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1.
Cell ; 186(9): 1968-1984.e20, 2023 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-37040760

RESUMEN

Somatic mutations in nonmalignant tissues accumulate with age and injury, but whether these mutations are adaptive on the cellular or organismal levels is unclear. To interrogate genes in human metabolic disease, we performed lineage tracing in mice harboring somatic mosaicism subjected to nonalcoholic steatohepatitis (NASH). Proof-of-concept studies with mosaic loss of Mboat7, a membrane lipid acyltransferase, showed that increased steatosis accelerated clonal disappearance. Next, we induced pooled mosaicism in 63 known NASH genes, allowing us to trace mutant clones side by side. This in vivo tracing platform, which we coined MOSAICS, selected for mutations that ameliorate lipotoxicity, including mutant genes identified in human NASH. To prioritize new genes, additional screening of 472 candidates identified 23 somatic perturbations that promoted clonal expansion. In validation studies, liver-wide deletion of Tbx3, Bcl6, or Smyd2 resulted in protection against hepatic steatosis. Selection for clonal fitness in mouse and human livers identifies pathways that regulate metabolic disease.


Asunto(s)
Enfermedades Metabólicas , Enfermedad del Hígado Graso no Alcohólico , Animales , Humanos , Masculino , Ratones , N-Metiltransferasa de Histona-Lisina/genética , Hígado/metabolismo , Mosaicismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo
2.
Cell ; 185(2): 379-396.e38, 2022 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-35021063

RESUMEN

The liver is the largest solid organ in the body, yet it remains incompletely characterized. Here we present a spatial proteogenomic atlas of the healthy and obese human and murine liver combining single-cell CITE-seq, single-nuclei sequencing, spatial transcriptomics, and spatial proteomics. By integrating these multi-omic datasets, we provide validated strategies to reliably discriminate and localize all hepatic cells, including a population of lipid-associated macrophages (LAMs) at the bile ducts. We then align this atlas across seven species, revealing the conserved program of bona fide Kupffer cells and LAMs. We also uncover the respective spatially resolved cellular niches of these macrophages and the microenvironmental circuits driving their unique transcriptomic identities. We demonstrate that LAMs are induced by local lipid exposure, leading to their induction in steatotic regions of the murine and human liver, while Kupffer cell development crucially depends on their cross-talk with hepatic stellate cells via the evolutionarily conserved ALK1-BMP9/10 axis.


Asunto(s)
Evolución Biológica , Hepatocitos/metabolismo , Macrófagos/metabolismo , Proteogenómica , Animales , Núcleo Celular/metabolismo , Hígado Graso/genética , Hígado Graso/patología , Homeostasis , Humanos , Macrófagos del Hígado/metabolismo , Antígenos Comunes de Leucocito/metabolismo , Lípidos/química , Hígado/metabolismo , Linfocitos/metabolismo , Ratones Endogámicos C57BL , Modelos Biológicos , Células Mieloides/metabolismo , Obesidad/patología , Proteoma/metabolismo , Transducción de Señal , Transcriptoma/genética
3.
Mol Cell ; 83(21): 3931-3939.e5, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37863053

RESUMEN

Ferroptosis, a regulated cell death pathway driven by accumulation of phospholipid peroxides, has been challenging to identify in physiological conditions owing to the lack of a specific marker. Here, we identify hyperoxidized peroxiredoxin 3 (PRDX3) as a marker for ferroptosis both in vitro and in vivo. During ferroptosis, mitochondrial lipid peroxides trigger PRDX3 hyperoxidation, a posttranslational modification that converts a Cys thiol to sulfinic or sulfonic acid. Once hyperoxidized, PRDX3 translocates from mitochondria to plasma membranes, where it inhibits cystine uptake, thereby causing ferroptosis. Applying hyperoxidized PRDX3 as a marker, we determined that ferroptosis is responsible for death of hepatocytes in mouse models of both alcoholic and nonalcoholic fatty liver diseases, the most prevalent chronic liver disorders. Our study highlights the importance of ferroptosis in pathophysiological conditions and opens the possibility to treat these liver diseases with drugs that inhibit ferroptosis.


