#angiogenesis

Liver Little

How do organs 'know' how big to get as an animal reaches maturity? Using a mix of techniques including 3D imaging, genetic mapping and cell tracking, this study finds that the blood vessels (vascularisation) developing in new-born mouse liver lobules – the units that make up the whole organ – contribute to determining the size of the liver at adulthood.

Read the published research article here

Video from work by D. Berfin Azizoglu and colleagues

Howard Hughes Medical Institute, Department of Developmental Biology, Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Communications, November 2025

Researchers Discover Key to Regenerating Blood Vessels

A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identifies a signaling pathway that is essential for angiogenesis, the growth of new blood vessels from pre-existing vessels.

Lymphatic 'Scavengers' Discovered in Brain Cells

University of Queensland scientists discovered a new type of lymphatic brain “scavenger” cell by studying tropical freshwater zebrafish — which share many of the same cell types and organs as humans.

Lead researcher Associate Professor Ben Hogan from UQ’s Institute for Molecular Bioscience said the fundamental discovery would help scientists understand how the brain forms and functions.

“It is rare to discover a cell type in the brain that we didn’t know about previously, and particularly a cell type that we didn’t expect to be there,” he said.

“The brain is the only organ without a known lymphatic system, so the fact that these cells are lymphatic in nature and surround the brain makes this finding quite a surprise.

“These cells appear to be the zebrafish version of cells described in humans called “mato” or lipid laden cells, which clear fats and lipids from the system but were not known to be lymphatic in nature.

“When wastes such as excess fats leak out of the bloodstream, it is the job of the lymphatic system to clean them out to avoid damaging our organs.”

Bridging the Gap

Building a bridge across a fast-flowing river requires a perilous first step – someone must reach across the gap. For years, scientists have wondered how cells manage this during angiogenesis, when new branches form in existing blood vessels. Here we see endothelial cells similar to those lining our vessels, arranged around the curved surface of an artificially grown ‘microvessel-on-a-chip’. Captured using 3D microscopy, some cells extend arm-like projections around the curve of the vessel which then pull away, flapping around in the current, while the cells remain attached to the vessel wall. This support allows the tiny 'arms' to stretch out to cells on the opposite side, a bit like a human chain across a river (although about a million times smaller). Investigating the genes and proteins involved may suggest targets for drugs aiming to block angiogenesis in some cancers.

Written by John Ankers

Video from work by Sabrina C. R. Staples and colleagues

Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada

Video originally published with a Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)

Published in Proceedings of the National Academy of Science (PNAS), April 2025

Pressure Vessel

New blood vessels arise from endothelial tip cells sprouting. This study in zebrafish reveals that along with polymerisation of the cell scaffold protein actin, hydrostatic pressure resulting from water intake though channels called aquaporins, underlies the push of tip cells into new territory

Read the published research article here

Video from work by Igor Kondrychyn and colleagues

Laboratory for Vascular Morphogenesis, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in eLife, February 2025

Sugar and Sprouts

Love sugar? Too much can damage your blood vessels, increasing your risk of diabetes and cardiovascular disease. Love artificial sweeteners? Unfortunately, they too may increase your risk of cardiovascular disease. Researchers investigated in zebrafish embryos. Fluorescence microscopy revealed exposing embryos to lots of sugar or artificial sweeteners caused excessive blood vessel sprouting (angiogenesis) along the length of the body (pictured) – a process linked to diabetic complications in humans, including cardiovascular disease. Looking closer at embryos exposed to artificial sweeteners, they found cells lining their blood vessels (endothelial cells) developed into cells that promote sprouting. Analysing the RNA of these cells revealed changes in gene activity, notably reduction of one, Foxo1a (highlighted in red in the vessels along the fish embryo), was underlying the increase in sprouting when the embryos were exposed to sugar. Further experiments confirmed activity of this gene played the same role in embryos exposed to artificial sweeteners, uncovering how these sugar alternatives can negatively affect blood vessels.

Written by Lux Fatimathas

Image from work by Xiaoning Wang, Jinxiang Zhao and Jiehuan Xu, and colleagues

Affiliated Hospital of Nantong University, Nantong Laboratory of Development and Diseases, School of Life Science; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China

Image contributed by the authors under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence

Published in eLife, October 2024

More or Less

After a heart attack, growing new blood vessels (angiogenesis) is essential to repair the damage. In cancer patients, preventing blood vessel growth can starve a tumour and prevent expansion. To investigate the effectiveness of potential new treatments to boost or block angiogenesis, researchers have developed a platform for testing the impact of various interventions on sprouting – the formation of new vessels from existing ones. They confirmed that cells lining the aorta – the body’s largest artery – sprout more in low oxygen conditions (pictured, right) than normal (left), showing the platform can support normal blood vessel growth patterns. They then screened 105 molecules and identified two enzymes that alter gene expression to regulate this vessel sprouting – one promoting growth and the other restricting it. This both provides promising information about these potential stop and go interventions, and provides a green light to screen future drugs.

Written by Anthony Lewis

Image from work by M. Beter and colleagues

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland

Image originally published with a Creative Commons Attribution – NonCommercial – NoDerivs (CC BY-NC-ND 4.0)

Published in Scientific Reports, January 2025

Pulled into Shape

Much like healthy tissues, cancers have needs. A blood supply brings both nutrients and oxygen, and developing cancers often encourage new blood vessels to form – a process called angiogenesis. Highlighted in red here, healthy endothelial cells similar to those lining human blood vessels, are pulled into new 'sprouting' patterns by the tips of mutant cells (green) similar to those found in cancer. Captured overnight under a powerful microscope, the reshaping of the healthy cells slows down or stops as the mutant cells lose contact. Researchers believe cancerous cells may use mechanical pulling forces help to 'reprogram' nearby vessels, like training a vine to grow up a wall, albeit 10,000-times smaller. Understanding the relationships between cancerous and healthy cells is vital to preventing invasion of nearby tissues, perhaps turning this need for blood into a targetable weakness in forms of cancer like cavernous haemangioma.

Written by John Ankers

Video from work by Apeksha Shapeti and colleagues

KU Leuven, Department of Mechanical Engineering, Biomechanics section, Leuven, Belgium

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Communications, October 2024