James P

2003-01-01

Over the past decade, apoptosis has emerged as an important field of study central to ongoing research in many diverse fields, from developmental biology to cancer research. Apoptosis proceeds by a highly coordinated series of events that includes enzyme activation, DNA fragmentation, and alterations in plasma membrane permeability. The detection of each of these phenotypic changes is accessible to advanced undergraduate cell and molecular biology students. We describe a 4-week laboratory sequence that integrates cell culture, fluorescence microscopy, DNA isolation and analysis, and western blotting (immunoblotting) to follow apoptosis in cultured human cells. Students working in teams chemically induce apoptosis, and harvest, process, and analyze cells, using their data to determine the order of events during apoptosis. We, as instructors, expose the students to an environment closely simulating what they would encounter in an active cell or molecular biology research laboratory by having students coordinate and perform multiple tasks simultaneously and by having them experience experimental design using current literature, data interpretation, and analysis to answer a single question. Students are assessed by examination of laboratory notebooks for completeness of experimental protocols and analysis of results and for completion of an assignment that includes questions pertaining to data interpretation and apoptosis.

Systematic reconstruction of TRANSPATH data into Cell System Markup Language

PubMed Central

Nagasaki, Masao; Saito, Ayumu; Li, Chen; Jeong, Euna; Miyano, Satoru

2008-01-01

Background Many biological repositories store information based on experimental study of the biological processes within a cell, such as protein-protein interactions, metabolic pathways, signal transduction pathways, or regulations of transcription factors and miRNA. Unfortunately, it is difficult to directly use such information when generating simulation-based models. Thus, modeling rules for encoding biological knowledge into system-dynamics-oriented standardized formats would be very useful for fully understanding cellular dynamics at the system level. Results We selected the TRANSPATH database, a manually curated high-quality pathway database, which provides a plentiful source of cellular events in humans, mice, and rats, collected from over 31,500 publications. In this work, we have developed 16 modeling rules based on hybrid functional Petri net with extension (HFPNe), which is suitable for graphical representing and simulating biological processes. In the modeling rules, each Petri net element is incorporated with Cell System Ontology to enable semantic interoperability of models. As a formal ontology for biological pathway modeling with dynamics, CSO also defines biological terminology and corresponding icons. By combining HFPNe with the CSO features, it is possible to make TRANSPATH data to simulation-based and semantically valid models. The results are encoded into a biological pathway format, Cell System Markup Language (CSML), which eases the exchange and integration of biological data and models. Conclusion By using the 16 modeling rules, 97% of the reactions in TRANSPATH are converted into simulation-based models represented in CSML. This reconstruction demonstrates that it is possible to use our rules to generate quantitative models from static pathway descriptions. PMID:18570683

Systematic reconstruction of TRANSPATH data into cell system markup language.

PubMed

Nagasaki, Masao; Saito, Ayumu; Li, Chen; Jeong, Euna; Miyano, Satoru

2008-06-23

Many biological repositories store information based on experimental study of the biological processes within a cell, such as protein-protein interactions, metabolic pathways, signal transduction pathways, or regulations of transcription factors and miRNA. Unfortunately, it is difficult to directly use such information when generating simulation-based models. Thus, modeling rules for encoding biological knowledge into system-dynamics-oriented standardized formats would be very useful for fully understanding cellular dynamics at the system level. We selected the TRANSPATH database, a manually curated high-quality pathway database, which provides a plentiful source of cellular events in humans, mice, and rats, collected from over 31,500 publications. In this work, we have developed 16 modeling rules based on hybrid functional Petri net with extension (HFPNe), which is suitable for graphical representing and simulating biological processes. In the modeling rules, each Petri net element is incorporated with Cell System Ontology to enable semantic interoperability of models. As a formal ontology for biological pathway modeling with dynamics, CSO also defines biological terminology and corresponding icons. By combining HFPNe with the CSO features, it is possible to make TRANSPATH data to simulation-based and semantically valid models. The results are encoded into a biological pathway format, Cell System Markup Language (CSML), which eases the exchange and integration of biological data and models. By using the 16 modeling rules, 97% of the reactions in TRANSPATH are converted into simulation-based models represented in CSML. This reconstruction demonstrates that it is possible to use our rules to generate quantitative models from static pathway descriptions.

Circulating membrane-derived microvesicles in redox biology.

PubMed

Larson, Michael Craig; Hillery, Cheryl A; Hogg, Neil

2014-08-01

Microparticles or microvesicles (MVs) are subcellular membrane blebs shed from all cells in response to various stimuli. MVs carry a battery of signaling molecules, many of them related to redox-regulated processes. The role of MVs, either as a cause or as a result of cellular redox signaling, has been increasingly recognized over the past decade. This is in part due to advances in flow cytometry and its detection of MVs. Notably, recent studies have shown that circulating MVs from platelets and endothelial cells drive reactive species-dependent angiogenesis; circulating MVs in cancer alter the microenvironment and enhance invasion through horizontal transfer of mutated proteins and nucleic acids and harbor redox-regulated matrix metalloproteinases and procoagulative surface molecules; and circulating MVs from red blood cells and other cells modulate cell-cell interactions through scavenging or production of nitric oxide and other free radicals. Although our recognition of MVs in redox-related processes is growing, especially in the vascular biology field, much remains unknown regarding the various biologic and pathologic functions of MVs. Like reactive oxygen and nitrogen species, MVs were originally believed to have a solely pathological role in biology. And like our understanding of reactive species, it is now clear that MVs also play an important role in normal growth, development, and homeostasis. We are just beginning to understand how MVs are involved in various biological processes-developmental, homeostatic, and pathological-and the role of MVs in redox signaling is a rich and exciting area of investigation. Copyright © 2014 Elsevier Inc. All rights reserved.

Biological instability in a chlorinated drinking water distribution network.

PubMed

Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

2014-01-01

The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10(3) cells mL(-1) to 4.66×10(5) cells mL(-1) in the network. While this parameter did not exceed 2.1×10(4) cells mL(-1) in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10(5) cells mL(-1). This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.

Biological Instability in a Chlorinated Drinking Water Distribution Network

PubMed Central

Nescerecka, Alina; Rubulis, Janis; Vital, Marius; Juhna, Talis; Hammes, Frederik

2014-01-01

The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×103 cells mL−1 to 4.66×105 cells mL−1 in the network. While this parameter did not exceed 2.1×104 cells mL−1 in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×105 cells mL−1. This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability. PMID:24796923

The cell as nexus: connections between the history, philosophy and science of cell biology.

PubMed

O'Malley, Maureen A; Müller-Wille, Staffan

2010-09-01

Although the cell is commonly addressed as the unit of life, historians and philosophers have devoted relatively little attention to this concept in comparison to other fundamental concepts of biology such as the gene or species. As a partial remedy to this neglect, we introduce the cell as a major point of connection between various disciplinary approaches, epistemic strategies, technological vectors and overarching biological processes such as metabolism, growth, reproduction and evolution. We suggest that the role of the cell as a nexus forms the basis for a new philosophical and historical appreciation of cell biology. This perspective focuses less on the cell as a well-defined, stable object and places more emphasis on its role as a mediator of fundamental biological processes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Accelerated biological ageing in HIV-infected individuals in South Africa: a case–control study

PubMed Central

Pathai, Sophia; Lawn, Stephen D.; Gilbert, Clare E.; McGuinness, Dagmara; McGlynn, Liane; Weiss, Helen A.; Port, Jennifer; Christ, Theresa; Barclay, Karen; Wood, Robin; Bekker, Linda-Gail; Shiels, Paul G.

2013-01-01

Objectives: Little is known about the impact of HIV infection on biological ageing in sub-Saharan Africa. The study aimed to assess biological ageing in South African HIV-infected adults and HIV-seronegative individuals using two validated biomarkers, telomere length and CDKN2A expression (a mediator of cellular senescence). Design: A case–control study. Methods: Two hundred and thirty-six HIV-infected adults aged at least 30 years and 250 age and sex frequency matched HIV-seronegative individuals were recruited from clinics in township communities in Cape Town. Biological ageing was evaluated by measurement of telomere length and CDKN2A expression in peripheral blood leukocytes. Results: The median ages of the HIV-infected and HIV-seronegative participants were 39 and 40 years, respectively. Among HIV-infected participants, 87.1% were receiving antiretroviral therapy (ART), their median CD4+ cell count was 468 cells/μl and 84.3% had undetectable viral load. Both biomarkers were validated against chronological age in HIV-seronegative individuals. Telomere length was significantly shorter in HIV-infected individuals than in HIV-seronegative individuals (mean relative T/S ratio ±SE:0.91 ± 0.007 vs. 1.07 ± 0.008, P < 0.0001). CD2NKA expression was higher in HIV-infected participants than in HIV-seronegative individuals (mean expression: 0.45 ± 0.02 vs. 0.36 ± 0.03, P = 0.003). Socioeconomic factors were not associated with biological ageing in HIV-infected participants. However, in participants on ART with undetectable viral load, biomarker levels indicated greater biological ageing in those with lower current CD4+ cell counts. Conclusion: Telomere length and CDKN2A expression were both consistent with increased biological ageing in HIV-infected individuals. Prospective studies of the impact of HIV on biological ageing in sub-Saharan Africa are warranted. PMID:23751258

PomBase: The Scientific Resource for Fission Yeast.

PubMed

Lock, Antonia; Rutherford, Kim; Harris, Midori A; Wood, Valerie

2018-01-01

The fission yeast Schizosaccharomyces pombe has become well established as a model species for studying conserved cell-level biological processes, especially the mechanics and regulation of cell division. PomBase integrates the S. pombe genome sequence with traditional genetic, molecular, and cell biological experimental data as well as the growing body of large datasets generated by emerging high-throughput methods. This chapter provides insight into the curation philosophy and data organization at PomBase, and provides a guide to using PomBase for infrequent visitors and anyone considering exploring S. pombe in their research.

Characterization of cell cultures in contact with different orthopedic implants biomaterials

NASA Astrophysics Data System (ADS)

Ouenzerfi, G.; Hannoun, A.; Hassler, M.; Brizuela, L.; Youjil, S.; Bougault, C.; Trunfio-Sfarghiu, A.-M.

2016-08-01

The aim of this study is to identify the role of biological and mechanical constraints (at the cellular level) surrounding living tissues (cartilage and bone) in the presence of different joint implant biomaterials. In this fact, cells cultures in the presence of different types of biomaterials (pyrolytic carbon, cobalt-Chromium, titanium) has been performed. These cell cultures were subjected to biological characterization tests and mechanical characterization. The obtained results correlate with the in vivo observations (a promotion of the creation of a neocartilagical tissue in contact with the Pyrolytic Carbon implants).

Hematopoiesis: an evolving paradigm for stem cell biology.

PubMed

Orkin, Stuart H; Zon, Leonard I

2008-02-22

Establishment and maintenance of the blood system relies on self-renewing hematopoietic stem cells (HSCs) that normally reside in small numbers in the bone marrow niche of adult mammals. This Review describes the developmental origins of HSCs and the molecular mechanisms that regulate lineage-specific differentiation. Studies of hematopoiesis provide critical insights of general relevance to other areas of stem cell biology including the role of cellular interactions in development and tissue homeostasis, lineage programming and reprogramming by transcription factors, and stage- and age-specific differences in cellular phenotypes.

Cell Models and Their Application for Studying Adipogenic Differentiation in Relation to Obesity: A Review

PubMed Central

Ruiz-Ojeda, Francisco Javier; Rupérez, Azahara Iris; Gomez-Llorente, Carolina; Gil, Angel; Aguilera, Concepción María

2016-01-01

Over the last several years, the increasing prevalence of obesity has favored an intense study of adipose tissue biology and the precise mechanisms involved in adipocyte differentiation and adipogenesis. Adipocyte commitment and differentiation are complex processes, which can be investigated thanks to the development of diverse in vitro cell models and molecular biology techniques that allow for a better understanding of adipogenesis and adipocyte dysfunction associated with obesity. The aim of the present work was to update the different animal and human cell culture models available for studying the in vitro adipogenic differentiation process related to obesity and its co-morbidities. The main characteristics, new protocols, and applications of the cell models used to study the adipogenesis in the last five years have been extensively revised. Moreover, we depict co-cultures and three-dimensional cultures, given their utility to understand the connections between adipocytes and their surrounding cells in adipose tissue. PMID:27376273

Energy of adhesion of human T cells to adsorption layers of monoclonal antibodies measured by a film trapping technique.

PubMed Central

Ivanov, I B; Hadjiiski, A; Denkov, N D; Gurkov, T D; Kralchevsky, P A; Koyasu, S

1998-01-01

A novel method for studying the interaction of biological cells with interfaces (e.g., adsorption monolayers of antibodies) is developed. The method is called the film trapping technique because the cell is trapped within an aqueous film of equilibrium thickness smaller than the cell diameter. A liquid film of uneven thickness is formed around the trapped cell. When observed in reflected monochromatic light, this film exhibits an interference pattern of concentric bright and dark fringes. From the radii of the fringes one can restore the shape of interfaces and the cell. Furthermore, one can calculate the adhesive energy between the cell membrane and the aqueous film surface (which is covered by a layer of adsorbed proteins and/or specific ligands), as well as the disjoining pressure, representing the force of interaction per unit area of the latter film. The method is applied to two human T cell lines: Jurkat and its T cell receptor negative (TCR-) derivative. The interaction of these cells with monolayers of three different monoclonal antibodies adsorbed at a water-air interface is studied. The results show that the adhesive energy is considerable (above 0.5 mJ/m2) when the adsorption monolayer contains antibodies acting as specific ligands for the receptors expressed on the cell surface. In contrast, the adhesive energy is close to zero in the absence of such a specific ligand-receptor interaction. In principle, the method can be applied to the study of the interaction of a variety of biological cells (B cells, natural killer cells, red blood cells, etc.) with adsorption monolayers of various biologically active molecules. In particular, film trapping provides a tool for the gentle micromanipulation of cells and for monitoring of processes (say the activation of a T lymphocyte) occurring at the single-cell level. PMID:9649417

Biological and mechanical evaluation of a Bio-Hybrid scaffold for autologous valve tissue engineering.

PubMed

Jahnavi, S; Saravanan, U; Arthi, N; Bhuvaneshwar, G S; Kumary, T V; Rajan, S; Verma, R S

2017-04-01

Major challenge in heart valve tissue engineering for paediatric patients is the development of an autologous valve with regenerative capacity. Hybrid tissue engineering approach is recently gaining popularity to design scaffolds with desired biological and mechanical properties that can remodel post implantation. In this study, we fabricated aligned nanofibrous Bio-Hybrid scaffold made of decellularized bovine pericardium: polycaprolactone-chitosan with optimized polymer thickness to yield the desired biological and mechanical properties. CD44 + , αSMA + , Vimentin + and CD105 - human valve interstitial cells were isolated and seeded on these Bio-Hybrid scaffolds. Subsequent biological evaluation revealed interstitial cell proliferation with dense extra cellular matrix deposition that indicated the viability for growth and proliferation of seeded cells on the scaffolds. Uniaxial mechanical tests along axial direction showed that the Bio-Hybrid scaffolds has at least 20 times the strength of the native valves and its stiffness is nearly 3 times more than that of native valves. Biaxial and uniaxial mechanical studies on valve interstitial cells cultured Bio-Hybrid scaffolds revealed that the response along the axial and circumferential direction was different, similar to native valves. Overall, our findings suggest that Bio-Hybrid scaffold is a promising material for future development of regenerative heart valve constructs in children. Copyright © 2016 Elsevier B.V. All rights reserved.

The biological safety of condom material can be determined using an in vitro cell culture system.

PubMed

Motsoane, N A; Pretorius, E; Bester, M J; Becker, P J

2001-01-01

Latex products have long been recognized as a cause of latex protein allergy. The increased usage of latex gloves, with the consequent increased occurrence of latex allergies appears to have escalated with increasing awareness of the transmission of HIV-AIDS and other infections. The use of condoms as a means to prevent the transmission of STD's (sexually transmitted diseases) and HIV-AIDS has been widely promoted. Although extensive testing is done to evaluate the physical quality of condoms, no information is available regarding the biological safety of condoms. This study was undertaken to determine the effects of short-term exposure to physiological levels of condom surface material on cell viability (MTT assay) and cell growth (crystal violet assay). A direct contact cell culture testing method (FDA test method F813-83 used to evaluate the cytotoxic potential of medical materials and devices) was used. The modified test method was found to be a sensitive test system for the evaluation of the biological safety of condoms. This study reveals the importance of evaluating the biological safety of all condoms that are commercially available, because of the potential health risk that may be associated with prolonged use of certain types of condoms.

Biologically active and biomimetic dual gelatin scaffolds for tissue engineering.

PubMed

Sánchez, P; Pedraz, J L; Orive, G

2017-05-01

We have designed, developed and optimized Genipin cross-linked 3D gelatin scaffolds that were biologically active and biomimetic, show a dual activity both for growth factor and cell delivery. Type B gelatin powder was dissolved in DI water. 100mg of genipin was dissolved in 10ml of DI water. Three genipin concentrations were prepared: 0.1%, 0.2% and 0.3% (w/v). Solutions were mixed at 40°C and under stirring and then left crosslinking for 72h. Scaffolds were obtained by punching 8 mm-cylinders into ethanol 70% solution for 10min and then freeze-drying. Scaffolds were biologically, biomechanically and morphologically evaluated. Cell adhesion and morphology of D1-Mesenchymal stem cells (MSCs) and L-929 fibroblast was studied. Vascular endothelial grwoth factor (VEGF) and Sonic hedgehog (SHH) were used as model proteins. Swelling ratio increased and younǵs module decreased along with the concentration of genipin. All scaffolds were biocompatible according to the toxicity test. MSC and L-929 cell adhesion improved in 0.2% of genipin, obtaining better results with MSCs. VEGF and SHH were released from the gels. This preliminary study suggest that the biologically active and dual gelatin scaffolds may be used for tissue engineering approaches like bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Ovary and fimbrial stem cells: biology, niche and cancer origins.

