scholarly journals The Importance of Proper Oxygenation in 3D Culture

2021 ◽  
Vol 9 ◽  
Author(s):  
Hubert M. Tse ◽  
Graeme Gardner ◽  
Juan Dominguez-Bendala ◽  
Christopher A. Fraker
Keyword(s):  
Cell Culture ◽  
Oxygen Consumption ◽  
Cell Function ◽  
Cultured Cells ◽  
Culture Media ◽  
Scale Up ◽  
3D Culture ◽  
Seeding Density ◽  
And Function

Cell culture typically employs inexpensive, disposable plasticware, and standard humidified CO2/room air incubators (5% CO2, ∼20% oxygen). These methods have historically proven adequate for the maintenance of viability, function, and proliferation of many cell types, but with broad variation in culture practices. With technological advances it is becoming increasingly clear that cell culture is not a “one size fits all” procedure. Recently, there is a shift toward comprehension of the individual physiological niches of cultured cells. As scale-up production of single cell and 3D aggregates for therapeutic applications has expanded, researchers have focused on understanding the role of many environmental metabolites/forces on cell function and viability. Oxygen, due to its role in cell processes and the requirement for adequate supply to maintain critical energy generation, is one such metabolite gaining increased focus. With the advent of improved sensing technologies and computational predictive modeling, it is becoming evident that parameters such as cell seeding density, culture media height, cellular oxygen consumption rate, and aggregate dimensions should be considered for experimental reproducibility. In this review, we will examine the role of oxygen in 3D cell culture with particular emphasis on primary islets of Langerhans and stem cell-derived insulin-producing SC-β cells, both known for their high metabolic demands. We will implement finite element modeling (FEM) to simulate historical and current culture methods in referenced manuscripts and innovations focusing on oxygen distribution. Our group and others have shown that oxygen plays a key role in proliferation, differentiation, and function of these 3D aggregates. Their culture in plastic consistently results in core regions of hypoxia/anoxia exacerbated by increased media height, aggregate dimensions, and oxygen consumption rates. Static gas permeable systems ameliorate this problem. The use of rotational culture and other dynamic culture systems also have advantages in terms of oxygen supply but come with the caveat that these endocrine aggregates are also exquisitely sensitive to mechanical perturbation. As recent work demonstrates, there is a strong rationale for the use of alternate in vitro systems to maintain physio-normal environments for cell growth and function for better phenotypic approximation of in vivo counterparts.

Protein Purification Techniques

2001 ◽  
Keyword(s):  
Cell Culture ◽  
Protein Purification ◽  
Mammalian Cell Culture ◽  
Scale Up ◽  
Analytical Techniques ◽  
Structure And Function ◽  
Unit Operations ◽  
Practical Guidelines ◽  
P Proteins ◽  
And Function

Proteins are an integral part of molecular and cellular structure and function and are probably the most purified type of biological molecule. In order to elucidate the structure and function of any protein it is first necessary to purify it. Protein purification techniques have evolved over the past ten years with improvements in equipment control, automation, and separation materials, and the introduction of new techniques such as affinity membranes and expanded beds. These developments have reduced the workload involved in protein purification, but there is still a need to consider how unit operations linked together to form a purification strategy, which can be scaled up if necessary. The two Practical Approach books on protein purification have therefore been thoroughly updated and rewritten where necessary. The core of both books is the provision of detailed practical guidelines aimed particularly at laboratory scale purification. Information on scale-up considerations is given where appropriate. The books are not comprehensive but do cover the major laboratory techniques and common sources of protein. Protein Purification Techniques focuses on unit operations and analytical techniques. It starts with an overview of purification strategy and then covers initial extraction and clarification techniques. The rest of the book concentrates on different purification methods with the emphasis being on chromatography. The final chapter considers general scale-up considerations. Protein Purification Applications describes purification strategies from common sources: mammalian cell culture, microbial cell culture, milk, animal tissue, and plant tissue. It also includes chapters on purification of inclusion bodies, fusion proteins, and purification for crystallography. A purification strategy that can produce a highly pure single protein from a crude mixture of proteins, carbohydrates, lipids, and cell debris to is a work of art to be admired. These books (available individually or as a set)are designed to give the laboratory worker the information needed to undertake the challenge of designing such a strategy.

scholarly journals Non-Coding RNA in Pancreas and β-Cell Development

2018 ◽  
Vol 4 (4) ◽  
pp. 41 ◽  
Author(s):  
Wilson K. M. Wong ◽  
Anja E. Sørensen ◽  
Mugdha V. Joglekar ◽  
Anand A. Hardikar ◽  
Louise T. Dalgaard
Keyword(s):  
Cell Function ◽  
Islet Cells ◽  
Current Knowledge ◽  
Cell Development ◽  
Pancreas Development ◽  
Β Cell ◽  
Neighboring Gene ◽  
Non Coding Rnas ◽  
And Function

