Interaction between the autophagy protein Beclin 1 and Na+,K+-ATPase during starvation, exercise, and ischemia
Álvaro F. Fernández, Yang Liu, Vanessa Ginet, Mingjun Shi, Jihoon Nah, Zhongju Zou, Anwu Zhou, Bruce A. Posner, Guanghua Xiao, Marion Tanguy, Valérie Paradis, Junichi Sadoshima, Pierre-Emmanuel Rautou, Julien Puyal, Ming Chang Hu, Beth Levine
Álvaro F. Fernández, Yang Liu, Vanessa Ginet, Mingjun Shi, Jihoon Nah, Zhongju Zou, Anwu Zhou, Bruce A. Posner, Guanghua Xiao, Marion Tanguy, Valérie Paradis, Junichi Sadoshima, Pierre-Emmanuel Rautou, Julien Puyal, Ming Chang Hu, Beth Levine
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Research Article Cell biology

Interaction between the autophagy protein Beclin 1 and Na+,K+-ATPase during starvation, exercise, and ischemia

Abstract

Autosis is a distinct form of cell death that requires both autophagy genes and the Na+,K+-ATPase pump. However, the relationship between the autophagy machinery and Na+,K+-ATPase is unknown. We explored the hypothesis that Na+,K+-ATPase interacts with the autophagy protein Beclin 1 during stress and autosis-inducing conditions. Starvation increased the Beclin 1/Na+,K+-ATPase interaction in cultured cells, and this was blocked by cardiac glycosides, inhibitors of Na+,K+-ATPase. Increases in Beclin 1/Na+,K+-ATPase interaction were also observed in tissues from starved mice, livers of patients with anorexia nervosa, brains of neonatal rats subjected to cerebral hypoxia-ischemia (HI), and kidneys of mice subjected to renal ischemia/reperfusion injury (IRI). Cardiac glycosides blocked the increased Beclin 1/Na+,K+-ATPase interaction during cerebral HI injury and renal IRI. In the mouse renal IRI model, cardiac glycosides reduced numbers of autotic cells in the kidney and improved clinical outcome. Moreover, blockade of endogenous cardiac glycosides increased Beclin 1/Na+,K+-ATPase interaction and autotic cell death in mouse hearts during exercise. Thus, Beclin 1/Na+,K+-ATPase interaction is increased in stress conditions, and cardiac glycosides decrease this interaction and autosis in both pathophysiological and physiological settings. This crosstalk between cellular machinery that generates and consumes energy during stress may represent a fundamental homeostatic mechanism.

Authors

Álvaro F. Fernández, Yang Liu, Vanessa Ginet, Mingjun Shi, Jihoon Nah, Zhongju Zou, Anwu Zhou, Bruce A. Posner, Guanghua Xiao, Marion Tanguy, Valérie Paradis, Junichi Sadoshima, Pierre-Emmanuel Rautou, Julien Puyal, Ming Chang Hu, Beth Levine

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Figure 3

Beclin 1 and Na+,K+-ATPase interact in vivo during cerebral HI and renal IRI.

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Beclin 1 and Na+,K+-ATPase interact in vivo during cerebral HI and renal...
(A and B) Representative Western blots (A) and quantitation (B) of coimmunoprecipitation of Beclin 1 with the α subunit of Na+,K+-ATPase in the hippocampus of rat pups that were sacrificed 6 hours after receiving intraperitoneal vehicle or neriifolin (0.22 mg/kg) and subjected to sham operation or cerebral HI. In B, bars represent mean ± SD (n = 4–5 rats per group). (C and D) Representative images (C) and quantitation (D) of PLAs of Beclin 1 and the α subunit of Na+,K+-ATPase in the CA3 hippocampal region of rat pups that were sacrificed 6 hours after receiving intraperitoneal vehicle or neriifolin (0.22 mg/kg) and subjected to sham operation or cerebral HI. In D, bars represent mean ± SEM (n = 5 rats per group, 4 randomly selected fields analyzed per animal). (E and F) Representative Western blots (E) and quantitation (F) of coimmunoprecipitation of the α subunit of Na+,K+-ATPase with Beclin 1 in kidneys from mice that were subjected to sham operation or renal IRI after peritoneal administration with either vehicle or ouabain (0.25 mg/kg). In F, bars represent mean ± SD (n = 3 mice per group). (G and H) Representative images (G) and quantitation (H) of PLAs of Beclin 1 and the α subunit of Na+,K+-ATPase in kidneys from mice that were subjected to sham operation or renal IRI after peritoneal administration with either vehicle or ouabain (0.25 mg/kg). In H, bars represent mean ± SEM (n = 5–7 mice per group, 10 randomly selected fields analyzed per mouse). For A and E, the same tissue sample of the sham group (lane 1 of gel) was used as a control for IgG immunoprecipitation. Asterisk, nonspecific band. Scale bars: 10 μm (C), 50 μm (G). *P < 0.05, **P < 0.01, and ***P < 0.001; 1-way (B and D) or 2-way (F and H) ANOVA test.