22 April 2013 Sprouting Cells Every inch inside our bodies is covered with a tree-like network of blood vessels. New branches grow from cells in the vessel walls that ‘sprout’ like shoots growing through the skin of a potato. This is controlled by molecules called growth factors. In these six-day-old mouse retinas (visualised using two techniques), new vessels are developing. A red fluorescent dye has been used to observe the patterns of two injected growth factors: VEGF-A (left two images) and VEGF-C (right two). Cell nuclei, both inside and outside the vessels, are stained blue, and the cells that make up the vessel walls are stained white. Both growth factors are densest around the vessel walls, and the green arrowheads point to where they have been taken into individual sprouting cells. Understanding this process may lead to new tools against diseases like cancer, as growth factors enable some tumours to develop their own blood supply. Written by Emma Stoye — Ralf Adams Masanori Nakayama Max Planck Institute for Molecular Biomedicine, Germany Publiehd in Nature Cell Biology 15: 249-260. Reprinted by permission from Macmillan Publishers Ltd: Copyright 2013
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22 April 2013

Sprouting Cells

Every inch inside our bodies is covered with a tree-like network of blood vessels. New branches grow from cells in the vessel walls that ‘sprout’ like shoots growing through the skin of a potato. This is controlled by molecules called growth factors. In these six-day-old mouse retinas (visualised using two techniques), new vessels are developing. A red fluorescent dye has been used to observe the patterns of two injected growth factors: VEGF-A (left two images) and VEGF-C (right two). Cell nuclei, both inside and outside the vessels, are stained blue, and the cells that make up the vessel walls are stained white. Both growth factors are densest around the vessel walls, and the green arrowheads point to where they have been taken into individual sprouting cells. Understanding this process may lead to new tools against diseases like cancer, as growth factors enable some tumours to develop their own blood supply.

Written by Emma Stoye

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19 April 2013 Life’s Support A healthy blood supply is essential to our lives. But before a single drop of blood can flow, cells lining a developing vessel (endothelial cells, pictured here in green with their nuclei stained blue) need to reach out to the surrounding tissue for support. This tiny feat of structural engineering is vital, but difficult to investigate inside the human body. Instead, these endothelial cells have been grown inside a man-made microenvironment – a ‘home-from-home’ recreation of a tissue’s natural chemicals and cells, constructed in a dish. Suitably comfortable, these cells behave as they would in a developing blood vessel, migrating towards deep-tissue cells (bunched-up on the right) that offer firm anchorage and support. Understanding the early stages of vessel formation, known as angiogenesis, might allow pre-emptive treatment of problems during foetal development, but also – as life’s processes often don’t discriminate – to stop new blood vessels developing towards hungry cancers. Written by John Ankers — Gordana Vunjak-Novakovic Columbia University, USA Published in PNAS 110(12): 4551-4556
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19 April 2013

Life’s Support

A healthy blood supply is essential to our lives. But before a single drop of blood can flow, cells lining a developing vessel (endothelial cells, pictured here in green with their nuclei stained blue) need to reach out to the surrounding tissue for support. This tiny feat of structural engineering is vital, but difficult to investigate inside the human body. Instead, these endothelial cells have been grown inside a man-made microenvironment – a ‘home-from-home’ recreation of a tissue’s natural chemicals and cells, constructed in a dish. Suitably comfortable, these cells behave as they would in a developing blood vessel, migrating towards deep-tissue cells (bunched-up on the right) that offer firm anchorage and support. Understanding the early stages of vessel formation, known as angiogenesis, might allow pre-emptive treatment of problems during foetal development, but also – as life’s processes often don’t discriminate – to stop new blood vessels developing towards hungry cancers.

Written by John Ankers

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Neglected Siege Tactics Sieges are a tried and tested tactic in war: if you can stop supplies passing through a city’s gates, it won’t be long before it surrenders. This principle also works on a microscopic scale, and could be important in the fight against sleeping sickness. The parasite that causes the disease has only one pathway to absorb and excrete chemicals, located in an area called the flagellar pocket. Using a nanoparticle, which attaches itself to the parasite’s surface, scientists can disrupt this vital gateway and stop the free movement of substances. The pocket (stained brighter green) of parasites exposed to this nanoparticle (third and forth columns) becomes swollen and distended, compared to those covered in a similar, but inert molecule (first and second column). With its supply line cut, the parasite quickly dies, offering hope to 30,000 sufferers across Africa at risk of coma and death from the disease. Written by Jan Piotrowski — Benoît Stijlemans VIB, Belgium Originally published under a Creative Commons Attribution license Published in PLOS Pathogens 7(6): e1002072
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Neglected Siege Tactics