Asunto(s)
Ferroptosis , Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Ferroptosis/genética , Enfermedad del Hígado Graso no Alcohólico/genética , Peróxidos , Peroxiredoxina III/genética , Compuestos de Sulfhidrilo
4.
Mol Cell ; 82(21): 4099-4115.e9, 2022 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-36208627

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive hepatic lipid accumulation, which can progress to nonalcoholic steatohepatitis (NASH). Histone deacetylase Sirtuin 6 (SIRT6) regulates NAFLD by regulating metabolism-related gene expression, but an extrachromosomal role for SIRT6 in NAFLD development remains elusive. We investigated whether SIRT6 functions on NAFLD in the cytoplasm. We found that SIRT6 binds saturated fatty acids, especially palmitic acid. This binding leads to its nuclear export, where it deacetylates long-chain acyl-CoA synthase 5 (ACSL5), thereby facilitating fatty acid oxidation. High-fat diet-induced NAFLD is suppressed by ACSL5 hepatic overexpression but is exacerbated by its depletion. As confirmation, overexpression of a deacetylated ACSL5 mimic attenuated NAFLD in Sirt6 liver-specific knockout mice. Moreover, NASH-hepatic tissues from both patients and diet-fed mice exhibited significantly reduced cytoplasmic SIRT6 levels and increased ACSL5 acetylation. The SIRT6/ACSL5 signaling pathway has a critical role in NAFLD progression and might constitute an avenue for therapeutic intervention.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Sirtuinas , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Acilcoenzima A/metabolismo , Ratones Endogámicos C57BL , Hígado/metabolismo , Metabolismo de los Lípidos , Ratones Noqueados , Ácidos Grasos/metabolismo , Sirtuinas/genética , Sirtuinas/metabolismo , Citoplasma/metabolismo
5.
Immunity ; 53(3): 641-657.e14, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32888418

RESUMEN

Metabolic-associated fatty liver disease (MAFLD) represents a spectrum of disease states ranging from simple steatosis to non-alcoholic steatohepatitis (NASH). Hepatic macrophages, specifically Kupffer cells (KCs), are suggested to play important roles in the pathogenesis of MAFLD through their activation, although the exact roles played by these cells remain unclear. Here, we demonstrated that KCs were reduced in MAFLD being replaced by macrophages originating from the bone marrow. Recruited macrophages existed in two subsets with distinct activation states, either closely resembling homeostatic KCs or lipid-associated macrophages (LAMs) from obese adipose tissue. Hepatic LAMs expressed Osteopontin, a biomarker for patients with NASH, linked with the development of fibrosis. Fitting with this, LAMs were found in regions of the liver with reduced numbers of KCs, characterized by increased Desmin expression. Together, our data highlight considerable heterogeneity within the macrophage pool and suggest a need for more specific macrophage targeting strategies in MAFLD.


Asunto(s)
Células de la Médula Ósea/citología , Activación de Macrófagos/inmunología , Macrófagos/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Osteopontina/metabolismo , Animales , Biomarcadores/metabolismo , Células Cultivadas , Desmina/metabolismo , Femenino , Macrófagos del Hígado/citología , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Proteoma/metabolismo , Transcriptoma/genética
6.
Physiol Rev ; 101(2): 683-731, 2021 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-32790577

RESUMEN

Over the past two decades, bile acids (BAs) have become established as important signaling molecules that enable fine-tuned inter-tissue communication from the liver, their site of production, over the intestine, where they are modified by the gut microbiota, to virtually any organ, where they exert their pleiotropic physiological effects. The chemical variety of BAs, to a large extent determined by the gut microbiome, also allows for a complex fine-tuning of adaptive responses in our body. This review provides an overview of the mechanisms by which BA receptors coordinate several aspects of physiology and highlights new therapeutic strategies for diseases underlying pathological BA signaling.