PubMed

Ng, Annie; Barker, Nick

2015-10-01

The mammalian ovary is covered by a single-layered epithelium that undergoes rupture and remodelling following each ovulation. Although resident stem cells are presumed to be crucial for this cyclic regeneration, their identity and mode of action have been elusive. Surrogate stemness assays and in vivo fate-mapping studies using recently discovered stem cell markers have identified stem cell pools in the ovary and fimbria that ensure epithelial homeostasis. Recent findings provide insights into intrinsic mechanisms and local extrinsic cues that govern the function of ovarian and fimbrial stem cells. These discoveries have advanced our understanding of stem cell biology in the ovary and fimbria, and lay the foundations for evaluating the contribution of resident stem cells to the initiation and progression of human epithelial ovarian cancer.

UV fluorescence excitation spectroscopy as a non-invasive predictor of epidermal proliferation and clinical performance of cosmetic formulations

NASA Astrophysics Data System (ADS)

Maidhof, Robert; Liebel, Frank; Hwang, Cheng; Ruvolo, Eduardo; Lyga, John

2017-02-01

The epidermis is the outermost layer of skin and is composed of cells primarily containing keratin. It consists of about ten layers of living cells (keratinocytes) and ten layers of dead cells (corneocytes). These cells are continually shed from the outside and replaced from the inside in a process called desquamation which is controlled by two biological events - proliferation and differentiation. One method to non-invasively study biological changes in the skin is using fluorescence excitation spectroscopy. Several characteristic excitation-emission peaks occur in skin that have been related to the epidermal and dermal composition. The magnitude of the peak that occurs at 295nm excitation (F295) has been linked to changes in skin proliferation, cell turnover, epidermal thickening, and skin aging. We hypothesize that changes in this fluorescent signal could be used to assess the potential activity of cosmetic anti-aging compounds to deliver a benefit to skin. Previous work with retinol and glycolic acid, two commonly used actives that effect epidermal proliferation and exfoliation, has demonstrated an increase in F295 (attributed to tryptophan excitation fluorescence). In this study we present the results of a placebo controlled study that aims to correlate changes in F295 with biological performance (epidermal thickening and Ki67 expression).

Long noncoding RNA, tissue differentiation-inducing nonprotein coding RNA is upregulated and promotes development of esophageal squamous cell carcinoma.

PubMed

Xu, Y; Qiu, M; Chen, Y; Wang, J; Xia, W; Mao, Q; Yang, L; Li, M; Jiang, F; Xu, L; Yin, R

2016-11-01

Esophageal squamous cell carcinoma (ESCC) is one of the major causes of cancer death worldwide, especially in Eastern Asia. Due to the poor prognosis, it is necessary to further dissect the underlying mechanisms and explore therapeutic targets of ESCC. Recently, studies show that long noncoding RNAs (lncRNAs) have critical roles in diverse biological processes, including tumorigenesis. Increasing evidence indicates that some lncRNAs are widely involved in the development and progression of ESCC, such as HOTAIR, SPRY4-IT1 and POU3F3. An emerging lncRNA, tissue differentiation-inducing nonprotein coding RNA (TINCR), has been studied in human cutaneous squamous cell carcinoma and has critical biological function, but its role in ESCC remains unknown. Here, we evaluated the expression profile of TINCR and its biological function in ESCC. In a cohort of 56 patients, TINCR was significantly overexpressed in ESCC tissues compared with paired adjacent normal tissues. Further, in vitro silencing TINCR via small interfering RNA (siRNA) inhibited the proliferation, migration and invasion of ESCC cells. Meantime, siRNA treatment induced apoptosis and blocked the progression of cell cycle. Taken together, our study suggests that TINCR promotes proliferation, migration and invasion of ESCC cells, acting as a potential oncogene of ESCC. © 2016 International Society for Diseases of the Esophagus.

Comparative Study of the Biological Activity of Allantoin and Aqueous Extract of the Comfrey Root.

PubMed

Savić, Vesna Lj; Nikolić, Vesna D; Arsić, Ivana A; Stanojević, Ljiljana P; Najman, Stevo J; Stojanović, Sanja; Mladenović-Ranisavljević, Ivana I

2015-08-01

This study investigates the biological activity of pure allantoin (PA) and aqueous extract of the comfrey (Symphytum officinale L.) root (AECR) standardized to the allantoin content. Cell viability and proliferation of epithelial (MDCK) and fibroblastic (L929) cell line were studied by using MTT test. Anti-irritant potential was determined by measuring electrical capacitance, erythema index (EI) and transepidermal water loss of artificially irritated skin of young healthy volunteers, 3 and 7 days after application of creams and gels with PA or AECR. Pure allantoin showed mild inhibitory effect on proliferation of both cell lines at concentrations 40 and 100 µg/ml, but more pronounced on MDCK cells. Aqueous extract of the comfrey root effect on cell proliferation in concentrations higher than 40 µg/ml was significantly stimulatory for L929 but inhibitory for MDCK cells. Pharmaceutical preparations that contained AECR showed better anti-irritant potential compared with PA. Creams showed better effect on hydration and EI compared with the gels that contained the same components. Our results indicate that the biological activity of the comfrey root extract cannot be attributed only to allantoin but is also likely the result of the interaction of different compounds present in AECR. Topical preparations that contain comfrey extract may have a great application in the treatment of skin irritation. Copyright © 2015 John Wiley & Sons, Ltd.

Analysis of biological effects in human endothelial cells after stimulated microgravity

NASA Astrophysics Data System (ADS)

Min, Zhang; Sun, Yeqing; Xu, Dan

Space environment is characterized by strong radiation, ultra-high vacuum, weak magnetic field and microgravity. Among them, microgravity (10-4-10-6g) in space is different from gravity (1g) on earth, possibly causing visual disorders, muscle alterations, bone loss and dysfunction of cardiovascular systems. To study about microgravity environment, the most advanced rotary cell culture system (RCCS-1) was used to do stimulated microgravity (SMG) experiments in the ground. Up to now, most of studies focus on the biological effects under stimulated microgravity, but it is less known about the cellular response after stimulated microgravity. In the present study, we explored the subsequent effects of stimulated microgravity on human endothelial cells (HUVEC-C) after these cells were cultured on RCCS-1 for 48 hours. We co-cultured HUVEC-C cells with Hillex-microcarriers in 60-mm culture dishes for 24h, followed by transferring them to RCCS-1 so that cells remain to be the state of SMG. In parallel, HUVEC-C cells were co-cultured with microcarriers in the ground condition. We found that stimulated microgravity induced cytoskeleton remodeling, cell cycle G2/M arrest and cellular senescence, consistent with previous reports. To study the subsequent effects of stimulated microgravity, we make cells detach from microcarriers and observed various effects including cell growth, cell adhesion, cytoskeleton, cell cycle, apoptosis and senescence. The results showed that those cells undergoing stimulated microgravity appeared obvious growth inhibition, a transition from the decrease in cell adhesion ability and cytoskeleton remodeling within 24h to induction of apoptosis and senescence-like phenotype in the later time with slight changes in cell cycle. Analysis of protein expression in western blot demonstrated that apoptosis-related protein PTEN was up-regulated on the time-dependent pattern after stimulated microgravity, indicating that PTEN-PI3K-Akt pathway might play an important role in apoptosis. Our study suggests that stimulated microgravity has the subsequent biological effects of HUVEC-C, providing new insight of understanding the global effect of microgravity on cellular response in human endothelial cells.

9 CFR 113.51 - Requirements for primary cells used for production of biologics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Requirements for primary cells used... VECTORS STANDARD REQUIREMENTS Ingredient Requirements § 113.51 Requirements for primary cells used for production of biologics. Primary cells used to prepare biological products shall be derived from normal...

9 CFR 113.51 - Requirements for primary cells used for production of biologics.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Requirements for primary cells used... VECTORS STANDARD REQUIREMENTS Ingredient Requirements § 113.51 Requirements for primary cells used for production of biologics. Primary cells used to prepare biological products shall be derived from normal...

9 CFR 113.51 - Requirements for primary cells used for production of biologics.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Requirements for primary cells used... VECTORS STANDARD REQUIREMENTS Ingredient Requirements § 113.51 Requirements for primary cells used for production of biologics. Primary cells used to prepare biological products shall be derived from normal...

9 CFR 113.51 - Requirements for primary cells used for production of biologics.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Requirements for primary cells used... VECTORS STANDARD REQUIREMENTS Ingredient Requirements § 113.51 Requirements for primary cells used for production of biologics. Primary cells used to prepare biological products shall be derived from normal...

9 CFR 113.51 - Requirements for primary cells used for production of biologics.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Requirements for primary cells used... VECTORS STANDARD REQUIREMENTS Ingredient Requirements § 113.51 Requirements for primary cells used for production of biologics. Primary cells used to prepare biological products shall be derived from normal...

A Network Biology Approach Identifies Molecular Cross-Talk between Normal Prostate Epithelial and Prostate Carcinoma Cells

PubMed Central

Trevino, Victor; Cassese, Alberto; Nagy, Zsuzsanna; Zhuang, Xiaodong; Herbert, John; Antzack, Philipp; Clarke, Kim; Davies, Nicholas; Rahman, Ayesha; Campbell, Moray J.; Bicknell, Roy; Vannucci, Marina; Falciani, Francesco

2016-01-01

Abstract The advent of functional genomics has enabled the genome-wide characterization of the molecular state of cells and tissues, virtually at every level of biological organization. The difficulty in organizing and mining this unprecedented amount of information has stimulated the development of computational methods designed to infer the underlying structure of regulatory networks from observational data. These important developments had a profound impact in biological sciences since they triggered the development of a novel data-driven investigative approach. In cancer research, this strategy has been particularly successful. It has contributed to the identification of novel biomarkers, to a better characterization of disease heterogeneity and to a more in depth understanding of cancer pathophysiology. However, so far these approaches have not explicitly addressed the challenge of identifying networks representing the interaction of different cell types in a complex tissue. Since these interactions represent an essential part of the biology of both diseased and healthy tissues, it is of paramount importance that this challenge is addressed. Here we report the definition of a network reverse engineering strategy designed to infer directional signals linking adjacent cell types within a complex tissue. The application of this inference strategy to prostate cancer genome-wide expression profiling data validated the approach and revealed that normal epithelial cells exert an anti-tumour activity on prostate carcinoma cells. Moreover, by using a Bayesian hierarchical model integrating genetics and gene expression data and combining this with survival analysis, we show that the expression of putative cell communication genes related to focal adhesion and secretion is affected by epistatic gene copy number variation and it is predictive of patient survival. Ultimately, this study represents a generalizable approach to the challenge of deciphering cell communication networks in a wide spectrum of biological systems. PMID:27124473

A Network Biology Approach Identifies Molecular Cross-Talk between Normal Prostate Epithelial and Prostate Carcinoma Cells.

PubMed

Trevino, Victor; Cassese, Alberto; Nagy, Zsuzsanna; Zhuang, Xiaodong; Herbert, John; Antczak, Philipp; Clarke, Kim; Davies, Nicholas; Rahman, Ayesha; Campbell, Moray J; Guindani, Michele; Bicknell, Roy; Vannucci, Marina; Falciani, Francesco

2016-04-01

The advent of functional genomics has enabled the genome-wide characterization of the molecular state of cells and tissues, virtually at every level of biological organization. The difficulty in organizing and mining this unprecedented amount of information has stimulated the development of computational methods designed to infer the underlying structure of regulatory networks from observational data. These important developments had a profound impact in biological sciences since they triggered the development of a novel data-driven investigative approach. In cancer research, this strategy has been particularly successful. It has contributed to the identification of novel biomarkers, to a better characterization of disease heterogeneity and to a more in depth understanding of cancer pathophysiology. However, so far these approaches have not explicitly addressed the challenge of identifying networks representing the interaction of different cell types in a complex tissue. Since these interactions represent an essential part of the biology of both diseased and healthy tissues, it is of paramount importance that this challenge is addressed. Here we report the definition of a network reverse engineering strategy designed to infer directional signals linking adjacent cell types within a complex tissue. The application of this inference strategy to prostate cancer genome-wide expression profiling data validated the approach and revealed that normal epithelial cells exert an anti-tumour activity on prostate carcinoma cells. Moreover, by using a Bayesian hierarchical model integrating genetics and gene expression data and combining this with survival analysis, we show that the expression of putative cell communication genes related to focal adhesion and secretion is affected by epistatic gene copy number variation and it is predictive of patient survival. Ultimately, this study represents a generalizable approach to the challenge of deciphering cell communication networks in a wide spectrum of biological systems.

ABCG2-overexpressing S1-M1-80 cell xenografts in nude mice keep original biochemistry and cell biological properties.

PubMed

Wang, Fang; Liang, Yong-Ju; Wu, Xing-Ping; Su, Xiao-Dong; Fu, Li-Wu

2012-03-01

S1-M1-80 cells, derived from human colon carcinoma S1 cells, are mitoxantrone-selected ABCG2-overexpressing cells and are widely used in in vitro studies of multidrug resistance(MDR). In this study, S1-M1-80 cell xenografts were established to investigate whether the MDR phenotype and cell biological properties were maintained in vivo. Our results showed that the proliferation, cell cycle, and ABCG2 expression level in S1-M1-80 cells were similar to those in cells isolated from S1-M1-80 cell xenografts (named xS1-M1-80 cells). Consistently, xS1-M1-80 cells exhibited high levels of resistance to ABCG2 substrates such as mitoxantrone and topotecan, but remained sensitive to the non-ABCG2 substrate cisplatin. Furthermore, the specific ABCG2 inhibitor Ko143 potently sensitized xS1-M1-80 cells to mitoxantrone and topotecan. These results suggest that S1-M1-80 cell xenografts in nude mice retain their original cytological characteristics at 9 weeks. Thus, this model could serve as a good system for further investigation of ABCG2-mediated MDR.

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

PubMed Central

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

2016-01-01

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

Commander Lousma works with EEVT experiment on aft middeck

NASA Image and Video Library

1982-03-31

S82-28911 (March 1982) --- The L-shaped experiment in the right half of this photo was one of a number of scientific experiments which made the trip for NASA's third space transportation system (STS-3) mission, along with astronauts Jack R. Lousma, pictured, and C. Gordon Fullerton. The experiment, making encore in space (it also flew on the Apollo Soyuz Test Project in 1985), is designed to evaluate the feasibility of separating cells according to their surface electrical charge. It is a forerunner to planned experiments with other equipment that will purify biological materials in the low gravity environment of space. The process of electrophoresis utilizes an electric field to separate cells, and other biological material in fluids without damaging the cells which can then be used in the study of cell biology, immunology and medical research. This photograph was taken with a 35mm camera by Fullerton. Photo credit: NASA

Controllability and observability of Boolean networks arising from biology

NASA Astrophysics Data System (ADS)

Li, Rui; Yang, Meng; Chu, Tianguang

2015-02-01

Boolean networks are currently receiving considerable attention as a computational scheme for system level analysis and modeling of biological systems. Studying control-related problems in Boolean networks may reveal new insights into the intrinsic control in complex biological systems and enable us to develop strategies for manipulating biological systems using exogenous inputs. This paper considers controllability and observability of Boolean biological networks. We propose a new approach, which draws from the rich theory of symbolic computation, to solve the problems. Consequently, simple necessary and sufficient conditions for reachability, controllability, and observability are obtained, and algorithmic tests for controllability and observability which are based on the Gröbner basis method are presented. As practical applications, we apply the proposed approach to several different biological systems, namely, the mammalian cell-cycle network, the T-cell activation network, the large granular lymphocyte survival signaling network, and the Drosophila segment polarity network, gaining novel insights into the control and/or monitoring of the specific biological systems.

Intracellular subsurface imaging using a hybrid shear-force feedback/scanning quantitative phase microscopy technique

NASA Astrophysics Data System (ADS)

Edward, Kert

Quantitative phase microscopy (QPM) allows for the imaging of translucent or transparent biological specimens without the need for exogenous contrast agents. This technique is usually applied towards the investigation of simple cells such as red blood cells which are typically enucleated and can be considered to be homogenous. However, most biological cells are nucleated and contain other interesting intracellular organelles. It has been established that the physical characteristics of certain subsurface structures such as the shape and roughness of the nucleus is well correlated with onset and progress of pathological conditions such as cancer. Although the acquired quantitative phase information of biological cells contains surface information as well as coupled subsurface information, the latter has been ignored up until now. A novel scanning quantitative phase imaging system unencumbered by 2pi ambiguities is hereby presented. This system is incorporated into a shear-force feedback scheme which allows for simultaneous phase and topography determination. It will be shown how subsequent image processing of these two data sets allows for the extraction of the subsurface component in the phase data and in vivo cell refractometry studies. Both fabricated samples and biological cells ranging from rat fibroblast cells to malaria infected human erythrocytes were investigated as part of this research. The results correlate quite well with that obtained via other microscopy techniques.

Biological and mechanical interplay at the Macro- and Microscales Modulates the Cell-Niche Fate.

