The function of tubular organs like the kidneys, lungs, and vessels of the vascular system is critically dependent on the length and diameter of the tubular branches of which they are composed. Several devastating pathological conditions like polycystic kidney disease and ischemias have been intimately linked to the aberrant sizes of tubular organs. Yet the underlying cellular and molecular mechanisms that control tube size are poorly understood, and, consequently, drugs that intervene in tubular organ disorders are lacking.
Over the past few years, the tracheal system of the fruit fly Drosophila has provided important general insights into epithelial organ morphogenesis. The flys tracheal system is a tubular network that functions in respiration by transporting oxygen throughout the insect body. In two separate new studies, researchers have taken advantage of the usefulness of the Drosophila tracheal system as a model for understanding the development of tubular organs. Both studies point to the important role played in this process by the luminal extracellular matrix (ECM)--a scaffold of sorts that provides structure to surrounding cells and tissues. Past work had shown that inside the tracheal tube, or lumen, the polysaccharide molecule chitin forms a cylinder that is essential for the coordinated dilation of the surrounding epithelium to its normal mature size: Mutants lacking chitin show tubes with irregular diameter.
In one of the new studies, a group led by Christos Samakovlis at Stockholm University has revealed further evidence for an "instructive" function of the luminal ECM in tube size control. They found that while uniform expansion of tube diameter requires the growth of a luminal chitin scaffold, the subsequent modification of this chitinous mandrel by specialized enzymes (called chitin deacetylases) instructs the termination of tube elongation. Mutations in two genes encoding these enzymes disrupt tubular morphogenesis. The authors additional discovery that proper luminal localization of one of the chitin deacetylases requires a specialized secretory pathway and intact structures called paracellular septate junctions provides a mechanistic model for tracheal tube size regulation.
Heidi Hardman | EurekAlert!
Atomic-level motion may drive bacteria's ability to evade immune system defenses
24.04.2017 | Indiana University
Two-dimensional melting of hard spheres experimentally unravelled after 60 years
24.04.2017 | University of Oxford
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
24.04.2017 | Physics and Astronomy
24.04.2017 | Materials Sciences
24.04.2017 | Life Sciences