EXTL2 and EXTL3 inhibition with siRNAs as a promising substrate reduction therapy for Sanfilippo C syndrome.
Sanfilippo syndrome is a rare lysosomal storage disorder caused by an impaired degradation of heparan sulfate (HS). It presents severe and progressive neurodegeneration and currently there is no effective treatment. Substrate reduction therapy (SRT) may be a useful option for neurological disorders of this kind, and several approaches have been tested to date. Here we use different siRNAs targeting EXTL2 and EXTL3 genes, which are important for HS synthesis, as SRT in Sanfilippo C patients' fibroblasts in order to decrease glycosaminoglycan (GAG) storage inside the lysosomes. The results show a high inhibition of the EXTL gene mRNAs (around 90%), a decrease in GAG synthesis after three days (30-60%) and a decrease in GAG storage after 14 days (up to 24%). Moreover, immunocytochemistry analyses showed a clear reversion of the phenotype after treatment. The in vitro inhibition of HS synthesis genes using siRNAs shown here is a first step in the development of a future therapeutic option for Sanfilippo C syndrome.
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica En Red de Enfermedades Raras (CIBERER), Spain.|Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.
Isaac
I
Canals
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica En Red de Enfermedades Raras (CIBERER), Spain.|Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.
Noelia
N
Benetó
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica En Red de Enfermedades Raras (CIBERER), Spain.|Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.
Mónica
M
Cozar
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica En Red de Enfermedades Raras (CIBERER), Spain.|Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.
Lluïsa
L
Vilageliu
Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.|Centro de Investigación Biomédica En Red de Enfermedades Raras (CIBERER), Spain.|Institut de Biomedicina de la Universitat de Barcelona (IBUB), Barcelona, Spain.
Daniel
D
Grinberg
D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D006025:Glycosaminoglycans / Q000378:metabolism; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D009084:Mucopolysaccharidosis III / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics*; D034741:RNA, Small Interfering / Q000235:genetics*; D014162:Transfection
D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D008565:Membrane Proteins; D017351:N-Acetylglucosaminyltransferases; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C110774:EXTL3 protein, human; C110834:EXTL2 protein, human