Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Single microRNA fine-tunes innate immune response

20.02.2008
Findings: A single microRNA, microRNA-223, in mice controls the production and activation of granulocytes, white blood cells essential for host defense against invading pathogens.

Relevance: This is the first microRNA shown to play a crucial role in the innate immune response. Absence of microRNA-223 increased the production, differentiation and activation of granulocytes, causing tissue inflammation and damage. Increased production of microRNA-223 may reduce inflammatory conditions and thus the effects of inflammatory diseases such as acute lung respiratory disease syndrome.

Over the last few years scientists have discovered hundreds of microRNAs—tiny RNAs that regulate the expression of protein-coding genes. However, the functions of these novel molecules in mammals are largely unknown.

Now, scientists in the lab of Whitehead Fellow Fernando Camargo have discovered the first microRNA shown to play a key role in the immune system’s early warning system—the innate immune response. The research, published online on February 17 by Nature, reveals that microRNA-223 controls the production and activation of granulocytes, white blood cells essential for host defense against invading pathogens. The findings may have implications for the treatment of inflammatory conditions as well as leukemia.

“MicroRNA-223 is unique because its expression is entirely restricted to a specific branch of the immune system,” says Camargo. “We found that microRNA-223 is crucial for the development and function of the innate branch of the immune system. Our work suggests that microRNA-223 physiologically fine-tunes both the generation and function of granulocytic cells, delimiting their production and dampening their activation.”

The study indicated that microRNA-223 targets Mefc2, a transcription factor that promotes the expansion of granulocyte cell progenitors. (Transcription factors are proteins that regulate gene expression.) By knocking out Mefc2, the authors found that some of the effects caused by microRNA-223 were eliminated.

The researchers demonstrated that mice modified to lack microRNA-223 expression had up to three times as many granulocytes in their bone marrow and blood. Moreover, the granulocytes matured more rapidly and then reacted more aggressively to stimuli. This increased activity caused tissue inflammation and damage within the lungs with age or, in an acute inflammation model, within the liver, muscle and kidneys.

“If you have an infection in the lungs, granulocytes will migrate to the site of the infection and attack,” says Jonathan Johnnidis, first author of the paper and a former technician in the Camargo lab, and now a graduate student in molecular biology at the University of Pennsylvania. “Once the infection is cleared granulocytes usually migrate away and settle down. However, in this case they didn’t stand down after they were done fighting. Instead they continued an inflammatory response that did more damage.”

“Like a hand grenade once you pop the trigger out, these granulocytes are going to explode, regardless of whether they are surrounded by healthy tissue or harmful bacteria,” adds Camargo. “Lack of microRNA-223 makes it much easier to activate the grenade.”

Camargo plans to further investigate the effect of this microRNA on disease. “Our work suggests that microRNA-223 physiologically fine-tunes both the generation and function of granulocytic cells, delimiting their production and preventing excessive activation,” he says. “Also, since many forms of leukemia express diminished levels of microRNA-223, we are investigating how silencing of this microRNA may contribute to the development of that disease.”

Cristin Carr | EurekAlert!
Further information:
http://www.wi.mit.edu

Further reports about: Camargo MicroRNA activation fine-tunes granulocyte immune inflammatory innate microRNA-223

More articles from Life Sciences:

nachricht Exciting Plant Vacuoles
14.06.2019 | Julius-Maximilians-Universität Würzburg

nachricht A microscopic topographic map of cellular function
13.06.2019 | University of Missouri-Columbia

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Concert of magnetic moments

14.06.2019 | Information Technology

Materials informatics reveals new class of super-hard alloys

14.06.2019 | Materials Sciences

New imaging modality targets cholesterol in arterial plaque

14.06.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>