Sieges are a tried and tested tactic in war: if you can stop supplies passing through a city’s gates, it won’t be long before it surrenders. This principle also works on a microscopic scale, and could be important in the fight against sleeping sickness. The parasite that causes the disease has only one pathway to absorb and excrete chemicals, located in an area called the flagellar pocket. Using a nanoparticle, which attaches itself to the parasite’s surface, scientists can disrupt this vital gateway and stop the free movement of substances. The pocket (stained brighter green) of parasites exposed to this nanoparticle (third and forth columns) becomes swollen and distended, compared to those covered in a similar, but inert molecule (first and second column). With its supply line cut, the parasite quickly dies, offering hope to 30,000 sufferers across Africa at risk of coma and death from the disease.

Written by Jan Piotrowski

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Source: bpod.mrc.ac.uk

Neglected Eyes By definition, neglected diseases are overlooked. Their effects are not often deadly, but can still wreak havoc among an estimated billion people in the world’s poorest populations. Trachoma, a bacterial infection that leads to blindness, is a prime example. Illustrated by this map, in which country size relates to numbers of trachoma cases, the overwhelming burden of the disease falls on Africa and South-East Asia. And, although it causes no large, media-attracting outbreaks, the disease nonetheless takes a dramatic toll. Over 40 million people need treatment, as the roughening of the eyelids and in-growing of their lashes slowly but steadily destroys their eyes. But it doesn’t have to be this way. Treatments costing as little as 50p would go a long way to eliminate the disease, and prevent further growth of the group of more than one million people who have already lost their sight because of the disease. Written by Jan Piotrowski — Copyright SASI Group (University of Sheffield) and Mark Newman (University of Michigan)
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Neglected Eyes

By definition, neglected diseases are overlooked. Their effects are not often deadly, but can still wreak havoc among an estimated billion people in the world’s poorest populations. Trachoma, a bacterial infection that leads to blindness, is a prime example. Illustrated by this map, in which country size relates to numbers of trachoma cases, the overwhelming burden of the disease falls on Africa and South-East Asia. And, although it causes no large, media-attracting outbreaks, the disease nonetheless takes a dramatic toll. Over 40 million people need treatment, as the roughening of the eyelids and in-growing of their lashes slowly but steadily destroys their eyes. But it doesn’t have to be this way. Treatments costing as little as 50p would go a long way to eliminate the disease, and prevent further growth of the group of more than one million people who have already lost their sight because of the disease.

Written by Jan Piotrowski

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Source: bpod.mrc.ac.uk

All Change Our bodies are made up of trillions of cells that become increasingly differentiated [specialised] as we grow and develop. Sometimes the differences between cell types can be seen using a light microscope (left), but sometimes biochemical techniques, like fluorescent labelling of specific proteins (right), are needed to visualise the differences. Using these methods, researchers studying cervical cancer have been able to follow the differentiation of the cells which line the cervix. At 16-weeks’ gestation (top row) the cells are just beginning to specialise. By 20-weeks (middle row) a second type of cells appears (yellow, right column). In adults (bottom row) the tissues are fully specialised and different types of cells are found in distinct parts of the cervix. The red-stained cells lining the v-shaped area in the adult cervix (bottom right) are particularly interesting as they may be where human papilloma virus (HPV) infects and cervical cancer starts. Written by Sarah McLusky — Christopher Crum, Brigham and Women’s Hospital, USA Wa Xian, Institute of Medical Biology, A-STAR, Singapore Published in PNAS 109(26): 10516-10521
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All Change

Our bodies are made up of trillions of cells that become increasingly differentiated [specialised] as we grow and develop. Sometimes the differences between cell types can be seen using a light microscope (left), but sometimes biochemical techniques, like fluorescent labelling of specific proteins (right), are needed to visualise the differences. Using these methods, researchers studying cervical cancer have been able to follow the differentiation of the cells which line the cervix. At 16-weeks’ gestation (top row) the cells are just beginning to specialise. By 20-weeks (middle row) a second type of cells appears (yellow, right column). In adults (bottom row) the tissues are fully specialised and different types of cells are found in distinct parts of the cervix. The red-stained cells lining the v-shaped area in the adult cervix (bottom right) are particularly interesting as they may be where human papilloma virus (HPV) infects and cervical cancer starts.