Asunto(s)
Envejecimiento/patología , Envejecimiento/fisiología , Ácidos y Sales Biliares/fisiología , Animales , Ácidos y Sales Biliares/biosíntesis , Enfermedades de los Conductos Biliares/metabolismo , Enfermedades de los Conductos Biliares/fisiopatología , Microbioma Gastrointestinal , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Humanos , Hígado/metabolismo
7.
Mol Cell ; 79(1): 30-42.e4, 2020 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-32473093

RESUMEN

Autophagy is activated by prolonged fasting but cannot overcome the ensuing hepatic lipid overload, resulting in fatty liver. Here, we describe a peroxisome-lysosome metabolic link that restricts autophagic degradation of lipids. Acyl-CoA oxidase 1 (Acox1), the enzyme that catalyzes the first step in peroxisomal ß-oxidation, is enriched in liver and further increases with fasting or high-fat diet (HFD). Liver-specific Acox1 knockout (Acox1-LKO) protected mice against hepatic steatosis caused by starvation or HFD due to induction of autophagic degradation of lipid droplets. Hepatic Acox1 deficiency markedly lowered total cytosolic acetyl-CoA levels, which led to decreased Raptor acetylation and reduced lysosomal localization of mTOR, resulting in impaired activation of mTORC1, a central regulator of autophagy. Dichloroacetic acid treatment elevated acetyl-CoA levels, restored mTORC1 activation, inhibited autophagy, and increased hepatic triglycerides in Acox1-LKO mice. These results identify peroxisome-derived acetyl-CoA as a key metabolic regulator of autophagy that controls hepatic lipid homeostasis.


Asunto(s)
Acetilcoenzima A/metabolismo , Acil-CoA Oxidasa/fisiología , Autofagia , Ácidos Grasos/química , Hígado Graso/patología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Peroxisomas/química , Acetilación , Animales , Proteína 5 Relacionada con la Autofagia/fisiología , Dieta Alta en Grasa/efectos adversos , Ayuno , Hígado Graso/etiología , Hígado Graso/metabolismo , Femenino , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Ratones , Ratones Noqueados , Mitocondrias/metabolismo , Oxidación-Reducción , Peroxisomas/metabolismo , Proteína Reguladora Asociada a mTOR/genética , Proteína Reguladora Asociada a mTOR/metabolismo
8.
Genes Dev ; 34(5-6): 321-340, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-32029456

RESUMEN

Poly(ADP-ribose) polymerases (PARPs or ARTDs), originally described as DNA repair factors, have metabolic regulatory roles. PARP1, PARP2, PARP7, PARP10, and PARP14 regulate central and peripheral carbohydrate and lipid metabolism and often channel pathological disruptive metabolic signals. PARP1 and PARP2 are crucial for adipocyte differentiation, including the commitment toward white, brown, or beige adipose tissue lineages, as well as the regulation of lipid accumulation. Through regulating adipocyte function and organismal energy balance, PARPs play a role in obesity and the consequences of obesity. These findings can be translated into humans, as evidenced by studies on identical twins and SNPs affecting PARP activity.


Asunto(s)
Adenosina Difosfato Ribosa/metabolismo , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Diferenciación Celular , Poli(ADP-Ribosa) Polimerasas/metabolismo , Metabolismo de los Hidratos de Carbono , Humanos , Metabolismo de los Lípidos/fisiología
9.
EMBO J ; 42(24): e113898, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37962490

RESUMEN

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing cause of morbidity with limited treatment options. Thus, accurate in vitro systems to test new therapies are indispensable. While recently, human liver organoid models have emerged to assess steatotic liver disease, a systematic evaluation of their translational potential is still missing. Here, we evaluated human liver organoid models of MASLD, comparatively testing disease induction in three conditions: oleic acid, palmitic acid, and TGF-ß1. Through single-cell analyses, we find that all three models induce inflammatory signatures, but only TGF-ß1 promotes collagen production, fibrosis, and hepatic stellate cell expansion. In striking contrast, oleic acid ameliorates fibrotic signatures and reduces the hepatic stellate cell population. Linking data from each model to gene expression signatures associated with MASLD disease progression further demonstrates that palmitic acid and TGF-ß1 more robustly model inflammation and fibrosis. Our findings highlight the importance of stratifying MASLD organoid models by signatures of clinical disease progression, provide a single-cell reference to benchmark future organoid injury models, and allow us to study evolving steatohepatitis, fibrosis, and HSC susceptibility to injury in a dynamic, multi-lineage human in vitro system.


