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1.
Int J Biol Sci ; 20(7): 2339-2355, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38725853

RESUMEN

Chronic cholestatic damage is associated to both accumulation of cytotoxic levels of bile acids and expansion of adult hepatic progenitor cells (HPC) as part of the ductular reaction contributing to the regenerative response. Here, we report a bile acid-specific cytotoxic response in mouse HPC, which is partially impaired by EGF signaling. Additionally, we show that EGF synergizes with bile acids to trigger inflammatory signaling and NLRP3 inflammasome activation in HPC. Aiming at understanding the impact of this HPC specific response on the liver microenvironment we run a proteomic analysis of HPC secretome. Data show an enrichment in immune and TGF-ß regulators, ECM components and remodeling proteins in HPC secretome. Consistently, HPC-derived conditioned medium promotes hepatic stellate cell (HSC) activation and macrophage M1-like polarization. Strikingly, EGF and bile acids co-treatment leads to profound changes in the secretome composition, illustrated by an abolishment of HSC activating effect and by promoting macrophage M2-like polarization. Collectively, we provide new specific mechanisms behind HPC regulatory action during cholestatic liver injury, with an active role in cellular interactome and inflammatory response regulation. Moreover, findings prove a key contribution for EGFR signaling jointly with bile acids in HPC-mediated actions.


Asunto(s)
Ácidos y Sales Biliares , Receptores ErbB , Inflamación , Ratones Endogámicos C57BL , Transducción de Señal , Animales , Ácidos y Sales Biliares/metabolismo , Receptores ErbB/metabolismo , Ratones , Inflamación/metabolismo , Células Madre/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Proteómica , Macrófagos/metabolismo , Células Estrelladas Hepáticas/metabolismo
2.
Biochim Biophys Acta Mol Basis Dis ; 1870(5): 167227, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38733774

RESUMEN

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). 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 17ß-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.

3.
An. R. Acad. Nac. Farm. (Internet) ; 90(1): 21-44, Ene-Mar, 2024. tab, ilus
Artículo en Español | IBECS | ID: ibc-232333

RESUMEN

La esquizofrenia es un trastorno neuropsiquiátrico crónico que afecta a 21 millones de personas en todo el mundo. Actualmente, los fármacos antipsicóticos de segunda generación o atípicos (FASG) son los medicamentos de elección para el tratamiento de esta enfermedad. Sin embargo, a pesar de su alta eficacia en contrarrestar la sintomatología neuropsiquiátrica de la esquizofrenia, observaciones clínicas recientes en pacientes tratados con FASG evidencian un aumento en la prevalencia de diferentes alteraciones metabólicas, entre las que se incluyen el aumento de peso corporal, la hiperglucemia y la dislipidemia. A pesar de que no se conocen en detalle los mecanismos moleculares responsables de estos efectos secundarios, cada vez más investigaciones apuntan a una relación entre los tratamientos con FASG y las alteraciones en los diferentes depósitos de tejido adiposo blanco, marrón y beige. En esta revisión analizamos el conocimiento actual en esta área destacando aspectos moleculares de la biología de los adipocitos, entre los que se encuentran los procesos de diferenciación, metabolismo lipídico, función termogénica y el proceso de pardeamiento o beiging.(AU)


Schizophrenia is a chronic neuropsychiatric disorder that affects 21 million people worldwide. Currently, second-generation or atypical antipsychotics (SGAs) are the first-line medications for the treatment of this disease. However, despite its high efficacy in counteracting the neuropsychiatric symptoms of schizophrenia, recent clinical investigations in patients treated with SGAs show an increase in the prevalence of pivotal metabolic alterations, including increased body weight, hyperglycemia and dyslipidemia. Although the molecular mechanisms responsible for these side effects are not fully understood, cumulative evidences associate SGA administration with alterations in the different adipose tissue depots of white, brown and beige adipocytes. In this review, we have recapitulated the current knowledge in this area with a particular focus on the molecular aspects of the adipocyte biology, including differentiation, lipid metabolism, thermogenic function and browning processes.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Esquizofrenia/tratamiento farmacológico , Metabolismo , Termogénesis , Antipsicóticos , Tejido Adiposo/efectos de los fármacos , Neuropsiquiatría , Farmacia
4.
Redox Biol ; 71: 103088, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38401290