Written by Sarah McLusky

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Source: bpod.mrc.ac.uk

Bright Eyes A growing foetus is sheltered from the outside world, but external conditions may still affect it. Only a tiny amount of light manages to get inside the womb, but new evidence suggests this may be essential to ensure eyes develop correctly. Inside each growing eye, a cup-shaped network of blood vessels forms to supply the early retina with oxygen and nutrients. After birth these vessels are no longer needed, so they slowly break down. The left-hand image shows the pattern of vessels (stained blue) in the eye of a healthy eight-day-old mouse. In genetically engineered mice that lack the light-absorbing protein melanopsin (right-hand image) the vessels fail to break down normally post-birth, persisting as a dense, tangled mess. Exactly the same thing happens if a foetus grows in total darkness. This discovery may help to explain certain eye abnormalities, although the influence of light during human pregnancy is still unknown. Written by Emma Stoye — Sujata Rao Cincinnati Children’s Hospital Medical Center, USA Reprinted by permission from Macmillan Publishers Ltd: Nature Copyright 2013 Published in Nature 2013
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Bright Eyes

A growing foetus is sheltered from the outside world, but external conditions may still affect it. Only a tiny amount of light manages to get inside the womb, but new evidence suggests this may be essential to ensure eyes develop correctly. Inside each growing eye, a cup-shaped network of blood vessels forms to supply the early retina with oxygen and nutrients. After birth these vessels are no longer needed, so they slowly break down. The left-hand image shows the pattern of vessels (stained blue) in the eye of a healthy eight-day-old mouse. In genetically engineered mice that lack the light-absorbing protein melanopsin (right-hand image) the vessels fail to break down normally post-birth, persisting as a dense, tangled mess. Exactly the same thing happens if a foetus grows in total darkness. This discovery may help to explain certain eye abnormalities, although the influence of light during human pregnancy is still unknown.

Written by Emma Stoye

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Source: bpod.mrc.ac.uk

Regulating Cell Size Studying the cells of our floral friends can reveal some basic principles about the cells in our own bodies. For example, both animal and plant cells generally need to regulate their size, and how they do it is a bit of a mystery. To gain insight, 3D microscopy is used to track how cells of the small flowering plant, Arabidopsis thaliana, grow and divide. In the developing flower bud (pictured), cells marked in blue are those selected for tracking, and green staining indicates cells that are replicating their DNA, in preparation for division. Researchers discovered that these bud cells don’t start DNA replication and cell division until they reach a certain volume. But in another part of the plant these processes aren’t coordinated, leading to more variable cell sizes. Examining molecular differences between these two regions will enable identification of genes and pathways that keep cell sizes in check. Written by Ruth Williams — Robert Sablowski John Innes Centre, UK Copyright Elsevier 2012 Published in Current Biology 22(19):1739–1746
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Regulating Cell Size

Studying the cells of our floral friends can reveal some basic principles about the cells in our own bodies. For example, both animal and plant cells generally need to regulate their size, and how they do it is a bit of a mystery. To gain insight, 3D microscopy is used to track how cells of the small flowering plant, Arabidopsis thaliana, grow and divide. In the developing flower bud (pictured), cells marked in blue are those selected for tracking, and green staining indicates cells that are replicating their DNA, in preparation for division. Researchers discovered that these bud cells don’t start DNA replication and cell division until they reach a certain volume. But in another part of the plant these processes aren’t coordinated, leading to more variable cell sizes. Examining molecular differences between these two regions will enable identification of genes and pathways that keep cell sizes in check.

Written by Ruth Williams

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Published in Current Biology 22(19):17391746
Nerve Garden A developing embryo needs regular care and attention. Like trees and shrubs in an ornamental garden, our nerve cells, or neurons, were regularly pruned to shape their growth in the womb. Here we see magnified areas from the brains of two fruit flies, Drosophila, viewed under a high-powered microscope and stained purple. Their neurons (stained green) have branch-like tips called axons which were pruned back before these pictures were taken to see how they would re-grow. The neurons on the left have blossomed into a thriving network of axons, 2,000 times smaller than the average bonsai tree. The neurons on the right, which lack the guidance of a gene called unf, have failed to re-grow correctly. Human versions of such ‘nerve gardening’ genes may one day be manipulated with drugs to help damaged nerves to regenerate after brain or spinal injuries. Written by John Ankers — Oren Schuldiner Weizmann Institute of Science, Israel Copyright Elsevier 2012 Published in Current Biology 22(19):1774–1782
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Nerve Garden

A developing embryo needs regular care and attention. Like trees and shrubs in an ornamental garden, our nerve cells, or neurons, were regularly pruned to shape their growth in the womb. Here we see magnified areas from the brains of two fruit flies, Drosophila, viewed under a high-powered microscope and stained purple. Their neurons (stained green) have branch-like tips called axons which were pruned back before these pictures were taken to see how they would re-grow. The neurons on the left have blossomed into a thriving network of axons, 2,000 times smaller than the average bonsai tree. The neurons on the right, which lack the guidance of a gene called unf, have failed to re-grow correctly. Human versions of such ‘nerve gardening’ genes may one day be manipulated with drugs to help damaged nerves to regenerate after brain or spinal injuries.

