Cancer cells show an increased glutamine consumption. The glutaminase (GLS) enzyme controls a limiting step in the glutamine catabolism. Breast tumors, especially the triple negative subtype, have a high expression of GLS. Our recent study demonstrated that GLS activity and ammonia production are inhibited by Sirtuin 5 (SIRT5). We have developed MC3138, a selective SIRT5 activator. Treatment with MC3138 mimicked the deacetylation effect mediated by SIRT5 overexpression. Moreover, GLS activity is regulated by inorganic phosphate (Pi). Considering the interconnected role of GLS, SIRT5 and Pi for cancer growth, our hypothesis is that activation of SIRT5 and reduction of Pi could represent a valid anti-tumoral strategy. Treating cells with MC3138 and lanthanum acetate, a Pi chelator, decreased cell viability and clonogenicity. We also observed a modulation of LC3 and ULK1 with MC3138 and lanthanum acetate. Interestingly, inhibition of mitophagy marker BNIP3 was observed only in the presence of MC3138. Such autophagy and mitophagy modulation was accompanied by an increase of cytosolic and mitochondrial reactive oxygen species (ROS). In conclusion, our results show how SIRT5 activation and/or Pi binding can represent a valid strategy to inhibit cell proliferation by reducing glutamine metabolism and mitophagy leading to a deleterious accumulation of ROS.

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with airways inflammation and lung parenchyma fibrosis. The primary goals of COPD treatment are to re-duce symptoms and risk of exacerbations, therefore pulmonary rehabilitation is considered the key component of managing COPD patients. Oxidative airway damage, inflammation and re-duction of endogenous antioxidant enzymes are known to play a crucial role in the pathogenesis of COPD. Natural antioxidants have also recently been considered as they play an important role in metabolism, DNA repair and fighting the effects of oxidative stress. In this paper we evaluated the response of 105 elderly COPD patients to pulmonary rehabilitation (PR), based on high or low vegetable consumption, by analyzing clinical parameters and biological measure-ments at baseline and after completion of the three weeks PR. We found that high vegetable in-take in normal diet, without any specific intervention, can increase the probability to success-fully respond to rehabilitation (65.4% of responders ate vegetables daily vs. 40.0% of Non-Responders, p=0.033). Three weeks of pulmonary rehabilitation are probably too short to reveal a reduction of the oxidative stress and DNA damage, but are enough to show an im-provement in the patient's inflammatory state.

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with airways inflammation and lung parenchyma fibrosis. The primary goals of COPD treatment are to re-duce symptoms and risk of exacerbations, therefore pulmonary rehabilitation is considered the key component of managing COPD patients. Oxidative airway damage, inflammation and re-duction of endogenous antioxidant enzymes are known to play a crucial role in the pathogenesis of COPD. Natural antioxidants have also recently been considered as they play an important role in metabolism, DNA repair and fighting the effects of oxidative stress. In this paper we evaluated the response of 105 elderly COPD patients to pulmonary rehabilitation (PR), based on high or low vegetable consumption, by analyzing clinical parameters and biological measure-ments at baseline and after completion of the three weeks PR. We found that high vegetable in-take in normal diet, without any specific intervention, can increase the probability to success-fully respond to rehabilitation (65.4% of responders ate vegetables daily vs. 40.0% of Non-Responders, p=0.033). Three weeks of pulmonary rehabilitation are probably too short to reveal a reduction of the oxidative stress and DNA damage, but are enough to show an im-provement in the patient's inflammatory state.