Aditi Kaveti ‘23
Radiation exposure is extremely harmful because it results in stem cell depletion and compromised bone marrow. These effects contribute to long-term deterioration of many physiological systems and cause the degradation of skeletal systems, which can lead to many fractures.
In a study done in part by Dr. Mei Lin Chan, an assistant professor at Stony Brook University, the interrelationship between the damaged bone marrow cell populations and the microarchitecture of the trabecular bone is explored. The trabecular bone, which is the porous bone portion found at the end of long bones, consists of a network of plates and rods called trabeculae. The pores are characterized by the trabecular number, which decreases as the bone pores become larger, and the trabecular separation, which is directly proportional to the size of the pores.
Dr. Chan and her team performed an investigation on the effects of radiation of trabecular bone by studying 8- and 16-week old male mice that were exposed to sublethal radiation of gamma rays. They evaluated the adult stem cells residing in bone marrow, and bone quantity and quality in the proximal tibia after 2 days, 10 days, and 8 weeks. The team compared the results with a control that had not been treated with radiation and found that after 2 days and 10 days, the amount of extracted bone marrow cells had reduced by about 65%. After 8 weeks, though, levels had recovered and returned to the age-matched control levels. However, researchers by as early as 10 days, there was a decline in bone volume and trabecular number and a converse increase in trabecular separation, which persisted to 8 weeks. Essentially, even though the radiation did not have lasting damage to bone marrow stem cell counts, it drastically increased the pores in the bone and thus compromised the durability of those organs. These complications bring attention to the idea that radiation can be more insidious and destructive than previously thought.
In the future, the team plans to investigate how to enable the prompt repair of the skeletal system and ultimately reduce the susceptibility to fractures.
 D. Green, et. al, Devastation of adult stem cell pools by irradiation precedes collapse of trabecular bone quality and quantity. J Bone Miner Res 27, 749-759(2012). https://doi.org/10.1002/jbmr.1505.
 Image retrieved from: https://commons.wikimedia.org/wiki/File:Bone_normal_and_degraded_micro_structure.jpg