Archive for the ‘Review articles’ Category

Issue 8 online now!

This month’s outside front cover features work from Jonathan Rocheleau and co-workers at the University of Toronto.

In their article, they introduce a novel method for flavoprotein autofluorescence imaging, to measure the dynamics of fatty acid oxidation linked to pancreatic islet metabolism. They were able to record real-time measurements from islets held stationary in flow using microfluidic devices.

Quantitative imaging of electron transfer flavoprotein autofluorescence reveals the dynamics of lipid partitioning in living pancreatic islets
Alan K. Lam, Pamuditha N. Silva, Svetlana M. Altamentova and Jonathan V. Rocheleau
DOI: 10.1039/C2IB20075A


Work from Konstantinos Konstantopoulos, Kathleen Stebe and colleagues from The Johns Hopkins University and the University of Pennsylvania, was the inspiration for the inside front cover this month.

The article focuses on receptor-mediated cell adhesion in shear flow, and uses an integrated experimental and mathematical approach to gain understanding of the process. Using a microfluidic device combined with a glass slide with P- or L-selectin immobilised onto specific sections, the critical patch length needed by HL-60 leukemic cells to start tethering under flow was investigated. The authors found that the length is prescribed by the minimum number of receptor–ligand bonds needed to start cell tethering and the tensile strength of the bonds.

Selectin-mediated adhesion in shear flow using micropatterned substrates: multiple-bond interactions govern the critical length for cell binding
ZiQiu Tong, Luthur Siu-Lun Cheung, Kathleen J. Stebe and Konstantinos Konstantopoulos
DOI: 10.1039/C2IB20036H


Lance Munn and collaborators at Massachusetts General Hospital and Harvard Medical School’s article features on the back cover of issue 8.

Their paper focuses on vascular anastomosis, and uses a microfluidic device to reproduce the process in vitro. Using a collagenous matrix, the vessels are able to sprout and grow together, forming perfused bridging connections. The authors feel that the device will ‘enable a new generation of studies of the mechanisms of angiogenesis and provide a novel and practical platform for drug screening’.

Anastomosis of endothelial sprouts forms new vessels in a tissue analogue of angiogenesis
Jonathan W. Song, Despina Bazou and Lance L. Munn
DOI: 10.1039/C2IB20061A

Also included in the issue is a review on the role of regucalcin in brain calcium signalling and papers focussing on a method to calculate the change of network metabolites for different time points of transcriptomic datasets and the differential effects of a soluble or immobilized VEGFR-binding peptide.

Read the rest of the issue online here.

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Reviewing the anti-cancer efficacy of curcumin

CurcuminCurcumin, a bioactive ingredient in the fragrant orange spice tumeric, is thought to be effective in suppressing tumor growth and promoting chemoprevention of certain cancers.

In this review article Bassel El-Rayes et al. summarise the recent studies which describe preventive and therapeutic effects of curcumin and its analogues.  In particular they concentrate on the breast cancer model, as curcumin has shown responses in reversing the human breast cancer cell resistance against paclitaxel and may be responsible for the lower incidence of breast cancer in Asian countries.

Read the rest of this interesting review, which also discusses new analogues of curcumin which show better bioavailability than the original molecule, here:

The impact of curcumin on breast cancer
Ganji Purnachandra Nagaraju, Sheik Aliya, Syed F. Zafar, Riyaz Basha, Roberto Diaz and Bassel F. El-Rayes
DOI: 10.1039/C2IB20088K

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Review: Regucalcin in brain calcium signalling and ageing

Incidences of brain illnesses such as Alzheimer’s and Parkinson’s disease are steadily increasing as the population ages. Calcium signalling in the brain is thought to be implicated in the onset of this diseases but the exact relationship between the two remains unknown.

This review by Masayoshi Yamaguchi from the University of Georgia discusses the role of the protein regucalcin, a calcium-binding protein involved in calcium signalling and its expression in the brain, which is known to decrease with age. This could represent part of a possible mechanism of how calcium levels in the brain alter over time. The paper looks at the effects of ageing on calcium signalling and what kind of role regucalcin could play as part of this as well as regucalcin’s role in calcium homeostasis.

Regucalcin has already been implicated in Alzheimer’s and Parkinson’s disease and could also be involved in a number of X-linked mental retardation conditions. This review is a good primer for anyone seeking to learn more about the role of calcium in both healthy and disease brain tissue.

Role of regucalcin in brain calcium signaling: involvement in ageing
Masayoshi Yamaguchi
DOI: 10.1039/C2IB20042B

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Organs-on-chips: breaking the in vitro impasse

Our latest hot review article is from Andries D. van der Meer and Albert van den Berg who review organs-on-chips, microengineered in vitro tissue models which may help us to overcome current limitations in generating realistic tissue models to understand human physiology and pathogenesis.