In this review, we provide an overview of the current knowledge on the role of different classes of non-coding RNAs for islet and β-cell development, maturation and function. MicroRNAs (miRNAs), a prominent class of small RNAs, have been investigated for more than two decades and patterns of the roles of different miRNAs in pancreatic fetal development, islet and β-cell maturation and function are now emerging. Specific miRNAs are dynamically regulated throughout the period of pancreas development, during islet and β-cell differentiation as well as in the perinatal period, where a burst of β-cell replication takes place. The role of long non-coding RNAs (lncRNA) in islet and β-cells is less investigated than for miRNAs, but knowledge is increasing rapidly. The advent of ultra-deep RNA sequencing has enabled the identification of highly islet- or β-cell-selective lncRNA transcripts expressed at low levels. Their roles in islet cells are currently only characterized for a few of these lncRNAs, and these are often associated with β-cell super-enhancers and regulate neighboring gene activity. Moreover, ncRNAs present in imprinted regions are involved in pancreas development and β-cell function. Altogether, these observations support significant and important actions of ncRNAs in β-cell development and function.

scholarly journals Oxygen and Glucose Levels in Cell Culture Media Determine Resveratrol’s Effects on Growth, Hydrogen Peroxide Production, and Mitochondrial Dynamics

Antioxidants ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 157 ◽  
Author(s):  
Joao Fonseca ◽  
Fereshteh Moradi ◽  
Andrew Valente ◽  
Jeffrey Stuart
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Culture ◽  
Cell Growth ◽  
Cultured Cells ◽  
Culture Media ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Network ◽  
Hydrogen Peroxide Production ◽  
Network Characteristics ◽  
Glucose Levels

Resveratrol is a plant-derived polyphenol that has been widely studied for its putative health promoting effects. Many of those studies have been conducted in cell culture, in supra-physiological levels of oxygen and glucose. Resveratrol interacts with reactive oxygen species (ROS) as an antioxidant or pro-oxidant. Resveratrol affects the expression and activities of ROS-producing enzymes and organelles. It is therefore important to consider how cell culture conditions might determine the effects of resveratrol on cultured cells. We determined the effects of resveratrol on cell growth, hydrogen peroxide production, and mitochondrial network characteristics in C2C12 mouse myoblasts and PC3 human prostate cancer cells under conditions of physiological (5%) and supra-physiological (18%) oxygen, and normo- (5 mM) and hyper-glycemia (25 mM). Interestingly, most effects of resveratrol on the parameters measured here were dependent upon prevailing oxygen and glucose levels during the experiment. Many of the effects of resveratrol on cell growth, hydrogen peroxide production, and mitochondrial network characteristics that were seen in 25 mM glucose and/or 18% oxygen were absent under the physiologically relevant conditions of 5 mM glucose with 5% oxygen. These findings emphasize the importance of using physiologically meaningful starting conditions for cell-culture experiments with resveratrol and indeed any manipulation affecting ROS metabolism and mitochondria.

scholarly journals A Triple Threat? The Role of Diet, Nutrition, and the Microbiota in T1D Pathogenesis

2021 ◽  
Vol 8 ◽  
Author(s):  
Emma E. Hamilton-Williams ◽  
Graciela L. Lorca ◽  
Jill M. Norris ◽  
Jessica L. Dunne
Keyword(s):  
Beta Cell ◽  
Intestinal Microbiota ◽  
Beta Cell Function ◽  
Cell Function ◽  
The Body ◽  
Islet Autoimmunity ◽  
Potential Mechanism ◽  
Modifiable Factors ◽  
And Function

In recent years the role of the intestinal microbiota in health and disease has come to the forefront of medical research. Alterations in the intestinal microbiota and several of its features have been linked to numerous diseases, including type 1 diabetes (T1D). To date, studies in animal models of T1D, as well as studies in human subjects, have linked several intestinal microbiota alterations with T1D pathogenesis. Features that are most often linked with T1D pathogenesis include decreased microbial diversity, the relative abundance of specific strains of individual microbes, and altered metabolite production. Alterations in these features as well as others have provided insight into T1D pathogenesis and shed light on the potential mechanism by which the microbiota plays a role in T1D pathogenesis, yet the underlying factors leading to these alterations remains unknown. One potential mechanism for alteration of the microbiota is through diet and nutrition. Previous studies have shown associations of diet with islet autoimmunity, but a direct contributing factor has yet to be identified. Diet, through introduction of antigens and alteration of the composition and function of the microbiota, may elicit the immune system to produce autoreactive responses that result in the destruction of the beta cells. Here, we review the evidence associating diet induced changes in the intestinal microbiota and their contribution to T1D pathogenesis. We further provide a roadmap for determining the effect of diet and other modifiable factors on the entire microbiota ecosystem, including its impact on both immune and beta cell function, as it relates to T1D. A greater understanding of the complex interactions between the intestinal microbiota and several interacting systems in the body (immune, intestinal integrity and function, metabolism, beta cell function, etc.) may provide scientifically rational approaches to prevent development of T1D and other childhood immune and allergic diseases and biomarkers to evaluate the efficacy of interventions.

