Deficits in Endogenous Adenosine Formation by Ecto-5′-Nucleotidase/CD73 Impair Neuromuscular Transmission and Immune Competence in Experimental Autoimmune Myasthenia Gravis

Figure 1

Neuromuscular and immunological deficits of rats with EAMG. Experiments were performed six weeks after immunization with the peptide R97-116 corresponding to the -subunit of nAChR in CFA (EAMG), as compared to age-matched naïve and control littermates. (a) Measurement of serum adenosine deaminase (ADA) activity. Results are mean ± SEM of 9 naïve, 13 control, and 12 EAMG rats. (one-way ANOVA following Dunnett’s modified -test) compared to naïve and control animals, respectively. (b) Flow cytometry analysis of intracellular FoxP3 expression in cells collected from popliteal and inguinal lymph nodes from naïve, control, and EAMG rats. Gating strategy to delimit cells is shown on the left dot plot. Dot plots on the right show FoxP3 expression within gated cells. Gate inside these dot plots correspond to FoxP3⁺ cells. Dot plots are a representative example of each indicated group. Numbers inside dot plots correspond to mean percentage ± SEM of FoxP3⁺ cells within population. Statistically significant difference between EAMG () and both naïve () and control () groups is indicated (; one-way ANOVA and Bonferroni’s post hoc test). (c) Confocal microscopy micrographs showing type I and type II motor endplates from hemidiaphragm sections labeled with TMR--BTX (red) from naïve, control, and EAMG animals. Scale bar: 10 m. (d) Reduction of contractile strength of isolated hemidiaphragm preparations from naïve, control, and EAMG animals during a 3 min period of intermittent phrenic nerve stimulation (17 pulses per second delivered at 50 Hz frequency). Results are mean SEM of 10 naïve, 6 control, and 5 EAMG rats. (one-way ANOVA following Dunnett’s modified -test) compared to naïve and control animals, respectively.

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