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. 2019 Dec 12;7(1):e645. doi: 10.1212/NXI.0000000000000645

Figure 3. SHP2 inhibition reverses effects of MuSK-Abs on AChR clusters in C2C12s and DOK7-overexpressing C2C12s.

Figure 3

(A) The treatment protocols are shown above the results. MuSK-Ab positive (n = 21) or healthy control sera (n = 2) were incubated with myotubes for 30 minutes, followed by agrin (1:800) with or without NSC-87877 (100 μM). After 12 hours, the AChR clusters were analyzed and expressed as a percentage of control serum results. The number (A.a) of the AChR clusters without NSC-87877 was clearly reduced by the MuSK-Abs (to 14%, 35%, and 60% at dilutions 1:10, 1:30, and 1:90, red columns); the size of the clusters was similarly reduced (A.b). In each case, the effects were partially or completely reversed by NSC-87877 (green columns). (B) Inverse correlation between the number of AChR clusters at 1:30 serum dilution and MuSK-Ab titers (nM) with or without NSC-87877. (C) Using a different protocol, AChR clusters were similarly reduced, and there was partial or complete protection by NSC-87877. (D) The effects of the different serum dilutions on AChR clusters and the protection by NSC-87877 were also seen in the DOK7-overexpressing C2C12s, although to a lesser extent. In A, C, and D, comparisons at each different serum concentration were analyzed by 2-sided t tests. For B, linear regression was computed by GraphPad Prism. The scatter plots show results of individual sera, with mean ± SDs. AChR = acetylcholine receptor; MuSK = muscle-specific kinase; SHP2 = SRC homology 2 domain-containing phosphotyrosine phosphatase 2.