RESUMEN

Acetaminophen (APAP)-induced liver injury is one of the most prevalent causes of acute liver failure (ALF). We assessed the role of the bone morphogenetic protein (BMP) type I receptors ALK2 and ALK3 in APAP-induced hepatotoxicity. The molecular mechanisms that regulate the balance between cell death and survival and the response to oxidative stress induced by APAP was assessed in cultured human hepatocyte-derived (Huh7) cells treated with pharmacological inhibitors of ALK receptors and with modulated expression of ALK2 or ALK3 by lentiviral infection, and in a mouse model of APAP-induced hepatotoxicity. Inhibition of ALK3 signalling with the pharmacological inhibitor DMH2, or by silencing of ALK3, showed a decreased cell death both by necrosis and apoptosis after APAP treatment. Also, upon APAP challenge, ROS generation was ameliorated and, thus, ROS-mediated JNK and P38 MAPK phosphorylation was reduced in ALK3-inhibited cells compared to control cells. These results were also observed in an experimental model of APAP-induced ALF in which post-treatment with DMH2 after APAP administration significantly reduced liver tissue damage, apoptosis and oxidative stress. This study shows the protective effect of ALK3 receptor inhibition against APAP-induced hepatotoxicity. Furthermore, findings obtained from the animal model suggest that BMP signalling might be a new pharmacological target for the treatment of ALF.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Enfermedad Hepática Inducida por Sustancias y Drogas , Morfolinas , Ratones , Animales , Humanos , Acetaminofén/efectos adversos , Especies Reactivas de Oxígeno/metabolismo , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/metabolismo , Hígado/metabolismo , Hepatocitos/metabolismo , Estrés Oxidativo , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Ratones Endogámicos C57BL
5.
Redox Biol ; 69: 103027, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38184999

RESUMEN

Non-alcoholic steatohepatitis (NASH) is a common chronic liver disease that compromises liver function, for which there is not a specifically approved medicine. Recent research has identified transcription factor NRF2 as a potential therapeutic target. However, current NRF2 activators, designed to inhibit its repressor KEAP1, exhibit unwanted side effects. Alternatively, we previously introduced PHAR, a protein-protein interaction inhibitor of NRF2/ß-TrCP, which induces a mild NRF2 activation and selectively activates NRF2 in the liver, close to normal physiological levels. Herein, we assessed the effect of PHAR in protection against NASH and its progression to fibrosis. We conducted experiments to demonstrate that PHAR effectively activated NRF2 in hepatocytes, Kupffer cells, and stellate cells. Then, we used the STAM mouse model of NASH, based on partial damage of endocrine pancreas and insulin secretion impairment, followed by a high fat diet. Non-invasive analysis using MRI revealed that PHAR protects against liver fat accumulation. Moreover, PHAR attenuated key markers of NASH progression, including liver steatosis, hepatocellular ballooning, inflammation, and fibrosis. Notably, transcriptomic data indicate that PHAR led to upregulation of 3 anti-fibrotic genes (Plg, Serpina1a, and Bmp7) and downregulation of 6 pro-fibrotic (including Acta2 and Col3a1), 11 extracellular matrix remodeling, and 8 inflammatory genes. Overall, our study suggests that the mild activation of NRF2 via the protein-protein interaction inhibitor PHAR holds promise as a strategy for addressing NASH and its progression to liver fibrosis.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Proteínas con Repetición de beta-Transducina , Fibrosis , Proteína 1 Asociada A ECH Tipo Kelch/genética , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico
6.
Metabolism ; 152: 155772, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38176644

RESUMEN

INTRODUCTION: The levels of the cellular energy sensor AMP-activated protein kinase (AMPK) have been reported to be decreased via unknown mechanisms in the liver of mice deficient in growth differentiation factor 15 (GDF15). This stress response cytokine regulates energy metabolism mainly by reducing food intake through its hindbrain receptor GFRAL. OBJECTIVE: To examine how GDF15 regulates AMPK. METHODS: Wild-type and Gdf15-/- mice, mouse primary hepatocytes and the human hepatic cell line Huh-7 were used. RESULTS: Gdf15-/- mice showed glucose intolerance, reduced hepatic phosphorylated AMPK levels, increased levels of phosphorylated mothers against decapentaplegic homolog 3 (SMAD3; a mediator of the fibrotic response), elevated serum levels of transforming growth factor (TGF)-ß1, as well as upregulated gluconeogenesis and fibrosis. In line with these observations, recombinant (r)GDF15 promoted AMPK activation and reduced the levels of phosphorylated SMAD3 and the markers of gluconeogenesis and fibrosis in the liver of mice and in mouse primary hepatocytes, suggesting that these effects may be independent of GFRAL. Pharmacological inhibition of SMAD3 phosphorylation in Gdf15-/- mice prevented glucose intolerance, the deactivation of AMPK and the increase in the levels of proteins involved in gluconeogenesis and fibrosis, suggesting that overactivation of the TGF-ß1/SMAD3 pathway is responsible for the metabolic alterations in Gdf15-/- mice. CONCLUSIONS: Overall, these findings indicate that GDF15 activates AMPK and inhibits gluconeogenesis and fibrosis by lowering the activity of the TGF-ß1/SMAD3 pathway.


