Metformin induce autophagy and UPR under intracystic glucose deprivation in in vitro metacestodes and in vivo experimental models of Echinococcus granulosus.

JULIA A LOOS; NEGRO PERLA S.; LEDO CAMILA; NICOLAO MA. CELESTE; PAVIA NATALIA; DIAZ MALENA; DEL RIO MARIANELA; DE LA CANAL LAURA; CUMINO ANDREA C

Mar del Plata

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2021

Sociedad Argentina de Investigaciones Clínica y Sociedades Conjuntas

METFORMIN INDUCES AUTOPHAGY AND UPR UNDER INTRACYSTIC GLUCOSE DEPRIVATION IN IN VITRO METACESTODES AND IN VIVO EXPERIMENTAL MODELS OF Echinococcus granulosus.Loos Julia A1, Perla S. Negro2, Ledo Camila1, Nicolao Ma. Celeste1, Pavia Natalia1, Díaz Malena1, Marianela Del Rio2, De la Canal Laura3, Cumino Andrea C1,4. 1Laboratorio de Zoonososis Parasitarias, IIPROSAM-Conicet-UNMDP, 2 Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, 3Instituto de Investigaciones Biológicas (IIB-Conicet-UNMDP), 3Departamento de Química y Bioquímica-FCEyN, Universidad Nacional de Mar del Plata.Metformin (Met) is an experimental antiechinococcal drug (Loos et al., 2017; 2020), which inhibits the complex I of the respiratory chain in in vitro Echinococcus larval stage, resulting in an indirect AMPK activation (by an increased ADP/ATP ratio due to ATP drop) and a subsequent inhibition of TOR signaling with autophagy induction (Loos et al., 2015, 2018). Here, we demonstrated that Met mediated the dephosphorylation of Eg-TOR in Ser3122, which trigger the reduction of its activity in metacestodes, responding also to exogenous insulin and rapamycin. Moreover, Met induced the overexpression of TFEB, a hub transcription factor that regulates lysosome biogenesis, lipid catabolism and autophagy in metazoa. In concordance with the mitochondrial depolarization induced by Met, an increase in total cellular Pi (an activator of PFK1) was detected, with stimulation of glycogen consumption (glycogenolysis) and, increase of glycolysis and the lactate fraction. Cumulatively, this supports the reduction in the glucose intracystic content demonstrated in vitro, as well as in two different experiments (50 and 250 mg/kg/day of Met) in the echinococcosis murine model. In this line of evidence, the energy starvation induced by Met causes endoplasmic reticulum stress-mediated unfolded protein response (UPR). In presence of a mannose-specific lectin (Helja-FITC) and using confocal microscopy, we found that parasite cells expanded their ER volume at least 3-fold under treatment with Met. Using thapsigargin, tunicamycin and Met-treated parasites, we validated the IRE activity by XBP1 splicing and demonstrated that Met induced the mRNA of Bip/Grp78d. In this context, we described that UPR induced after Met-treatment can take place upon glucose deprivation in the parasite, suggesting that the anthelminthic effects of Met result from sustained autophagy mediated by activation of the AMPK-TOR-TFEB signaling pathway interdependent with UPR activation, especially through the IRE/XBP arm.El trabajo ´METFORMIN INDUCES AUTOPHAGY AND UPR UNDER INTRACYSTIC GLUCOSE DEPRIVATION IN IN VITRO METACESTODES AND IN VIVO EXPERIMENTAL MODELS OF Echinococcus granulosus.´ ha sido evaluado por el comité con resultado ´Aceptado´ .ID: 43Categoría: E-Poster