July 2018
Volume 59, Issue 9
Open Access
ARVO Annual Meeting Abstract  |   July 2018
Single particle tracking of nicotinic acetylcholine receptors (AChRs): implication for the pathogenesis of ocular myasthenia gravis (MG)
Author Affiliations & Notes
  • Wei He
    Department of Ophthalmology, Stanford University, Palo Alto, California, United States
  • Yang Sun
    Department of Ophthalmology, Stanford University, Palo Alto, California, United States
  • Footnotes
    Commercial Relationships   Wei He, None; Yang Sun, None
  • Footnotes
    Support  NIH/NEI K08-EY022058 (Y.S.), R01-EY025295 (Y.S.), VA merit CX001298 (Y.S.), Ziegler Foundation for the Blind (Y.S.), Research for Prevention of Blindness Unrestricted grant (Stanford), Lowe syndrome association (Y.S.), NEI P30 grant (Stanford).
Investigative Ophthalmology & Visual Science July 2018, Vol.59, 333. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Wei He, Yang Sun; Single particle tracking of nicotinic acetylcholine receptors (AChRs): implication for the pathogenesis of ocular myasthenia gravis (MG). Invest. Ophthalmol. Vis. Sci. 2018;59(9):333.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Myasthenia gravis (MG) is a neuromuscular junction (NMJ) disease caused by autoimmune targeting of the acetylcholine receptors (AChRs), which are accumulated at high concentrations in the postsynaptic muscle membrane. Eighty percent of patients with myasthenia gravis (MG) initially present with the ocular muscles, leading to double vision. This study investigates the accumulation of the AChRs in the NMJ in the primary cell cultures for molecular regulations of MG.

Methods : The dynamics of AChRs on live muscle cells isolated from the Xenopus primary culture were examined using the single particle tracking (SPT) technique. Single AChRs were labeled with quantum dots coated with streptavidin, which binds to biotinylated α-bungarotoxin. The NMJ was induced on the muscle cells by the heparin-binding growth-associated molecule (HB-GAM) coated silica beads. After 2-4 hours of HB-GAM bead treatment, multiple AChRs were recorded on the muscle membrane. As a control for the polarization of cortical actin in a parallel pattern, fibronectin was stamp-printed in square shapes with different sizes and the polarized pattern for actin filaments was examined with phalloidin staining.

Results : AChRs travel to the synaptic area in three different patterns, per SPT. Most strikingly, around 9% AChR trajectories showed clear linear trajectories toward the HB-GAM beads.
The linear trajectories are localized to the plasma membrane rather than endocytosed, as shown by the quenching of the surface quantum dots induced by cell membrane impermeable quenching dyes.
The linear track is guided by the cortical actin pattern. Although the linear trajectories exhibit a radiant pattern towards the beads, line shape trajectories show the parallel pattern on the muscle cells with parallel polarized cortical actin patterns.

Conclusions : The cortical actin networks control the accumulation of the AChRs towards the NMJ. Given that AChR signaling in NMJ is conserved between the ocular muscle and the skeletal muscle, this study shows the potential for understanding the role of cortical actins in ocular MG.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

Figure 1 Single particle tracking on muscle cells coated with HB-GAM. Differently colored trajectories are superimposed on the cluster image in grayscale, cell boundaries are indicated by white lines, and the bead locations are marked by open green circles.

Figure 1 Single particle tracking on muscle cells coated with HB-GAM. Differently colored trajectories are superimposed on the cluster image in grayscale, cell boundaries are indicated by white lines, and the bead locations are marked by open green circles.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×