Asunto(s)
Intolerancia a la Glucosa , Factor de Crecimiento Transformador beta1 , Humanos , Proteínas Quinasas Activadas por AMP/metabolismo , Fibrosis , Gluconeogénesis , Intolerancia a la Glucosa/metabolismo , Factor 15 de Diferenciación de Crecimiento/genética , Hígado/metabolismo , Transducción de Señal , Proteína smad3 , Factor de Crecimiento Transformador beta1/metabolismo
7.
FASEB J ; 38(2): e23418, 2024 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-38226870

RESUMEN

miRNAs are short single-stranded noncoding RNAs that participate as epigenetic regulators in inflammatory bowel disease. Most miRNAs detectable in serum are concentrated in exosomes, with relevant cargo for immunobiological processes. We set to evaluate the exosomes miRNAs content in the serum of patients with Crohn's disease (CD) and run a prospective observational study on CD patients on biological monotherapy and healthy controls. miRNA cargo was evaluated in peripheral blood-derived exosomes. Serum autophagy and inflammatory substrates were measured. Patients were followed for 6 months. Patients (n = 28) showed an overexpression of miR-376a-3p and a downregulation of miR-20a-5p compared to controls (n = 10), without significant differences between patients according to biologics. Serum autophagy substrates ATG4C (r = .57; p = .001) and ACRV1C (r = .66; p = .001) inversely correlated with miR-376a-3p expression, whereas IGF1R correlated with miR-20a-5p expression (r = .42; p = .02). Th1-related cytokines correlated with miR-376a-3p expression, whereas the Th17-associated cytokines inversely correlated with miR-20a-5p expression. Smoking (ß = -2.301 CI 95% -3.790/-0.811, p = .004) remained as independent factor related to the overexpression of miR-376a-3p, whereas diagnosis before 16 years of age (ß = 2.044 CI 95% 0.934/3.154, p = .001) and a younger age of patients (ß = -.720 CI 95% -0.108/-0.035, p = .001) were related to decreased miR-20a-5p expression. Seven patients (25%) had a flare in the 6-month follow-up. Patients with overexpression of miR-376a-3p at the baseline showed an increased risk of flare during this period (OR 0.475 [0.237-0.950], p = .035). Finally, a comparative miRNA signature between biologic monotherapies was also explored. Targeting miR-376a-3p and miR-20a-5p epigenetic regulators may yield homeostatic effects on relevant biological processes related to disease progression in CD patients.


Asunto(s)
Enfermedad de Crohn , Exosomas , MicroARNs , ARN Pequeño no Traducido , Humanos , Enfermedad de Crohn/genética , MicroARNs/genética , Fumar , Autofagia/genética , Citocinas
8.
Nutrients ; 16(2)2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38257166

RESUMEN

The loss of functional beta-cell mass in diabetes is directly linked to the development of diabetic complications. Although dietary flavonoids have demonstrated antidiabetic properties, their potential effects on pancreatic beta-cell preservation and their synergistic benefits with antidiabetic drugs remain underexplored. We have developed a potential functional food enriched in flavonoids by combining cocoa powder and carob flour (CCB), which has shown antidiabetic effects. Here, we investigated the ability of the CCB, alone or in combination with metformin, to preserve pancreatic beta cells in an established diabetic context and their potential synergistic effect. Zucker diabetic fatty rats (ZDF) were fed a CCB-rich diet or a control diet, with or without metformin, for 12 weeks. Markers of pancreatic oxidative stress and inflammation, as well as relative beta-cell mass and beta-cell apoptosis, were analyzed. Results demonstrated that CCB feeding counteracted pancreatic oxidative stress by enhancing the antioxidant defense and reducing reactive oxygen species. Moreover, the CCB suppressed islet inflammation by preventing macrophage infiltration into islets and overproduction of pro-inflammatory cytokines, along with the inactivation of nuclear factor kappa B (NFκB). As a result, the CCB supplementation prevented beta-cell apoptosis and the loss of beta cells in ZDF diabetic animals. The observed additive effect when combining the CCB with metformin underscores its potential as an adjuvant therapy to delay the progression of type 2 diabetes.


