Inhibition of the mitochondria-shaping protein Opa1 restores sensitivity to Gefitinib in a lung adenocarcinomaresistant cell line

Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it

The cristae modulator Optic atrophy 1 requires mitochondrial ATP synthase oligomers to safeguard mitochondrial function

It is unclear how the mitochondrial fusion protein Optic atrophy 1 (OPA1), which inhibits cristae remodeling, protects from mitochondrial dysfunction. Here we identify the mitochondrial F1Fo-ATP synthase as the effector of OPA1 in mitochondrial protection. In OPA1 overexpressing cells, the loss of proton electrochemical gradient caused by respiratory chain complex III inhibition is blunted and this protection is abolished by the ATP synthase inhibitor oligomycin. Mechanistically, OPA1 and ATP synthase can interact, but recombinant OPA1 fails to promote oligomerization of purified ATP synthase reconstituted in liposomes, suggesting that OPA1 favors ATP synthase oligomerization and reversal activity by modulating cristae shape. When ATP synthase oligomers are genetically destabilized by silencing the key dimerization subunit e, OPA1 is no longer able to preserve mitochondrial function and cell viability upon complex III inhibition. Thus, OPA1 protects mitochondria from respiratory chain inhibition by stabilizing cristae shape and favoring ATP synthase oligomerization

Developmental and Tumor Angiogenesis Requires the Mitochondria-Shaping Protein Opa1

While endothelial cell (EC) function is influenced by mitochondrial metabolism, the role of mitochondrial dynamics in angiogenesis, the formation of new blood vessels from existing vasculature, is unknown. Here we show that the inner mitochondrial membrane mitochondrial fusion protein optic atrophy 1 (OPA1) is required for angiogenesis. In response to angiogenic stimuli, OPA1 levels rapidly increase to limit nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) signaling, ultimately allowing angiogenic genes expression and angiogenesis. Endothelial Opa1 is indeed required in an NFκB-dependent pathway essential for developmental and tumor angiogenesis, impacting tumor growth and metastatization. A first-in-class small molecule-specific OPA1 inhibitor confirms that EC Opa1 can be pharmacologically targeted to curtail tumor growth. Our data identify Opa1 as a crucial component of physiological and tumor angiogenesis

Pharmacological modulation of mitochondrial dynamics: identification of a specific OPA1 inhibitor to enhance apoptotic release of cytochrome c.

The GTPase activity of OPA1, a dynamin-related mitochondrial protein upregulated in several tumors, controls cristae remodeling, cytochrome c release and apoptosis. To pharmacologically target OPA1 in cancer, we setup and iterated a high-throughput screening of a diversity based chemical library of 10,000 drug-like small molecules for recombinant purified OPA1 GTPase activity inhibition, identifying 8 candidates that were confirmed in a secondary screen. The most promising hit (MYLS22) was highly specific, as it could bind to recombinant OPA1 GTPase and did not inhibit recombinant Dynamin 1 GTPase activity. MYLS22 was not mitochondriotoxic, but it increased OPA1 oligomers disassembly and cytochrome c release in response to the proapoptotic stimulus BID in purified mitochondria and to hydrogen peroxide in cells, where MYLS22 caused the expected mitochondrial fragmentation. MYLS22 also phenocopied the inhibition of breast cancer cells migration caused by OPA1 silencing. Thus, we identified a first-in-kind OPA1 inhibitor with potential anti-cancer properties

Determination of blood metabolites in early lactation dairy cows using milk mid-infrared spectra

During early lactation, dairy cows normally experience an unbalanced energy status that can lead to the occurrence of several metabolic disorders. Blood metabolic profile is a valid tool to monitor and identify metabolic diseases, but blood sampling and analysis is a time-consuming and expensive procedure, being also stressful for the animals. Mid-infrared (MIR) spectroscopy is routinely implemented for milk composition analysis of cow milk, being a cost-effective and non-destructive method. Thus, the aim of this study was to investigate the feasibility of predicting blood metabolites from milk MIR spectra. To achieve this goal, 20 herds rearing Holstein-Friesian, Brown Swiss or Simmental dairy cows, located in Trentino Alto Adige and Veneto regions, have been visited between December 2017 and June 2018. At each visit, blood and milk samples were collected within one hour from all lactating cows within 35 days in milk. Blood samples were analysed through reference procedures and milk MIR spectra were collected during milk analyses. Backward interval partial least squares (BiPLS) algorithm was applied to build prediction models for considered metabolic traits. Results showed that BiPLS improved the predictive ability of the models for the studied traits compared with traditional PLS analysis. Blood \u3b2-hydroxybutyrate, urea, non-esterified fatty acids and cholesterol were the most predictable traits, with coefficients of determination in external validation of 0.71, 0.64, 0.55 and 0.45, respectively. On the other hand, prediction models for other analysed metabolites were not enough accurate for routine analysis or population studies. Results of the present study suggest the potential of milk MIR spectra to predict important blood metabolites, leading to the possibility to easily access to metabolic status information of early lactation cows

Inhibition of the mitochondria-shaping protein Opa1 restores sensitivity to Gefitinib in a lung adenocarcinomaresistant cell line

Abstract Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it

Inhibition of the mitochondria-shaping protein Opa1 restores sensitivity to Gefitinib in a lung adenocarcinomaresistant cell line

Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it