Written by John Ankers

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Published in Current Biology 22(19):17741782

Source: bpod.mrc.ac.uk

Couch Mouse There might be a sinister threat lurking behind the innocent smiles of the Powerpuff Girls. Scientists and parents alike are increasingly worried that excessive screen gazing might affect children’s development. But testing it scientifically presents a challenge. One new approach is to simulate the situation in mice: young mice were exposed to flashing lights and audio from shows such as Pokémon and the Powerpuff Girls for six hours every day (pictured). Following this ‘overstimulation’ their behaviour was assessed, and the mice showed poorer short-term memory, impaired learning, and unusual behaviour. There are parallels between patterns of brain development in humans and mice, and the researchers hoped to successfully mimic interference with neural circuitry. But overstimulation is a hard concept to define, and may not be the same for mice and children. Such studies must be interpreted with caution, but are not without scientific potential. This could be well worth watching. Written by Anthony Lewis — Dimitri A. Christakis Seattle Children’s Research Institute, USA Originally published under Creative Commons (CC-BY-NC-SA 3.0) Published in Scientific Reports 2:546
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Couch Mouse

There might be a sinister threat lurking behind the innocent smiles of the Powerpuff Girls. Scientists and parents alike are increasingly worried that excessive screen gazing might affect children’s development. But testing it scientifically presents a challenge. One new approach is to simulate the situation in mice: young mice were exposed to flashing lights and audio from shows such as Pokémon and the Powerpuff Girls for six hours every day (pictured). Following this ‘overstimulation’ their behaviour was assessed, and the mice showed poorer short-term memory, impaired learning, and unusual behaviour. There are parallels between patterns of brain development in humans and mice, and the researchers hoped to successfully mimic interference with neural circuitry. But overstimulation is a hard concept to define, and may not be the same for mice and children. Such studies must be interpreted with caution, but are not without scientific potential. This could be well worth watching.

Written by Anthony Lewis

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Source: bpod.mrc.ac.uk

Backseat Drivers Tucked away between our spine and stomach lies our pancreas. Faults within this vital organ can cause diseases like diabetes or pancreatitis. These conditions often strike later in life, but problems can also stem from early in development. Inside a mouse embryo, the pancreas is just beginning to take shape (pictured). All the different cells originate from a single layer of tissue, called the epithelium (labelled blue), which is surrounded by a type of ‘packing’ tissue called mesenchyme (labelled green). Mesenchyme cells are like mini backseat drivers, giving out molecular instructions that influence the growth and development of the epithelium. Here (the inset shows a close-up), epithelium is transforming into insulin-producing beta cells, which contain a protein called PDX (labelled red). If the mesenchyme is destroyed the instructions are silenced and the growth of beta cells halts, illustrating the importance of the packing tissue for this growing organ’s fate. Written by Emma Stoye — Matthias Hebrok Diabetes Center, University of California, San Francisco, USA Image originally published under Creative Commons Attribution License Published in PLOS Biology 9(9): e1001143
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Backseat Drivers

Tucked away between our spine and stomach lies our pancreas. Faults within this vital organ can cause diseases like diabetes or pancreatitis. These conditions often strike later in life, but problems can also stem from early in development. Inside a mouse embryo, the pancreas is just beginning to take shape (pictured). All the different cells originate from a single layer of tissue, called the epithelium (labelled blue), which is surrounded by a type of ‘packing’ tissue called mesenchyme (labelled green). Mesenchyme cells are like mini backseat drivers, giving out molecular instructions that influence the growth and development of the epithelium. Here (the inset shows a close-up), epithelium is transforming into insulin-producing beta cells, which contain a protein called PDX (labelled red). If the mesenchyme is destroyed the instructions are silenced and the growth of beta cells halts, illustrating the importance of the packing tissue for this growing organ’s fate.

Written by Emma Stoye

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Source: bpod.mrc.ac.uk