Asunto(s)
Hígado Graso , Cirrosis Hepática , Humanos , Cirrosis Hepática/genética , Cirrosis Hepática/metabolismo , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismo , Hígado Graso/genética , Perfilación de la Expresión Génica , Progresión de la Enfermedad
10.
Mol Cell ; 75(3): 644-660.e5, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-31398325

RESUMEN

Cell-cell communication via ligand-receptor signaling is a fundamental feature of complex organs. Despite this, the global landscape of intercellular signaling in mammalian liver has not been elucidated. Here we perform single-cell RNA sequencing on non-parenchymal cells isolated from healthy and NASH mouse livers. Secretome gene analysis revealed a highly connected network of intrahepatic signaling and disruption of vascular signaling in NASH. We uncovered the emergence of NASH-associated macrophages (NAMs), which are marked by high expression of triggering receptors expressed on myeloid cells 2 (Trem2), as a feature of mouse and human NASH that is linked to disease severity and highly responsive to pharmacological and dietary interventions. Finally, hepatic stellate cells (HSCs) serve as a hub of intrahepatic signaling via HSC-derived stellakines and their responsiveness to vasoactive hormones. These results provide unprecedented insights into the landscape of intercellular crosstalk and reprogramming of liver cells in health and disease.


Asunto(s)
Comunicación Celular/genética , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Análisis de Secuencia de ARN , Animales , Reprogramación Celular/genética , Modelos Animales de Enfermedad , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Humanos , Ligandos , Hígado/patología , Macrófagos/metabolismo , Macrófagos/patología , Ratones , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Transducción de Señal/genética , Análisis de la Célula Individual
11.
Annu Rev Physiol ; 85: 363-381, 2023 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-36260807

RESUMEN

Insulin action is impaired in type 2 diabetes. The functions of the hormone are an integrated product of insulin secretion from pancreatic ß-cells and insulin clearance by receptor-mediated endocytosis and degradation, mostly in liver (hepatocytes) and, to a lower extent, in extrahepatic peripheral tissues. Substantial evidence indicates that genetic or acquired abnormalities of insulin secretion or action predispose to type 2 diabetes. In recent years, along with the discovery of the molecular foundation of receptor-mediated insulin clearance, such as through the membrane glycoprotein CEACAM1, a consensus has begun to emerge that reduction of insulin clearance contributes to the disease process. In this review, we consider the evidence suggesting a pathogenic role for reduced insulin clearance in insulin resistance, obesity, hepatic steatosis, and type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Humanos , Insulina/metabolismo , Hígado/metabolismo , Obesidad , Enfermedad del Hígado Graso no Alcohólico/metabolismo
12.
EMBO Rep ; 25(1): 378-403, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38177901

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is mainly characterized by excessive fat accumulation in the liver, and it is associated with liver-related complications and adverse systemic diseases. NAFLD has become the most prevalent liver disease; however, effective therapeutic agents for NAFLD are still lacking. We combined clinical data with proteomics and metabolomics data, and found that the mitochondrial nucleoside diphosphate kinase NME4 plays a central role in mitochondrial lipid metabolism. Nme4 is markedly upregulated in mice fed with high-fat diet, and its expression is positively correlated with the level of steatosis. Hepatic deletion of Nme4 suppresses the progression of hepatic steatosis. Further studies demonstrated that NME4 interacts with several key enzymes in coenzyme A (CoA) metabolism and increases the level of acetyl-CoA and malonyl-CoA, which are the major lipid components of the liver in NAFLD. Increased level of acetyl-CoA and malonyl-CoA  lead to increased triglyceride levels and lipid accumulation in the liver. Taken together, these findings reveal that NME4 is a critical regulator of NAFLD progression and a potential therapeutic target for NAFLD.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Acetilcoenzima A/metabolismo , Reprogramación Metabólica , Hígado/metabolismo , Metabolismo de los Lípidos/genética , Dieta Alta en Grasa/efectos adversos , Lípidos , Ratones Endogámicos C57BL
13.
Eur J Immunol ; 54(4): e2149641, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38314819

