Myotonic dystrophy CTG repeat expansion alters Ca 2+ channel functional expression in PC12 cells
2007; Wiley; Volume: 581; Issue: 23 Linguagem: Inglês
10.1016/j.febslet.2007.08.020
ISSN1873-3468
AutoresArturo Andrade, Mario Bermúdez de León, Óscar Hernández‐Hernández, Bulmaro Cisneros, Ricardo Felix,
Tópico(s)Hereditary Neurological Disorders
ResumoWe previously reported that expression of myotonic dystrophy (DM1) expanded CUG repeats impedes NGF‐induced differentiation in a PC12 clone (CTG90 cells). Here, we present evidence for changes in the fractional contribution of distinct voltage‐gated Ca 2+ channels, key elements in neurotrophin‐promoted differentiation, to the total Ca 2+ current in the CTG90 cells. Patch‐clamp recordings showed that the relative proportion of pharmacologically isolated Ca 2+ channel types differed between control and CTG90 cells. Particularly, the functional expression of N‐type channels was significantly reduced. Though quantitative real‐time RT‐PCR revealed that transcripts for the pore‐forming subunit encoding the N‐type channels remained unchanged, the protein level analyzed by semi‐quantitative Western blotting was down‐regulated in the CTG90 cells. These data suggest modifications in the processing of N‐type Ca 2+ channels in PC12 cells expressing the DM1 mutation.
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