RESUMEN
Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disorder caused by deficiency of the iduronate-2-sulfatase (IDS) enzyme, resulting in cellular accumulation of glycosaminoglycans (GAGs) throughout the body. Treatment of MPS II remains a considerable challenge as current enzyme replacement therapies do not adequately control many aspects of the disease, including skeletal and neurological manifestations. We developed an IDS transport vehicle (ETV:IDS) that is engineered to bind to the transferrin receptor; this design facilitates receptor-mediated transcytosis of IDS across the blood-brain barrier and improves its distribution into the brain while maintaining distribution to peripheral tissues. Here we show that chronic systemic administration of ETV:IDS in a mouse model of MPS II reduced levels of peripheral and central nervous system GAGs, microgliosis, and neurofilament light chain, a biomarker of neuronal injury. Additionally, ETV:IDS rescued auricular and skeletal abnormalities when introduced in adult MPS II mice. These effects were accompanied by improvements in several neurobehavioral domains, including motor skills, sensorimotor gating, and learning and memory. Together, these results highlight the therapeutic potential of ETV:IDS for treating peripheral and central abnormalities in MPS II. DNL310, an investigational ETV:IDS molecule, is currently in clinical trials as a potential treatment for patients with MPS II.
Asunto(s)
Barrera Hematoencefálica/metabolismo , Terapia de Reemplazo Enzimático/métodos , Iduronato Sulfatasa/administración & dosificación , Mucopolisacaridosis II/tratamiento farmacológico , Receptores de Transferrina/metabolismo , Vesículas Transportadoras/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Glicosaminoglicanos/metabolismo , Iduronato Sulfatasa/genética , Memoria/efectos de los fármacos , Ratones , Ratones Noqueados , Destreza Motora/efectos de los fármacos , Mucopolisacaridosis II/genética , Mucopolisacaridosis II/metabolismo , Mucopolisacaridosis II/fisiopatología , Fenotipo , Filtrado Sensorial/efectos de los fármacos , Esqueleto/efectos de los fármacos , Aprendizaje Espacial/efectos de los fármacos , TranscitosisRESUMEN
The thioredoxin fusion protein expression system from invitrogen was modified so that 32P-labelled recombinant proteins can be easily obtained in large quantities for functional studies. Proteins that are prone to form the inclusion bodies can be functionally expressed as thioredoxin fusion proteins in Escherichia coli. After expression, the recombinant proteins can be easily phosphorylated with 32P-gamma ATP and the 32P-labelled protein can be obtained functionally via a mild proteolytic digestion to cleave off the thioredoxin moiety. A deletion construct of the Ah receptor nuclear translocator protein was used as an example to illustrate how this protein expression system works.