Asunto(s)
Cacao , Chocolate , Diabetes Mellitus Tipo 2 , Galactanos , Células Secretoras de Insulina , Mananos , Metformina , Gomas de Plantas , Ratas , Animales , Metformina/farmacología , Ratas Zucker , Flavonoides/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/farmacología , Alimentos Funcionales , Inflamación
9.
Free Radic Biol Med ; 210: 448-461, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38036067

RESUMEN

Non-alcoholic steatohepatitis (NASH) is one of the fastest growing liver diseases worldwide, and oxidative stress is one of NASH main key drivers. Nicotinamide adenine dinucleotide phosphate (NADPH) is the ultimate donor of reductive power to a number of antioxidant defences. Here, we explored the potential of increasing NADPH levels to prevent NASH progression. We used nicotinamide riboside (NR) supplementation or a G6PD-tg mouse line harbouring an additional copy of the human G6PD gene. In a NASH mouse model induced by feeding mice a methionine-choline deficient (MCD) diet for three weeks, both tools increased the hepatic levels of NADPH and ameliorated the NASH phenotype induced by the MCD intervention, but only in female mice. Boosting NADPH levels in females increased the liver expression of the antioxidant genes Gsta3, Sod1 and Txnrd1 in NR-treated mice, or of Gsr for G6PD-tg mice. Both strategies significantly reduced hepatic lipid peroxidation. NR-treated female mice showed a reduction of steatosis accompanied by a drop of the hepatic triglyceride levels, that was not observed in G6PD-tg mice. NR-treated mice tended to reduce their lobular inflammation, showed a reduction of the NK cell population and diminished transcription of the damage marker Lcn2. G6PD-tg female mice exhibited a reduction of their lobular inflammation and hepatocyte ballooning induced by the MCD diet, that was related to a reduction of the monocyte-derived macrophage population and the Tnfa, Ccl2 and Lcn2 gene expression. As conclusion, boosting hepatic NADPH levels attenuated the oxidative lipid damage and the exhausted antioxidant gene expression specifically in female mice in two different models of NASH, preventing the progression of the inflammatory process and hepatic injury.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Femenino , Ratones , Humanos , Animales , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , NADP/metabolismo , Antioxidantes/metabolismo , Hígado/metabolismo , Inflamación/metabolismo , Colina/metabolismo , Metionina/metabolismo , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad
10.
Biomed Pharmacother ; 167: 115623, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37783154

RESUMEN

Elafibranor is a dual peroxisome proliferator-activated receptor (PPAR)α and ß/δ agonist that has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we examined the effects of elafibranor in mice fed a choline-deficient high-fat diet (CD-HFD), a model of metabolic dysfunction-associated steatohepatitis (MASH) that presents obesity and insulin resistance. Our findings revealed that elafibranor treatment ameliorated steatosis, inflammation, and fibrogenesis in the livers of CD-HFD-fed mice. Unexpectedly, elafibranor also increased the levels of the epithelial-mesenchymal transition (EMT)-promoting protein S100A4 via PPARß/δ activation. The increase in S100A4 protein levels caused by elafibranor was accompanied by changes in the levels of markers associated with the EMT program. The S100A4 induction caused by elafibranor was confirmed in the BRL-3A rat liver cells and a mouse primary hepatocyte culture. Furthermore, elafibranor reduced the levels of ASB2, a protein that promotes S100A4 degradation, while ASB2 overexpression prevented the stimulating effect of elafibranor on S100A4. Collectively, these findings reveal an unexpected hepatic effect of elafibranor on increasing S100A4 and promoting the EMT program.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , PPAR delta , PPAR-beta , Animales , Ratones , Ratas , Dieta Alta en Grasa , Transición Epitelial-Mesenquimal , Hígado , Enfermedad del Hígado Graso no Alcohólico/metabolismo , PPAR delta/metabolismo , PPAR-beta/agonistas , PPAR-beta/metabolismo , PPAR-beta/uso terapéutico
11.
Biomed Pharmacother ; 168: 115667, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37826940

RESUMEN

Soluble epoxide hydrolase (sEH) is a drug target with the potential for therapeutic utility in the areas of inflammation, neurodegenerative disease, chronic pain, and diabetes, among others. Proteolysis-targeting chimeras (PROTACs) molecules offer new opportunities for targeting sEH, due to its capacity to induce its degradation. Here, we describe that the new ALT-PG2, a PROTAC that degrades sEH protein in the human hepatic Huh-7 cell line, in isolated mouse primary hepatocytes, and in the liver of mice. Remarkably, sEH degradation caused by ALT-PG2 was accompanied by an increase in the phosphorylated levels of AMP-activated protein kinase (AMPK), while phosphorylated extracellular-signal-regulated kinase 1/2 (ERK1/2) was reduced. Consistent with the key role of these kinases on endoplasmic reticulum (ER) stress, ALT-PG2 attenuated the levels of ER stress and inflammatory markers. Overall, the findings of this study indicate that targeting sEH with degraders is a promising pharmacological strategy to promote AMPK activation and to reduce ER stress and inflammation.


