Several strategies against Alzheimer disease (AD) are directed to target Aβ-peptides. The ability of transthyretin (TTR) to bind Aβ-peptides and the positive effect exerted by some TTR stabilizers for modulating the TTR-Aβ interaction have been previously studied. Herein, key structural features of the interaction between TTR and the Aβ(12-28) peptide (3), the essential recognition element of Aβ, have been unravelled by STD-NMR spectroscopy methods in solution. Molecular aspects related to the role of the TTR stabilizer iododiflunisal (IDIF, 5) on the TTR-Aβ complex have been also examined. The NMR results, assisted by molecular modeling protocols, have provided a structural model for the TTR-Aβ interaction, as well as for the ternary complex formed in the presence of IDIF. This basic structural information could be relevant for providing light on the mechanisms involved in the ameliorating effects of AD symptoms observed in AD/TTR animal models after IDIF treatment and eventually for designing new molecules toward AD therapeutic drugs.

Transthyretin (TTR) has a well-established role in neuroprotection, evidenced in Alzheimer's Disease (AD). By targeting TTR we have setup a drug discovery program of small-molecule compounds that act as chaperones, enhancing TTR/ amyloid-β peptide (Aβ) interactions. In a first stage, we carried out two computational drug repurposing approaches. In a second stage, the computationally selected compounds were assessed for their ability to bind and stabilize the TTR tetramer, using thyroxine displacement tests, and by assessing the level of monomers, respectively. In a third stage, the selected 53 best performing molecules were run through our in-house validated high-throughput screening ternary test. By targeting TTR in our AD drug discovery program, small-molecule chaperones (SMCs) have been discovered, providing the basis for a novel target for Alzheimer's disease (AD) based on their enhancement of the TTR/A interaction.Among the SMCs, we have found our lead small-molecule compound Iododiflunisal (IDIF), a molecule in the discovery phase, one investigational drug (luteolin), and 3 marketed drugs (sulindac, olsalazine and flufenamic), which could be directly repurposed or repositioned for clinical use. Importantly, we found that not all TTR tetramer stabilizers are good SMCs in vitro, emphasizing the importance of our discovery program. A small set of these SMCs will be prioritized to enter preclinical safety studies, to validate TTR as a target in vivo, and to select one repurposed drug as a candidate to enter clinical trials for AD. We envisage that this new target will feed the currently exhausted pipeline of drugs in phase I for AD with the goal of increasing AD disease-modifying therapies.Compounds assayed in different assays; selected compounds after computational screening; T4 displacement assays; TTR stability assays; selected compounds for ternary assays; results from the HTS assays; kinetics of aggregation of A(12-28) peptide with TTR or TTR complexed with representative comppunds of the 53 selected molecules; ITC studies of the binary interaction A(12-28) + TTR and the ternary interactions [A(12-28) + [(TTR+SMC)]; ITC studies of the binary interactions (TTR+SMC).

Oncogenic RAS proteins are important for driving tumour formation, and for maintenance of the transformed phenotype, and thus their relevance as a cancer therapeutic target is undeniable. We focused here on obtaining peptidomimetics, which have good pharmacological properties, to block Ras–effector interaction. Computational analysis was used to identify hot spots of RAS relevant for these interactions and to screen a library of peptidomimetics. Nine compounds were synthesized and assayed for their activity as RAS inhibitors in cultured cells. Most of them induced a reduction in ERK and AKT activation by EGF, a marker of RAS activity. The most potent inhibitor disrupted Raf and PI3K interaction with oncogenic KRAS, corroborating its mechanism of action as an inhibitor of protein–protein interactions, and thus validating our computational methodology. Most interestingly, improvement of one of the compounds allowed us to obtain a peptidomimetic that decreased the survival of pancreatic cancer cell lines harbouring oncogenic KRAS.

Transthyretin (TTR) has a well-established role in neuroprotection, evidenced in Alzheimer's Disease (AD). By targeting TTR we have setup a drug discovery program of small-molecule compounds that act as chaperones, enhancing TTR/ amyloid-β peptide (Aβ) interactions. In a first stage, we carried out two computational drug repurposing approaches. In a second stage, the computationally selected compounds were assessed for their ability to bind and stabilize the TTR tetramer, using thyroxine displacement tests, and by assessing the level of monomers, respectively. In a third stage, the selected 53 best performing molecules were run through our in-house validated high-throughput screening ternary test. By targeting TTR in our AD drug discovery program, small-molecule chaperones (SMCs) have been discovered, providing the basis for a novel target for Alzheimer's disease (AD) based on their enhancement of the TTR/A interaction. Among the SMCs, we have found our lead small-molecule compound Iododiflunisal (IDIF), a molecule in the discovery phase, one investigational drug (luteolin), and 3 marketed drugs (sulindac, olsalazine and flufenamic), which could be directly repurposed or repositioned for clinical use. Importantly, we found that not all TTR tetramer stabilizers are good SMCs in vitro, emphasizing the importance of our discovery program. A small set of these SMCs will be prioritized to enter preclinical safety studies, to validate TTR as a target in vivo, and to select one repurposed drug as a candidate to enter clinical trials for AD. We envisage that this new target will feed the currently exhausted pipeline of drugs in phase I for AD with the goal of increasing AD disease-modifying therapies.

Transthyretin (TTR) has a well-established role in neuroprotection, evidenced in Alzheimer’s Disease (AD). By targeting TTR we have setup a drug discovery program of small-molecule compounds that act as chaperones, enhancing TTR/ amyloid-β peptide (Aβ) interactions. In a first stage, we carried out two computational drug repurposing approaches. In a second stage, the computationally selected compounds were assessed for their ability to bind and stabilize the TTR tetramer, using thyroxine displacement tests, and by assessing the level of monomers, respectively. In a third stage, the selected 53 best performing molecules were run through our in-house validated high-throughput screening ternary test. By targeting TTR in our AD drug discovery program, small-molecule chaperones (SMCs) have been discovered, providing the basis for a novel target for Alzheimer’s disease (AD) based on their enhancement of the TTR/Abeta interaction. Among the SMCs, we have found our lead small-molecule compound Iododiflunisal (IDIF), a molecule in the discovery phase, one investigational drug (luteolin), and 3 marketed drugs (sulindac, olsalazine and flufenamic), which could be directly repurposed or repositioned for clinical use. Importantly, we found that not all TTR tetramer stabilizers are good SMCs in vitro, emphasizing the importance of our discovery program. A small set of these SMCs will be prioritized to enter preclinical safety studies, to validate TTR as a target in vivo, and to select one repurposed drug as a candidate to enter clinical trials for AD. We envisage that this new target will feed the currently exhausted pipeline of drugs in phase I for AD with the goal of increasing AD disease-modifying therapies.