Featured Research

from universities, journals, and other organizations

Scientists Create Mouse Model That Mimics Human Dental Disorder

Date:
July 10, 2003
Source:
NIH/National Institute Of Dental And Craniofacial Research
Summary:
A team led by scientists at the National Institute of Dental and Craniofacial Research (NIDCR) has created a mouse model with tooth defects similar to those of people with dentinogenesis imperfecta III. The model will allow scientists to learn more about how the hereditary disorder arises and provides a tool for developing and testing treatments.

A team led by scientists at the National Institute of Dental and Craniofacial Research (NIDCR) has created a mouse model with tooth defects similar to those of people with dentinogenesis imperfecta III. The model will allow scientists to learn more about how the hereditary disorder arises and provides a tool for developing and testing treatments. The researchers report their findings in the July 4 issue of the Journal of Biological Chemistry.

Related Articles


Dr. Ashok Kulkarni and his colleagues created the mouse model by deleting or 'knocking ou' the dentin sialophosphoprotein (DSPP) gene, thought to be responsible for coordinating the mineralization of a tooth's dentin. The animals' teeth showed discoloration, large pulp cavities, and pulp exposure. Detailed studies of the teeth revealed abnormalities in the dentin. Dentin is a hard material similar to bone that makes up about three-fourths of an adult tooth. It lies between the outer enamel and the innermost core of the tooth called the dental pulp.

"Our study shows that DSPP plays a key role in orchestrating the process of dentin mineralization, or maturation," said senior author Dr. Kulkarni from the NIDCR Functional Genomics Unit and Gene Targeting Facility. "This mouse model shows for the first time some of the molecular events regulated by DSPP that are involved in dentin mineralization. For example, we found that DSPP probably regulates two proteoglycans, or proteins, during this process, something we didn't expect to find." Dentin formation requires several steps: First, dentin-forming cells secrete the proteins that make up dentin's scaffolding. Mineralization occurs as dentin hardens when calcium is deposited onto this framework. The areas that are first to mineralize grow and then fuse to create one calcified mass that is the mature dentin.

Dentinogenesis imperfecta, classified into three subtypes, occurs in about 1 in 8,000 newborns in the U.S. The teeth can be bluish or brownish with a somewhat translucent appearance. On x-ray, the teeth of patients with dentinogenesis imperfecta III (DGI-III) appear as 'shell teeth,' with a layer of enamel, a thin layer of dentin, and very large pulp chambers. Because of the unstable dentin, the enamel can shear off and expose the dentin, which could then wear down to the pulp. Most of those severely affected with DGI-III are candidates for dentures or implants by age 30 despite dental intervention.

In-depth studies of the DGI-III animal teeth revealed an abnormally large area of unmineralized dentin, or predentin, and an irregular border between the predentin and its mature counterpart. Additionally, there was evidence of partially mature dentin trapped between areas that were fully mineralized. In a normal tooth, the mature dentin would be mineralized completely, the scientists said.

Other studies found unusually large amounts of two proteoglycans called decorin and biglycan within the unmineralized areas. "The theory is that these two proteoglycans help promote mineralization," said Dr. Taduru Sreenath, the study's first author. "But without DSPP to give the correct instructions, these proteins are too active and, in fact, interfere with the process." Dr. Sreenath explained that in normal dentin, decorin and biglycan are probably degraded and then mineralization proceeds.

Collaborating with Drs. Kulkarni and Sreenath were NIDCR's Tamizchelvi Thyagarajan, Bradford Hall, and Glenn Longenecker; Rena D'Souza from the University of Texas Health Science Center at Houston; Sung Hong and J. Tim Wright from the University of North Carolina, Chapel Hill; Mary MacDougall, from the University of Texas Health Science Center at San Antonio; and John Sauk from the University of Maryland at Baltimore.

The NIDCR is one of the National Institutes of Health in Bethesda, Md. NIH is an agency of the U.S. Department of Health and Human Services.


Story Source:

The above story is based on materials provided by NIH/National Institute Of Dental And Craniofacial Research. Note: Materials may be edited for content and length.


Cite This Page:

NIH/National Institute Of Dental And Craniofacial Research. "Scientists Create Mouse Model That Mimics Human Dental Disorder." ScienceDaily. ScienceDaily, 10 July 2003. <www.sciencedaily.com/releases/2003/07/030710092042.htm>.
NIH/National Institute Of Dental And Craniofacial Research. (2003, July 10). Scientists Create Mouse Model That Mimics Human Dental Disorder. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2003/07/030710092042.htm
NIH/National Institute Of Dental And Craniofacial Research. "Scientists Create Mouse Model That Mimics Human Dental Disorder." ScienceDaily. www.sciencedaily.com/releases/2003/07/030710092042.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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