Overview

Bones are simple, right? White, hard, strong, forming a static skeleton that supports our body. 

Actually, living bone is anything but simple. It’s a dynamic, changing tissue affected by the expression of many genes. Sometimes the changes are not good, as with osteoporosis, which drastically reduces bone density and strength. 

Osteoporosis susceptibility derives from both genetic and environmental factors. Risks rise and fall with certain behaviors. Not surprisingly, diet, exercise and smoking play significant roles. Faculty at the Laboratory study osteoporosis in both clinical and laboratory environments, researching the genetics of bone mineral density (BMD) acquisition and maintenance. It’s a formidable challenge to find the genes involved, but candidate genes have been identified, all of which demonstrate rich genetic regulation for bone.

Research

Low bone mineral density heightens risk of fractures, which take a huge toll on both elderly patients and the health care system.

Jackson Laboratory researchers are working to identify the many genes that determine bone composition and the mechanisms by which diet influences bone health. Bone-mass traits are highly heritable.

Research Scientist Cheryl Ackert-Bicknell, Ph.D., is identifying the genes that regulate bone mineral density. She's also examining how diet — specifically dietary fat — affects the composition of bone.  She was a member of a research team led by Maine scientists that identified a protein that controls the amount of marrow fat inside bones.

Their investigation showed that, with age, the red marrow found in long bones is replaced with yellow or fatty marrow. In those who have suffered an osteoporotic fracture, there are more marrow-residing fat cells as compared to age-matched patients who have never experienced fractures.

Personal Connections

As director of the Emmaus Homeless Shelter in Ellsworth, Maine, Sister Lucille MacDonald works tirelessly to ease the pain and stress of people facing difficult times. But she faces her own difficulty: the bone disease osteoporosis.

Her mother had osteoporosis and suffered a fractured hip. Sister Lucille was diagnosed with it in 2005.

"I've inherited weakness in my bones," she says. "I actively work to strengthen them. I take Fosamax, do weight-bearing exercises and eat a healthy diet. But I already have osteoporosis."

Osteoporosis affects an estimated 10 million Americans, 80 percent of them women. Another 34 million people are at high risk, and the number is growing.

Osteoporosis is one of the m any genetic diseases researched at The Jackson Laboratory. Bone-mass traits are highly heritable, and Research Scientist Cheryl Ackert-Bicknell, Ph.D., is identifying the genes that regulate bone mineral density. She's also examining how diet - specifically dietary fat - affects the composition of bone.

"I have shown that fat interacts with certain genetic backgrounds to affect bone and possibly exacerbate osteoporosis," she says. "Understanding the relationship between bone and dietary fat is extremely important, particularly given the high fat content in typical American diets."