Hemopoiesis Regulated Negatively In Aged Monkeys

Biological aging is associated with a progressive loss of regulation of cellular, tissue and organ interaction, ultimately resulting in senescence. In humans, accelerated marrow adipogenesis has been associated with aging and several chronic conditions, including diabetes mellitus and osteoporosis. Studies of the hemopoietic system using nonhuman primates have provided important information for understanding the mechanism of human hemopoiesis. Excellent reconstitution of donor hemopoietic cells in a collagen gel group has been observed in the long term in mice. We therefore investigated whether the method would be helpful for reconstituting hemopoiesis in the fatty tibias of monkeys. Nine- to 11-year-old monkeys were used for this study to examine if hemopoiesis could be restored in the fatty marrow of old monkeys. Bone marrow cells were collected from the humerus using the perfusion method, mixed with cultured bone marrow stroma cells in collagen gel, and then injected into the tibia of the same monkey. Clot sections were made from the tibias 1, 2 and 6 weeks after the bone marrow transplantation. However, no bone marrow cells were observed at any of the time points. These results suggested that adipocytes negatively regulate bone marrow reconstitution.