PubMed

Sarig, Udi; Sarig, Hadar; Gora, Aleksander; Krishnamoorthi, Muthu Kumar; Au-Yeung, Gigi Chi Ting; de-Berardinis, Elio; Chaw, Su Yin; Mhaisalkar, Priyadarshini; Bogireddi, Hanumakumar; Ramakrishna, Seeram; Boey, Freddy Yin Chiang; Venkatraman, Subbu S; Machluf, Marcelle

2018-03-02

Tissue development, regeneration, or de-novo tissue engineering in-vitro, are based on reciprocal cell-niche interactions. Early tissue formation mechanisms, however, remain largely unknown given complex in-vivo multifactoriality, and limited tools to effectively characterize and correlate specific micro-scaled bio-mechanical interplay. We developed a unique model system, based on decellularized porcine cardiac extracellular matrices (pcECMs)-as representative natural soft-tissue biomaterial-to study a spectrum of common cell-niche interactions. Model monocultures and 1:1 co-cultures on the pcECM of human umbilical vein endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) were mechano-biologically characterized using macro- (Instron), and micro- (AFM) mechanical testing, histology, SEM and molecular biology aspects using RT-PCR arrays. The obtained data was analyzed using developed statistics, principal component and gene-set analyses tools. Our results indicated biomechanical cell-type dependency, bi-modal elasticity distributions at the micron cell-ECM interaction level, and corresponding differing gene expression profiles. We further show that hMSCs remodel the ECM, HUVECs enable ECM tissue-specific recognition, and their co-cultures synergistically contribute to tissue integration-mimicking conserved developmental pathways. We also suggest novel quantifiable measures as indicators of tissue assembly and integration. This work may benefit basic and translational research in materials science, developmental biology, tissue engineering, regenerative medicine and cancer biomechanics.

Nanotechnology in the regulation of stem cell behavior

NASA Astrophysics Data System (ADS)

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

2013-10-01

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

Modelling the collective response of heterogeneous cell populations to stationary gradients and chemical signal relay

NASA Astrophysics Data System (ADS)

Pineda, M.; Eftimie, R.

2017-12-01

The directed motion of cell aggregates toward a chemical source occurs in many relevant biological processes. Understanding the mechanisms that control this complex behavior is of great relevance for our understanding of developmental biological processes and many diseases. In this paper, we consider a self-propelled particle model for the movement of heterogeneous subpopulations of chemically interacting cells towards an imposed stable chemical gradient. Our simulations show explicitly how self-organisation of cell populations (which could lead to engulfment or complete cell segregation) can arise from the heterogeneity of chemotactic responses alone. This new result complements current theoretical and experimental studies that emphasise the role of differential cell-cell adhesion on self-organisation and spatial structure of cellular aggregates. We also investigate how the speed of individual cell aggregations increases with the chemotactic sensitivity of the cells, and decreases with the number of cells inside the aggregates

Neural Stem Cells (NSCs) and Proteomics.

PubMed

Shoemaker, Lorelei D; Kornblum, Harley I

2016-02-01

Neural stem cells (NSCs) can self-renew and give rise to the major cell types of the CNS. Studies of NSCs include the investigation of primary, CNS-derived cells as well as animal and human embryonic stem cell (ESC)-derived and induced pluripotent stem cell (iPSC)-derived sources. NSCs provide a means with which to study normal neural development, neurodegeneration, and neurological disease and are clinically relevant sources for cellular repair to the damaged and diseased CNS. Proteomics studies of NSCs have the potential to delineate molecules and pathways critical for NSC biology and the means by which NSCs can participate in neural repair. In this review, we provide a background to NSC biology, including the means to obtain them and the caveats to these processes. We then focus on advances in the proteomic interrogation of NSCs. This includes the analysis of posttranslational modifications (PTMs); approaches to analyzing different proteomic compartments, such the secretome; as well as approaches to analyzing temporal differences in the proteome to elucidate mechanisms of differentiation. We also discuss some of the methods that will undoubtedly be useful in the investigation of NSCs but which have not yet been applied to the field. While many proteomics studies of NSCs have largely catalogued the proteome or posttranslational modifications of specific cellular states, without delving into specific functions, some have led to understandings of functional processes or identified markers that could not have been identified via other means. Many challenges remain in the field, including the precise identification and standardization of NSCs used for proteomic analyses, as well as how to translate fundamental proteomics studies to functional biology. The next level of investigation will require interdisciplinary approaches, combining the skills of those interested in the biochemistry of proteomics with those interested in modulating NSC function. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The informational architecture of the cell.

PubMed

Walker, Sara Imari; Kim, Hyunju; Davies, Paul C W

2016-03-13

We compare the informational architecture of biological and random networks to identify informational features that may distinguish biological networks from random. The study presented here focuses on the Boolean network model for regulation of the cell cycle of the fission yeast Schizosaccharomyces pombe. We compare calculated values of local and global information measures for the fission yeast cell cycle to the same measures as applied to two different classes of random networks: Erdös-Rényi and scale-free. We report patterns in local information processing and storage that do indeed distinguish biological from random, associated with control nodes that regulate the function of the fission yeast cell-cycle network. Conversely, we find that integrated information, which serves as a global measure of 'emergent' information processing, does not differ from random for the case presented. We discuss implications for our understanding of the informational architecture of the fission yeast cell-cycle network in particular, and more generally for illuminating any distinctive physics that may be operative in life. © 2016 The Author(s).

The technology and biology of single-cell RNA sequencing.

PubMed

Kolodziejczyk, Aleksandra A; Kim, Jong Kyoung; Svensson, Valentine; Marioni, John C; Teichmann, Sarah A

2015-05-21

The differences between individual cells can have profound functional consequences, in both unicellular and multicellular organisms. Recently developed single-cell mRNA-sequencing methods enable unbiased, high-throughput, and high-resolution transcriptomic analysis of individual cells. This provides an additional dimension to transcriptomic information relative to traditional methods that profile bulk populations of cells. Already, single-cell RNA-sequencing methods have revealed new biology in terms of the composition of tissues, the dynamics of transcription, and the regulatory relationships between genes. Rapid technological developments at the level of cell capture, phenotyping, molecular biology, and bioinformatics promise an exciting future with numerous biological and medical applications. Copyright © 2015 Elsevier Inc. All rights reserved.

FACS-based Isolation of Neural and Glioma Stem Cell Populations from Fresh Human Tissues Utilizing EGF Ligand

PubMed Central

Tome-Garcia, Jessica; Doetsch, Fiona; Tsankova, Nadejda M.

2018-01-01

Direct isolation of human neural and glioma stem cells from fresh tissues permits their biological study without prior culture and may capture novel aspects of their molecular phenotype in their native state. Recently, we demonstrated the ability to prospectively isolate stem cell populations from fresh human germinal matrix and glioblastoma samples, exploiting the ability of cells to bind the Epidermal Growth Factor (EGF) ligand in fluorescence-activated cell sorting (FACS). We demonstrated that FACS-isolated EGF-bound neural and glioblastoma populations encompass the sphere-forming colonies in vitro, and are capable of both self-renewal and multilineage differentiation. Here we describe in detail the purification methodology of EGF-bound (i.e., EGFR+) human neural and glioma cells with stem cell properties from fresh postmortem and surgical tissues. The ability to prospectively isolate stem cell populations using native ligand-binding ability opens new doors for understanding both normal and tumor cell biology in uncultured conditions, and is applicable for various downstream molecular sequencing studies at both population and single-cell resolution. PMID:29516026

Molecular Pharmacology of Malignant Pleural Mesothelioma: Challenges and Perspectives From Preclinical and Clinical Studies.

PubMed

Thellung, Stefano; Favoni, Roberto E; Würth, Roberto; Nizzari, Mario; Pattarozzi, Alessandra; Daga, Antonio; Florio, Tullio; Barbieri, Federica

2016-01-01

Malignant pleural mesothelioma (MPM) is one of the deadliest and most heterogeneous tumors, highly refractory to multimodal therapeutic approach, including surgery, chemo- and radiotherapy. Preclinical and clinical studies exploring the efficacy of drugs targeting tyrosine kinases, angiogenesis and histone deacetylases, did not fulfil the expected clinical benefits. Thus, novel molecular targets should be identified from a definite knowledge of the unique biology and most relevant transduction pathways of MPM cells. Cancer stem cells (CSCs) are a subset of malignant precursors responsible for initiation, progression, resistance to cytotoxic drugs, recurrence and metastatic diffusion of tumor cells. CSCs are putative driving factors for MPM development and contribute to its clinical and biological heterogeneity; hence, targeted eradication of CSCs represents an ineludible goal to counteract MPM aggressiveness. In this context, innovative preclinical models could be exploited to identify novel intracellular pathway inhibitors able to target CSC viability. Novel drug targets have been identified among key factors responsible for the oncogenic transformation of mesothelial cells, often directly induced by asbestos. These include mitogenic and anti-apoptotic signaling that may also be activated by autocrine and paracrine cytokine pathways controlling cell plasticity. Both signaling pathways affecting proto-oncogene and transcription factor expression, or genetic and epigenetic alterations, such as mutations in cell cycle genes and silencing of tumor suppressor genes, represent promising disease-specific targets. In this review we describe current knowledge of MPM cell biology, focusing on potential targets to be tested in pharmacological studies, and highlighting results and challenges of clinical translation.

Investigating the role of retinal Müller cells with approaches in genetics and cell biology.

PubMed

Fu, Suhua; Zhu, Meili; Ash, John D; Wang, Yunchang; Le, Yun-Zheng

2014-01-01

Müller cells are major macroglia and play many essential roles as a supporting cell in the retina. As Müller cells only constitute a small portion of retinal cells, investigating the role of Müller glia in retinal biology and diseases is particularly challenging. To overcome this problem, we first generated a Cre/lox-based conditional gene targeting system that permits the genetic manipulation and functional dissection of gene of interests in Müller cells. To investigate diabetes-induced alteration of Müller cells, we recently adopted methods to analyze Müller cells survival/death in vitro and in vivo. We also used normal and genetically altered primary cell cultures to reveal the mechanistic insights for Müller cells in biological and disease processes. In this article, we will discuss the applications and limitations of these methodologies, which may be useful for research in retinal Müller cell biology and pathophysiology.

Interplay of migratory and division forces as a generic mechanism for stem cell patterns

NASA Astrophysics Data System (ADS)

Hannezo, Edouard; Coucke, Alice; Joanny, Jean-François

2016-02-01

In many adult tissues, stem cells and differentiated cells are not homogeneously distributed: stem cells are arranged in periodic "niches," and differentiated cells are constantly produced and migrate out of these niches. In this article, we provide a general theoretical framework to study mixtures of dividing and actively migrating particles, which we apply to biological tissues. We show in particular that the interplay between the stresses arising from active cell migration and stem cell division give rise to robust stem cell patterns. The instability of the tissue leads to spatial patterns which are either steady or oscillating in time. The wavelength of the instability has an order of magnitude consistent with the biological observations. We also discuss the implications of these results for future in vitro and in vivo experiments.

76 FR 53479 - Center for Scientific Review; Notice of Closed Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

...; Community-Level Health Promotion Study Section. Date: September 26-27, 2011. Time: 8:30 a.m. to 5 p.m...: Center for Scientific Review Special Emphasis Panel; Member Conflict: Cancer Biology and Genetics. Date....gov . Name of Committee: Cell Biology Integrated Review Group; Development--2 Study Section. Date...

Fundamentals of microfluidic cell culture in controlled microenvironments†

PubMed Central

Young, Edmond W. K.; Beebe, David J.

2010-01-01

Microfluidics has the potential to revolutionize the way we approach cell biology research. The dimensions of microfluidic channels are well suited to the physical scale of biological cells, and the many advantages of microfluidics make it an attractive platform for new techniques in biology. One of the key benefits of microfluidics for basic biology is the ability to control parameters of the cell microenvironment at relevant length and time scales. Considerable progress has been made in the design and use of novel microfluidic devices for culturing cells and for subsequent treatment and analysis. With the recent pace of scientific discovery, it is becoming increasingly important to evaluate existing tools and techniques, and to synthesize fundamental concepts that would further improve the efficiency of biological research at the microscale. This tutorial review integrates fundamental principles from cell biology and local microenvironments with cell culture techniques and concepts in microfluidics. Culturing cells in microscale environments requires knowledge of multiple disciplines including physics, biochemistry, and engineering. We discuss basic concepts related to the physical and biochemical microenvironments of the cell, physicochemical properties of that microenvironment, cell culture techniques, and practical knowledge of microfluidic device design and operation. We also discuss the most recent advances in microfluidic cell culture and their implications on the future of the field. The goal is to guide new and interested researchers to the important areas and challenges facing the scientific community as we strive toward full integration of microfluidics with biology. PMID:20179823

Fractal avalanche ruptures in biological membranes

NASA Astrophysics Data System (ADS)

Gözen, Irep; Dommersnes, Paul; Czolkos, Ilja; Jesorka, Aldo; Lobovkina, Tatsiana; Orwar, Owe

2010-11-01

Bilayer membranes envelope cells as well as organelles, and constitute the most ubiquitous biological material found in all branches of the phylogenetic tree. Cell membrane rupture is an important biological process, and substantial rupture rates are found in skeletal and cardiac muscle cells under a mechanical load. Rupture can also be induced by processes such as cell death, and active cell membrane repair mechanisms are essential to preserve cell integrity. Pore formation in cell membranes is also at the heart of many biomedical applications such as in drug, gene and short interfering RNA delivery. Membrane rupture dynamics has been studied in bilayer vesicles under tensile stress, which consistently produce circular pores. We observed very different rupture mechanics in bilayer membranes spreading on solid supports: in one instance fingering instabilities were seen resulting in floral-like pores and in another, the rupture proceeded in a series of rapid avalanches causing fractal membrane fragmentation. The intermittent character of rupture evolution and the broad distribution in avalanche sizes is consistent with crackling-noise dynamics. Such noisy dynamics appear in fracture of solid disordered materials, in dislocation avalanches in plastic deformations and domain wall magnetization avalanches. We also observed similar fractal rupture mechanics in spreading cell membranes.

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

PubMed

Kubli, Dieter A; Sussman, Mark A

2017-05-01

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

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

PubMed Central

Kubli, Dieter A.; Sussman, Mark A.

2017-01-01

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

ROBUSTNESS OF SIGNALING GRADIENT IN DROSOPHILA WING IMAGINAL DISC

PubMed Central

Lei, Jinzhi; Wan, Frederic Y. M.; Lander, Arthur D.; Nie, Qing

2012-01-01

Quasi-stable gradients of signaling protein molecules (known as morphogens or ligands) bound to cell receptors are known to be responsible for differential cell signaling and gene expressions. From these follow different stable cell fates and visually patterned tissues in biological development. Recent studies have shown that the relevant basic biological processes yield gradients that are sensitive to small changes in system characteristics (such as expression level of morphogens or receptors) or environmental conditions (such as temperature changes). Additional biological activities must play an important role in the high level of robustness observed in embryonic patterning for example. It is natural to attribute observed robustness to various type of feedback control mechanisms. However, our own simulation studies have shown that feedback control is neither necessary nor sufficient for robustness of the morphogen decapentaplegic (Dpp) gradient in wing imaginal disc of Drosophilas. Furthermore, robustness can be achieved by substantial binding of the signaling morphogen Dpp with nonsignaling cell surface bound molecules (such as heparan sulfate proteoglygans) and degrading the resulting complexes at a sufficiently rapid rate. The present work provides a theoretical basis for the results of our numerical simulation studies. PMID:24098092

Biological response in vitro of skeletal muscle cells treated with different intensity continuous and pulsed ultrasound fields

NASA Astrophysics Data System (ADS)

Abrunhosa, Viviane M.; Mermelstein, Claudia S.; Costa, Manoel L.; Costa-Felix, Rodrigo P. B.

2011-02-01

Therapeutic ultrasound has been used in physiotherapy to accelerate tissue healing. Although the ultrasonic wave is widely used in clinical practice, not much is known about the biological effects of ultrasound on cells and tissues. This study aims to evaluate the biological response of ultrasound in primary cultures of chick myogenic cells. To ensure the metrological reliability of whole measurement process, the ultrasound equipment was calibrated in accordance with IEC 61689:2007. The skeletal muscle cells were divided in four samples. One sample was used as a control group and the others were submitted to different time and intensity and operation mode of ultrasound: 1) 0.5 W/cm2 continuous for 5 minutes, 2) 0.5 W/cm2 pulsed for 5 minutes, 3) 1.0 W/cm2 pulsed for 10 minutes. The samples were analyzed with phase contrast optical microscopy before and after the treatment. The results showed alignment of myogenic cells in the sample treated with 0.5 W/cm2 continuous during 5 minutes when compared with the control group and the other samples. This study is a first step towards a metrological and scientific based protocol to cells and tissues treatment under different ultrasound field exposures.

Learning the Cell Structures with Three-Dimensional Models: Students' Achievement by Methods, Type of School and Questions' Cognitive Level

NASA Astrophysics Data System (ADS)

Lazarowitz, Reuven; Naim, Raphael

2013-08-01

The cell topic was taught to 9th-grade students in three modes of instruction: (a) students "hands-on," who constructed three-dimensional cell organelles and macromolecules during the learning process; (b) teacher demonstration of the three-dimensional model of the cell structures; and (c) teaching the cell topic with the regular learning material in an expository mode (which use one- or two-dimensional cell structures as are presented in charts, textbooks and microscopic slides). The sample included 669, 9th-grade students from 25 classes who were taught by 22 Biology teachers. Students were randomly assigned to the three modes of instruction, and two tests in content knowledge in Biology were used. Data were treated with multiple analyses of variance. The results indicate that entry behavior in Biology was equal for all the study groups and types of schools. The "hands-on" learning group who build three-dimensional models through the learning process achieved significantly higher on academic achievements and on the high and low cognitive questions' levels than the other two groups. The study indicates the advantages students may have being actively engaged in the learning process through the "hands-on" mode of instruction/learning.

Immortalized N/TERT keratinocytes as an alternative cell source in 3D human epidermal models.