Simple versus realistic in vitro tissue modelsThey discuss organs-on-chip as platforms for engineered microenvironments, as well as taking a detailed look at the lung-on-a-chip, blood vessel-on-a-chip, liver-on-a-chip and the future of this exciting field.

The article is currently free to access for 4 weeks, so why not take a look:

Organs-on-chips: breaking the in vitro impasse
Andries D. van der Meer and Albert van den Berg
Integr. Biol., 2012, Advance Article
DOI: 10.1039/C2IB00176D

Organs-on-chips your thing? Why not take a look at the latest development, a gut-on-a-chip.

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Perspective: Single-cell analysis platforms to study stem cell self-renewal

Stem cells are defined by their ability to self-renew or to differentiate into a range of somatic cell types. Adult stem cells, such as haematopoietic stem cells are found in specialised niches within the body and have been studied for decades. Much of our knowledge about these cells is based on in vitro experiments but the effects of moving them from their in vivo niche to culture conditions are unclear.

This Perspective from Penney Gilbert and colleagues from the USA and Sweden focuses on adult stem cells found in skeletal muscle, also known as satellite cells. They address the problem that, once extracted from muscle and placed into culture, satellite cells quickly lose their ability to self-renew, complicating studies into their biology. The development of new bioengineering approaches, such as hydrogel microwell arrays, could solve this problem. These approaches can accurately monitor the behaviour of satellite cells and provide robust data sets, thanks to the number of different tests that can be carried out in parallel.

To illustrate the usefulness of such tools, the authors show how stem cell division and self-renewal can be tracked in clonal assays using time-lapse microscopy. By increasing the stiffness of the hydrogel microwells in the assays, satellite cells can be maintained in culture for up to one week and successfully engraft back into mouse muscle.

Stem cells hold the potential to become part of powerful medical treatments and therapies, but only if we understand how we are changing them by removing them from their niche. This Perspective pushes this issue to the fore and offers some suggestions as to how we can further improve stem cell culture. Read this HOT review for free for the next four weeks (following a simple registration for individual users)

A single cell bioengineering approach to elucidate mechanisms of adult stem cell self-renewal
Penney M. Gilbert, Stephane Corbel, Regis Doyonnas, Karen Havenstrite, Klas E. G. Magnusson and Helen M. Blau
DOI: 10.1039/C2IB00148A

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Have you seen our collection of review articles? Topics from DNA assembly for synthetic biology to regulating tumor cell invasion

During 2011 we published a number of topical reviews on a wide range of topics by expert researchers in their fields. We’ve collected some of them below but take a look here for the whole list, we hope you’ll find something interesting in your area.

Graphical abstract C0IB00115EBiophysical regulation of tumor cell invasion: moving beyond matrix stiffness
Amit Pathak and Sanjay Kumar

DNA assembly for synthetic biology: from parts to pathways and beyond
Tom Ellis, Tom Adie and Geoff S. Baldwin

Apoptotic cell signaling in cancer progression and therapy
Jessica Plati, Octavian Bucur and Roya Khosravi-Far

Social selection and the evolution of cooperative groups: The example of the cellular slime moulds
Vidyanand Nanjundiah and Santosh Sathe

Graphical abstract C0IB00103AAn architectural genetic and epigenetic perspective
Gary S. Stein, Janet L. Stein, Andre J. van Wijnen, Jane B. Lian, Sayyed K. Zaidi, Jeffrey A. Nickerson, Martin A. Montecino and Daniel W. Young

Insights on the permeability of wide protein channels: measurement and interpretation of ion selectivity
Vicente M. Aguilella, María Queralt-Martín, Marcel Aguilella-Arzo and Antonio Alcaraz

The origins of cancer robustness and evolvability
Tianhai Tian, Sarah Olson, James M. Whitacre and Angus Harding

If you have an idea for a review article that hasn’t been covered and you would like to see included, contact the Editorial Office – we’d love to hear from you.

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Critical review: Concepts in photoreception

The ability to sense light, known as photoreception, is the basis of all visual sensory systems found on Earth. In this Critical Review from Laura Barsanti and colleagues from the Istituto di Biofisica in Pisa, the basic concepts of photoreception are explored using Eugelena gracilis as an example. E. gracilis is an unicellular alga which uses a basic photoreception system to exploit light for use in photosynthesis.

The review outlines the different photoreceptive systems that are found in organisms and the proteins, signalling pathways and other physiological features which allow these systems to function. This information is then tied together by looking at photoreception in E. gracilis and the technology used to discover how these microscopic organisms sense light.

