TABLE 1.

Effects of erythropoietin in the bone in vivo.

Type	Genetic background	Bone phenotype	Mechanism	References
Transgenic animal models of EPO signaling
Tg6	Overexpression of human EPO driven by PDGF-β promoter, males and females	Trabecular bone loss, thin cortical bone, decreased marrow adiposity – femora	Increased bone resorption and reduced bone formation rate	Hiram-Bab et al., 2015; Suresh et al., 2019a
ΔEpoRE	Epor−/− mice rescued by erythroid restricted EPOR transgene (GATA-1 locus hematopoietic regulatory domain driving mouse EPOR cDNA), males and females	Reduced trabecular bone, cortical bone unaffected, increased marrow adiposity – femora	Increased bone resorption with age; reduced osteogenic potential of osteoblasts	Suresh et al., 2019a
Mice with EPOR deletion in osteoblasts	Mice generated by crossing Osteocalcin (Bglap)-Cre mice with Eporfloxp/floxp mice, males and females	Reduced trabecular bone, cortical bone, and marrow adiposity unaffected – femora	No change in bone resorption; reduced osteogenic potential of osteoblasts; reduced osteocytes and increased empty lacunae	Suresh et al., 2020b
EPO administration in healthy animals
Wild-type mice	C57BL6 strain, female	Trabecular bone loss – femora	Increased bone resorption	Hiram-Bab et al., 2015; Suresh et al., 2019a
Wild-type mice	C57BL6 strain, male	Trabecular bone loss – tibiae	Increase in both bone resorption and bone formation	Singbrant et al., 2011
Wild-type mice	C57BL6 strain, gender unknown	Increased bone mineral density and bone volume – vertebrae	Increased osteoblasts on bone surface	Shiozawa et al., 2010
ΔEpoRE	C57BL6 background, females	No changes in trabecular or cortical bone – femora	No changes in osteoblasts or osteoclasts	Suresh et al., 2019a
Mice with EPOR deletion in osteoblasts	C57BL6 background, males and females	Non-significant reduction in trabecular bone in males, intact trabecular bone in females, cortical bone unaffected in both males and females – femora	No changes in osteoblasts or osteoclasts	Suresh et al., 2020b