PubMed

Smits, Jos P H; Niehues, Hanna; Rikken, Gijs; van Vlijmen-Willems, Ivonne M J J; van de Zande, Guillaume W H J F; Zeeuwen, Patrick L J M; Schalkwijk, Joost; van den Bogaard, Ellen H

2017-09-19

The strong societal urge to reduce the use of experimental animals, and the biological differences between rodent and human skin, have led to the development of alternative models for healthy and diseased human skin. However, the limited availability of primary keratinocytes to generate such models hampers large-scale implementation of skin models in biomedical, toxicological, and pharmaceutical research. Immortalized cell lines may overcome these issues, however, few immortalized human keratinocyte cell lines are available and most do not form a fully stratified epithelium. In this study we compared two immortalized keratinocyte cell lines (N/TERT1, N/TERT2G) to human primary keratinocytes based on epidermal differentiation, response to inflammatory mediators, and the development of normal and inflammatory human epidermal equivalents (HEEs). Stratum corneum permeability, epidermal morphology, and expression of epidermal differentiation and host defence genes and proteins in N/TERT-HEE cultures was similar to that of primary human keratinocytes. We successfully generated N/TERT-HEEs with psoriasis or atopic dermatitis features and validated these models for drug-screening purposes. We conclude that the N/TERT keratinocyte cell lines are useful substitutes for primary human keratinocytes thereby providing a biologically relevant, unlimited cell source for in vitro studies on epidermal biology, inflammatory skin disease pathogenesis and therapeutics.

Current concept in neural regeneration research: NSCs isolation, characterization and transplantation in various neurodegenerative diseases and stroke: A review

PubMed Central

Vishwakarma, Sandeep K.; Bardia, Avinash; Tiwari, Santosh K.; Paspala, Syed A.B.; Khan, Aleem A.

2013-01-01

Since last few years, an impressive amount of data has been generated regarding the basic in vitro and in vivo biology of neural stem cells (NSCs) and there is much far hope for the success in cell replacement therapies for several human neurodegenerative diseases and stroke. The discovery of adult neurogenesis (the endogenous production of new neurons) in the mammalian brain more than 40 years ago has resulted in a wealth of knowledge about stem cells biology in neuroscience research. Various studies have done in search of a suitable source for NSCs which could be used in animal models to understand the basic and transplantation biology before treating to human. The difficulties in isolating pure population of NSCs limit the study of neural stem behavior and factors that regulate them. Several studies on human fetal brain and spinal cord derived NSCs in animal models have shown some interesting results for cell replacement therapies in many neurodegenerative diseases and stroke models. Also the methods and conditions used for in vitro culture of these cells provide an important base for their applicability and specificity in a definite target of the disease. Various important developments and modifications have been made in stem cells research which is needed to be more specified and enrolment in clinical studies using advanced approaches. This review explains about the current perspectives and suitable sources for NSCs isolation, characterization, in vitro proliferation and their use in cell replacement therapies for the treatment of various neurodegenerative diseases and strokes. PMID:25685495

[Effects of fibronectin on cytodifferentiation (T56) of human squamous cell carcinoma of tongue].

PubMed

Huang, Y; Yang, F

1994-12-01

Fibronectin (FN) are large glycoproteins that have been implicated in a wide variety of cellular properties, including cell adhesion, morphology, cytoskeletal organization, migration, differentiation, and oncogenic transformation. T56 cells were treated with 20, 50, and 100 micrograms/ml of FN for 48 h, and the changes in cells were analysed qualitatively and quantitatively with the methods of transmission electron microscopy, enzyme cytochemistry, and cell electrophoresis, etc. The studies were made to test the effects of FN on T56 cells in biological behaviour in terms of cell growth, multiplication, cell metabolism, cell electrophoresis and surface morphology. The results indicated that FN could partially restore T56 cell normal epidermic cell's phenotype, inhibit cell mitosis, increase contact of cells, decrease the number of microvilli and ruffles, and promote cell oxybiotic metabolism. These results suggest that FN might relate in many aspects to the biological behaviour of T56 cell and could affect changes in the behaviour.

Modelling cell wall growth using a fibre-reinforced hyperelastic-viscoplastic constitutive law

NASA Astrophysics Data System (ADS)

Huang, R.; Becker, A. A.; Jones, I. A.

2012-04-01

A fibre-reinforced hyperelastic-viscoplastic model using a finite strain Finite Element (FE) analysis is presented to study the expansive growth of cell walls. Based on the connections between biological concepts and plasticity theory, e.g. wall-loosening and plastic yield, wall-stiffening and plastic hardening, the modelling of cell wall growth is established within a framework of anisotropic viscoplasticity aiming to represent the corresponding biology-controlled behaviour of a cell wall. In order to model in vivo growth, special attention is paid to the differences between a living cell and an isolated wall. The proposed hyperelastic-viscoplastic theory provides a unique framework to clarify the interplay between cellulose microfibrils and cell wall matrix and how this interplay regulates sustainable growth in a particular direction while maintaining the mechanical strength of the cell walls by new material deposition. Moreover, the effect of temperature is taken into account. A numerical scheme is suggested and FE case studies are presented and compared with experimental data.

Proliferation and enrichment of CD133(+) glioblastoma cancer stem cells on 3D chitosan-alginate scaffolds.

PubMed

Kievit, Forrest M; Florczyk, Stephen J; Leung, Matthew C; Wang, Kui; Wu, Jennifer D; Silber, John R; Ellenbogen, Richard G; Lee, Jerry S H; Zhang, Miqin

2014-11-01

Emerging evidence implicates cancer stem cells (CSCs) as primary determinants of the clinical behavior of human cancers, representing an ideal target for next-generation anti-cancer therapies. However CSCs are difficult to propagate in vitro, severely limiting the study of CSC biology and drug development. Here we report that growing cells from glioblastoma (GBM) cell lines on three dimensional (3D) porous chitosan-alginate (CA) scaffolds dramatically promotes the proliferation and enrichment of cells possessing the hallmarks of CSCs. CA scaffold-grown cells were found more tumorigenic in nude mouse xenografts than cells grown from monolayers. Growing in CA scaffolds rapidly promoted expression of genes involved in the epithelial-to-mesenchymal transition that has been implicated in the genesis of CSCs. Our results indicate that CA scaffolds have utility as a simple and inexpensive means to cultivate CSCs in vitro in support of studies to understand CSC biology and develop more effective anti-cancer therapies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rewiring cells: synthetic biology as a tool to interrogate the organizational principles of living systems.

PubMed

Bashor, Caleb J; Horwitz, Andrew A; Peisajovich, Sergio G; Lim, Wendell A

2010-01-01

The living cell is an incredibly complex entity, and the goal of predictively and quantitatively understanding its function is one of the next great challenges in biology. Much of what we know about the cell concerns its constituent parts, but to a great extent we have yet to decode how these parts are organized to yield complex physiological function. Classically, we have learned about the organization of cellular networks by disrupting them through genetic or chemical means. The emerging discipline of synthetic biology offers an additional, powerful approach to study systems. By rearranging the parts that comprise existing networks, we can gain valuable insight into the hierarchical logic of the networks and identify the modular building blocks that evolution uses to generate innovative function. In addition, by building minimal toy networks, one can systematically explore the relationship between network structure and function. Here, we outline recent work that uses synthetic biology approaches to investigate the organization and function of cellular networks, and describe a vision for a synthetic biology toolkit that could be used to interrogate the design principles of diverse systems.

Mechano-biological Coupling of Cellular Responses to Microgravity

NASA Astrophysics Data System (ADS)

Long, Mian; Wang, Yuren; Zheng, Huiqiong; Shang, Peng; Duan, Enkui; Lü, Dongyuan

2015-11-01

Cellular response to microgravity is a basic issue in space biological sciences as well as space physiology and medicine. It is crucial to elucidate the mechano-biological coupling mechanisms of various biological organisms, since, from the principle of adaptability, all species evolved on the earth must possess the structure and function that adapts their living environment. As a basic element of an organism, a cell usually undergoes mechanical and chemical remodeling to sense, transmit, transduce, and respond to the alteration of gravitational signals. In the past decades, new computational platforms and experimental methods/techniques/devices are developed to mimic the biological effects of microgravity environment from the viewpoint of biomechanical approaches. Mechanobiology of plant gravisensing in the responses of statolith movements along the gravity vector and the relevant signal transduction and molecular regulatory mechanisms are investigated at gene, transcription, and protein levels. Mechanotransduction of bone or immune cell responses and stem cell development and tissue histogenesis are elucidated under microgravity. In this review, several important issues are briefly discussed. Future issues on gravisensing and mechanotransducing mechanisms are also proposed for ground-based studies as well as space missions.

Comparative Phytochemical Analysis of Essential Oils from Different Biological Parts of Artemisia herba alba and Their Cytotoxic Effect on Cancer Cells

PubMed Central

Tilaoui, Mounir; Ait Mouse, Hassan; Jaafari, Abdeslam; Zyad, Abdelmajid

2015-01-01

Purpose Carrying out the chemical composition and antiproliferative effects against cancer cells from different biological parts of Artemisia herba alba. Methods Essential oils were studied by gas chromatography coupled to mass spectrometry (GC–MS) and their antitumoral activity was tested against P815 mastocytoma and BSR kidney carcinoma cell lines; also, in order to evaluate the effect on normal human cells, oils were tested against peripheral blood mononuclear cells PBMCs. Results Essential oils from leaves and aerial parts (mixture of capitulum and leaves) were mainly composed by oxygenated sesquiterpenes 39.89% and 46.15% respectively; capitulum oil contained essentially monoterpenes (22.86%) and monocyclic monoterpenes (21.48%); esters constituted the major fraction (62.8%) of stem oil. Essential oils of different biological parts studied demonstrated a differential antiproliferative activity against P815 and BSR cancer cells; P815 cells are the most sensitive to the cytotoxic effect. Leaves and capitulum essential oils are more active than aerial parts. Interestingly, no cytotoxic effect of these essential oils was observed on peripheral blood mononuclear cells. Conclusion Our results showed that the chemical composition variability of essential oils depends on the nature of botanical parts of Artemisia herba alba. Furthermore, we have demonstrated that the differential cytotoxic effect depends not only on the essential oils concentration, but also on the target cells and the botanical parts of essential oils used. PMID:26196123

Genome Editing to Study Ca2+ Homeostasis in Zebrafish Cone Photoreceptors.

PubMed

Brockerhoff, Susan E

2017-01-01

Photoreceptors are specialized sensory neurons with unique biological features. Phototransduction is well understood due in part to the exclusive expression and function of the molecular components of this cascade. Many other processes are less well understood, but also extremely important for understanding photoreceptor function and for treating disease. One example is the role of Ca 2+ in the cell body and overall compartmentalization and regulation of Ca 2+ within the cell. The recent development of CRISPR/Cas9 genome editing techniques has made it possible to rapidly and cheaply alter specific genes. This will help to define the biological function of elusive processes that have been more challenging to study. CRISPR/Cas9 has been optimized in many systems including zebrafish, which already has some distinct advantages for studying photoreceptor biology and function. These new genome editing technologies and the continued use of the zebrafish model system will help advance our understanding of important understudied aspects of photoreceptor biology.

"Life-bearing molecules" versus "life-embodying systems": Two contrasting views on the what-is-life (WIL) problem persisting from the early days of molecular biology to the post-genomic cell- and organism-level biology.

PubMed

Sato, Naoki

2018-05-01

"What is life?" is an ultimate biological quest for the principle that makes organisms alive. This 'WIL problem' is not, however, a simple one that we have a straightforward strategy to attack. From the beginning, molecular biology tried to identify molecules that bear the essence of life: the double helical DNA represented replication, and enzymes were micro-actuators of biological activities. A dominating idea behind these mainstream biological studies relies on the identification of life-bearing molecules, which themselves are models of life. Another, prevalent idea emphasizes that life resides in the whole system of an organism, but not in some particular molecules. The behavior of a complex system may be considered to embody the essence of life. The thermodynamic view of life system in the early 20th century was remodeled as physics of complex systems and systems biology. The two views contrast with each other, but they are no longer heritage of the historical dualism in biology, such as mechanism/materialism versus vitalism, or reductionism versus holism. These two views are both materialistic and mechanistic, and act as driving forces of modern biology. In reality, molecules function in a context of systems, whereas systems presuppose functional molecules. A key notion to reconcile this conflict is that subjects of biological studies are given before we start to study them. Cell- or organism-level biology is destined to the dialectic of molecules and systems, but this antagonism can be resolved by dynamic thinking involving biological evolution. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

PubMed Central

Randolph, Matthew E.; Pavlath, Grace K.

2015-01-01

The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

Division of Biological and Medical Research annual research summary, 1983

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

Barr, S.H.

1984-08-01

This research summary contains brief descriptions of research in the following areas: (1) mechanisms of hepatocarcinogenesis; (2) role of metals in cocarcinogenesis and the use of liposomes for metal mobilization; (3) control of mutagenesis and cell differentiation in cultured cells by tumor promoters; (4) radiation effects in mammalian cells; (5) radiation carcinogenesis and radioprotectors; (6) life shortening, tumor induction, and tissue dose for fission-neutron and gamma-ray irradiations; (7) mammalian genetics and biostatistics; (8) radiation toxicity studies; (9) hematopoiesis in chronic toxicity; (10) molecular biology studies; (11) chemical toxicology; (12) carcinogen identification and metabolism; (13) metal metabolism and toxicity; and (14)more » neurobehavioral chronobiology. (ACR)« less

PURIFICATION OF RAT LEYDIG CELLS: INCREASED YIELDS AFTER UNIT-GRAVITY SEDIMENTATION OF COLLAGENASE-DISPERSED INTERSTITIAL CELLS

EPA Science Inventory

Abstract

Procedures for purification of Leydig cells have facilitated studies of their regulatory biology. A multistep procedure, that includes a filtration with nylon mesh (100 micron pore size) to separate interstitial cells from the seminiferous tubules, combining centr...

Industrial systems biology and its impact on synthetic biology of yeast cell factories.

PubMed

Fletcher, Eugene; Krivoruchko, Anastasia; Nielsen, Jens

2016-06-01

Engineering industrial cell factories to effectively yield a desired product while dealing with industrially relevant stresses is usually the most challenging step in the development of industrial production of chemicals using microbial fermentation processes. Using synthetic biology tools, microbial cell factories such as Saccharomyces cerevisiae can be engineered to express synthetic pathways for the production of fuels, biopharmaceuticals, fragrances, and food flavors. However, directing fluxes through these synthetic pathways towards the desired product can be demanding due to complex regulation or poor gene expression. Systems biology, which applies computational tools and mathematical modeling to understand complex biological networks, can be used to guide synthetic biology design. Here, we present our perspective on how systems biology can impact synthetic biology towards the goal of developing improved yeast cell factories. Biotechnol. Bioeng. 2016;113: 1164-1170. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

From noise to synthetic nucleoli: can synthetic biology achieve new insights?

PubMed

Ciechonska, Marta; Grob, Alice; Isalan, Mark

2016-04-18

Synthetic biology aims to re-organise and control biological components to make functional devices. Along the way, the iterative process of designing and testing gene circuits has the potential to yield many insights into the functioning of the underlying chassis of cells. Thus, synthetic biology is converging with disciplines such as systems biology and even classical cell biology, to give a new level of predictability to gene expression, cell metabolism and cellular signalling networks. This review gives an overview of the contributions that synthetic biology has made in understanding gene expression, in terms of cell heterogeneity (noise), the coupling of growth and energy usage to expression, and spatiotemporal considerations. We mainly compare progress in bacterial and mammalian systems, which have some of the most-developed engineering frameworks. Overall, one view of synthetic biology can be neatly summarised as "creating in order to understand."

Stem cells in drug discovery, tissue engineering, and regenerative medicine: emerging opportunities and challenges.

PubMed

Nirmalanandhan, Victor Sanjit; Sittampalam, G Sitta

2009-08-01

Stem cells, irrespective of their origin, have emerged as valuable reagents or tools in human health in the past 2 decades. Initially, a research tool to study fundamental aspects of developmental biology is now the central focus of generating transgenic animals, drug discovery, and regenerative medicine to address degenerative diseases of multiple organ systems. This is because stem cells are pluripotent or multipotent cells that can recapitulate developmental paths to repair damaged tissues. However, it is becoming clear that stem cell therapy alone may not be adequate to reverse tissue and organ damage in degenerative diseases. Existing small-molecule drugs and biologicals may be needed as "molecular adjuvants" or enhancers of stem cells administered in therapy or adult stem cells in the diseased tissues. Hence, a combination of stem cell-based, high-throughput screening and 3D tissue engineering approaches is necessary to advance the next wave of tools in preclinical drug discovery. In this review, the authors have attempted to provide a basic account of various stem cells types, as well as their biology and signaling, in the context of research in regenerative medicine. An attempt is made to link stem cells as reagents, pharmacology, and tissue engineering as converging fields of research for the next decade.

In vitro evaluation of low-intensity light radiation on murine melanoma (B16F10) cells.

PubMed

Peidaee, P; Almansour, N M; Pirogova, E

2016-03-01

Changes in the energy state of biomolecules induced by electromagnetic radiation lead to changes in biological functions of irradiated biomolecules. Using the RRM approach, it was computationally predicted that far-infrared light irradiation in the range of 3500-6000 nm affects biological activity of proto-oncogene proteins. This in vitro study evaluates quantitatively and qualitatively the effects of selected far-infrared exposures in the computationally determined wavelengths on mouse melanoma B16F10 cells and Chinese hamster ovarian (CHO) cells by MTT (thiazolyl blue tetrazolium bromide) cell proliferation assay and confocal laser-scanning microscopy (CLSM). This paper also presents the findings obtained from irradiating B16F10 and CHO cells by the selected wavelengths in visible and near-infrared range. The MTT results show that far-infrared wavelength irradiation induces detrimental effect on cellular viability of B16F10 cells, while that of normal CHO cells is not affected considerably. Moreover, CLSM images demonstrate visible cellular detachment of cancer cells. The observed effects support the hypothesis that far-infrared light irradiation within the computationally determined wavelength range induces biological effect on cancer cells. From irradiation of selected visible and near-infrared wavelengths, no visible changes were detected in cellular viability of either normal or cancer cells.

Biological atomism and cell theory.

