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Tag: UCP1

Absence of MCJ/DnaJC15 promotes brown adipose tissue thermogenesis

Beatriz Cicuéndez, Alfonso Mora, Juan Antonio López, Andrea Curtabbi, Javier Pérez-García, Begoña Porteiro, Daniel Jimenez-Blasco, Pedro Latorre-Muro, Paula Vo, Madison Jerome, Beatriz Gómez-Santos, Rafael Romero-Becerra, Magdalena Leiva, Elena Rodríguez, Marta León, Luis Leiva-Vega, Noemi Gómez-Lado, Jorge L. Torres, Lourdes Hernández-Cosido, Pablo Aguiar, Miguel Marcos, Martin Jastroch, Andreas Daiber, Patricia Aspichueta, Juan Pedro Bolaños, Jessica B. Spinelli, Pere Puigserver, José Antonio Enriquez, Jesús Vázquez, Cintia Folgueira & Guadalupe Sabio.

Obesity poses a global health challenge, demanding a deeper understanding of adipose tissue (AT) and its mitochondria. This study describes the role of the mitochondrial protein Methylation-controlled J protein (MCJ/DnaJC15) in orchestrating brown adipose tissue (BAT) thermogenesis.

Mitochondia from brown fat (Image: Beatriz Cicuéndez).

Here we show how MCJ expression decreases during obesity, as evident in human and mouse adipose tissue samples. MCJKO mice, even without UCP1, a fundamental thermogenic protein, exhibit elevated BAT thermogenesis. Electron microscopy unveils changes in mitochondrial morphology resembling BAT activation. Proteomic analysis confirms these findings and suggests involvement of the eIF2α mediated stress response. The pivotal role of eIF2α is scrutinized by in vivo CRISPR deletion of eIF2α in MCJKO mice, abrogating thermogenesis.

These findings uncover the importance of MCJ as a regulator of BAT thermogenesis, presenting it as a promising target for obesity therapy.

Estrogens prevent the hypothalamus-periphery crosstalk induced by olanzapine intraperitoneal treatment in female mice: effects on brown/beige adipose tissues and liver

Vítor Ferreira, Cintia Folgueira, Ángela Montes-San Lorenzo, Andrea Rodríguez-López, Eva Gonzalez-Iglesias, Pablo Zubiaur, Francisco Abad-Santos, Guadalupe Sabio, Patricia Rada & Ángela M Valverde.

Olanzapine (OLA) is a highly obesogenic second-generation antipsychotic (SGA). Recently we demonstrated that, contrarily to OLA oral treatment, intraperitoneal (i.p.) administration resulted in weight loss and absence of hepatic steatosis in wild-type (WT) and protein tyrosine phosphatase 1B (PTP1B)-deficient (KO) male mice. This protection relied on two central-peripheral axes connecting hypothalamic AMPK with brown/inguinal white adipose tissue (BAT/iWAT) uncoupling protein-1 (UCP-1) and hypothalamic JNK with hepatic fatty acid synthase (FAS).

Olanzapine reduces body weight exclusively in ovariectomized mice (Image: Cintia Folgueira).

Herein, we addressed OLA i.p. treatment effects in WT and PTP1B-KO female mice. Contrarily to our previous results in WT females receiving OLA orally, the i.p. treatment did not induce weight gain or hyperphagia. Molecularly, in females OLA failed to diminish hypothalamic phospho-AMPK or elevate BAT UCP-1 and energy expenditure (EE) despite the preservation of iWAT browning. Conversely, OLA i.p. treatment in ovariectomized mice reduced hypothalamic phospho-AMPK, increased BAT/iWAT UCP-1 and EE, and induced weight loss as occurred in males. Pretreatment of hypothalamic neurons with 17β-estradiol (E2) abolished OLA effects on AMPK. Moreover, neither hypothalamic JNK activation nor hepatic FAS upregulation were found in WT and PTP1B-KO females receiving OLA via i.p. Importantly, this axis was reestablished upon ovariectomy. In this line, E2 prevented OLA-induced phospho-JNK in hypothalamic neurons.

These results support the role of estrogens in sex-related dimorphism in OLA treatment. This study evidenced the benefit of OLA i.p. administration in preventing its obesogenic effects in female mice that could offer clinical value.

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