Affected energy metabolism under manganese stress governs cellular toxicity.
Gursharan KaurVineet KumarAmit AroraAjay Tomarnull AshishRuna SurDipak DuttaPublished in: Scientific reports (2017)
Excessive manganese exposure is toxic, but a comprehensive biochemical picture of this assault is poorly understood. Whether oxidative stress or reduced energy metabolism under manganese exposure causes toxicity is still a debate. To address this, we chose Δmnt P Escherichia coli, a highly manganese-sensitive strain, in this study. Combining microarray, proteomics, and biochemical analyses, we show that the chronic manganese exposure rewires diverse regulatory and metabolic pathways. Manganese stress affects protein and other macromolecular stability, and envelope biogenesis. Most importantly, manganese exposure disrupts both iron-sulfur cluster and heme-enzyme biogenesis by depleting cellular iron level. Therefore, the compromised function of the iron-dependent enzymes in the tricarboxylic acid cycle, and electron transport chain impede ATP synthesis, leading to severe energy deficiency. Manganese stress also evokes reactive oxygen species, inducing oxidative stress. However, suppressing oxidative stress does not improve oxidative phosphorylation and cell growth. On the contrary, iron supplementation resumed cell growth stimulating oxidative phosphorylation. Therefore, we hypothesize that affected energy metabolism is the primal cause of manganese toxicity.
Keyphrases
- oxidative stress
- oxide nanoparticles
- escherichia coli
- reactive oxygen species
- induced apoptosis
- dna damage
- ischemia reperfusion injury
- mass spectrometry
- small molecule
- early onset
- diabetic rats
- stress induced
- iron deficiency
- staphylococcus aureus
- body mass index
- heat stress
- biofilm formation
- heat shock
- binding protein
- drug induced
- candida albicans