Asunto(s)
Epóxido Hidrolasas , Enfermedades Neurodegenerativas , Humanos , Animales , Ratones , Proteínas Quinasas Activadas por AMP/metabolismo , Inflamación , Estrés del Retículo Endoplásmico/fisiología
12.
Mol Metab ; 74: 101749, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37271337

RESUMEN

OBJECTIVE: Maresin 1 (MaR1) is a docosahexaenoic acid-derived proresolving lipid mediator with insulin-sensitizing and anti-steatosis properties. Here, we aim to unravel MaR1 actions on brown adipose tissue (BAT) activation and white adipose tissue (WAT) browning. METHODS: MaR1 actions were tested in cultured murine brown adipocytes and in human mesenchymal stem cells (hMSC)-derived adipocytes. In vivo effects of MaR1 were tested in diet-induced obese (DIO) mice and lean WT and Il6 knockout (Il6-/-) mice. RESULTS: In cultured differentiated murine brown adipocytes, MaR1 reduces the expression of inflammatory genes, while stimulates glucose uptake, fatty acid utilization and oxygen consumption rate, along with the upregulation of mitochondrial mass and genes involved in mitochondrial biogenesis and function and the thermogenic program. In Leucine Rich Repeat Containing G Protein-Coupled Receptor 6 (LGR6)-depleted brown adipocytes using siRNA, the stimulatory effect of MaR1 on thermogenic genes was abrogated. In DIO mice, MaR1 promotes BAT remodeling, characterized by higher expression of genes encoding for master regulators of mitochondrial biogenesis and function and iBAT thermogenic activation, together with increased M2 macrophage markers. In addition, MaR1-treated DIO mice exhibit a better response to cold-induced BAT activation. Moreover, MaR1 induces a beige adipocyte signature in inguinal WAT of DIO mice and in hMSC-derived adipocytes. MaR1 potentiates Il6 expression in brown adipocytes and BAT of cold exposed lean WT mice. Interestingly, the thermogenic properties of MaR1 were abrogated in Il6-/- mice. CONCLUSIONS: These data reveal MaR1 as a novel agent that promotes BAT activation and WAT browning by regulating thermogenic program in adipocytes and M2 polarization of macrophages. Moreover, our data suggest that LGR6 receptor is mediating MaR1 actions on brown adipocytes, and that IL-6 is required for the thermogenic effects of MaR1.


Asunto(s)
Tejido Adiposo Pardo , Ácidos Docosahexaenoicos , Ratones , Humanos , Animales , Tejido Adiposo Pardo/metabolismo , Ácidos Docosahexaenoicos/farmacología , Ácidos Docosahexaenoicos/metabolismo , Interleucina-6/metabolismo , Tejido Adiposo Blanco/metabolismo , Adipocitos Marrones/metabolismo
13.
JHEP Rep ; 5(8): 100756, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37360906

