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1.
Mol Syst Biol ; 20(3): 187-216, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38216754

RESUMEN

Chronic liver diseases are worldwide on the rise. Due to the rapidly increasing incidence, in particular in Western countries, metabolic dysfunction-associated steatotic liver disease (MASLD) is gaining importance as the disease can develop into hepatocellular carcinoma. Lipid accumulation in hepatocytes has been identified as the characteristic structural change in MASLD development, but molecular mechanisms responsible for disease progression remained unresolved. Here, we uncover in primary hepatocytes from a preclinical model fed with a Western diet (WD) an increased basal MET phosphorylation and a strong downregulation of the PI3K-AKT pathway. Dynamic pathway modeling of hepatocyte growth factor (HGF) signal transduction combined with global proteomics identifies that an elevated basal MET phosphorylation rate is the main driver of altered signaling leading to increased proliferation of WD-hepatocytes. Model-adaptation to patient-derived hepatocytes reveal patient-specific variability in basal MET phosphorylation, which correlates with patient outcome after liver surgery. Thus, dysregulated basal MET phosphorylation could be an indicator for the health status of the liver and thereby inform on the risk of a patient to suffer from liver failure after surgery.


Asunto(s)
Carcinoma Hepatocelular , Hígado Graso , Neoplasias Hepáticas , Humanos , Fosforilación , Fosfatidilinositol 3-Quinasas/metabolismo , Hepatocitos/metabolismo , Factor de Crecimiento de Hepatocito/metabolismo , Hígado Graso/metabolismo , Neoplasias Hepáticas/patología
2.
BMC Endocr Disord ; 24(1): 135, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39090659

RESUMEN

BACKGROUND: Prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is higher in men than in women. Hormonal and genetic causes may account for the sex differences in MASLD. Current human in vitro liver models do not sufficiently take the influence of biological sex and sex hormones into consideration. METHODS: Primary human hepatocytes (PHHs) were isolated from liver specimen of female and male donors and cultured with sex hormones (17ß-estradiol, testosterone and progesterone) for up to 72 h. mRNA expression levels of 8 hepatic lipid metabolism genes were analyzed by RT-qPCR. Sex hormones and their metabolites were determined in cell culture supernatants by LC-MS analyses. RESULTS: A sex-specific expression was observed for LDLR (low density lipoprotein receptor) with higher mRNA levels in male than female PHHs. All three sex hormones were metabolized by PHHs and the effects of hormones on gene expression levels varied depending on hepatocyte sex. Only in female PHHs, 17ß-estradiol treatment affected expression levels of PPARA (peroxisome proliferator-activated receptor alpha), LIPC (hepatic lipase) and APOL2 (apolipoprotein L2). Further changes in mRNA levels of female PHHs were observed for ABCA1 (ATP-binding cassette, sub-family A, member 1) after testosterone and for ABCA1, APOA5 (apolipoprotein A-V) and PPARA after progesterone treatment. Only the male PHHs showed changing mRNA levels for LDLR after 17ß-estradiol and for APOA5 after testosterone treatment. CONCLUSIONS: Male and female PHHs showed differences in their expression levels of hepatic lipid metabolism genes and their responsiveness towards sex hormones. Thus, cellular sex should be considered, especially when investigating the pathophysiological mechanisms of MASLD.


Asunto(s)
Hormonas Esteroides Gonadales , Hepatocitos , Metabolismo de los Lípidos , Humanos , Masculino , Femenino , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Metabolismo de los Lípidos/efectos de los fármacos , Hormonas Esteroides Gonadales/farmacología , Hormonas Esteroides Gonadales/metabolismo , Células Cultivadas , Persona de Mediana Edad , Testosterona/farmacología , Testosterona/metabolismo , Estradiol/farmacología , Adulto , Progesterona/farmacología , Progesterona/metabolismo , Factores Sexuales
3.
Hepatology ; 73(2): 795-810, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32286709

RESUMEN

BACKGROUND AND AIMS: Zone-dependent differences in expression of metabolic enzymes along the portocentral axis of the acinus are a long-known feature of liver metabolism. A prominent example is the preferential localization of the enzyme, glutamine synthetase, in pericentral hepatocytes, where it converts potentially toxic ammonia to the valuable amino acid, glutamine. However, with the exception of a few key regulatory enzymes, a comprehensive and quantitative assessment of zonal differences in the abundance of metabolic enzymes and, much more important, an estimation of the associated functional differences between portal and central hepatocytes is missing thus far. APPROACH AND RESULTS: We addressed this problem by establishing a method for the separation of periportal and pericentral hepatocytes that yields sufficiently pure fractions of both cell populations. Quantitative shotgun proteomics identified hundreds of differentially expressed enzymes in the two cell populations. We used zone-specific proteomics data for scaling of the maximal activities to generate portal and central instantiations of a comprehensive kinetic model of central hepatic metabolism (Hepatokin1). CONCLUSIONS: The model simulations revealed significant portal-to-central differences in almost all metabolic pathways involving carbohydrates, fatty acids, amino acids, and detoxification.