RESUMEN

Metabolic dysfunction-associated steatotic liver disease (MASLD) is an increasingly common complication of obesity, affecting over a quarter of the global adult population. A key event in the pathophysiology of MASLD is the development of metabolic-associated steatohepatitis (MASH), which greatly increases the chances of developing cirrhosis and hepatocellular carcinoma. The underlying cause of MASH is multifactorial, but accumulating evidence indicates that the inflammatory process in the hepatic microenvironment typically follows a pattern that can be roughly divided into three stages: (1) Detection of hepatocyte stress by tissue-resident immune cells including γδ T cells and CD4-CD8- double-negative T cells, followed by their secretion of pro-inflammatory mediators, most notably IL-17A. (2) Recruitment of pro-inflammatory cells, mostly of the myeloid lineage, and initiation of inflammation through secretion of effector-type cytokines such as TNF, TGF-ß, and IL-1ß. (3) Escalation of the inflammatory response by recruitment of lymphocytes including Th17, CD8 T, and B cells leading to chronic inflammation, hepatic stellate cell activation, and fibrosis. Here we will discuss these three stages and how they are consecutively linked like falling domino tiles to the pathophysiology of MASH. Moreover, we will highlight the clinical potential of inflammation as a biomarker and therapeutic target for the treatment of MASLD.


Asunto(s)
Hígado Graso , Neoplasias Hepáticas , Enfermedades Metabólicas , Adulto , Humanos , Linfocitos B , Inflamación , Microambiente Tumoral
14.
Proc Natl Acad Sci U S A ; 119(48): e2119824119, 2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36409897

RESUMEN

Fatty acids are vital for the survival of eukaryotes, but when present in excess can have deleterious consequences. The AMP-activated protein kinase (AMPK) is an important regulator of multiple branches of metabolism. Studies in purified enzyme preparations and cultured cells have shown that AMPK is allosterically activated by small molecules as well as fatty acyl-CoAs through a mechanism involving Ser108 within the regulatory AMPK ß1 isoform. However, the in vivo physiological significance of this residue has not been evaluated. In the current study, we generated mice with a targeted germline knock-in (KI) mutation of AMPKß1 Ser108 to Ala (S108A-KI), which renders the site phospho-deficient. S108A-KI mice had reduced AMPK activity (50 to 75%) in the liver but not in the skeletal muscle. On a chow diet, S108A-KI mice had impairments in exogenous lipid-induced fatty acid oxidation. Studies in mice fed a high-fat diet found that S108A-KI mice had a tendency for greater glucose intolerance and elevated liver triglycerides. Consistent with increased liver triglycerides, livers of S108A-KI mice had reductions in mitochondrial content and respiration that were accompanied by enlarged mitochondria, suggestive of impairments in mitophagy. Subsequent studies in primary hepatocytes found that S108A-KI mice had reductions in palmitate- stimulated Cpt1a and Ppargc1a mRNA, ULK1 phosphorylation and autophagic/mitophagic flux. These data demonstrate an important physiological role of AMPKß1 Ser108 phosphorylation in promoting fatty acid oxidation, mitochondrial biogenesis and autophagy under conditions of high lipid availability. As both ketogenic diets and intermittent fasting increase circulating free fatty acid levels, AMPK activity, mitochondrial biogenesis, and mitophagy, these data suggest a potential unifying mechanism which may be important in mediating these effects.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Ácidos Grasos , Ratones , Animales , Fosforilación , Ácidos Grasos/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Mitocondrias/metabolismo , Homeostasis , Autofagia , Triglicéridos/metabolismo
15.
Med Res Rev ; 44(2): 568-586, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37899676