Why not find out more by downloading this hot article here:

Fundamental questions and concepts about photoreception and the case of Euglena gracilis
Laura Barsanti, Valtere Evangelista, Vincenzo Passarelli, Anna Maria Frassanito and Paolo Gualtieri
DOI: 10.1039/C1IB00115A

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Perspective on agent-based modelling

Mathematical and computational modelling are powerful tools for studying changes in a population over time, however, they function under the assumption that the modelled population is homogenous. Clearly, this does not account for the natural variation seen in populations of organisms, cells and even molecules. This Perspective from Mike Holcombe and colleagues from the University of Sheffield, University of Sussex, University of Ulster and the Rutherford Appleton Laboratory presents a solution to this problem in the form of agent-based or individual-based modelling.

Agent-based modelling allows undefined and unknown parameters to be included in the model, which more accurately represents what is known about the system under study. The article shows the application of agent-based modelling in a number of different scenarios; from immunological pathways to foraging ants. These examples demonstrate just how versatile this modelling method can be.

The authors believe that agent-based modelling could make in virtuo study as much of a part of scientific enquiry as in vitro and in vivo work. See if you agree by downloading the article here:

Modelling complex biological systems using an agent-based approach
Mike Holcombe, Salem Adra, Mesude Bicak, Shawn Chin, Simon Coakley, Alison I. Graham, Jeffrey Green, Chris Greenough, Duncan Jackson, Mariam Kiran, Sheila MacNeil, Afsaneh Maleki-Dizaji, Phil McMinn, Mark Pogson, Robert Poole, Eva Qwarnstrom, Francis Ratnieks, Matthew D. Rolfe, Rod Smallwood, Tao Sun and David Worth
DOI: 10.1039/C1IB00042J

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Review: Biomaterials in cell motility research

This review from Hyung-Do Kim and Shelly Peyton from MIT and the University of Massachusetts looks at cell motility, which plays a crucial role in a diverse  range of situations; from development in the early embryo to metastatic tumours in cancer. It is also a key component of tissue regeneration, where cells are encouraged to colonise a scaffold.

Cell movement can be directed by numerous stimuli including the presence of growth factors and cytokines as well as the makeup of the extracellular matrix which the cell is bound to. But the majority of this knowledge is based upon work using two-dimensional in vitro cultures. To discover more about cell motility, there is a need to develop 3D culture systems, which more accurately represent the tissue environment in vivo. This has been a rapidly expanding field of research in the last two decades with more and more synthetic biomaterials being developed to meet this need.

This review is a recognition of the work which has been done so far and outlines the route it should now take. It takes a closer look at how biomaterials can be used to discover more about different aspects controlling cell motility including chemotaxis, haptotaxis and the effects of the extracellular matrix. The authors call on cell biologists to incorporate these biomaterials into their research and to work together with biomaterials scientists to further our knowledge.

Download the article now to look at the current state of the use of biomaterials in cell motility research – it’s free to access for the next four weeks:

Bio-inspired materials for parsing matrix physicochemical control of cell migration: A Review
Hyung-Do Kim and Shelly R. Peyton
Integr. Biol., 2011, Advance Article
DOI: 10.1039/C1IB00069A

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Red blood cells – getting to places other cells can’t reach

The ability of red blood cells to fit into even the smallest capillary is key to their function of delivering oxygen to tissues around the body. Diseases such as malaria and diabetes can reduce the cells’ deformability, which in turn contributes to the pathology of the disease. Transfused red blood cells can also suffer from an impaired deformability, potentially causing blockages in blood vessels. Deformation of red blood cells has also been observed to induce the release of signalling molecules such as ATP. A greater understanding of the underlying mechanics of cell deformation and molecule release would not only help researchers, but could also  improve the clinical outcome of patients.

This review from Jiandi Wan, Alison Forsyth and Howard Stone from Princeton University presents several mechanical studies which have shown some of the dynamics involved in red blood cell deformation and also discusses what has been learned so far about ATP release from deformed cells.

Red blood cell deformation has been studied under both static and flow conditions. In static conditions, cell deformation is most commonly studied using micropipette aspiration where changes in deformation due to increased stress can be measured as area expansion, shear and bending moduli. These values then show how resistant the cell is to deformation under force. Other, more recent, techniques such as fluorescence labelling can add greater depth to these data by showing changes in the membrane at the molecular level.

Flow conditions subject the cells to hydrodynamic stresses and more accurately replicate the conditions the cells experience in vivo. Under these conditions, the cells show a more complex range of dynamics, such as tank-treading where shear stress crosses the cell membrane and induces circulation within the cytoplasm. These dynamics can also be explained using mathematical models, where flow speed and stress values can be adjusted.

The authors also describe the role that ATP released from red blood cells has in stimulating vasodilation. This ATP release is thought to occur through ABC transporters and is stimulated by a certain duration of shear stress on the cell.

Despite being an area of study for over 50 years, this review shows just how much modern tools can deepen our understanding of it even further. Take a look at the review here:

Red blood cell dynamics: from cell deformation to ATP release
Jiandi Wan, Alison M. Forsyth and Howard A. Stone
Integr. Biol., 2011, Advance Article
DOI: 10.1039/C1IB00044F

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