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Forn-Cuni, G.

Publications and source records attributed to Forn-Cuni, G..

4 recordsLinked to original sources

Accelerating drug development in infectious diseases using zebrafish disease models supported by pharmacokinetic pharmacodynamic modeling as new approach methodology (NAM)

The development of novel therapeutics for infectious diseases remains a global health priority. To accelerate the treatment development, innovative strategies through new approach methodology (NAM) are needed to bridge speed of in vitro with predictive power of in vivo studies, while reducing mammalian experiments. The zebrafish (Danio rerio), particularly the embryo/larva, has been established as a valuable non-mammalian in vivo model in biomedical research. We developed a standardized and streamlined workflow for the zebrafish as NAM, which consisted of 3 steps: drug selection and efficacy evaluation, internal exposure assessment, and PKPD modelling. Compounds with higher tolerated doses than minimum inhibitory concentration were selected. Drug efficacy was quantified through longitudinal individual fluorescence microscopy at baseline and 24 and 48h on treatment. Drug exposure was quantified in larval homogenates and exposure medium from 0-48h on treatment. The PKPD relationship was quantified by non-linear mixed effects modelling. For case study bedaquiline, PKPD was quantified using a one-compartment model with age-depending elimination, and an Emax concentration-response relationship on the delayed logistic bacterial growth function, with an EC50 of 26.6 {micro}g/mL and an Emax of 1.07-1.37. In the case of clarithromycin, in contrast, negligible internal exposure after waterborne treatment were observed, illustrating the risk of false negatives without internal exposure assessments. Bactericidal efficacy was confirmed by intravenous drug injections, showing a clear dose dependent antimycobacterial effect. The standardized zebrafish NAM workflow presented here facilitates the translation of drug efficacy to higher vertebrates, reducing rodent studies to confirmatory or replacing them completely, thus accelerating drug development.

pharmacology and toxicology↗

Simultaneous targeting of AMPK and mTOR is a novel therapeutic strategy against prostate cancer

Metastatic colonization by circulating cancer cells is a highly inefficient process. To colonize distant organs, disseminating cancer cells must overcome many obstacles in foreign microenvironments, and only a small fraction of them survives this process. How these disseminating cancer cells cope with stress and initiate metastatic process is not fully understood. In this study, we report that the metastatic onset of prostate cancer cells is associated with the dynamic conversion of metabolism signaling pathways governed by the energy sensors AMPK and mTOR. While in circulation in blood flow, the disseminating cancer cells display decreased mTOR and increased AMPK activities that protect them from stress-induced death. However, after metastatic onset, the mTOR-AMPK activities are reversed, enabling mTOR-dependent tumor growth. Suppression of this dynamic conversion by co-targeting of AMPK and mTOR signaling significantly suppresses prostate cancer cell and tumor organoid growth in vitro and experimental metastasis in vivo, suggesting that this can be a therapeutic approach against metastasizing prostate cancer.

cancer biology↗

XePhIR: The zebrafish Xenograft Phenotype Interactive Repository

Zebrafish xenografts are an established model in cancer biology, with a steadily rising number of models and users. However, as of yet, there is no platform dedicated to standardizing protocols and sharing data regarding zebrafish xenograft phenotypes. Here, we present the Xenograft Phenotype Interactive Repository (XePhIR, www.xephir.org) as an independent data sharing platform to deposit, share and repurpose zebrafish xenograft data. Deposition of data and publication with XePhIR will be done after the acceptation of the original publication. This will enhance the reach of the original research article, enhance visibility, and does not interfere with publication or copyrights of the original article. With XePhIR, we strive to fulfill these objectives and reason that this resource will enhance reproducibility and showcase the appeal and applicability of the zebrafish xenograft model.

cancer biology↗

Deficiency in the autophagy modulator Dram1 exacerbates pyroptotic cell death of Mycobacteria-infected macrophages

DNA Damage Regulated Autophagy Modulator 1 (DRAM1) is a stress-inducible regulator of autophagy and cell death. DRAM1 has been implicated in cancer, myocardial infarction, and infectious diseases, but the molecular and cellular functions of this transmembrane protein remain poorly understood. Previously, we have proposed DRAM1 as a host resistance factor for tuberculosis (TB) and a potential target for host-directed anti-infective therapies. In this study, we generated a zebrafish dram1 mutant and investigated its loss-of-function effects during Mycobacterium marinum (Mm) infection, a widely used model in TB research. In agreement with previous knockdown analysis, dram1 mutation increased the susceptibility of zebrafish larvae to Mm infection. RNA sequencing revealed major effects of Dram1 deficiency on metabolic, immune response, and cell death pathways during Mm infection, whereas only minor effects on proteinase and metabolic pathways were found under uninfected conditions. Furthermore, unchallenged dram1 mutants did not display overt autophagic defects, but autophagic targeting of Mm was reduced in absence of Dram1. The phagocytic ability of macrophages in dram1 mutants was unaffected, but acidification of Mm-containing vesicles was strongly reduced, indicating that Dram1 is required for phagosome maturation. By in vivo imaging we observed that Dram1-deficient macrophages fail to restrict Mm during early stages of infection. The resulting increase in bacterial burden could be reverted by knockdown of inflammatory caspase a (caspa) and gasdermin Eb (gsdmeb), demonstrating pyroptosis as the mechanism underlying premature cell death of Mm-infected macrophages in dram1 mutants. Collectively, these data demonstrate that dissemination of mycobacterial infection in zebrafish larvae is promoted in absence of Dram1 due to reduced maturation of mycobacteria-containing vesicles, failed intracellular containment, and consequent pyroptotic cell death of infected macrophages. These results provide new evidence that Dram1 plays a central role in host resistance to intracellular infection, acting at the crossroad of autophagy and cell death.

immunology↗