This pilot study found some improvements in GAG concentration, hair morphology, and cognitive function in these pediatric patients with Sanfilippo syndrome treated with genistin-rich soy isoflavone extract for 1 year. Clinical trials are needed to evaluate the efficacy and safety of this potential treatment.

Hematopoietic stem cell gene therapy for neurological disorders relies on transmigration of donor-derived monocytes to the brain, where they can engraft as microglia and deliver therapeutic proteins. Many mouse studies use whole-body irradiation to investigate brain transmigration pathways, but chemotherapy is generally used clinically. The current evidence for transmigration to the brain after chemotherapy is conflicting. We compared hematopoietic donor cell brain engraftment after bone marrow (BM) transplants in busulfan- or irradiation-conditioned mice. Significantly more donor-derived microglial cells engrafted posttransplant in busulfan-conditioned brain compared with the irradiated, in both the short and long term. Although total Iba-1(+) microglial content was increased in irradiated brain in the short term, it was similar between groups over long-term engraftment. MCP-1, a key regulator of monocyte transmigration, showed long-term elevation in busulfan-conditioned brain, whereas irradiated brains showed long-term elevation of the proinflammatory chemokine interleukin 1α (IL-1α), with increased in situ proliferation of resident microglia, and significant increases in the relative number of amoeboid activated microglia in the brain. This has implications for the choice of conditioning regimen to promote hematopoietic cell brain engraftment and the relevance of irradiation in mouse models of transplantation.

BackgroundNeurodegenerative metabolic disorders such as mucopolysaccharidosis IIIB (MPSIIIB or Sanfilippo disease) accumulate undegraded substrates in the brain and are often unresponsive to enzyme replacement treatments due to the impermeability of the blood brain barrier to enzyme. MPSIIIB is characterised by behavioural difficulties, cognitive and later motor decline, with death in the second decade of life. Most of these neurodegenerative lysosomal storage diseases lack effective treatments. We recently described significant reductions of accumulated heparan sulphate substrate in liver of a mouse model of MPSIIIB using the tyrosine kinase inhibitor genistein.Methodology/Principal FindingsWe report here that high doses of genistein aglycone, given continuously over a 9 month period to MPSIIIB mice, significantly reduce lysosomal storage, heparan sulphate substrate and neuroinflammation in the cerebral cortex and hippocampus, resulting in correction of the behavioural defects observed. Improvements in synaptic vesicle protein expression and secondary storage in the cerebral cortex were also observed.Conclusions/SignificanceGenistein may prove useful as a substrate reduction agent to delay clinical onset of MPSIIIB and, due to its multimodal action, may provide a treatment adjunct for several other neurodegenerative metabolic diseases.

No abstract