RESUMEN

Background & Aims: Lipotoxicity triggers non-alcoholic fatty liver disease (NAFLD) progression owing to the accumulation of toxic lipids in hepatocytes including saturated fatty acids (SFAs), which activate pro-inflammatory pathways. We investigated the impact of hepatocyte- or circulating-derived small extracellular vesicles (sEV) secreted under NAFLD conditions on liver inflammation and hepatocyte insulin signalling. Methods: sEV released by primary mouse hepatocytes, characterised and analysed by lipidomics, were added to mouse macrophages/Kupffer cells (KC) to monitor internalisation and inflammatory responses. Insulin signalling was analysed in hepatocytes exposed to conditioned media from sEV-loaded macrophages/KC. Mice were i.v. injected sEV to study liver inflammation and insulin signalling. Circulating sEV from mice and humans with NAFLD were used to evaluate macrophage-hepatocyte crosstalk. Results: Numbers of sEV released by hepatocytes increased under NAFLD conditions. Lipotoxic sEV were internalised by macrophages through the endosomal pathway and induced pro-inflammatory responses that were ameliorated by pharmacological inhibition or deletion of Toll-like receptor-4 (TLR4). Hepatocyte insulin signalling was impaired upon treatment with conditioned media from macrophages/KC loaded with lipotoxic sEV. Both hepatocyte-released lipotoxic sEV and the recipient macrophages/KC were enriched in palmitic (C16:0) and stearic (C18:0) SFAs, well-known TLR4 activators. Upon injection, lipotoxic sEV rapidly reached KC, triggering a pro-inflammatory response in the liver monitored by Jun N-terminal kinase (JNK) phosphorylation, NF-κB nuclear translocation, pro-inflammatory cytokine expression, and infiltration of immune cells into the liver parenchyma. sEV-mediated liver inflammation was attenuated by pharmacological inhibition or deletion of TLR4 in myeloid cells. Macrophage inflammation and subsequent hepatocyte insulin resistance were also induced by circulating sEV from mice and humans with NAFLD. Conclusions: We identified hepatocyte-derived sEV as SFA transporters targeting macrophages/KC and activating a TLR4-mediated pro-inflammatory response enough to induce hepatocyte insulin resistance. Impact and Implications: Small extracellular vesicles (sEV) released by the hepatocytes under non-alcoholic fatty liver disease (NAFLD) conditions cause liver inflammation and insulin resistance in hepatocytes via paracrine hepatocyte-macrophage-hepatocyte crosstalk. We identified sEV as transporters of saturated fatty acids (SFAs) and potent lipotoxic inducers of liver inflammation. TLR4 deficiency or its pharmacological inhibition ameliorated liver inflammation induced by hepatocyte-derived lipotoxic sEV. Evidence of this macrophage-hepatocyte interactome was also found in patients with NAFLD, pointing to the relevance of sEV in SFA-mediated lipotoxicity in NAFLD.

14.
Metabolism ; 145: 155630, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37315889

RESUMEN

OBJECTIVE: Succinate and succinate receptor 1 (SUCNR1) are linked to fibrotic remodeling in models of non-alcoholic fatty liver disease (NAFLD), but whether they have roles beyond the activation of hepatic stellate cells remains unexplored. We investigated the succinate/SUCNR1 axis in the context of NAFLD specifically in hepatocytes. METHODS: We studied the phenotype of wild-type and Sucnr1-/- mice fed a choline-deficient high-fat diet to induce non-alcoholic steatohepatitis (NASH), and explored the function of SUCNR1 in murine primary hepatocytes and human HepG2 cells treated with palmitic acid. Lastly, plasma succinate and hepatic SUCNR1 expression were analyzed in four independent cohorts of patients in different NAFLD stages. RESULTS: Sucnr1 was upregulated in murine liver and primary hepatocytes in response to diet-induced NASH. Sucnr1 deficiency provoked both beneficial (reduced fibrosis and endoplasmic reticulum stress) and detrimental (exacerbated steatosis and inflammation and reduced glycogen content) effects in the liver, and disrupted glucose homeostasis. Studies in vitro revealed that hepatocyte injury increased Sucnr1 expression, which when activated improved lipid and glycogen homeostasis in damaged hepatocytes. In humans, SUCNR1 expression was a good determinant of NAFLD progression to advanced stages. In a population at risk of NAFLD, circulating succinate was elevated in patients with a fatty liver index (FLI) ≥60. Indeed, succinate had good predictive value for steatosis diagnosed by FLI, and improved the prediction of moderate/severe steatosis through biopsy when added to an FLI algorithm. CONCLUSIONS: We identify hepatocytes as target cells of extracellular succinate during NAFLD progression and uncover a hitherto unknown function for SUCNR1 as a regulator of hepatocyte glucose and lipid metabolism. Our clinical data highlight the potential of succinate and hepatic SUCNR1 expression as markers to diagnose fatty liver and NASH, respectively.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Humanos , Ratones , Modelos Animales de Enfermedad , Fibrosis , Glucosa/metabolismo , Glucógeno/metabolismo , Hepatocitos/metabolismo , Hígado/metabolismo , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Succinatos/metabolismo , Succinatos/farmacología
15.
Artículo en Inglés | MEDLINE | ID: mdl-37156296

