Periodic Reporting for period 5 - rEnDOx (REDOX SIGNALING AND METABOLIC STATES IN ANGIOGENESIS IN HEALTH AND DISEASE)
Reporting period: 2022-04-01 to 2022-12-31
We have performed a global quantification of reduced and oxidized cysteine residues of all endothelial proteins by performing the first redox proteomic analysis in human ECs. New molecular targets involved in metabolism and redox homeostasis of endothelial cells has been identifies and will be investigated.
We are investigating the role for Ubiad1 in pathological angiogenesis by define a novel role for Ubiad1 in blocking tumor growth by inhibiting tumor angiogenesis. We aim to provide experimental proofs that therapies based on redox enzymes (e.g. Ubiad1) inactivation/blockade are valuable alternatives strategies for anti-angiogenesis in cancer therapy. We are shedding lights on redoxome changes induced by lack of UBIAD1 and indication of its molecular function. We expect to identify known (e.g. VEGFR) but also unknown endothelial-specific enzymes/transducers whose function is regulated by UBIAD1-mediated redox signaling. A positive outcome for these experiments will give a strong rationale to identify UBIAD1 inhibitors by small molecule screening, ultimately offering the possibility for industrial valorisation.
We demonstrate the existence of specific metabolites of the mevalonate pathways controlling angiogenesis, such as IPP and DMAPP. We generate and characterize zebrafish mutants and inducible cre/loxP mouse Tg lines for modelling mevalonate metabolism in physiological and pathological angiogenesis. We did that by identifying and manipulating IDI1 and FDPS metabolic enzymes (within the mevalonate pathway whose loss-of function has anti-angiogenic effects). We are working to provide evidences that manipulation of these enzymes of mevalonate pathway by loss-of-function approaches might be a new therapeutic way to block neoangiogenesis in tumors by improving anti-VEGF cancer therapy. Our data could offer a solid rationale to screen for new mevalonate pathway inhibitors, ultimately offering the possibility for industrial valorisation.
The objectives of the project are those initially proposed. A better understand of the role of redox homoeostasis in endothelial cells as well as in cancer cells represent an urgent need for the society. The possibility to alter redox state with antioxidants and supplement need to be explored and fully comprehend. We aim to continue to do that in this grant.
We have set up and performed in ECs (HUVECs) a redox proteomic approach, called OXICAT, through which we define different angiogenic conditions for what we explore change in cysteine redox state. Among the target we identified G6PD and PGD, two key enzymes of the PPP pathway. The role of PPP in angiogenesis has not been much studied. To this end we tested the role of PPP in the angiogenic processes in vitro and in vivo models. Recent insights establish how endothelial cells communicate with each other and with their environment to form a branched vascular network. We believe that a better understanding of these pathways might allow to identify new targets that could contribute to the development of new therapy in the treatment of vascular diseases.
Based on the identification of the molecular mechanism through which UBIAD1 regulate redox state in ECs and investigate the genetic inactivating UBIAD1 in mouse models of tumor angiogenesis.
We start to address the function of the mevalonate pathway in developmental angiogenesis and in current anti-angiogenic therapies. Mevalonate (MVA) pathway is an essential anabolic metabolic pathway that produces sterols and isoprenoid metabolites, however, its role in angiogenesis is still unclear. The isomerization of un-reactive isopentenyldiphosphate (IPP) into its reactive isomer dimethyl-allylpyrophosphate (DMAPP) in the MVA pathway is the key rate-limiting step of the terpenoid biosynthesis and it is catalyzed by the enzyme isopentenyl-diphosphate isomerase 1 (IDI1). The product of the reaction, DMAPP, is used in the synthesis of MVA metabolites and to isopentenylate adenosine (A) residues in the anticodons of tRNA by TRIT1 (tRNA isopentenyltransferase 1), modification which is required to generate full expression of selenoproteins. Here we aimed to investigate the role of IDI1 as possible targeting of angiogenesis. Our preliminary results highlight the importance of IDI1 and isoprenoid pathway in endothelial homeostasis. However, additional studies are required to clarify the role of this enzyme in pathological angiogenesis.
Briefly, we develop new tools to identify, measure and regulate ROS in endothelial cell in vivo and in vitro.
New molecular targets involved in metabolism and redox homeostasis of endothelial cells has been identified and will be investigated. In particular, focusing on their role in normal angiogenesis and in the context of a pathological condition such tumor angiogenesis and cancer progression.
We achieved almost all the aims proposed in the original proposal. We believe that our recent discovery on UBIAD1 and IDI1 enzyme and the genetic experiment characterized by a loss-of-function of those targets will provide clear evidence in a 5 year frame of the crucial role of redox signaling and metabolic state in angiogenesis opening to new exciting hypothesis on how to design redox-based therapies for pathological angiogenesis in humans.