Gene Associated with Rare Adrenal Disorder Appears To Trigger Cell Death, According to NIH Study

July 13, 2010 | by

A gene implicated in Carney complex, a rare disorder of the adrenal glands, appears to function as a molecular switch to limit cell growth and division, according to a study by researchers at the National Institutes of Health and other institutions. Mice lacking functional copies of the gene in the adrenal glands developed an overgrowth of adrenal tissue and were more susceptible to tumors in the gland.

The adrenal glands — one located on top of each kidney — produce hormones which help control heart rate, blood pressure, and other important body functions.

The researchers discovered that the normal process by which cells in the adrenal gland grow old and die is put on hold when the gene, known as Prkar1a, is deactivated. The Prkar1a gene is known to be involved in how the cell regulates its activities.

“Loss of Prkar1a appears to lead to unchecked cell growth in the adrenal glands,” said Dr. Constantine A. Stratakis, M.D., acting director of the Division of Intramural Research of the Eunice Kennedy Shriver National Institute of Child Health and Human Development and an author of the paper. “Our hope is that future studies of the gene and its functions will lead to a greater understanding of how certain types of cancer develop and ways to limit their growth.

The findings were published online in PLoS Genetics. The study’s first author is Isabelle Sahut-Barnola of Clermont University, France. Other authors include researchers at Ohio State University, Columbus and at three French institutions.

Carney complex is a rare disorder of the adrenal glands (http://ghr.nlm.nih.gov/condition/carney-complex). Individuals with Carney complex typically develop Cushing’s syndrome, a combination of weight gain, high blood pressure, diabetes, and other symptoms stemming from the overproduction of the hormone cortisol, which is produced by the adrenal glands. People with Carney complex are also predisposed to developing benign tumors of the heart and connective tissue, as well as benign and cancerous tumors of the adrenal and other glands. Previous studies have shown that people with Carney complex are likely to have a mutation in the Prkar1a gene.

Vitamin D Status is Not Associated with Risk for Less Common Cancers

June 18, 2010 | by

Despite hopes that higher blood levels of vitamin D might reduce cancer risk, a large study finds no protective effect against non-Hodgkin lymphoma or cancer of the endometrium, esophagus, stomach, kidney, ovary, or pancreas. In this study, carried out by researchers from the National Cancer Institute (NCI), part of the National Institutes of Health, and many other research institutions, data based on blood samples originally drawn for 10 individual studies were combined to investigate whether people with high levels of vitamin D were less likely to develop these rarer cancers. Details of these analyses appear as a set of papers in the June 18, 2010, online issue of the American Journal of Epidemiology, and in print in the July 2010 issue.

“We did not see lower cancer risk in persons with high vitamin D blood concentrations compared to normal concentrations for any of these cancers,” said Demetrius Albanes, M.D., NCI, one of the study investigators. “And, at the other end of the vitamin D spectrum, we did not see higher cancer risk for participants with low levels.”

Gene Linked to Alzheimers Disease Plays Key Role in Cell Survival

June 10, 2010 | by

Scientists have discovered that a gene linked to Alzheimer’s disease may play a beneficial role in cell survival by enabling neurons to clear away toxic proteins. A study funded by the National Institute on Aging (NIA), part of the National Institutes of Health, shows the presenilin 1 (PS1) gene is essential to the function of lysosomes, the cell component that digests and recycles unwanted proteins. However, mutations in the PS1 gene — a known risk factor for a rare, early onset form of Alzheimer’s disease – disrupt this crucial process.

Ralph Nixon, M.D., Ph.D., of the Nathan Kline Institute, Orangeburg, N.Y., and New York University Langone Medical Center, directed the study involving researchers from the United States, Europe, Japan and Canada. Also supported in part by the Alzheimer’s Association, the study appears in the June 10, 2010, online issue of Cell.

Researchers have theorized for more than a decade that PS1 mutations linked to early-onset Alzheimer’s, a rare form of the disease that usually affects people between ages 30 and 60, may trigger abnormally high levels of beta-amyloid protein to clump together in the brain.

Amyloid deposits and tau protein tangles are hallmarks of both early-onset and the sporadic, more common form of the disease found in people aged 60 and older. These new findings, however, suggest PS1 mutations may play a more general role in the development of early-onset Alzheimer’s.

Information on Gum Disease Now Available on NIHSeniorHealth.gov

May 12, 2010 | by

Good oral health is key to quality of life. When your mouth is healthy, you can eat the foods you need for good nutrition and can feel better about smiling, talking, and laughing. However, periodontal (gum) disease — an infection of the gums and tissues that hold teeth in place — can harm oral health and is a leading cause of tooth loss among older adults. Because it’s an important topic for seniors, a section on gum disease has just been added to NIHSeniorHealth.gov. It’s the premier health and wellness website for older adults developed by the National Institute on Aging (NIA) and the National Library of Medicine (NLM), both part of the National Institutes of Health.

“The new periodontal disease section on NIHSeniorHealth.gov is an excellent source of easy-to-understand information that will help older people learn about periodontal disease and how they can prevent it,” said Lawrence A. Tabak, D.D.S., Ph.D., director of NIH’s National Institute of Dental and Craniofacial Research. “Periodontal disease does not have to be a part of aging. Proper dental hygiene and regular dental visits can help people reduce their chance of developing periodontal disease as they age.”

Endometrial Stem Cells Restore Brain Dopamine Levels

May 6, 2010 | by

Endometrial stem cells injected into the brains of mice with a laboratory-induced form of Parkinson’s disease appeared to take over the functioning of brain cells eradicated by the disease.

The finding raises the possibility that women with Parkinson’s disease could serve as their own stem cell donors. Similarly, because endometrial stem cells are readily available and easy to collect, banks of endometrial stem cells could be stored for men and women with Parkinson’s disease.

“These early results are encouraging,” said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that funded the study. “Endometrial stem cells are widely available, easy to access and appear to take on the characteristics of nervous system tissue readily.”

Parkinson’s disease results from a loss of brain cells that produce the chemical messenger dopamine, which aids the transmission of brain signals that coordinate movement.

This is the first time that researchers have successfully transplanted stem cells derived from the endometrium, or the lining of the uterus, into another kind of tissue (the brain) and shown that these cells can develop into cells with the properties of that tissue.