RESUMEN

Podocytes are specialized epithelial cells that maintain the glomerular filtration barrier. These cells are susceptible to lipotoxicity in the obese state and irreversibly lost during kidney disease leading to proteinuria and renal injury. PPARγ is a nuclear receptor whose activation can be renoprotective. This study examined the role of PPARγ in the lipotoxic podocyte using a PPARγ knockout (PPARγKO) cell line and since the activation of PPARγ by Thiazolidinediones (TZD) is limited by their side effects, it explored other alternative therapies to prevent podocyte lipotoxic damage. Wild-type and PPARγKO podocytes were exposed to the fatty acid palmitic acid (PA) and treated with the TZD (Pioglitazone) and/or the Retinoid X receptor (RXR) agonist Bexarotene (BX). It revealed that podocyte PPARγ is essential for podocyte function. PPARγ deletion reduced key podocyte proteins including podocin and nephrin while increasing basal levels of oxidative and ER stress causing apoptosis and cell death. A combination therapy of low-dose TZD and BX activated both the PPARγ and RXR receptors reducing PA-induced podocyte damage. This study confirms the crucial role of PPARγ in podocyte biology and that their activation in combination therapy of TZD and BX may be beneficial in the treatment of obesity-related kidney disease.


Asunto(s)
Enfermedades Renales , Podocitos , Tiazolidinedionas , Humanos , PPAR gamma/metabolismo , Pioglitazona/farmacología , Tiazolidinedionas/metabolismo , Tiazolidinedionas/farmacología , Tiazolidinedionas/uso terapéutico , Enfermedades Renales/tratamiento farmacológico , Bexaroteno/farmacología
16.
Redox Biol ; 63: 102741, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37230004

RESUMEN

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. 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.


Asunto(s)
Hígado Graso , Transducción de Señal , Masculino , Animales , Ratones , Olanzapina/metabolismo , Transducción de Señal/fisiología , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , Proteínas Quinasas Activadas por AMP/metabolismo , Hígado/metabolismo , Hígado Graso/tratamiento farmacológico , Hígado Graso/genética , Hígado Graso/prevención & control , Ratones Noqueados , Inflamación/metabolismo , Ácido Graso Sintasas/metabolismo , Aumento de Peso , Hipotálamo/metabolismo , Ratones Endogámicos C57BL
17.
Biomark Res ; 11(1): 46, 2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37106416

RESUMEN

BACKGROUND & AIMS: Advanced hepatic fibrosis is the main risk factor of liver-related morbidity and mortality in patients with chronic liver disease. In this study, we assessed the potential role of bone morphogenetic protein 8A (BMP8A) as a novel target involved in liver fibrosis progression. METHODS: Histological assessment and BMP8A expression were determined in different murine models of hepatic fibrosis. Furthermore, serum BMP8A was measured in mice with bile duct ligation (BDL), in 36 subjects with histologically normal liver (NL) and in 85 patients with biopsy-proven non-alcoholic steatohepatitis (NASH): 52 with non- or mild fibrosis (F0-F2) and 33 with advanced fibrosis (F3-F4). BMP8A expression and secretion was also determined in cultured human hepatocyte-derived (Huh7) and human hepatic stellate (LX2) cells stimulated with transforming growth factor ꞵ (TGFꞵ). RESULTS: Bmp8a mRNA levels were significantly upregulated in livers from fibrotic mice compared to control animals. Notably, serum BMP8A levels were also elevated in BDL mice. In addition, in vitro experiments showed increased expression and secretion to the culture supernatant of BMP8A in both Huh7 and LX2 cells treated with TGFꞵ. Noteworthy, we found that serum BMP8A levels were significantly higher in NASH patients with advanced fibrosis than in those with non- or mild fibrosis. In fact, the AUROC of circulating BMP8A concentrations to identify patients with advanced fibrosis (F3-F4) was 0.74 (p˂0.0001). Moreover, we developed an algorithm based on serum BMP8A levels that showed an AUROC of 0.818 (p˂0.0001) to predict advanced fibrosis in NASH patients. CONCLUSION: This study provides experimental and clinical evidence indicating that BMP8A is a novel molecular target linked to liver fibrosis and introduces an efficient algorithm based on serum BMP8A levels to screen patients at risk for advanced hepatic fibrosis.

