Tag: lipid metabolism (Page 3 of 9)

Predoctoral contract in metabolism

07/09/2023 / Sabio lab

We are seeking a highly motivated candidate, who would like to start a scientific career doing their doctoral thesis working in understanding p38 kinases role in how the communiation between organs affect the metabolic. This work will be supervised by Dr. Guadalupe Sabio.

We offer incorporation to CNIC via an FPU predoctoral contract. Interested candidates will need to apply before 19 September 2023 in the following CNIC website:

METABOkines: Comunicación celular en el metabolismo: Implicación de la vía de las p38s.

PID2022-138525OB-I00

ELEGIBILITY CRITERIA

This call is open to applicants from all nationalities holding a Master’s degree in Biomedical Sciences.
An excellent academic record and previous research experience during their undergraduate period will be valued very positively.
Authorship of publicacions in indexed journal will be valued very positively.
Candidates must have a solid working knowledge of English.

Hypothalamic JNK1-hepatic fatty acid synthase axis mediates a metabolic rewiring that prevents hepatic steatosis in male mice treated with olanzapine via intraperitoneal: Additional effects of PTP1B inhibition

26/05/2023 / Sabio lab

Vitor Ferreira, Cintia Folgueira, María García-Altares, Maria Guillén, Mónica Ruíz-Rosario, Giada DiNunzio, Irma Garcia-Martinez, Rosa Alen, Christoph Bookmeyer, John G. Jones, Juan C. Cigudosa, Pilar López-Larrubia, Xavier Correig-Blanchar, Roger J. Davis, Guadalupe Sabio, Patricia Rada & Ángela M. Valverde.

Olanzapine (OLA), a widely used second-generation antipsychotic (SGA), causes weight gain and metabolic alterations when administered orally to patients. Recently, we demonstrated that, contrarily to the oral treatment which induces weight gain, OLA administered via intraperitoneal (i.p.) in male mice resulted in body weight loss. This protection was due to an increase in energy expenditure (EE) through a mechanism involving the modulation of hypothalamic AMPK activation by higher OLA levels reaching this brain region compared to those of the oral treatment. Since clinical studies have shown hepatic steatosis upon chronic treatment with OLA, herein we further investigated the role of the hypothalamus-liver interactome upon OLA administration in wild-type (WT) and protein tyrosine phosphatase 1B knockout (PTP1B-KO) mice, a preclinical model protected against metabolic syndrome. WT and PTP1B-KO male mice were fed an OLA-supplemented diet or treated via i.p.

Olanzapine iniection increases hypothalamic JNK phosphorylation (Imagen: Cintia Folgueira).

Mechanistically, we found that OLA i.p. treatment induces mild oxidative stress and inflammation in the hypothalamus in a JNK1-independent and dependent manner, respectively, without features of cell dead. Hypothalamic JNK activation up-regulated lipogenic gene expression in the liver though the vagus nerve. This effect concurred with an unexpected metabolic rewiring in the liver in which ATP depletion resulted in increased AMPK/ACC phosphorylation. This starvation-like signature prevented steatosis. By contrast, intrahepatic lipid accumulation was observed in WT mice treated orally with OLA; this effect being absent in PTP1B-KO mice. We also demonstrated an additional benefit of PTP1B inhibition against hypothalamic JNK activation, oxidative stress and inflammation induced by chronic OLA i.p. treatment, thereby preventing hepatic lipogenesis.

The protection conferred by PTP1B deficiency against hepatic steatosis in the oral OLA treatment or against oxidative stress and neuroinflammation in the i.p. treatment strongly suggests that targeting PTP1B might be also a therapeutic strategy to prevent metabolic comorbidities in patients under OLA treatment in a personalized manner.

Redox Biol. 2023; 63: 102741.

The outcome of boosting mitochondrial activity in alcoholic liver disease (ALD) is organ-dependent

08/02/2023 / Sabio lab

Naroa Goikoetxea-Usandizaga, Miren Bravo, Leire Egia-Mendikute, Leticia Abecia, Marina Serrano-Maciá, Rocío G Urdinguio, Marc Clos-García, Rubén Rodríguez-Agudo, Raquel Araujo-Legido, Lucía López-Bermudo, Teresa C Delgado, Sofía Lachiondo-Ortega, Irene González-Recio, Clàudia Gil-Pitarch, Ainize Peña-Cearra, Jorge Simón, Raquel Benedé-Ubieto, Silvia Ariño, Jose M Herranz, Mikel Azkargorta, Julio Salazar-Bermeo, Nuria Martí, Marta Varela-Rey, Juan M Falcón-Pérez, Óscar Lorenzo, Rubén Nogueiras, Félix Elortza Yulia A Nevzorova, Francisco J Cubero, Domingo Saura, Luis Alfonso Martínez-Cruz, Guadalupe Sabio, Asís Palazón, Pau Sancho-Bru, Natalia Elguezabal, Mario F Fraga, Matías A Ávila, Ramón Bataller, José J G Marín, Franz Martín & María Luz Martínez-Chantar.

Objective: Alcoholic liver disease (ALD) accounts for 70% of liver-related deaths in Europe, with no effective approved therapies. Although mitochondrial dysfunction is one of the earliest manifestations of alcohol-induced injury, restoring mitochondrial activity remains a problematic strategy due to oxidative stress. Here, we identify methylation-controlled J protein (MCJ) as a mediator for ALD progression and hypothesize that targeting MCJ may help recovering mitochondrial fitness without collateral oxidative damage.

Design: C57BL/6 mice (Wild-type (Wt), Mcj knockout (MCJ-KO) and Mcj liver-specific silencing (MCJ-LSS) underwent the NIAAA dietary protocol (Lieber-DeCarli diet containing 5% (vol/vol) ethanol for 10 days, plus a single binge ethanol feeding at day 11). To evaluate the impact of a restored mitochondrial activity in ALD, liver, gut, and pancreas where characterized, focusing on lipid metabolism, glucose homeostasis, intestinal permeability, and microbiota composition.

Results: MCJ, a protein acting as an endogenous negative regulator of mitochondrial respiration, is downregulated in the early stages of ALD and increases with the severity of the disease. Whole-body deficiency of MCJ is detrimental during ALD because it exacerbates the systemic effects of alcohol abuse through altered intestinal permeability, increased endotoxemia, and dysregulation of pancreatic function, which overall worsens liver injury. On the other hand, liver-specific Mcj silencing prevents main ALD hallmarks, i.e., mitochondrial dysfunction, steatosis, inflammation, and oxidative stress, as it restores the NAD+/NADH ratio and SIRT1 function, hence preventing de novo lipogenesis and improving lipid oxidation.

Conclusion: Improving mitochondrial respiration by liver-specific Mcj silencing might become a novel therapeutic approach for treating ALD.

Hepatology 2023; doi: 10.1097/HEP.0000000000000303.