RESUMEN

Nonalcoholic fatty liver disease, also called metabolic dysfunction-associated steatotic liver disease, is the most common liver disease worldwide and has no approved pharmacotherapy. Due to its beneficial effects on metabolic regulation, inflammation suppression, cell death prevention, and fibrogenesis inhibition, farnesoid X receptor (FXR) is widely accepted as a promising therapeutic target for nonalcoholic steatosis (NASH) or called metabolic dysfunction-associated steatohepatitis (MASH). Many FXR agonists have been developed for NASH/MASH therapy. Obeticholic acid (OCA) is the pioneering frontrunner FXR agonist and the first demonstrating success in clinical trials. Unfortunately, OCA did not receive regulatory approval as a NASH pharmacotherapy because its moderate benefits did not outweigh its safety risks, which may cast a shadow over FXR-based drug development for NASH/MASH. This review summarizes the milestones in the development of OCA for NASH/MASH and discuss its limitations, including moderate hepatoprotection and the undesirable side effects of dyslipidemia, pruritus, cholelithiasis, and liver toxicity risk, in depth. More importantly, we provide perspectives on FXR-based therapy for NASH/MASH, hoping to support a successful bench-to-clinic transition.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Humanos , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Ácido Quenodesoxicólico/farmacología , Ácido Quenodesoxicólico/uso terapéutico
16.
J Lipid Res ; 65(3): 100513, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38295985

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease without specific Food and Drug Administration-approved drugs. Recent advances suggest that chromatin remodeling and epigenetic alteration contribute to the development of NAFLD. The functions of the corresponding molecular modulator in NAFLD, however, are still elusive. KDM1A, commonly known as lysine-specific histone demethylase 1, has been reported to increase glucose uptake in hepatocellular carcinoma. In addition, a recent study suggests that inhibition of KDM1A reduces lipid accumulation in primary brown adipocytes. We here investigated the role of KDM1A, one of the most important histone demethylases, in NAFLD. In this study, we observed a significant upregulation of KDM1A in NAFLD mice, monkeys, and humans compared to the control group. Based on these results, we further found that the KDM1A can exacerbate lipid accumulation and inflammation in hepatocytes and mice. Mechanistically, KDM1A exerted its effects by elevating chromatin accessibility, subsequently promoting the development of NAFLD. Furthermore, the mutation of KDM1A blunted its capability to promote the development of NAFLD. In summary, our study discovered that KDM1A exacerbates hepatic steatosis and inflammation in NAFLD via increasing chromatin accessibility, further indicating the importance of harnessing chromatin remodeling and epigenetic alteration in combating NAFLD. KDM1A might be considered as a potential therapeutic target in this regard.


Asunto(s)
Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Humanos , Ratones , Animales , Enfermedad del Hígado Graso no Alcohólico/genética , Cromatina/genética , Histona Demetilasas/genética , Inflamación/genética , Lípidos
17.
Diabetologia ; 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38869512