scholarly journals The Modern Western Diet Rich in Advanced Glycation End-Products (AGEs): An Overview of Its Impact on Obesity and Early Progression of Renal Pathology

Nutrients ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1748 ◽  
Author(s):  
Arianna Bettiga ◽  
Francesco Fiorio ◽  
Federico Di Marco ◽  
Francesco Trevisani ◽  
Annalisa Romani ◽  
...  
Keyword(s):  
Chronic Diseases ◽  
Advanced Glycation End Products ◽  
Cell Function ◽  
Advanced Glycation ◽  
Covalent Bonds ◽  
Physiological Processes ◽  
Glycation End Products ◽  
End Products ◽  
And Function

Advanced glycation end-products (AGEs) are an assorted group of molecules formed through covalent bonds between a reduced sugar and a free amino group of proteins, lipids, and nucleic acids. Glycation alters their structure and function, leading to impaired cell function. They can be originated by physiological processes, when not counterbalanced by detoxification mechanisms, or derive from exogenous sources such as food, cigarette smoke, and air pollution. Their accumulation increases inflammation and oxidative stress through the activation of various mechanisms mainly triggered by binding to their receptors (RAGE). So far, the pathogenic role of AGEs has been evidenced in inflammatory and chronic diseases such as chronic kidney disease, cardiovascular disease, and diabetic nephropathy. This review focuses on the AGE-induced kidney damage, by describing the molecular players involved and investigating its link to the excess of body weight and visceral fat, hallmarks of obesity. Research regarding interventions to reduce AGE accumulation has been of great interest and a nutraceutical approach that would help fighting chronic diseases could be a very useful tool for patients’ everyday lives.

scholarly journals Impact of Dissolved Oxygen during UV-Irradiation on the Chemical Composition and Function of CHO Cell Culture Media

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0150957 ◽  
Author(s):  
Sarah M. Meunier ◽  
Biljana Todorovic ◽  
Emma V. Dare ◽  
Afroza Begum ◽  
Simon Guillemette ◽  
...  
Keyword(s):  
Cell Culture ◽  
Chemical Composition ◽  
Dissolved Oxygen ◽  
Uv Irradiation ◽  
Culture Media ◽  
Cho Cell ◽  
Cell Culture Media ◽  
Cho Cell Culture ◽  
And Function

scholarly journals Chemokines: understanding their role in T-lymphocyte biology

1998 ◽  
Vol 333 (3) ◽  
pp. 457-470 ◽  
Author(s):  
Stephen G. WARD ◽  
John WESTWICK
Keyword(s):  
T Lymphocytes ◽  
Chemokine Receptors ◽  
Protein Tyrosine Kinase ◽  
Cell Function ◽  
Signalling Pathways ◽  
Cc Chemokine ◽  
Intracellular Signalling Pathways ◽  
And Function ◽  
Hiv 1

The chemokines are a complex superfamily of small, secreted proteins that were initially characterized through their chemotactic effects on a variety of leucocytes. The superfamily is divided into families based on structural and genetic considerations and have been termed the CXC, CC, C and CX3C families. Chemokines from these families have a key role in the recruitment and function of T lymphocytes. Moreover, T lymphocytes have also been identified as a source of a number of chemokines. T lymphocytes also express most of the known CXC and CC chemokine receptors to an extent that depends on their state of activation/differentiation and/or the activating stimuli. The expression of two chemokine receptors, namely CXCR4 and CCR5, together with the regulated production of their respective ligands, appears to be extremely important in determining sensitivity of T cells to HIV-1 infection. The intracellular events which mediate the effects of chemokines, particularly those elicited by the CC chemokine RANTES, include activation of both G-protein- and protein tyrosine kinase-coupled signalling pathways. The present review describes our current understanding of the structure and expression of chemokines and their receptors, the effects of chemokines on T-cell function(s), the intracellular signalling pathways activated by chemokines and the role of certain chemokines and chemokine receptors in determining sensitivity to HIV-1 infection.

scholarly journals The Importance of Mimicking Dermal-Epidermal Junction for Skin Tissue Engineering: A Review