PubMed

Nicholson, Daniel J

2010-09-01

Biological atomism postulates that all life is composed of elementary and indivisible vital units. The activity of a living organism is thus conceived as the result of the activities and interactions of its elementary constituents, each of which individually already exhibits all the attributes proper to life. This paper surveys some of the key episodes in the history of biological atomism, and situates cell theory within this tradition. The atomistic foundations of cell theory are subsequently dissected and discussed, together with the theory's conceptual development and eventual consolidation. This paper then examines the major criticisms that have been waged against cell theory, and argues that these too can be interpreted through the prism of biological atomism as attempts to relocate the true biological atom away from the cell to a level of organization above or below it. Overall, biological atomism provides a useful perspective through which to examine the history and philosophy of cell theory, and it also opens up a new way of thinking about the epistemic decomposition of living organisms that significantly departs from the physicochemical reductionism of mechanistic biology. Copyright © 2010 Elsevier Ltd. All rights reserved.

Student Perceptions of the Cell Biology Laboratory Learning Environment in Four Undergraduate Science Courses in Spain

ERIC Educational Resources Information Center

De Juan, Joaquin; Pérez-Cañaveras, Rosa M.; Segovia, Yolanda; Girela, Jose Luis; Martínez-Ruiz, Noemi; Romero-Rameta, Alejandro; Gómez-Torres, Maria José; Vizcaya-Moreno, M. Flores

2016-01-01

Cell biology is an academic discipline that organises and coordinates the learning of the structure, function and molecular composition of cells in some undergraduate biomedical programs. Besides course content and teaching methodologies, the laboratory environment is considered a key element in the teaching of and learning of cell biology. The…

Three-dimensional printing of Hela cells for cervical tumor model in vitro.

PubMed

Zhao, Yu; Yao, Rui; Ouyang, Liliang; Ding, Hongxu; Zhang, Ting; Zhang, Kaitai; Cheng, Shujun; Sun, Wei

2014-09-01

Advances in three-dimensional (3D) printing have enabled the direct assembly of cells and extracellular matrix materials to form in vitro cellular models for 3D biology, the study of disease pathogenesis and new drug discovery. In this study, we report a method of 3D printing for Hela cells and gelatin/alginate/fibrinogen hydrogels to construct in vitro cervical tumor models. Cell proliferation, matrix metalloproteinase (MMP) protein expression and chemoresistance were measured in the printed 3D cervical tumor models and compared with conventional 2D planar culture models. Over 90% cell viability was observed using the defined printing process. Comparisons of 3D and 2D results revealed that Hela cells showed a higher proliferation rate in the printed 3D environment and tended to form cellular spheroids, but formed monolayer cell sheets in 2D culture. Hela cells in 3D printed models also showed higher MMP protein expression and higher chemoresistance than those in 2D culture. These new biological characteristics from the printed 3D tumor models in vitro as well as the novel 3D cell printing technology may help the evolution of 3D cancer study.

Weak Ergodicity Breaking of Receptor Motion in Living Cells Stemming from Random Diffusivity

NASA Astrophysics Data System (ADS)

Manzo, Carlo; Torreno-Pina, Juan A.; Massignan, Pietro; Lapeyre, Gerald J.; Lewenstein, Maciej; Garcia Parajo, Maria F.

2015-01-01

Molecular transport in living systems regulates numerous processes underlying biological function. Although many cellular components exhibit anomalous diffusion, only recently has the subdiffusive motion been associated with nonergodic behavior. These findings have stimulated new questions for their implications in statistical mechanics and cell biology. Is nonergodicity a common strategy shared by living systems? Which physical mechanisms generate it? What are its implications for biological function? Here, we use single-particle tracking to demonstrate that the motion of dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN), a receptor with unique pathogen-recognition capabilities, reveals nonergodic subdiffusion on living-cell membranes In contrast to previous studies, this behavior is incompatible with transient immobilization, and, therefore, it cannot be interpreted according to continuous-time random-walk theory. We show that the receptor undergoes changes of diffusivity, consistent with the current view of the cell membrane as a highly dynamic and diverse environment. Simulations based on a model of an ordinary random walk in complex media quantitatively reproduce all our observations, pointing toward diffusion heterogeneity as the cause of DC-SIGN behavior. By studying different receptor mutants, we further correlate receptor motion to its molecular structure, thus establishing a strong link between nonergodicity and biological function. These results underscore the role of disorder in cell membranes and its connection with function regulation. Because of its generality, our approach offers a framework to interpret anomalous transport in other complex media where dynamic heterogeneity might play a major role, such as those found, e.g., in soft condensed matter, geology, and ecology.

Using a "Primer Unit" in an Introductory Biology Course: "A Soft Landing"

ERIC Educational Resources Information Center

Marbach-Ad, Gili; Ribke, Melina; Gershoni, Jonathan M.

2006-01-01

This study aimed to facilitate students' entrance to an introductory cell biology course for biology majors. The most prominent difficulty in this introductory course, is students' poor background-knowledge, such as a lack of understanding of very basic concepts and terms, and the huge differences in students' background knowledge. In order to…

Verbal Final Exam in Introductory Biology Yields Gains in Student Content Knowledge and Longitudinal Performance

ERIC Educational Resources Information Center

Luckie, Douglas B.; Rivkin, Aaron M.; Aubry, Jacob R.; Marengo, Benjamin J.; Creech, Leah R.; Sweeder, Ryan D.

2013-01-01

We studied gains in student learning over eight semesters in which an introductory biology course curriculum was changed to include optional verbal final exams (VFs). Students could opt to demonstrate their mastery of course material via structured oral exams with the professor. In a quantitative assessment of cell biology content knowledge,…

A Drosophila LexA Enhancer-Trap Resource for Developmental Biology and Neuroendocrine Research

PubMed Central

Kockel, Lutz; Huq, Lutfi M.; Ayyar, Anika; Herold, Emma; MacAlpine, Elle; Logan, Madeline; Savvides, Christina; Kim, Grace E. S.; Chen, Jiapei; Clark, Theresa; Duong, Trang; Fazel-Rezai, Vahid; Havey, Deanna; Han, Samuel; Jagadeesan, Ravi; Kim, Eun Soo Jackie; Lee, Diane; Lombardo, Kaelina; Piyale, Ida; Shi, Hansen; Stahr, Lydia; Tung, Dana; Tayvah, Uriel; Wang, Flora; Wang, Ja-Hon; Xiao, Sarah; Topper, Sydni M.; Park, Sangbin; Rotondo, Cheryl; Rankin, Anne E.; Chisholm, Townley W.; Kim, Seung K.

2016-01-01

Novel binary gene expression tools like the LexA-LexAop system could powerfully enhance studies of metabolism, development, and neurobiology in Drosophila. However, specific LexA drivers for neuroendocrine cells and many other developmentally relevant systems remain limited. In a unique high school biology course, we generated a LexA-based enhancer trap collection by transposon mobilization. The initial collection provides a source of novel LexA-based elements that permit targeted gene expression in the corpora cardiaca, cells central for metabolic homeostasis, and other neuroendocrine cell types. The collection further contains specific LexA drivers for stem cells and other enteric cells in the gut, and other developmentally relevant tissue types. We provide detailed analysis of nearly 100 new LexA lines, including molecular mapping of insertions, description of enhancer-driven reporter expression in larval tissues, and adult neuroendocrine cells, comparison with established enhancer trap collections and tissue specific RNAseq. Generation of this open-resource LexA collection facilitates neuroendocrine and developmental biology investigations, and shows how empowering secondary school science can achieve research and educational goals. PMID:27527793

A Drosophila LexA Enhancer-Trap Resource for Developmental Biology and Neuroendocrine Research.

PubMed

Kockel, Lutz; Huq, Lutfi M; Ayyar, Anika; Herold, Emma; MacAlpine, Elle; Logan, Madeline; Savvides, Christina; Kim, Grace E S; Chen, Jiapei; Clark, Theresa; Duong, Trang; Fazel-Rezai, Vahid; Havey, Deanna; Han, Samuel; Jagadeesan, Ravi; Kim, Eun Soo Jackie; Lee, Diane; Lombardo, Kaelina; Piyale, Ida; Shi, Hansen; Stahr, Lydia; Tung, Dana; Tayvah, Uriel; Wang, Flora; Wang, Ja-Hon; Xiao, Sarah; Topper, Sydni M; Park, Sangbin; Rotondo, Cheryl; Rankin, Anne E; Chisholm, Townley W; Kim, Seung K

2016-10-13

Novel binary gene expression tools like the LexA-LexAop system could powerfully enhance studies of metabolism, development, and neurobiology in Drosophila However, specific LexA drivers for neuroendocrine cells and many other developmentally relevant systems remain limited. In a unique high school biology course, we generated a LexA-based enhancer trap collection by transposon mobilization. The initial collection provides a source of novel LexA-based elements that permit targeted gene expression in the corpora cardiaca, cells central for metabolic homeostasis, and other neuroendocrine cell types. The collection further contains specific LexA drivers for stem cells and other enteric cells in the gut, and other developmentally relevant tissue types. We provide detailed analysis of nearly 100 new LexA lines, including molecular mapping of insertions, description of enhancer-driven reporter expression in larval tissues, and adult neuroendocrine cells, comparison with established enhancer trap collections and tissue specific RNAseq. Generation of this open-resource LexA collection facilitates neuroendocrine and developmental biology investigations, and shows how empowering secondary school science can achieve research and educational goals. Copyright © 2016 Kockel et al.

Models to Study NK Cell Biology and Possible Clinical Application.

PubMed

Zamora, Anthony E; Grossenbacher, Steven K; Aguilar, Ethan G; Murphy, William J

2015-08-03

Natural killer (NK) cells are large granular lymphocytes of the innate immune system, responsible for direct targeting and killing of both virally infected and transformed cells. NK cells rapidly recognize and respond to abnormal cells in the absence of prior sensitization due to their wide array of germline-encoded inhibitory and activating receptors, which differs from the receptor diversity found in B and T lymphocytes that is due to the use of recombination-activation gene (RAG) enzymes. Although NK cells have traditionally been described as natural killers that provide a first line of defense prior to the induction of adaptive immunity, a more complex view of NK cells is beginning to emerge, indicating they may also function in various immunoregulatory roles and have the capacity to shape adaptive immune responses. With the growing appreciation for the diverse functions of NK cells, and recent technological advancements that allow for a more in-depth understanding of NK cell biology, we can now begin to explore new ways to manipulate NK cells to increase their clinical utility. In this overview unit, we introduce the reader to various aspects of NK cell biology by reviewing topics ranging from NK cell diversity and function, mouse models, and the roles of NK cells in health and disease, to potential clinical applications. © 2015 by John Wiley & Sons, Inc. Copyright © 2015 John Wiley & Sons, Inc.

Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

PubMed

Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

2016-03-01

Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

Conditioned medium: a new alternative for cryopreservation of equine umbilical cord mesenchymal stem cells.

PubMed

Maia, Leandro; Dias, Marianne Camargos; de Moraes, Carolina Nogueira; de Paula Freitas-Dell'Aqua, Camila; da Mota, Ligia S L Silveira; Santiloni, Valquíria; da Cruz Landim-Alvarenga, Fernanda

2017-03-01

Cryopreservation is a feasible alternative to maintaining several cell lines, particularly for immediate therapeutic use, transportation of samples, and implementation of new in vitro studies. This work parts from the hypothesis that the medium of cryopreservation composed by 90% of conditioned medium (CM) supports cryopreservation of equine umbilical cord intervascular matrix mesenchymal stem cells (UCIM-MSCs), allowing the maintenance of the biological properties for the establishment of cell banks intended for therapeutic use and in vitro studies. Thus, we evaluated the viability, apoptosis/necrosis rates, immunophenotypic profile (IP), chromosomal stability, clonicity, and differentiation potential of UCIM-MSCs cryopreserved with four different mediums (with FBS: M1, M3, M4 and without FBS: M2). After 3 months of cryopreservation, samples were thawed and analyzed. The potential of differentiation in the mesodermal lineages, clonicity, and the chromosomal stability were maintained after cryopreservation of UCIM-MSCs with medium containing FBS. Changes (P < 0.05) at IP for some markers were observed at cells cryopreserved with medium M1-M3. Only the UCIM-MSCs cryopreserved with the CM (M4) had similar viability post-thaw (P = 0.23) when compared with fresh cells. We proved the hypothesis that the medium of cryopreservation containing CM supports the cryopreservation of UCIM-MSCs, at the experimental conditions, being the medium that better maintains the biological characteristics observed at fresh cells. Thus, future studies of UCIM-MSCs secretome should be conducted to better understand the beneficial and protective effects of the CM during the freezing process. © 2017 International Federation for Cell Biology.

Microbial cell budgets of an Arctic glacier surface quantified using flow cytometry.

PubMed

Irvine-Fynn, T D L; Edwards, A; Newton, S; Langford, H; Rassner, S M; Telling, J; Anesio, A M; Hodson, A J

2012-11-01

Uncertainty surrounds estimates of microbial cell and organic detritus fluxes from glacier surfaces. Here, we present the first enumeration of biological particles draining from a supraglacial catchment, on Midtre Lovénbreen (Svalbard) over 36 days. A stream cell flux of 1.08 × 10(7)  cells m(-2)  h(-1) was found, with strong inverse, non-linear associations between water discharge and biological particle concentrations. Over the study period, a significant decrease in cell-like particles exhibiting 530 nm autofluorescence was noted. The observed total fluvial export of ~7.5 × 10(14) cells equates to 15.1-72.7 g C, and a large proportion of these cells were small (< 0.5 μm in diameter). Differences between the observed fluvial export and inputs from ice-melt and aeolian deposition were marked: results indicate an apparent storage rate of 8.83 × 10(7)  cells m(-2)  h(-1). Analysis of surface ice cores revealed cell concentrations comparable to previous studies (6 × 10(4)  cells ml(-1)) but, critically, showed no variation with depth in the uppermost 1 m. The physical retention and growth of particulates at glacier surfaces has two implications: to contribute to ice mass thinning through feedbacks altering surface albedo, and to potentially seed recently deglaciated terrain with cells, genes and labile organic matter. This highlights the merit of further study into glacier surface hydraulics and biological processes. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

BASiCS: Bayesian Analysis of Single-Cell Sequencing Data.

PubMed

Vallejos, Catalina A; Marioni, John C; Richardson, Sylvia

2015-06-01

Single-cell mRNA sequencing can uncover novel cell-to-cell heterogeneity in gene expression levels in seemingly homogeneous populations of cells. However, these experiments are prone to high levels of unexplained technical noise, creating new challenges for identifying genes that show genuine heterogeneous expression within the population of cells under study. BASiCS (Bayesian Analysis of Single-Cell Sequencing data) is an integrated Bayesian hierarchical model where: (i) cell-specific normalisation constants are estimated as part of the model parameters, (ii) technical variability is quantified based on spike-in genes that are artificially introduced to each analysed cell's lysate and (iii) the total variability of the expression counts is decomposed into technical and biological components. BASiCS also provides an intuitive detection criterion for highly (or lowly) variable genes within the population of cells under study. This is formalised by means of tail posterior probabilities associated to high (or low) biological cell-to-cell variance contributions, quantities that can be easily interpreted by users. We demonstrate our method using gene expression measurements from mouse Embryonic Stem Cells. Cross-validation and meaningful enrichment of gene ontology categories within genes classified as highly (or lowly) variable supports the efficacy of our approach.

A scientific role for Space Station Freedom: Research at the cellular level

NASA Technical Reports Server (NTRS)

Johnson, Terry C.; Brady, John N.

1993-01-01

The scientific importance of Space Station Freedom is discussed in light of the valuable information that can be gained in cellular and developmental biology with regard to the microgravity environment on the cellular cytoskeleton, cellular responses to extracellular signal molecules, morphology, events associated with cell division, and cellular physiology. Examples of studies in basic cell biology, as well as their potential importance to concerns for future enabling strategies, are presented.

Investigating Novice and Expert Conceptions of Genetically Modified Organisms.

PubMed

Potter, Lisa M; Bissonnette, Sarah A; Knight, Jonathan D; Tanner, Kimberly D

2017-01-01

The aspiration of biology education is to give students tools to apply knowledge learned in the classroom to everyday life. Genetic modification is a real-world biological concept that relies on an in-depth understanding of the molecular behavior of DNA and proteins. This study investigated undergraduate biology students' conceptions of genetically modified organisms (GMOs) when probed with real-world, molecular and cellular, and essentialist cues, and how those conceptions compared across biology expertise. We developed a novel written assessment tool and administered it to 120 non-biology majors, 154 entering biology majors, 120 advanced biology majors (ABM), and nine biology faculty. Results indicated that undergraduate biology majors rarely included molecular and cellular rationales in their initial explanations of GMOs. Despite ABM demonstrating that they have much of the biology knowledge necessary to understand genetic modification, they did not appear to apply this knowledge to explaining GMOs. Further, this study showed that all undergraduate student populations exhibited evidence of essentialist thinking while explaining GMOs, regardless of their level of biology training. Finally, our results suggest an association between scientifically accurate ideas and the application of molecular and cellular rationales, as well as an association between misconceptions and essentialist rationales. © 2017 L. M. Potter et al. CBE—Life Sciences Education © 2016 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).

NMR-based Metabolomics Applications in Biological and Environmental Science

EPA Science Inventory

As a complimentary tool to other omics platforms, metabolomics is increasingly being used bybiologists to study the dynamic response of biological systems (cells, tissues, or wholeorganisms) under diverse physiological or pathological conditions. Metabolomics deals with the quali...

Transcriptional and epigenetic control in mouse pluripotency: lessons from in vivo and in vitro studies.

