In the September 2009 issue of Blood, Syres et al. [1] report on syngeneic bone marrow cell (BMC) and haematopoietic stem cell (HSC)
therapy as a successful treatment in a mouse model of
cystinosis, an autosomal recessive
metabolic disease caused by a defect in the transport of
cystine across the lysosomal membrane. The accumulation of
cystine crystals in lysosomes leads to a multi-organ dysfunction including proximal tubulopathy and
renal failure, corneal deposits,
myopathy and central nervous system defects. By using Ctns knock-out (Ctns(-/-)) mice as a model for
cystinosis, Syres et al. show that BMC
transplantation leads to a major reduction of
cystine content in all tissues tested, reflected by a significant attenuation of the development and progression of kidney injury and reduction in the number of mice with corneal
cystine crystals. These changes were correlated with the engraftment of donor BMC producing a functional
cystine transporter in the tissues tested. The
transplantation of mouse HSC had the same
therapeutic effect than whole BMC in this model, which is important as such HSC can readily be isolated from peripheral blood in humans. This work suggests that BMC or HSC
transplantation is a potential treatment for
cystinosis and other renal tubular disorders.