18.
Biochim Biophys Acta Gene Regul Mech ; 1866(2): 194938, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37086967

RESUMEN

Dysregulation of cholesterol homeostasis is associated with several pathologies including cardiovascular diseases and neurological disorders such as Alzheimer's disease (AD). MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of cholesterol metabolism. We previously established the role of miR-7 in regulating insulin resistance and amyloidosis, which represents a common pathological feature between type 2 diabetes and AD. We show here an additional metabolic function of miR-7 in cholesterol biosynthesis. We found that miR-7 blocks the last steps of the cholesterol biosynthetic pathway in vitro by targeting relevant genes including DHCR24 and SC5D posttranscriptionally. Intracranial infusion of miR-7 on an adeno-associated viral vector reduced the expression of DHCR24 in the brain of wild-type mice, supporting in vivo miR-7 targeting. We also found that cholesterol regulates endogenous levels of miR-7 in vitro, correlating with transcriptional regulation through SREBP2 binding to its promoter region. In parallel to SREBP2 inhibition, the levels of miR-7 and hnRNPK (the host gene of miR-7) were concomitantly reduced in brain in a mouse model of Niemann Pick type C1 disease and in murine fatty liver, which are both characterized by intracellular cholesterol accumulation. Taken together, the results establish a novel regulatory feedback loop by which miR-7 modulates cholesterol homeostasis at the posttranscriptional level, an effect that could be exploited for therapeutic interventions against prevalent human diseases.


Asunto(s)
Diabetes Mellitus Tipo 2 , MicroARNs , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Humanos , Ratones , Animales , MicroARNs/genética , MicroARNs/metabolismo , Regulación de la Expresión Génica , Colesterol/metabolismo , Homeostasis , Proteínas del Tejido Nervioso/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/metabolismo
19.
Mol Cell Endocrinol ; 561: 111828, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36526026

RESUMEN

Second-generation antipsychotics (SGAs), used as the cornerstone treatment for schizophrenia and other mental disorders, can cause adverse metabolic effects (e.g. obesity and type 2 diabetes). We investigated the effects of SGAs on adipocyte differentiation and metabolism. The presence of therapeutic concentrations of aripiprazole (ARI) or its active metabolite dehydroaripiprazole (DARI) during human adipocyte differentiation impaired adipocyte glucose uptake while the expression of gene markers of fatty acid oxidation were increased. Additionally, the use of a supra-therapeutic concentration of ARI inhibited adipocyte differentiation. Furthermore, olanzapine (OLA), a highly obesogenic SGA, directly increased leptin gene expression but did not affect adipocyte differentiation and metabolism. These molecular insights are novel, and suggest that ARI, but not OLA, may directly act via alterations in adipocyte differentiation and potentially by causing a switch from glucose to lipid utilization in human adipocytes. Additionally, SGAs may effect crosstalk with other organs, such as the brain, to exert their adverse metabolic effects.


Asunto(s)
Antipsicóticos , Diabetes Mellitus Tipo 2 , Humanos , Antipsicóticos/efectos adversos , Olanzapina/farmacología , Olanzapina/metabolismo , Aripiprazol/farmacología , Aripiprazol/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Piperazinas/metabolismo , Piperazinas/farmacología , Piperazinas/uso terapéutico , Adipocitos/metabolismo
20.
Pharmacol Res ; 187: 106578, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36435271

RESUMEN

BACKGROUND AND AIMS: Metformin, the most prescribed drug for the treatment of type 2 diabetes mellitus, has been recently reported to promote weight loss by upregulating the anorectic cytokine growth differentiation factor 15 (GDF15). Since the antidiabetic effects of metformin are mostly mediated by the activation of AMPK, a key metabolic sensor in energy homeostasis, we examined whether the activation of this kinase by metformin was dependent on GDF15. METHODS: Cultured hepatocytes and myotubes, and wild-type and Gdf15-/- mice were utilized in a series of studies to investigate the involvement of GDF15 in the activation of AMPK by metformin. RESULTS: A low dose of metformin increased GDF15 levels without significantly reducing body weight or food intake, but it ameliorated glucose intolerance and activated AMPK in the liver and skeletal muscle of wild-type mice but not Gdf15-/- mice fed a high-fat diet. Cultured hepatocytes and myotubes treated with metformin showed AMPK-mediated increases in GDF15 levels independently of its central receptor GFRAL, while Gdf15 knockdown blunted the effect of metformin on AMPK activation, suggesting that AMPK is required for the metformin-mediated increase in GDF15, which in turn is needed to sustain the full activation of this kinase independently of the CNS. CONCLUSION: Overall, these findings uncover a novel mechanism through which GDF15 upregulation by metformin is involved in achieving and sustaining full AMPK activation by this drug independently of the CNS.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Diabetes Mellitus Tipo 2 , Factor 15 de Diferenciación de Crecimiento , Hipoglucemiantes , Metformina , Animales , Ratones , Proteínas Quinasas Activadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Factor 15 de Diferenciación de Crecimiento/genética , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Metformina/farmacología , Metformina/uso terapéutico , Retroalimentación Fisiológica
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