Physiological characterization of human muscle acetylcholine receptors from ALS patients

Eleonora Palma, Maurizio Inghilleri, Luca Conti, Cristina Deflorio, Vittorio Frasca, Alessia Manteca, Floriana Pichiorri, Cristina Roseti, Gregorio Torchia, Cristina Limatola, Francesca Grassi, Ricardo Miledid

Research output: Contribution to journalArticle

Abstract

Amyotrophic lateral sclerosis (ALS) is characterized by progressive degeneration of motor neurons leading to muscle paralysis. Research in transgenic mice suggests that the muscle actively contributes to the disease onset, but such studies are difficult to pursue in humans and in vitro models would represent a good starting point. In this work we show that tiny amounts of muscle from ALS or from control denervated muscle, obtained by needle biopsy, are amenable to functional characterization by two different technical approaches: "microtransplantation" of muscle membranes into Xenopus oocytes and culture of myogenic satellite cells. Acetylcholine (ACh)-evoked currents and unitary events were characterized in oocytes and multinucleated myotubes. We found that ALS acetylcholine receptors (AChRs) retain their native physiological characteristics, being activated by ACh and nicotine and blocked by α-bungarotoxin (α-BuTX), d-tubocurarine (dTC), and galantamine. The reversal potential of ACh-evoked currents and the unitary channel behavior were also typical of normal muscle AChRs. Interestingly, in oocytes injected with muscle membranes derived from ALS patients, the AChRs showed a significant decrease in ACh affinity, compared with denervated controls. Finally, riluzole, the only drug currently used against ALS, reduced, in a dose-dependent manner, the ACh-evoked currents, indicating that its action remains to be fully characterized. The two methods described here will be important tools for elucidating the role of muscle in ALS pathogenesis and for developing drugs to counter the effects of this disease.

Original languageEnglish
Pages (from-to)20184-20188
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume108
Issue number50
DOIs
Publication statusPublished - Dec 13 2011

    Fingerprint

Keywords

  • Patch-clamp
  • Voltage-clamp

ASJC Scopus subject areas

  • General

Cite this

Palma, E., Inghilleri, M., Conti, L., Deflorio, C., Frasca, V., Manteca, A., Pichiorri, F., Roseti, C., Torchia, G., Limatola, C., Grassi, F., & Miledid, R. (2011). Physiological characterization of human muscle acetylcholine receptors from ALS patients. Proceedings of the National Academy of Sciences of the United States of America, 108(50), 20184-20188. https://doi.org/10.1073/pnas.1117975108