PubMed

Habibi, Ehsan; Stunnenberg, Hendrik G

2017-10-01

Pluripotent cells were first derived from mouse blastocysts several decades ago. Since then, our knowledge of the molecular events that occur in the pre-implantation embryo has been vastly progressing. The emergence of epigenetics has revolutionized stem cell and developmental biology and further deepened our understanding of the underlying molecular mechanisms controlling the early embryo development. In particular, the emergence of massive parallel sequencing technologies has opened new avenues and became indispensable tools in modern biology. Additionally, development of new and exciting techniques for genome manipulation (TALEN and CRISPR/Cas9) and in vivo imaging provide unique opportunities to perturb and trace biological systems at very high resolution. Finally, recent single-cell - omics combined with sophisticated computational methodologies allow accurate, quantitative measurements for deconvolution of cellular variation in complex cell populations. Collectively, these achievements enabled the detailed characterization and monitoring of various cell states and trajectories during early stages of embryonic development. Here we review recent studies of the transcriptional and epigenetic changes during very early stages of mouse embryo development and compare these with pluripotent cells grown in vitro under different culture conditions. We discuss whether the in vitro cell states have an 'epi-phenocopy' in the embryo and refine our understanding of the circuitries controlling pluripotency and lineage commitment during early stages of mouse development. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Stem cells - biological update and cell therapy progress

PubMed Central

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

2015-01-01

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

In vitro and in vivo approaches to study osteocyte biology.

PubMed

Kalajzic, Ivo; Matthews, Brya G; Torreggiani, Elena; Harris, Marie A; Divieti Pajevic, Paola; Harris, Stephen E

2013-06-01

Osteocytes, the most abundant cell population of the bone lineage, have been a major focus in the bone research field in recent years. This population of cells that resides within mineralized matrix is now thought to be the mechanosensory cell in bone and plays major roles in the regulation of bone formation and resorption. Studies of osteocytes had been impaired by their location, resulting in numerous attempts to isolate primary osteocytes and to generate cell lines representative of the osteocytic phenotype. Progress has been achieved in recent years by utilizing in vivo genetic technology and generation of osteocyte directed transgenic and gene deficiency mouse models. We will provide an overview of the current in vitro and in vivo models utilized to study osteocyte biology. We discuss generation of osteocyte-like cell lines and isolation of primary osteocytes and summarize studies that have utilized these cellular models to understand the functional role of osteocytes. Approaches that attempt to selectively identify and isolate osteocytes using fluorescent protein reporters driven by regulatory elements of genes that are highly expressed in osteocytes will be discussed. In addition, recent in vivo studies utilizing overexpression or conditional deletion of various genes using dentin matrix protein (Dmp1) directed Cre recombinase are outlined. In conclusion, evaluation of the benefits and deficiencies of currently used cell lines/genetic models in understanding osteocyte biology underlines the current progress in this field. The future efforts will be directed towards developing novel in vitro and in vivo models that would additionally facilitate in understanding the multiple roles of osteocytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Live-cell imaging of invasion and intravasation in an artificial microvessel platform.

PubMed

Wong, Andrew D; Searson, Peter C

2014-09-01

Methods to visualize metastasis exist, but additional tools to better define the biologic and physical processes underlying invasion and intravasation are still needed. One difficulty in studying metastasis stems from the complexity of the interface between the tumor microenvironment and the vascular system. Here, we report the development of an investigational platform that positions tumor cells next to an artificial vessel embedded in an extracellular matrix. On this platform, we used live-cell fluorescence microscopy to analyze the complex interplay between metastatic cancer cells and a functional artificial microvessel that was lined with endothelial cells. The platform recapitulated known interactions, and its use demonstrated the capabilities for a systematic study of novel physical and biologic parameters involved in invasion and intravasation. In summary, our work offers an important new tool to advance knowledge about metastasis and candidate antimetastatic therapies. ©2014 American Association for Cancer Research.

New tools for the analysis of glial cell biology in Drosophila.

PubMed

Awasaki, Takeshi; Lee, Tzumin

2011-09-01

Because of its genetic, molecular, and behavioral tractability, Drosophila has emerged as a powerful model system for studying molecular and cellular mechanisms underlying the development and function of nervous systems. The Drosophila nervous system has fewer neurons and exhibits a lower glia:neuron ratio than is seen in vertebrate nervous systems. Despite the simplicity of the Drosophila nervous system, glial organization in flies is as sophisticated as it is in vertebrates. Furthermore, fly glial cells play vital roles in neural development and behavior. In addition, powerful genetic tools are continuously being created to explore cell function in vivo. In taking advantage of these features, the fly nervous system serves as an excellent model system to study general aspects of glial cell development and function in vivo. In this article, we review and discuss advanced genetic tools that are potentially useful for understanding glial cell biology in Drosophila. Copyright © 2011 Wiley-Liss, Inc.

Biological indicators in response to radiofrequency/microwave exposure.

PubMed

Marjanović, Ana Marija; Pavičić, Ivan; Trošić, Ivančica

2012-09-01

Over the years, due to rapid technological progress, radiation from man-made sources exceeded that of natural origin. There is a general concern regarding a growing number of appliances that use radiofrequency/ microwave (RF/MW) radiation with particular emphasis on mobile communication systems. Since nonthermal biological effects and mechanisms of RF/MW radiation are still uncertain, laboratory studies on animal models, tissues, cells, and cell free system are of extraordinary importance in bioelectromagnetic research. We believe that such investigations play a supporting role in public risk assessment. Cellular systems with the potential for a clear response to RF/MW exposures should be used in those studies. It is known that organism is a complex electrochemical system where processes of oxidation and reduction regularly occur. One of the plausible mechanisms is connected with generation of reactive oxygen species (ROS). Depending on concentration, ROS can have both beneficial and deleterious effects. Positive effects are connected with cell signalling, defence against infectious agents, and proliferative cell ability. On the other hand, excessive production, which overloads antioxidant defence mechanism, leads to cellular damage with serious potential for disease development. ROS concentration increase within the cell caused by RF/MW radiation seems to be a biologically relevant hypothesis to give clear insight into the RF/MW action at non-thermal level of radiation. In order to better understand the exact mechanism of action and its consequences, further research is needed in the field. We would like to present current knowledge on possible biological mechanisms of RF/MW actions.

Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

PubMed

Hu, C; Cao, H; Pan, X; Li, J; He, J; Pan, Q; Xin, J; Yu, X; Li, J; Wang, Y; Zhu, D; Li, L

2016-03-17

Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

A Multicenter Study To Evaluate the Performance of High-Throughput Sequencing for Virus Detection

PubMed Central

Ng, Siemon H. S.; Vandeputte, Olivier; Aljanahi, Aisha; Deyati, Avisek; Cassart, Jean-Pol; Charlebois, Robert L.; Taliaferro, Lanyn P.

2017-01-01

ABSTRACT The capability of high-throughput sequencing (HTS) for detection of known and unknown viruses makes it a powerful tool for broad microbial investigations, such as evaluation of novel cell substrates that may be used for the development of new biological products. However, like any new assay, regulatory applications of HTS need method standardization. Therefore, our three laboratories initiated a study to evaluate performance of HTS for potential detection of viral adventitious agents by spiking model viruses in different cellular matrices to mimic putative materials for manufacturing of biologics. Four model viruses were selected based upon different physical and biochemical properties and commercial availability: human respiratory syncytial virus (RSV), Epstein-Barr virus (EBV), feline leukemia virus (FeLV), and human reovirus (REO). Additionally, porcine circovirus (PCV) was tested by one laboratory. Independent samples were prepared for HTS by spiking intact viruses or extracted viral nucleic acids, singly or mixed, into different HeLa cell matrices (resuspended whole cells, cell lysate, or total cellular RNA). Data were obtained using different sequencing platforms (Roche 454, Illumina HiSeq1500 or HiSeq2500). Bioinformatic analyses were performed independently by each laboratory using available tools, pipelines, and databases. The results showed that comparable virus detection was obtained in the three laboratories regardless of sample processing, library preparation, sequencing platform, and bioinformatic analysis: between 0.1 and 3 viral genome copies per cell were detected for all of the model viruses used. This study highlights the potential for using HTS for sensitive detection of adventitious viruses in complex biological samples containing cellular background. IMPORTANCE Recent high-throughput sequencing (HTS) investigations have resulted in unexpected discoveries of known and novel viruses in a variety of sample types, including research materials, clinical materials, and biological products. Therefore, HTS can be a powerful tool for supplementing current methods for demonstrating the absence of adventitious or unwanted viruses in biological products, particularly when using a new cell line. However, HTS is a complex technology with different platforms, which needs standardization for evaluation of biologics. This collaborative study was undertaken to investigate detection of different virus types using two different HTS platforms. The results of the independently performed studies demonstrated a similar sensitivity of virus detection, regardless of the different sample preparation and processing procedures and bioinformatic analyses done in the three laboratories. Comparable HTS detection of different virus types supports future development of reference virus materials for standardization and validation of different HTS platforms. PMID:28932815

Implant Surface Design Regulates Mesenchymal Stem Cell Differentiation and Maturation

PubMed Central

Boyan, B.D.; Cheng, A.; Olivares-Navarrete, R.; Schwartz, Z.

2016-01-01

Changes in dental implant materials, structural design, and surface properties can all affect biological response. While bulk properties are important for mechanical stability of the implant, surface design ultimately contributes to osseointegration. This article reviews the surface parameters of dental implant materials that contribute to improved cell response and osseointegration. In particular, we focus on how surface design affects mesenchymal cell response and differentiation into the osteoblast lineage. Surface roughness has been largely studied at the microscale, but recent studies have highlighted the importance of hierarchical micron/submicron/nanosurface roughness, as well as surface roughness in combination with surface wettability. Integrins are transmembrane receptors that recognize changes in the surface and mediate downstream signaling pathways. Specifically, the noncanonical Wnt5a pathway has been implicated in osteoblastic differentiation of cells on titanium implant surfaces. However, much remains to be elucidated. Only recently have studies been conducted on the differences in biological response to implants based on sex, age, and clinical factors; these all point toward differences that advocate for patient-specific implant design. Finally, challenges in implant surface characterization must be addressed to optimize and compare data across studies. An understanding of both the science and the biology of the materials is crucial for developing novel dental implant materials and surface modifications for improved osseointegration. PMID:26927483

Study of energetic-particle-irradiation induced biological effect on Rhizopus oryzae through synchrotron-FTIR micro-spectroscopy

NASA Astrophysics Data System (ADS)

Liu, Jinghua; Qi, Zeming; Huang, Qing; Wei, Xiaoli; Ke, Zhigang; Fang, Yusheng; Tian, Yangchao; Yu, Zengliang

2013-01-01

Energetic particles exist ubiquitously and cause varied biological effects such as DNA strand breaks, lipid peroxidation, protein modification, cell apoptosis or death. An emerging biotechnology based on ion-beam technique has been developed to serve as an effective tool for mutation breeding of crops and microbes. In order to improve the effectiveness of ion-beam biotechnology for mutation breeding, it is indispensible to gain a better understanding of the mechanism of the interactions between the energetic ions and biological systems which is still elusive. A new trend is to conduct more comprehensive research which is based on micro-scaled observation of the changes of the cellular structures and compositions under the interactions. For this purpose, advanced synchrotron FTIR (s-FTIR) microscopy was employed to monitor the cellular changes of single fungal hyphae under irradiation of α-particles from 241Am. Intracellular contents of ROS, MDA, GSSG/GSH and activities of CAT and SOD were measured via biochemical assay. Ion-irradiation on Rhizopus oryzae causes localized vacuolation, autolysis of cell wall and membrane, lipid peroxidation, DNA damage and conformational changes of proteins, which have been clearly revealed by the s-FTIR microspectroscopy. The different changes of cell viability, SOD and CAT activities can be explained by the ROS-involved chemical reactions. Evidently, the elevated level of ROS in hyphal cells upon irradiation plays the key role in the caused biological effect. This study demonstrates that s-FTIR microspectroscopy is an effective tool to study the damage of fungal hyphae caused by ionizing radiation and it facilitates the exploit of the mechanism for the interactions between the energetic ions and biological systems.

Transport, manipulation, and reaction of biological cells on-chip using electrokinetic effects.

PubMed

Li, P C; Harrison, D J

1997-04-15

A microfluidic system was fabricated on a glass chip to study mobilization of biological cells on-chip. Electroosmotic and/or electrophoretic pumping were used to drive the cell transport within a network of capillary channels. Whole cells such as Saccharomyces cerevisiae, canine erythrocyte, and Escherichia coli were employed in this work. Photographs are presented to illustrate how cells are selected and transported from one location to another within the capillary network, with velocities up to about 0.5 mm/s in capillaries with a 15- x 55-microns cross section. The mixing of canine erythrocytes with the lysing agent sodium dodecyl sulfate, at an intersection within the chip, was performed to demonstrate that cell selection and subsequent reaction can be accomplished within the microchip.

Lipid Rafts in Mast Cell Biology

PubMed Central

Silveira e Souza, Adriana Maria Mariano; Mazucato, Vivian Marino; Jamur, Maria Célia; Oliver, Constance

2011-01-01

Mast cells have long been recognized to have a direct and critical role in allergic and inflammatory reactions. In allergic diseases, these cells exert both local and systemic responses, including allergic rhinitis and anaphylaxis. Mast cell mediators are also related to many chronic inflammatory conditions. Besides the roles in pathological conditions, the biological functions of mast cells include roles in innate immunity, involvement in host defense mechanisms against parasites, immunomodulation of the immune system, tissue repair, and angiogenesis. Despite their growing significance in physiological and pathological conditions, much still remains to be learned about mast cell biology. This paper presents evidence that lipid rafts or raft components modulate many of the biological processes in mast cells, such as degranulation and endocytosis, play a role in mast cell development and recruitment, and contribute to the overall preservation of mast cell structure and organization. PMID:21490812

Relative biological effectiveness in canine osteosarcoma cells irradiated with accelerated charged particles

PubMed Central

Maeda, Junko; Cartwright, Ian M.; Haskins, Jeremy S.; Fujii, Yoshihiro; Fujisawa, Hiroshi; Hirakawa, Hirokazu; Uesaka, Mitsuru; Kitamura, Hisashi; Fujimori, Akira; Thamm, Douglas H.; Kato, Takamitsu A.

2016-01-01

Heavy ions, characterized by high linear energy transfer (LET) radiation, have advantages compared with low LET protons and photons in their biological effects. The application of heavy ions within veterinary clinics requires additional background information to determine heavy ion efficacy. In the present study, comparison of the cell-killing effects of photons, protons and heavy ions was investigated in canine osteosarcoma (OSA) cells in vitro. A total of four canine OSA cell lines with various radiosensitivities were irradiated with 137Cs gamma-rays, monoenergetic proton beams, 50 keV/µm carbon ion spread out Bragg peak beams and 200 keV/µm iron ion monoenergetic beams. Clonogenic survival was examined using colony-forming as says, and relative biological effectiveness (RBE) values were calculated relative to gamma-rays using the D10 value, which is determined as the dose (Gy) resulting in 10% survival. For proton irradiation, the RBE values for all four cell lines were 1.0–1.1. For all four cell lines, exposure to carbon ions yielded a decreased cell survival compared with gamma-rays, with the RBE values ranging from 1.56–2.10. Iron ions yielded the lowest cell survival among tested radiation types, with RBE values ranging from 3.51–3.69 observed in the three radioresistant cell lines. The radiosensitive cell line investigated demonstrated similar cell survival for carbon and iron ion irradiation. The results of the present study suggest that heavy ions are more effective for killing radioresistant canine OSA cells when compared with gamma-rays and protons. This markedly increased efficiency of cell killing is an attractive reason for utilizing heavy ions for radioresistant canine OSA. PMID:27446477

Stem-Cell-Based Tumorigenesis in Adult Drosophila.

PubMed

Hou, S X; Singh, S R

2017-01-01

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

[Treatment of wrinkles of the upper lip by emulsified fat or "Nanofat": Biological and clinical study about 4 cases].

PubMed

Mesguich Batel, F; Bertrand, B; Magalon, J; François, P; Velier, M; Veran, J; Mallet, S; Jouve, E; Sabatier, F; Casanova, D

2018-02-01

Emulsified fat injection showed its interest in aesthetic facial surgery. The adipose tissue harvested is mechanically emulsified and filtered. The suspension obtained is injected into the dermis through small diameter needles (27 to 30 gauges). The objective of our study was to evaluate the biological composition of emulsified fat and its clinical effectiveness in the treatment of peri-oral wrinkles in 4 patients aged 50 to 59 years. Each patient received an intradermal injection of emulsified fat in the peri-oral wrinkles prepared from abdominal fat under local anesthesia. The cell viability, stromal vascular fraction (FVS) composition in emulsified fat and the adipocyte differentiation capacity of mesenchymal stem cells (MSC) were studied. The clinical results were evaluated by standardized photographs, 3D microphotography, confocal microscopy, and self-evaluation of patient satisfaction over a period of 4 months. The biological study of the emulsified fat found a lysis of all the adipocytes. The mean number of FVS cells was 126,330±2758 cells by cc of emulsified fat with preserved cell viability (85.1±6.84 %) and a good proportion of regeneratives cells (18.77±6.2 %). The clinical study found a tendency to decrease the volume of wrinkles on standardized photography and 3D microphotography no significative. Patients were satisfied with treatment with an average score of 7±1.15/10 to 4 months. Intradermal injection of emulsified fat seems to be an interesting treatment of face wrinkles. Our study has shown its safety, but additional studies seems necessary to confirm its clinical efficacy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Searching and Mining Visually Observed Phenotypes of Maize Mutants

USDA-ARS?s Scientific Manuscript database

There are thousands of maize mutants, which are invaluable resources for plant research. Geneticists use them to study underlying mechanisms of biochemistry, cell biology, cell development, and cell physiology. To streamline the understanding of such complex processes, researchers need the most curr...

Theories and models on the biological of cells in space

NASA Technical Reports Server (NTRS)

Todd, P.; Klaus, D. M.

