scholarly journals A Quantitative Proteomics Approach to Gain Insight into NRF2-KEAP1 Skeletal Muscle System and Its Cysteine Redox Regulation

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1655
Author(s):  
Rafay Abu ◽  
Li Yu ◽  
Ashok Kumar ◽  
Lie Gao ◽  
Vikas Kumar

Mammalian skeletal muscle (SkM) tissue engages the Nrf2-Keap1-dependent antioxidant defense mechanism to respond adaptively to stress. Redox homeostasis mediated by the reversible modification of selective cysteines is the prevalent mode of regulation. The protein targets of SkM redox regulation are largely unknown. We previously reported the proteomic profiles of soleus (Sol) and extensor digitorum longus (EDL) with Nrf2 or Keap1 gene deletion, using SkM-specific Nrf2 or Keap1 knockout models; iMS-Nrf2flox/flox; and iMS-Keap1flox/flox. Here, we employed these two animal models to understand the global expression profile of red tibialis anterior (RTA) using a label free approach and its redox proteomics using iodoacetyl tandem mass tag (iodoTMTTM)-labeled cysteine quantitation. We quantified 298 proteins that were significantly altered globally in the RTA with Nrf2 deficiency but only 21 proteins in the Keap1 KO samples. These proteins are involved in four intracellular signaling pathways: sirtuin signaling, Nrf2 mediated oxidative stress response, oxidative phosphorylation, and mitochondrion dysfunction. Moreover, we identified and quantified the cysteine redox peptides of 34 proteins, which are associated with mitochondrial oxidative phosphorylation, energy metabolism, and extracellular matrix. Our findings suggest that Nrf2-deficient RTA is implicated in metabolic myopathy, mitochondrial disorders, and motor dysfunction, possibly due to an enhanced oxidative modification of the structure and functional proteins in skeletal myocytes.

1995 ◽  
Vol 268 (6) ◽  
pp. C1474-C1484 ◽  
Author(s):  
J. A. Jeneson ◽  
H. V. Westerhoff ◽  
T. R. Brown ◽  
C. J. Van Echteld ◽  
R. Berger

The postulated strictly linear descriptions of the rate dependence of oxidative phosphorylation in skeletal muscle on the free energy of ATP hydrolysis (delta GP) over the range of physiological steady states fail to harmonize with reported findings of identical basal respiration rates in mammalian muscles at different delta GP values. The relevance of an extension of the strictly linear description to a description deriving from enzyme kinetics that predicts a sigmoidal dependence was investigated in human finger flexor muscle using 31P-nuclear magnetic resonance spectroscopy. At constant pH 7.0, the experimental variation of adenine nucleotide concentrations with power output, which reflects the rate of oxidative phosphorylation, was compared with predictions by various formulations of adenine nucleotide control of respiration. The quasi-linear sigmoidal description was found to be statistically equivalent but physiologically superior to the strictly linear description. The predicted maximal oxidatively sustained steady-state power output and rate-dependent sensitivity of respiration to changes in delta GP were in agreement both with theoretical considerations and with experimental observations in the present study and other studies of intact mammalian skeletal muscle.


2021 ◽  
Vol 22 (8) ◽  
pp. 3920
Author(s):  
Violetta V. Kravtsova ◽  
Inna I. Paramonova ◽  
Natalia A. Vilchinskaya ◽  
Maria V. Tishkova ◽  
Vladimir V. Matchkov ◽  
...  

Sustained sarcolemma depolarization due to loss of the Na,K-ATPase function is characteristic for skeletal muscle motor dysfunction. Ouabain, a specific ligand of the Na,K-ATPase, has a circulating endogenous analogue. We hypothesized that the Na,K-ATPase targeted by the elevated level of circulating ouabain modulates skeletal muscle electrogenesis and prevents its disuse-induced disturbances. Isolated soleus muscles from rats intraperitoneally injected with ouabain alone or subsequently exposed to muscle disuse by 6-h hindlimb suspension (HS) were studied. Conventional electrophysiology, Western blotting, and confocal microscopy with cytochemistry were used. Acutely applied 10 nM ouabain hyperpolarized the membrane. However, a single injection of ouabain (1 µg/kg) prior HS was unable to prevent the HS-induced membrane depolarization. Chronic administration of ouabain for four days did not change the α1 and α2 Na,K-ATPase protein content, however it partially prevented the HS-induced loss of the Na,K-ATPase electrogenic activity and sarcolemma depolarization. These changes were associated with increased phosphorylation levels of AMP-activated protein kinase (AMPK), its substrate acetyl-CoA carboxylase and p70 protein, accompanied with increased mRNA expression of interleikin-6 (IL-6) and IL-6 receptor. Considering the role of AMPK in regulation of the Na,K-ATPase, we suggest an IL-6/AMPK contribution to prevent the effects of chronic ouabain under skeletal muscle disuse.


2011 ◽  
Vol 108 (38) ◽  
pp. 16098-16103 ◽  
Author(s):  
Q.-A. Sun ◽  
D. T. Hess ◽  
L. Nogueira ◽  
S. Yong ◽  
D. E. Bowles ◽  
...  

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