2021 ◽  
Vol 8 (11) ◽  
pp. 148
Author(s):  
Mina Aleemardani ◽  
Michael Zivojin Trikić ◽  
Nicola Helen Green ◽  
Frederik Claeyssens
Keyword(s):  
Tissue Engineering ◽  
Cell Function ◽  
Multiple Roles ◽  
Primary Role ◽  
Skin Substitutes ◽  
Anatomical Structures ◽  
And Function ◽  
Bioengineered Skin ◽  
Physical Boundary

There is a distinct boundary between the dermis and epidermis in the human skin called the basement membrane, a dense collagen network that creates undulations of the dermal–epidermal junction (DEJ). The DEJ plays multiple roles in skin homeostasis and function, namely, enhancing the adhesion and physical interlock of the layers, creating niches for epidermal stem cells, regulating the cellular microenvironment, and providing a physical boundary layer between fibroblasts and keratinocytes. However, the primary role of the DEJ has been determined as skin integrity; there are still aspects of it that are poorly investigated. Tissue engineering (TE) has evolved promising skin regeneration strategies and already developed TE scaffolds for clinical use. However, the currently available skin TE equivalents neglect to replicate the DEJ anatomical structures. The emergent ability to produce increasingly complex scaffolds for skin TE will enable the development of closer physical and physiological mimics to natural skin; it also allows researchers to study the DEJ effect on cell function. Few studies have created patterned substrates that could mimic the human DEJ to explore their significance. Here, we first review the DEJ roles and then critically discuss the TE strategies to create the DEJ undulating structure and their effects. New approaches in this field could be instrumental for improving bioengineered skin substitutes, creating 3D engineered skin, identifying pathological mechanisms, and producing and screening drugs.

scholarly journals Protein manipulation using single copies of short peptide tags in cultured cells and in Drosophila melanogaster

Development ◽  
2021 ◽  
Vol 148 (6) ◽  
Author(s):  
M. Alessandra Vigano ◽  
Clara-Maria Ell ◽  
Manuela M. M. Kustermann ◽  
Gustavo Aguilar ◽  
Shinya Matsuda ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Specific Protein ◽  
Cellular Processes ◽  
Cell Compartments ◽  
Peptide Tags ◽  
Genetic Level ◽  
Protein Binders ◽  
And Function

ABSTRACT Cellular development and function rely on highly dynamic molecular interactions among proteins distributed in all cell compartments. Analysis of these interactions has been one of the main topics in cellular and developmental research, and has been mostly achieved by the manipulation of proteins of interest (POIs) at the genetic level. Although genetic strategies have significantly contributed to our current understanding, targeting specific interactions of POIs in a time- and space-controlled manner or analysing the role of POIs in dynamic cellular processes, such as cell migration or cell division, would benefit from more-direct approaches. The recent development of specific protein binders, which can be expressed and function intracellularly, along with advancement in synthetic biology, have contributed to the creation of a new toolbox for direct protein manipulations. Here, we have selected a number of short-tag epitopes for which protein binders from different scaffolds have been generated and showed that single copies of these tags allowed efficient POI binding and manipulation in living cells. Using Drosophila, we also find that single short tags can be used for POI manipulation in vivo.

A Microfluidic Sensing System with a Multichannel Surface Plasmon Resonance Chip: Damage-free Characterization of Cells by Pattern Recognition

2020 ◽  
Author(s):  
Hiroka Sugai ◽  
Shunsuke Tomita ◽  
Sayaka Ishihara ◽  
Kyoko Yoshioka ◽  
Ryoji Kurita
Keyword(s):  
Cell Culture ◽  
Pattern Recognition ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Cultured Cells ◽  
Culture Media ◽  
Biological Research ◽  
Cell Culture Media

<p>The development of a versatile sensing strategy for the damage-free characterization of cultured cells is of great importance for both fundamental biological research and industrial applications. Here, we present a pattern-recognition-based cell-sensing approach using a multichannel surface plasmon resonance (SPR) chip. The chip, in which five cysteine derivatives with different structures are immobilized on Au films, is capable of generating five unique SPR sensorgrams for the cell-secreted molecules that are contained in cell culture media. An automatic statistical program was built to acquire kinetic parameters from the SPR sensorgrams and to select optimal parameters as “pattern information” for subsequent multivariate analysis. Our system rapidly (~ 10 min) provides the complex information by merely depositing a small amount of cell culture media (~ 25 µL) onto the chip, and the amount of information obtained is comparable to that furnished by a combination of conventional laborious biochemical assays. This non-invasive pattern-recognition-based cell-sensing approach could potentially be employed as a versatile tool for characterizing cells. </p>

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