RESUMEN

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously termed non-alcoholic fatty liver disease (NAFLD), is defined as steatotic liver disease (SLD) in the presence of one or more cardiometabolic risk factor(s) and the absence of harmful alcohol intake. The spectrum of MASLD includes steatosis, metabolic dysfunction-associated steatohepatitis (MASH, previously NASH), fibrosis, cirrhosis and MASH-related hepatocellular carcinoma (HCC). This joint EASL-EASD-EASO guideline provides an update on definitions, prevention, screening, diagnosis and treatment for MASLD. Case-finding strategies for MASLD with liver fibrosis, using non-invasive tests, should be applied in individuals with cardiometabolic risk factors, abnormal liver enzymes and/or radiological signs of hepatic steatosis, particularly in the presence of type 2 diabetes or obesity with additional metabolic risk factor(s). A stepwise approach using blood-based scores (such as the fibrosis-4 index [FIB-4]) and, sequentially, imaging techniques (such as transient elastography) is suitable to rule-out/in advanced fibrosis, which is predictive of liver-related outcomes. In adults with MASLD, lifestyle modification-including weight loss, dietary changes, physical exercise and discouraging alcohol consumption-as well as optimal management of comorbidities-including use of incretin-based therapies (e.g. semaglutide, tirzepatide) for type 2 diabetes or obesity, if indicated-is advised. Bariatric surgery is also an option in individuals with MASLD and obesity. If locally approved and dependent on the label, adults with non-cirrhotic MASH and significant liver fibrosis (stage ≥2) should be considered for a MASH-targeted treatment with resmetirom, which demonstrated histological effectiveness on steatohepatitis and fibrosis with an acceptable safety and tolerability profile. No MASH-targeted pharmacotherapy can currently be recommended for the cirrhotic stage. Management of MASH-related cirrhosis includes adaptations of metabolic drugs, nutritional counselling, surveillance for portal hypertension and HCC, as well as liver transplantation in decompensated cirrhosis.

18.
Diabetologia ; 67(3): 430-442, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38182909

RESUMEN

Beyond their conventional roles in intracellular energy production, some traditional metabolites also function as extracellular messengers that activate cell-surface G-protein-coupled receptors (GPCRs) akin to hormones and neurotransmitters. These signalling metabolites, often derived from nutrients, the gut microbiota or the host's intermediary metabolism, are now acknowledged as key regulators of various metabolic and immune responses. This review delves into the multi-dimensional aspects of succinate, a dual metabolite with roots in both the mitochondria and microbiome. It also connects the dots between succinate's role in the Krebs cycle, mitochondrial respiration, and its double-edge function as a signalling transmitter within and outside the cell. We aim to provide an overview of the role of the succinate-succinate receptor 1 (SUCNR1) axis in diabetes, discussing the potential use of succinate as a biomarker and the novel prospect of targeting SUCNR1 to manage complications associated with diabetes. We further propose strategies to manipulate the succinate-SUCNR1 axis for better diabetes management; this includes pharmacological modulation of SUCNR1 and innovative approaches to manage succinate concentrations, such as succinate administration and indirect strategies, like microbiota modulation. The dual nature of succinate, both in terms of origins and roles, offers a rich landscape for understanding the intricate connections within metabolic diseases, like diabetes, and indicates promising pathways for developing new therapeutic strategies.


Asunto(s)
Diabetes Mellitus Tipo 2 , Succinatos , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Succinatos/metabolismo
19.
Diabetologia ; 67(6): 961-973, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38334817

RESUMEN

Fatty liver plays a pivotal role in the pathogenesis of the metabolic syndrome and type 2 diabetes. According to an updated classification, any individual with liver steatosis and one or more features of the metabolic syndrome, without excess alcohol consumption or other known causes of steatosis, has metabolic dysfunction-associated steatotic liver disease (MASLD). Up to 60-70% of all individuals with type 2 diabetes have MASLD. However, the prevalence of advanced liver fibrosis in type 2 diabetes remains uncertain, with reported estimates of 10-20% relying on imaging tests and likely overestimating the true prevalence. All stages of MASLD impact prognosis but fibrosis is the best predictor of all-cause and liver-related mortality risk. People with type 2 diabetes face a two- to threefold increase in the risk of liver-related death and hepatocellular carcinoma, with 1.3% progressing to severe liver disease over 7.7 years. Because reliable methods for detecting steatosis are lacking, MASLD mostly remains an incidental finding on imaging. Regardless, several medical societies advocate for universal screening of individuals with type 2 diabetes for advanced fibrosis. Proposed screening pathways involve annual calculation of the Fibrosis-4 (FIB-4) index, followed by a secondary test such as transient elastography (TE) for intermediate-to-high-risk individuals. However, owing to unsatisfactory biomarker specificity, these pathways are expected to channel approximately 40% of all individuals with type 2 diabetes to TE and 20% to tertiary care, with a false discovery rate of up to 80%, raising concerns about feasibility. There is thus an urgent need to develop more effective strategies for surveying the liver in type 2 diabetes. Nonetheless, weight loss through lifestyle changes, pharmacotherapy or bariatric surgery remains the cornerstone of management, proving highly effective not only for metabolic comorbidities but also for MASLD. Emerging evidence suggests that fibrosis biomarkers may serve as tools for risk-based targeting of weight-loss interventions and potentially for monitoring response to therapy.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hígado Graso , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Hígado Graso/epidemiología , Hígado Graso/diagnóstico , Hígado/patología , Hígado/metabolismo , Hígado/diagnóstico por imagen , Cirrosis Hepática/epidemiología , Cirrosis Hepática/complicaciones , Síndrome Metabólico/epidemiología , Síndrome Metabólico/complicaciones
20.
Diabetologia ; 67(3): 483-493, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38117293

RESUMEN

AIMS/HYPOTHESIS: We aimed to determine whether the use of glucagon-like peptide-1 receptor agonists (GLP-1RA) in individuals with non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus decreases the risk of new-onset adverse cardiovascular events (CVEs) and mortality rate compared with other glucose-lowering drugs in a real setting at a population level. METHODS: We conducted a population-based propensity-matched retrospective cohort study using TriNetX. The cohort comprised patients over 20 years old who were newly treated with glucose-lowering drugs between 1 January 2013 and 31 December 2021, and followed until 30 September 2022. New users of GLP-1RAs were matched based on age, demographics, comorbidities and medication use by using 1:1 propensity matching with other glucose-lowering drugs. The primary outcome was the new onset of adverse CVEs, including heart failure, composite incidence of major adverse cardiovascular events (MACE; defined as unstable angina, myocardial infarction, or coronary artery procedures or surgeries) and composite cerebrovascular events (defined as the first occurrence of stroke, transient ischaemic attack, cerebral infarction, carotid intervention or surgery), and the secondary outcome was all-cause mortality. Cox proportional hazards models were used to estimate HRs. RESULTS: The study involved 2,835,398 patients with both NAFLD and type 2 diabetes. When compared with the sodium-glucose cotransporter 2 (SGLT2) inhibitors group, the GLP-1RAs group showed no evidence of a difference in terms of new-onset heart failure (HR 0.97; 95% CI 0.93, 1.01), MACE (HR 0.95; 95% CI 0.90, 1.01) and cerebrovascular events (HR 0.99; 95% CI 0.94, 1.03). Furthermore, the two groups had no evidence of a difference in mortality rate (HR 1.06; 95% CI 0.97, 1.15). Similar results were observed across sensitivity analyses. Compared with other second- or third-line glucose-lowering medications, the GLP-1RAs demonstrated a lower rate of adverse CVEs, including heart failure (HR 0.88; 95% CI 0.85, 0.92), MACE (HR 0.89; 95% CI 0.85, 0.94), cerebrovascular events (HR 0.93; 95% CI 0.89, 0.96) and all-cause mortality rate (HR 0.70; 95% CI 0.66, 0.75). CONCLUSIONS/INTERPRETATION: In individuals with NAFLD and type 2 diabetes, GLP-1RAs are associated with lower incidences of adverse CVEs and all-cause mortality compared with metformin or other second- and third-line glucose-lowering medications. However, there was no significant difference in adverse CVEs or all-cause mortality when compared with those taking SGLT2 inhibitors.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Insuficiencia Cardíaca , Enfermedad del Hígado Graso no Alcohólico , Humanos , Adulto Joven , Adulto , Diabetes Mellitus Tipo 2/epidemiología , Hipoglucemiantes/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Agonistas Receptor de Péptidos Similares al Glucagón , Glucosa , Estudios Retrospectivos , Estudios de Cohortes , Resultado del Tratamiento , Insuficiencia Cardíaca/complicaciones , Receptor del Péptido 1 Similar al Glucagón/agonistas
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