1996-01-01

A wide variety of observations on cells in space, admittedly made under constraining and unnatural conditions in may cases, have led to experimental results that were surprising or unexpected. Reproducibility, freedom from artifacts, and plausibility must be considered in all cases, even when results are not surprising. The papers in symposium on 'Theories and Models on the Biology of Cells in Space' are dedicated to the subject of the plausibility of cellular responses to gravity -- inertial accelerations between 0 and 9.8 m/sq s and higher. The mechanical phenomena inside the cell, the gravitactic locomotion of single eukaryotic and prokaryotic cells, and the effects of inertial unloading on cellular physiology are addressed in theoretical and experimental studies.

Proton beam writing of microstructures in Agar gel for patterned cell growth

NASA Astrophysics Data System (ADS)

Larisch, Wolfgang; Koal, Torsten; Werner, Ronald; Hohlweg, Marcus; Reinert, Tilo; Butz, Tilman

2011-10-01

A rather useful prerequisite for many biological and biophysical studies, e.g., for cell-cell communication or neuronal networks, is confined cell growth on micro-structured surfaces. Solidified Agar layers have smooth surfaces which are electrically neutral and thus inhibit receptor binding and cell adhesion. For the first time, Agar microstructures have been manufactured using proton beam writing (PBW). In the irradiated Agar material the polysaccharides are split into oligosaccharides which can easily be washed off leaving Agar-free areas for cell adhesion. The beam diameter of 1 μm allows the fabrication of compartments accommodating single cells which are connected by micrometer-sized channels. Using the external beam the production process is very fast. Up to 50 Petri dishes can be produced per day which makes this technique very suitable for biological investigations which require large throughputs.

Modeling the formation of cell-matrix adhesions on a single 3D matrix fiber.

PubMed

Escribano, J; Sánchez, M T; García-Aznar, J M

2015-11-07

Cell-matrix adhesions are crucial in different biological processes like tissue morphogenesis, cell motility, and extracellular matrix remodeling. These interactions that link cell cytoskeleton and matrix fibers are built through protein clutches, generally known as adhesion complexes. The adhesion formation process has been deeply studied in two-dimensional (2D) cases; however, the knowledge is limited for three-dimensional (3D) cases. In this work, we simulate different local extracellular matrix properties in order to unravel the fundamental mechanisms that regulate the formation of cell-matrix adhesions in 3D. We aim to study the mechanical interaction of these biological structures through a three dimensional discrete approach, reproducing the transmission pattern force between the cytoskeleton and a single extracellular matrix fiber. This numerical model provides a discrete analysis of the proteins involved including spatial distribution, interaction between them, and study of the different phenomena, such as protein clutches unbinding or protein unfolding. Copyright © 2015 Elsevier Ltd. All rights reserved.

BASiCS: Bayesian Analysis of Single-Cell Sequencing Data

PubMed Central

Vallejos, Catalina A.; Marioni, John C.; Richardson, Sylvia

2015-01-01

Single-cell mRNA sequencing can uncover novel cell-to-cell heterogeneity in gene expression levels in seemingly homogeneous populations of cells. However, these experiments are prone to high levels of unexplained technical noise, creating new challenges for identifying genes that show genuine heterogeneous expression within the population of cells under study. BASiCS (Bayesian Analysis of Single-Cell Sequencing data) is an integrated Bayesian hierarchical model where: (i) cell-specific normalisation constants are estimated as part of the model parameters, (ii) technical variability is quantified based on spike-in genes that are artificially introduced to each analysed cell’s lysate and (iii) the total variability of the expression counts is decomposed into technical and biological components. BASiCS also provides an intuitive detection criterion for highly (or lowly) variable genes within the population of cells under study. This is formalised by means of tail posterior probabilities associated to high (or low) biological cell-to-cell variance contributions, quantities that can be easily interpreted by users. We demonstrate our method using gene expression measurements from mouse Embryonic Stem Cells. Cross-validation and meaningful enrichment of gene ontology categories within genes classified as highly (or lowly) variable supports the efficacy of our approach. PMID:26107944

A Transparent Window into Biology: A Primer on Caenorhabditis elegans.

PubMed

Corsi, Ann K; Wightman, Bruce; Chalfie, Martin

2015-06-01

A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues. Copyright © 2015 Corsi, Wightman, and Chalfie.

Computational Tools for Stem Cell Biology

PubMed Central

Bian, Qin; Cahan, Patrick

2016-01-01

For over half a century, the field of developmental biology has leveraged computation to explore mechanisms of developmental processes. More recently, computational approaches have been critical in the translation of high throughput data into knowledge of both developmental and stem cell biology. In the last several years, a new sub-discipline of computational stem cell biology has emerged that synthesizes the modeling of systems-level aspects of stem cells with high-throughput molecular data. In this review, we provide an overview of this new field and pay particular attention to the impact that single-cell transcriptomics is expected to have on our understanding of development and our ability to engineer cell fate. PMID:27318512

Computational Tools for Stem Cell Biology.

PubMed

Bian, Qin; Cahan, Patrick

2016-12-01

For over half a century, the field of developmental biology has leveraged computation to explore mechanisms of developmental processes. More recently, computational approaches have been critical in the translation of high throughput data into knowledge of both developmental and stem cell biology. In the past several years, a new subdiscipline of computational stem cell biology has emerged that synthesizes the modeling of systems-level aspects of stem cells with high-throughput molecular data. In this review, we provide an overview of this new field and pay particular attention to the impact that single cell transcriptomics is expected to have on our understanding of development and our ability to engineer cell fate. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of different air-abrasive powders on cell viability at biologically contaminated titanium dental implants surfaces.

PubMed

Schwarz, Frank; Ferrari, Daniel; Popovski, Kristian; Hartig, Brigitte; Becker, Jürgen

2009-01-01

Studies have indicated that oral biofilm formation at structured titanium surfaces interferes with cell adhesion and proliferation, and its removal by means of conventional treatment procedures may not be sufficient to render these surfaces biologically acceptable. Therefore, the aim of the study was to evaluate the influence of different air-abrasive powders on cell viability at biologically contaminated titanium dental implant surfaces. Intraoral splints were used to collect an in vivo biofilm on sandblasted and acid-etched titanium discs for 48 h. A single (1x) and repeated (2x) use of four different powders (amino acid glycine or sodium bicarbonate particles; range of mean particle size (d(v50)):20-75 microm) was applied at two distances (1 and 2 mm) and angles (30 degrees and 90 degrees) to the surfaces. Specimens (2x) were incubated with SaOs-2 cells for 7 days. Residual biofilm (RB) areas (%), and surface alterations (SEM) (1x and 2x), as well as SaOs-2 cell viability, expressed as mitochondrial cell activity (MA) (counts/second) (2x specimens), were assessed. Comparable mean RB areas were observed within and between groups after both 1x (RB: 0.0% +/- 0.0% to 5.7% +/- 5.7%) and 2x (RB: 0.0% +/- 0.0%) treatments. All surface treatments did not lead to MA (2x) values comparable to the sterile control group. However, sodium bicarbonate particles resulted in significantly higher MA (2x) values than amino acid glycine powders of different sizes. This was associated with pronounced alterations of the surface morphology (2x). Within the limits of the present study, it was concluded that SaOs-2 cell viability at biologically contaminated titanium surfaces was mainly influenced by the particle type of the powder. (c) 2008 Wiley Periodicals, Inc.

History of the molecular biology of cytomegaloviruses.

PubMed

Stinski, Mark F

2014-01-01

The history of the molecular biology of cytomegaloviruses from the purification of the virus and the viral DNA to the cloning and expression of the viral genes is reviewed. A key genetic element of cytomegalovirus (the CMV promoter) contributed to our understanding of eukaryotic cell molecular biology and to the development of lifesaving therapeutic proteins. The study of the molecular biology of cytomegaloviruses also contributed to the development of antivirals to control the viral infection.

[THE PHYSICAL CHEMICAL, BIOLOGICAL BASICS OF CELLS ABSORPTION OF UNESTERIFIED FATTY ACIDS; ALBUMIN, CAVEOLIN, CLATHRIN AND LIPID-BINDING PROTEINS OF CYTOPLASM (THE LECTURE)].

PubMed

Titov, V N; Shoibonov, B B

2016-03-01

From aposition of phylogenetic theory of general pathology, obesity and metabolic syndrome are pathology of fatty cells. However, the first is a pathology of phylogenetically early visceral fatty cells of omentum. They supply with substratum of energy realization of biologic function of trophology, homeostasis, endoecology and adaptation. The visceral fatty cells of omentum have no receptors to insulin and synthesize adaptively insulin and they are not characterized by biologic reaction of proliferation. The obesity is a pathology of late in phylogenesis subcutaneous adpocytes. They are insulin-dependent and supply with substratum of energy realization of one biologic function of locomotion--movement at the expense of constriction of cross-striated miocytes. The adipocytes in terms of adaptation synthesize humoral mediator adponectin and actively implement biologic function of proliferation. Under both aphysiologic conditions increases passive by gradient of concentration, absorption by cells albumin-unbound free fatty acids in unionized form in micellae's composition. The passive aphysiologic absorption of free fatty acids by cells which under intracellular compartmentalization don't oxidize mitochondria results in synthesis, accumulation of triglycerides in cytoplasm of cells which don't implement it physiologically. The aphysiologic absorption of free fatty acids by cells, their etherification in triglyceride, in particular, in phylogenetically late β-cells of islets and either late cardiomyocytes which fatty acids don't synthesize de novo results in development of aphysiologic processes and disorder of function. From position of biology, these cells in vivo are subjected to loss similar to apoptosis. The formation of corpuscles of apoptosis compromise biologic function of endoecology activating biologic reaction of inflammation.

Isolation and genetic analysis of pure cells from forensic biological mixtures: The precision of a digital approach.

PubMed

Fontana, F; Rapone, C; Bregola, G; Aversa, R; de Meo, A; Signorini, G; Sergio, M; Ferrarini, A; Lanzellotto, R; Medoro, G; Giorgini, G; Manaresi, N; Berti, A

2017-07-01

Latest genotyping technologies allow to achieve a reliable genetic profile for the offender identification even from extremely minute biological evidence. The ultimate challenge occurs when genetic profiles need to be retrieved from a mixture, which is composed of biological material from two or more individuals. In this case, DNA profiling will often result in a complex genetic profile, which is then subject matter for statistical analysis. In principle, when more individuals contribute to a mixture with different biological fluids, their single genetic profiles can be obtained by separating the distinct cell types (e.g. epithelial cells, blood cells, sperm), prior to genotyping. Different approaches have been investigated for this purpose, such as fluorescent-activated cell sorting (FACS) or laser capture microdissection (LCM), but currently none of these methods can guarantee the complete separation of different type of cells present in a mixture. In other fields of application, such as oncology, DEPArray™ technology, an image-based, microfluidic digital sorter, has been widely proven to enable the separation of pure cells, with single-cell precision. This study investigates the applicability of DEPArray™ technology to forensic samples analysis, focusing on the resolution of the forensic mixture problem. For the first time, we report here the development of an application-specific DEPArray™ workflow enabling the detection and recovery of pure homogeneous cell pools from simulated blood/saliva and semen/saliva mixtures, providing full genetic match with genetic profiles of corresponding donors. In addition, we assess the performance of standard forensic methods for DNA quantitation and genotyping on low-count, DEPArray™-isolated cells, showing that pure, almost complete profiles can be obtained from as few as ten haploid cells. Finally, we explore the applicability in real casework samples, demonstrating that the described approach provides complete separation of cells with outstanding precision. In all examined cases, DEPArray™ technology proves to be a groundbreaking technology for the resolution of forensic biological mixtures, through the precise isolation of pure cells for an incontrovertible attribution of the obtained genetic profiles. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Multiway modeling and analysis in stem cell systems biology

PubMed Central

2008-01-01

Background Systems biology refers to multidisciplinary approaches designed to uncover emergent properties of biological systems. Stem cells are an attractive target for this analysis, due to their broad therapeutic potential. A central theme of systems biology is the use of computational modeling to reconstruct complex systems from a wealth of reductionist, molecular data (e.g., gene/protein expression, signal transduction activity, metabolic activity, etc.). A number of deterministic, probabilistic, and statistical learning models are used to understand sophisticated cellular behaviors such as protein expression during cellular differentiation and the activity of signaling networks. However, many of these models are bimodal i.e., they only consider row-column relationships. In contrast, multiway modeling techniques (also known as tensor models) can analyze multimodal data, which capture much more information about complex behaviors such as cell differentiation. In particular, tensors can be very powerful tools for modeling the dynamic activity of biological networks over time. Here, we review the application of systems biology to stem cells and illustrate application of tensor analysis to model collagen-induced osteogenic differentiation of human mesenchymal stem cells. Results We applied Tucker1, Tucker3, and Parallel Factor Analysis (PARAFAC) models to identify protein/gene expression patterns during extracellular matrix-induced osteogenic differentiation of human mesenchymal stem cells. In one case, we organized our data into a tensor of type protein/gene locus link × gene ontology category × osteogenic stimulant, and found that our cells expressed two distinct, stimulus-dependent sets of functionally related genes as they underwent osteogenic differentiation. In a second case, we organized DNA microarray data in a three-way tensor of gene IDs × osteogenic stimulus × replicates, and found that application of tensile strain to a collagen I substrate accelerated the osteogenic differentiation induced by a static collagen I substrate. Conclusion Our results suggest gene- and protein-level models whereby stem cells undergo transdifferentiation to osteoblasts, and lay the foundation for mechanistic, hypothesis-driven studies. Our analysis methods are applicable to a wide range of stem cell differentiation models. PMID:18625054

The secretion and biological function of tumor suppressor maspin as an exosome cargo protein.

PubMed

Dean, Ivory; Dzinic, Sijana H; Bernardo, M Margarida; Zou, Yi; Kimler, Vickie; Li, Xiaohua; Kaplun, Alexander; Granneman, James; Mao, Guangzhao; Sheng, Shijie

2017-01-31

Maspin is an epithelial-specific tumor suppressor shown to exert its biological effects as an intracellular, cell membrane-associated, and secreted free molecule. A recent study suggests that upon DNA-damaging g-irradiation, tumor cells can secrete maspin as an exosome-associated protein. To date, the biological significance of exosomal secretion of maspin is unknown. The current study aims at addressing whether maspin is spontaneously secreted as an exosomal protein to regulate tumor/stromal interactions. We prepared exosomes along with cell extracts and vesicle-depleted conditioned media (VDCM) from normal epithelial (CRL2221, MCF-10A and BEAS-2B) and cancer (LNCaP, PC3 and SUM149) cell lines. Atomic force microscopy and dynamic light scattering analysis revealed similar size distribution patterns and surface zeta potentials between the normal cells-derived and tumor cells-derived exosomes. Electron microscopy revealed that maspin was encapsulated by the exosomal membrane as a cargo protein. While western blotting revealed that the level of exosomal maspin from tumor cell lines was disproportionally lower relative to the levels of corresponding intracellular and VDCM maspin, as compared to that from normal cell lines, maspin knockdown in MCF-10A cells led to maspin-devoid exosomes, which exhibited significantly reduced suppressive effects on the chemotaxis activity of recipient NIH3T3 fibroblast cells. These data are the first to demonstrate the potential of maspin delivered by exosomes to block tumor-induced stromal response, and support the clinical application of exosomal maspin in cancer diagnosis and treatment.

Novel image analysis methods for quantification of in situ 3-D tendon cell and matrix strain.

PubMed

Fung, Ashley K; Paredes, J J; Andarawis-Puri, Nelly

2018-01-23

Macroscopic tendon loads modulate the cellular microenvironment leading to biological outcomes such as degeneration or repair. Previous studies have shown that damage accumulation and the phases of tendon healing are marked by significant changes in the extracellular matrix, but it remains unknown how mechanical forces of the extracellular matrix are translated to mechanotransduction pathways that ultimately drive the biological response. Our overarching hypothesis is that the unique relationship between extracellular matrix strain and cell deformation will dictate biological outcomes, prompting the need for quantitative methods to characterize the local strain environment. While 2-D methods have successfully calculated matrix strain and cell deformation, 3-D methods are necessary to capture the increased complexity that can arise due to high levels of anisotropy and out-of-plane motion, particularly in the disorganized, highly cellular, injured state. In this study, we validated the use of digital volume correlation methods to quantify 3-D matrix strain using images of naïve tendon cells, the collagen fiber matrix, and injured tendon cells. Additionally, naïve tendon cell images were used to develop novel methods for 3-D cell deformation and 3-D cell-matrix strain, which is defined as a quantitative measure of the relationship between matrix strain and cell deformation. The results support that these methods can be used to detect strains with high accuracy and can be further extended to an in vivo setting for observing temporal changes in cell and matrix mechanics during degeneration and healing. Copyright © 2017. Published by Elsevier Ltd.

Ultrasound-mediated structural changes in cells revealed by FTIR spectroscopy: a contribution to the optimization of gene and drug delivery.

PubMed

Grimaldi, Paola; Di Giambattista, Lucia; Giordani, Serena; Udroiu, Ion; Pozzi, Deleana; Gaudenzi, Silvia; Bedini, Angelico; Giliberti, Claudia; Palomba, Raffaele; Castellano, Agostina Congiu

2011-12-15

Ultrasound effects on biological samples are gaining a growing interest concerning in particular, the intracellular delivery of drugs and genes in a safe and in a efficient way. Future progress in this field will require a better understanding of how ultrasound and acoustic cavitation affect the biological system properties. The morphological changes of cells due to ultrasound (US) exposure have been extensively studied, while little attention has been given to the cells structural changes. We have exposed two different cell lines to 1 MHz frequency ultrasound currently used in therapy, Jurkat T-lymphocytes and NIH-3T3 fibroblasts, both employed as models respectively in the apoptosis and in the gene therapy studies. The Fourier Transform Infrared (FTIR) Spectroscopy was used as probe to reveal the structural changes in particular molecular groups belonging to the main biological systems. The genotoxic damage of cells exposed to ultrasound was ascertained by the Cytokinesis-Block Micronucleus (CBMN) assay. The FTIR spectroscopy results, combined with multivariate statistical analysis, regarding all cellular components (lipids, proteins, nucleic acids) of the two cell lines, show that Jurkat cells are more sensitive to therapeutic ultrasound in the lipid and protein regions, whereas the NIH-3T3 cells are more sensitive in the nucleic acids region; a meaningful genotoxic effect is present in both cell lines only for long sonication times while in the Jurkat cells also a significant cytotoxic effect is revealed for long times of exposure to ultrasound. Copyright © 2011 Elsevier B.V. All rights reserved.

