Featured Research

from universities, journals, and other organizations

Medical researchers breath new life into fight against primary killer of premature infants

Date:
October 21, 2011
Source:
Salk Institute
Summary:
A new discovery might explain why some premature infants fail to respond to existing treatments for a deadly respiratory distress syndrome and offers clues for new ways to treat the breathing disorder.

These microscopic images of lung tissue from newborn mice show a cross section of the alveoli, the buds in lungs where air exchange takes place. The air sacs (white) in the alveoli on the left, which were taken from a normal mouse, have expanded fully, indicating the animal could breath normally. Those on the right have failed to expand, because the mouse suffered from a new respiratory syndrome discovered by Salk scientists.
Credit: Courtesy of Salk Institute for Biological Studies

A discovery by scientists at the Salk Institute for Biological Studies might explain why some premature infants fail to respond to existing treatments for a deadly respiratory distress syndrome (RDS) and offers clues for new ways to treat the breathing disorder.

Related Articles


The scientists identified a new form of RDS in newborn mice and traced the problem to a cellular receptor for thyroid hormone, a key player in many developmental processes in the body. They found that two drugs used for treating overactive thyroid glands saved mice with a deadly genetic alteration that mimicked the newly discovered lung problem.

"We've added a piece of the puzzle that had been missing for decades," says Ronald Evans, a Howard Hughes Medical Institute Investigator and the March of Dimes Chair in Developmental and Molecular Biology at Salk. "This gives us an entirely new avenue for explaining and treating RDS and other respiratory problems that occur in infants."

RDS affects about one percent of infants born in the United States and is the leading cause of death among premature babies. The disease occurs because the infants' lungs are not yet fully developed at birth and lack a slippery substance called surfactant, which is necessary for the lungs to inflate with air.

To encourage the lungs to develop faster and produce the surfactant, doctors treat many expecting mothers and premature infants with glucocorticoids, steroid drugs that speed maturation of surfactant-producing cells, known as type 2 pneumocytes.

In some cases, however, infants fail to respond to the steroid treatment, and die from the respiratory syndrome, which suggests that some other biological mechanism might be at work.

To explain this, the Salk researchers turned their attention to another type of cell lining the lungs, type 1 pneumocytes, flat cells that allow air exchange between the blood stream and the lung's interior.

"We knew that both types of cells, type 1 and type 2 pneumocytes, would be important for lung development, " says Liming Pei, a postdoctoral research associate who led the project. "While a lot is known about type 2 cells, the type 1 cell is poorly understood."

The researchers developed a strain of mice in which they disrupted the ability of type 1 pneumocytes to respond normally to thyroid hormone, which prevented the cells from maturing.

Unlike type 2 pneumocytes, which mature rapidly in infants given steroid hormone, the type 1 cells failed to respond to steroid treatment and the mice died due to the inability of their lungs to function.

However, mice treated with the medications propylthiouracil or methimazole, normally given to people with thyroid disease, recovered from the disorder and their type 1 cells matured normally.

"This might explain why some infants don't respond to steroid treatment, which only targets the type 2 pneumocytes," Evans says. "There may be an entirely different underlying problem than what the doctor is treating."

The findings identify cell sensors (called thyroid hormone receptors) that help type 1 pneumocytes mature and suggest that drugs controlling this hormone could help premature infants' lungs function earlier.

The genetic make up of mice and humans is very similar, so the researchers are optimistic that their findings will eventually lead to new treatments for infants with RDS. "These mechanisms could also play a role healing lung tissues," Pei says. "They might help older children and adults who have suffered lung damage from flu, asthma, emphysema or other types of respiratory disorders."

He cautioned, however, that the thyroid drugs used in the study are only approved for adults, and that their use in infants would have to be explored with caution. However, because their properties are well known there is clear potential for their use in infants.

The findings of the research, which was funded by the Francis Family Foundation, the Leona M. and Harry B. Helmsley Charitable Trust, the March of Dimes and the National Institutes of Health, was published yesterday in Nature Medicine.


Story Source:

The above story is based on materials provided by Salk Institute. Note: Materials may be edited for content and length.


Journal Reference:

  1. Liming Pei, Mathias Leblanc, Grant Barish, Annette Atkins, Russell Nofsinger, Jamie Whyte, David Gold, Mingxiao He, Kazuko Kawamura, Hai-Ri Li, Michael Downes, Ruth T Yu, Henry C Powell, Jerry B Lingrel, Ronald M Evans. Thyroid hormone receptor repression is linked to type I pneumocyte–associated respiratory distress syndrome. Nature Medicine, 2011; DOI: 10.1038/nm.2450

Cite This Page:

Salk Institute. "Medical researchers breath new life into fight against primary killer of premature infants." ScienceDaily. ScienceDaily, 21 October 2011. <www.sciencedaily.com/releases/2011/10/111018092350.htm>.
Salk Institute. (2011, October 21). Medical researchers breath new life into fight against primary killer of premature infants. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2011/10/111018092350.htm
Salk Institute. "Medical researchers breath new life into fight against primary killer of premature infants." ScienceDaily. www.sciencedaily.com/releases/2011/10/111018092350.htm (accessed October 26, 2014).

Share This



More Health & Medicine News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
Toxin-Packed Stem Cells Used To Kill Cancer

Toxin-Packed Stem Cells Used To Kill Cancer

Newsy (Oct. 25, 2014) — A Harvard University Research Team created genetically engineered stem cells that are able to kill cancer cells, while leaving other cells unharmed. Video provided by Newsy
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins