NASA Study May Help Osteoporosis Patients

After some special mice return from a trip in space, Rick Sumner, Ph.D. and colleagues will be using them to get more information on molecular basis of bone loss in space. Dr. Sumner, chairperson of the Department of Anatomy and Cell Biology at Rush University, is highly involved in the NASA-funded study, which according to the July 18, 2016 news release will attempt to, “…identify changes that occur in the activity of osteocyte cells during space flights. It will try to determine which genes inside osteocytes get turned on or off when there’s no gravity, thus secreting more or less of a protein. It also will explore how these molecular changes are linked to decreases in bone density and strength.”

“Astronauts in space face similar bone loss as people with osteoporosis—but at an accelerated rate. The bones of astronauts weaken when they spend time in space due to the “use it or lose it” phenomenon, Dr. Sumner says.

The study—still in the planning stages—is led by Indiana University’s Alexander Robling, Ph.D., associate professor of anatomy and cell biology. Also involved are scientists from Baylor College of Medicine, Baylor College of Dentistry, and the National Center of Biotechnology in Spain.

Asked about the most challenging aspects of setting up this study, Dr. Sumner told OTW, “Fundamentally, being able to bring back biological material that will be suitable for the molecular and genetic analyses will be a major challenge.”

Dr. Robling added, “Our biggest challenge by far is bringing samples back down to earth for analysis, in a manner that is suitable for molecular analysis. Nucleic acids and proteins have to be processed and stored in very particular ways so that degradation of the material is avoided. Proper processing really boils down to crew time (the amount of time a particular crew member can spend on our experiment). Thus, crew time is the biggest ‘rate-limiting enzyme’ in this reaction.”

“It’s easy to take for granted how effortless simple experimental procedures are here on earth, in a 1G environment (e.g., pipetting liquids, setting your forceps down and not having them float away, safe use of volatile reagents). These procedures can take 5 to 10 times as long on the Space Station, and additional safety precautions are also involved.”

Dr. Sumner told OTW, “The project hopes to identify new targets and pathways that affect how bone adapts to a change in its mechanical environment. Thus, the project should provide fundamental information on the genes and pathways involved in stress-shielding in addition to having implications for disuse osteoporosis.”

Dr. Robling noted, “One of the things we hope to learn is how the basic molecular biology of the osteocyte changes when it is exposed to zero gravity. We also hope to quantify changes in the material properties of new bone that is deposited in microgravity, and also microgravity-induced changes in the material properties of pre-existing bone, i.e., bone that was deposited in a 1G environment but now finds itself in a microgravity environment (this is the Rush/Sumner component). Orthopaedic surgeons must deal with the earth-equivalent of microgravity—mechanical disuse, both before (e.g., bed rest, paralysis) and after (e.g., casting, fixation) they intervene surgically. Our study should elucidate both biomolecular and physical-chemical matrix changes stemming from microgravity/disuse that affect skeletal integrity.”