Fluid models and simulations of biological cell phenomena

NASA Technical Reports Server (NTRS)

Greenspan, H. P.

1982-01-01

The dynamics of coated droplets are examined within the context of biofluids. Of specific interest is the manner in which the shape of a droplet, the motion within it as well as that of aggregates of droplets can be controlled by the modulation of surface properties and the extent to which such fluid phenomena are an intrinsic part of cellular processes. From the standpoint of biology, an objective is to elucidate some of the general dynamical features that affect the disposition of an entire cell, cell colonies and tissues. Conventionally averaged field variables of continuum mechanics are used to describe the overall global effects which result from the myriad of small scale molecular interactions. An attempt is made to establish cause and effect relationships from correct dynamical laws of motion rather than by what may have been unnecessary invocation of metabolic or life processes. Several topics are discussed where there are strong analogies droplets and cells including: encapsulated droplets/cell membranes; droplet shape/cell shape; adhesion and spread of a droplet/cell motility and adhesion; and oams and multiphase flows/cell aggregates and tissues. Evidence is presented to show that certain concepts of continuum theory such as suface tension, surface free energy, contact angle, bending moments, etc. are relevant and applicable to the study of cell biology.

Enhanced Deposition by Electrostatic Field-Assistance Aggravating Diesel Exhaust Aerosol Toxicity for Human Lung Cells.

PubMed

Stoehr, Linda C; Madl, Pierre; Boyles, Matthew S P; Zauner, Roland; Wimmer, Monika; Wiegand, Harald; Andosch, Ancuela; Kasper, Gerhard; Pesch, Markus; Lütz-Meindl, Ursula; Himly, Martin; Duschl, Albert

2015-07-21

Air pollution is associated with increased risk of cardiovascular and pulmonary diseases, but conventional air quality monitoring gives no information about biological consequences. Exposing human lung cells at the air-liquid interface (ALI) to ambient aerosol could help identify acute biological responses. This study investigated electrode-assisted deposition of diesel exhaust aerosol (DEA) on human lung epithelial cells (A549) in a prototype exposure chamber. A549 cells were exposed to DEA at the ALI and under submerged conditions in different electrostatic fields (EFs) and were assessed for cell viability, membrane integrity, and IL-8 secretion. Qualitative differences of the DEA and its deposition under different EFs were characterized using scanning mobility particle sizer (SMPS) measurements, transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). Upon exposure to DEA only, cell viability decreased and membrane impairment increased for cells at the ALI; submerged cells were unaffected. These responses were enhanced upon application of an EF, as was DEA deposition. No adverse effects were observed for filtered DEA or air only, confirming particle-induced responses. The prototype exposure chamber proved suitable for testing DEA-induced biological responses of cells at the ALI using electrode-assisted deposition and may be useful for analysis of other air pollutants.

Physiologically based microenvironment for in vitro neural differentiation of adipose-derived stem cells.

PubMed

Graziano, Adriana Carol Eleonora; Avola, Rosanna; Perciavalle, Vincenzo; Nicoletti, Ferdinando; Cicala, Gianluca; Coco, Marinella; Cardile, Venera

2018-03-26

The limited capacity of nervous system to promote a spontaneous regeneration and the high rate of neurodegenerative diseases appearance are keys factors that stimulate researches both for defining the molecular mechanisms of pathophysiology and for evaluating putative strategies to induce neural tissue regeneration. In this latter aspect, the application of stem cells seems to be a promising approach, even if the control of their differentiation and the maintaining of a safe state of proliferation should be troubled. Here, we focus on adipose tissue-derived stem cells and we seek out the recent advances on the promotion of their neural differentiation, performing a critical integration of the basic biology and physiology of adipose tissue-derived stem cells with the functional modifications that the biophysical, biomechanical and biochemical microenvironment induces to cell phenotype. The pre-clinical studies showed that the neural differentiation by cell stimulation with growth factors benefits from the integration with biomaterials and biophysical interaction like microgravity. All these elements have been reported as furnisher of microenvironments with desirable biological, physical and mechanical properties. A critical review of current knowledge is here proposed, underscoring that a real advance toward a stable, safe and controllable adipose stem cells clinical application will derive from a synergic multidisciplinary approach that involves material engineer, basic cell biology, cell and tissue physiology.

Unified Mie and fractal scattering by cells and experimental study on application in optical characterization of cellular and subcellular structures.

PubMed

Xu, Min; Wu, Tao T; Qu, Jianan Y

2008-01-01

A unified Mie and fractal model for light scattering by biological cells is presented. This model is shown to provide an excellent global agreement with the angular dependent elastic light scattering spectroscopy of cells over the whole visible range (400 to 700 nm) and at all scattering angles (1.1 to 165 deg) investigated. Mie scattering from the bare cell and the nucleus is found to dominate light scattering in the forward directions, whereas the random fluctuation of the background refractive index within the cell, behaving as a fractal random continuous medium, is found to dominate light scattering at other angles. Angularly dependent elastic light scattering spectroscopy aided by the unified Mie and fractal model is demonstrated to be an effective noninvasive approach to characterize biological cells and their internal structures. The acetowhitening effect induced by applying acetic acid on epithelial cells is investigated as an example. The changes in morphology and refractive index of epithelial cells, nuclei, and subcellular structures after the application of acetic acid are successfully probed and quantified using the proposed approach. The unified Mie and fractal model may serve as the foundation for optical detection of precancerous and cancerous changes in biological cells and tissues based on light scattering techniques.

Utilization of different anti-viral mechanisms by mammalian embryonic stem cells and differentiated cells.

PubMed

Guo, Yan-Lin

2017-01-01

Embryonic stem cells (ESCs) have received tremendous attention because of their potential applications in regenerative medicine. Over the past two decades, intensive research has not only led to the generation of various types of cells from ESCs that can be potentially used for the treatment of human diseases but also led to the formation of new concepts and breakthroughs that have significantly impacted our understanding of basic cell biology and developmental biology. Recent studies have revealed that ESCs and other types of pluripotent cells do not have a functional interferon (IFN)-based anti-viral mechanism, challenging the idea that the IFN system is developed as the central component of anti-viral innate immunity in all types of cells in vertebrates. This finding also provided important insight into a question that has been uncertain for a long time: whether or not the RNA interference (RNAi) anti-viral mechanism operates in mammalian cells. An emerging paradigm is that mammals may have adapted distinct anti-viral mechanisms at different stages of organismal development; the IFN-based system is mainly used by differentiated somatic cells, while the RNAi anti-viral mechanism may be used in ESCs. This paper discusses the molecular basis and biological implications for mammals to have different anti-viral mechanisms during development.

[Study of microorganism sterilization by instant microwave and electromagnetic pulse].

PubMed

Lu, Zhiyuan; Shi, Pinpin; Zhu, Manzuo; Sun, Wenquan; Ding, Hua; Hou, Jianqiang

2008-08-01

The sterilization effects of constant electromagnetic wave and instant pulse on foods and traditional Chinese medical pills are introduced in this paper. From the velum's voltage variation caused by the outward electric filed,the dielectric properties of membranaceous ion and the pass rate of the membranaceous ion, we could analyze the biological heating effect and the biological non-heating effect. The sterilization effect of constant electromagnetic wave is based on the biological heating effect, while the instant electromagnetic pulse is based on the biological non-heating effect. With the applied electronic field, the voltage of membrane could increase, which results in the gates of K+ open, and the flowing out of K+. And the variation of the membranaceous voltage makes the gates of Ca2+ open. The Ca2+ of large consistency could come into the cell by the gradient of voltage. It could induce the death of the cells. The greater the variation of membranaceous voltage becomes, the higher will be the death rate of the cells.

Systems biology of stored blood cells: can it help to extend the expiration date?

PubMed

Paglia, Giuseppe; Palsson, Bernhard Ø; Sigurjonsson, Olafur E

2012-12-05

With increasingly stringent regulations regarding deferral and elimination of blood donors it will become increasingly important to extend the expiration date of blood components beyond the current allowed storage periods. One reason for the storage time limit for blood components is that platelets and red blood cells develop a condition called storage lesions during their storage in plastic blood containers. Systems biology provides comprehensive bio-chemical descriptions of organisms through quantitative measurements and data integration in mathematical models. The biological knowledge for a target organism can be translated in a mathematical format and used to compute physiological properties. The use of systems biology represents a concrete solution in the study of blood cell storage lesions, and it may open up new avenues towards developing better storage methods and better storage media, thereby extending the storage period of blood components. This article is part of a Special Issue entitled: Integrated omics. Copyright © 2012 Elsevier B.V. All rights reserved.

Variation in external representations as part of the classroom lecture:An investigation of virtual cell animations in introductory photosynthesis instruction.

PubMed

Goff, Eric E; Reindl, Katie M; Johnson, Christina; McClean, Phillip; Offerdahl, Erika G; Schroeder, Noah L; White, Alan R

2017-05-01

The use of external representations (ERs) to introduce concepts in undergraduate biology has become increasingly common. Two of the most prevalent are static images and dynamic animations. While previous studies comparing static images and dynamic animations have resulted in somewhat conflicting findings in regards to learning outcomes, the benefits of each have been shown individually. Using ERs developed by the Virtual Cell Animation project, we aim to further investigate student learning using different ERs as part of an introductory biology lecture. We focus our study on the topic of photosynthesis as reports have noted that students struggle with a number of basic photosynthesis concepts. Students (n = 167) in ten sections of introductory biology laboratory were introduced to photosynthesis concepts by instructional lectures differing only in the format of the embedded ERs. Normalized gain scores were calculated, showing that students who learned with dynamic animations outperformed students who learned from static images on the posttest. The results of this study provide possible instructional guidelines for those delivering photosynthesis instruction in the introductory biology classroom. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):226-234, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

Establishment of Cancer Stem Cell Cultures from Human Conventional Osteosarcoma.

PubMed

Palmini, Gaia; Zonefrati, Roberto; Mavilia, Carmelo; Aldinucci, Alessandra; Luzi, Ettore; Marini, Francesca; Franchi, Alessandro; Capanna, Rodolfo; Tanini, Annalisa; Brandi, Maria Luisa

2016-10-14

The current improvements in therapy against osteosarcoma (OS) have prolonged the lives of cancer patients, but the survival rate of five years remains poor when metastasis has occurred. The Cancer Stem Cell (CSC) theory holds that there is a subset of tumor cells within the tumor that have stem-like characteristics, including the capacity to maintain the tumor and to resist multidrug chemotherapy. Therefore, a better understanding of OS biology and pathogenesis is needed in order to advance the development of targeted therapies to eradicate this particular subset and to reduce morbidity and mortality among patients. Isolating CSCs, establishing cell cultures of CSCs, and studying their biology are important steps to improving our understanding of OS biology and pathogenesis. The establishment of human-derived OS-CSCs from biopsies of OS has been made possible using several methods, including the capacity to create 3-dimensional stem cell cultures under nonadherent conditions. Under these conditions, CSCs are able to create spherical floating colonies formed by daughter stem cells; these colonies are termed "cellular spheres". Here, we describe a method to establish CSC cultures from primary cell cultures of conventional OS obtained from OS biopsies. We clearly describe the several passages required to isolate and characterize CSCs.

Comparative Biology of Decellularized Lung Matrix: Implications of Species Mismatch in Regenerative Medicine

PubMed Central

Balestrini, Jenna L.; Gard, Ashley L.; Gerhold, Kristin A.; Wilcox, Elise C.; Liu, Angela; Schwan, Jonas; Le, Andrew V.; Baevova, Pavlina; Dimitrievska, Sashka; Zhao, Liping; Sundaram, Sumati; Sun, Huanxing; Rittié, Laure; Dyal, Rachel; Broekelmann, Tom J.; Mecham, Robert P.; Schwartz, Martin A.; Niklason, Laura E.; White, Eric S.

2016-01-01

Lung engineering is a promising technology, relying on re-seeding of either human or xenographic decellularized matrices with patient-derived pulmonary cells. Little is known about the species-specificity of decellularization in various models of lung regeneration, or if species dependent cell-matrix interactions exist within these systems. Therefore decellularized scaffolds were produced from rat, pig, primate and human lungs, and assessed by measuring residual DNA, mechanical properties, and key matrix proteins (collagen, elastin, glycosaminoglycans). To study intrinsic matrix biologic cues, human endothelial cells were seeded onto acellular slices and analyzed for markers of cell health and inflammation. Despite similar levels of collagen after decellularization, human and primate lungs were stiffer, contained more elastin, and retained fewer glycosaminoglycans than pig or rat lung scaffolds. Human endothelial cells seeded onto human and primate lung tissue demonstrated less expression of vascular cell adhesion molecule and activation of nuclear factor-κB compared to those seeded onto rodent or porcine tissue. Adhesion of endothelial cells was markedly enhanced on human and primate tissues. Our work suggests that species-dependent biologic cues intrinsic to lung extracellular matrix could have profound effects on attempts at lung regeneration. PMID:27344365

Single Cell Multiplex Protein Measurements through Rare Earth Element Immunolabeling, Laser Capture Microdissection and Inductively Coupled Mass Spectrometry.

PubMed

Liba, Amir; Wanagat, Jonathan

2014-11-01

Complex diseases such as heart disease, stroke, cancer, and aging are the primary causes of death in the US. These diseases cause heterogeneous conditions among cells, conditions that cannot be measured in tissue homogenates and require single cell approaches. Understanding protein levels within tissues is currently assayed using various molecular biology techniques (e.g., Western blots) that rely on milligram to gram quantities of tissue homogenates or immunofluorescent (IF) techniques that are limited by spectral overlap. Tissue homogenate studies lack references to tissue structure and mask signals from individual or rare cellular events. Novel techniques are required to bring protein measurement sensitivity to the single cell level and offer spatiotemporal resolution and scalability. We are developing a novel approach to protein quantification by exploiting the inherently low concentration of rare earth elements (REE) in biological systems. By coupling REE-antibody immunolabeling of cells with laser capture microdissection (LCM) and ICP-QQQ, we are achieving multiplexed protein measurement in histological sections of single cells. This approach will add to evolving single cell techniques and our ability to understand cellular heterogeneity in complex biological systems and diseases.

Droplet Microfluidic Platform for the Determination of Single-Cell Lactate Release.

PubMed

Mongersun, Amy; Smeenk, Ian; Pratx, Guillem; Asuri, Prashanth; Abbyad, Paul

2016-03-15

Cancer cells release high levels of lactate that has been correlated to increased metastasis and tumor recurrence. Single-cell measurements of lactate release can identify malignant cells and help decipher metabolic cancer pathways. We present here a novel droplet microfluidic method that allows the fast and quantitative determination of lactate release in many single cells. Using passive forces, droplets encapsulated cells are positioned in an array. The single-cell lactate release rate is determined from the increase in droplet fluorescence as the lactate is enzymatically converted to a fluorescent product. The method is used to measure the cell-to-cell variance of lactate release in K562 leukemia and U87 glioblastoma cancer cell lines and under the chemical inhibition of lactate efflux. The technique can be used in the study of cancer biology, but more broadly in cell biology, to capture the full range of stochastic variations in glycolysis activity in heterogeneous cell populations in a repeatable and high-throughput manner.

IL-7 and CD4 T Follicular Helper Cells in HIV-1 Infection

PubMed Central

Chiodi, Francesca; Bekele, Yonas; Lantto Graham, Rebecka; Nasi, Aikaterini

2017-01-01

IL-7 was previously shown to upregulate the expression of molecules important for interaction of CD4+ T cells with B cells. It is poorly studied whether IL-7 has a role in the biology of T follicular helper (Tfh) cells and whether IL-7 dysregulates the expression of B-cell costimulatory molecules on Tfh cells. We review the literature and provide arguments in favor of IL-7 being involved in the biology of human Tfh cells. The CD127 IL-7 receptor is expressed on circulating Tfh and non-Tfh cells, and we show that IL-7, but not IL-6 or IL-21, upregulates the expression of CD70 and PD-1 on these cells. We conclude that IL-7, a cytokine whose level is elevated during HIV-1 infection, may have a role in increased expression of B cell costimulatory molecules on Tfh cells and lead to abnormal B cell differentiation. PMID:28473831

Clustering Single-Cell Expression Data Using Random Forest Graphs.

PubMed

Pouyan, Maziyar Baran; Nourani, Mehrdad

2017-07-01

Complex tissues such as brain and bone marrow are made up of multiple cell types. As the study of biological tissue structure progresses, the role of cell-type-specific research becomes increasingly important. Novel sequencing technology such as single-cell cytometry provides researchers access to valuable biological data. Applying machine-learning techniques to these high-throughput datasets provides deep insights into the cellular landscape of the tissue where those cells are a part of. In this paper, we propose the use of random-forest-based single-cell profiling, a new machine-learning-based technique, to profile different cell types of intricate tissues using single-cell cytometry data. Our technique utilizes random forests to capture cell marker dependences and model the cellular populations using the cell network concept. This cellular network helps us discover what cell types are in the tissue. Our experimental results on public-domain datasets indicate promising performance and accuracy of our technique in extracting cell populations of complex tissues.