Asunto(s)
Hepatocitos/enzimología , Hígado/metabolismo , Aminoácidos/metabolismo , Amoníaco/metabolismo , Animales , Arginasa/metabolismo , Metabolismo de los Hidratos de Carbono , Células Cultivadas , Ácidos Grasos , Glucoquinasa/metabolismo , Glutaminasa/metabolismo , L-Lactato Deshidrogenasa/metabolismo , Hígado/citología , Masculino , Ratones , Modelos Animales , Cultivo Primario de Células , Proteómica , Análisis Espacial
4.
Int J Mol Sci ; 23(23)2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36499681

RESUMEN

Hepatocellular carcinoma (HCC) is a severe complication of advanced alcoholic liver disease, which is modulated by genetic predisposition. Identifying new genetic loci might improve screening. Genetic variation of SAMM50 was linked to HCC. We aimed to validate this finding in a large cohort of patients with advanced alcoholic liver disease (ALD). A large, well-characterised cohort of patients with alcoholic cirrhosis without (n = 674) and with (n = 386) HCC, as well as controls with HCC due to viral hepatitis (n = 134), controls with heavy alcohol abuse without liver disease (n = 266) and healthy subjects (n = 237), were genotyped for SAMM50 rs3827385 and rs3761472 and for PNPLA3 rs738409. Genotype frequencies were compared between patients with alcohol-associated cirrhosis with and without HCC by uni- and multivariate analysis. Minor variants in both SAMM50 rs3827385 and rs3761472 were significantly more frequent in patients with alcoholic HCC versus alcoholic cirrhosis and versus the control cohorts. An even stronger association was noted for PNPLA3 rs738409. The univariate analysis resulted in an odds ratio (OR) of 1.8 for carriers of at least one minor variant of SAMM50 rs3827385 and rs3761472 (each p < 0.001), but this association was lost in multivariate analysis with age (OR 1.1/year), male sex (OR 3.2), diabetes (OR 1.9) and carriage of PNPLA3 148M (OR 2.1) remaining in the final model. Although minor variants of both SAMM50 loci are strongly associated with alcoholic HCC, this association is not independent of carriage of the well-known risk variant PNPLA3 148M.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Masculino , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Lipasa/genética , Polimorfismo de Nucleótido Simple , Proteínas de la Membrana/genética , Cirrosis Hepática Alcohólica/genética , Predisposición Genética a la Enfermedad , Factores de Riesgo , Genotipo
5.
Gut ; 70(5): 940-950, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32591434

RESUMEN

OBJECTIVE: The rs641738C>T variant located near the membrane-bound O-acyltransferase domain containing 7 (MBOAT7) locus is associated with fibrosis in liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcohol-related liver disease, hepatitis B and C. We aim to understand the mechanism by which the rs641738C>T variant contributes to pathogenesis of NAFLD. DESIGN: Mice with hepatocyte-specific deletion of MBOAT7 (Mboat7Δhep) were generated and livers were characterised by histology, flow cytometry, qPCR, RNA sequencing and lipidomics. We analysed the association of rs641738C>T genotype with liver inflammation and fibrosis in 846 NAFLD patients and obtained genotype-specific liver lipidomes from 280 human biopsies. RESULTS: Allelic imbalance analysis of heterozygous human liver samples pointed to lower expression of the MBOAT7 transcript on the rs641738C>T haplotype. Mboat7Δhep mice showed spontaneous steatosis characterised by increased hepatic cholesterol ester content after 10 weeks. After 6 weeks on a high fat, methionine-low, choline-deficient diet, mice developed increased hepatic fibrosis as measured by picrosirius staining (p<0.05), hydroxyproline content (p<0.05) and transcriptomics, while the inflammatory cell populations and inflammatory mediators were minimally affected. In a human biopsied NAFLD cohort, MBOAT7 rs641738C>T was associated with fibrosis (p=0.004) independent of the presence of histological inflammation. Liver lipidomes of Mboat7Δhep mice and human rs641738TT carriers with fibrosis showed increased total lysophosphatidylinositol levels. The altered lysophosphatidylinositol and phosphatidylinositol subspecies in MBOAT7Δhep livers and human rs641738TT carriers were similar. CONCLUSION: Mboat7 deficiency in mice and human points to an inflammation-independent pathway of liver fibrosis that may be mediated by lipid signalling and a potentially targetable treatment option in NAFLD.


Asunto(s)
Aciltransferasas/genética , Cirrosis Hepática/genética , Proteínas de la Membrana/genética , Enfermedad del Hígado Graso no Alcohólico/genética , Aciltransferasas/deficiencia , Adulto , Anciano , Animales , Biopsia , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Genotipo , Haplotipos , Humanos , Inflamación/genética , Masculino , Proteínas de la Membrana/deficiencia , Ratones Endogámicos C57BL , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
6.
Liver Int ; 41(9): 2139-2148, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34051061

RESUMEN

BACKGROUND & AIMS: Bacterial translocation drives liver disease progression. We investigated whether functional genetic variants in toll-like receptor 5 (TLR5), the receptor for bacterial flagellin, affect the risk for hepatocellular carcinoma (HCC). METHODS: Healthy controls (n = 212), patients with alcohol abuse without liver disease (n = 382), and patients from a discovery cohort of alcohol-associated cirrhosis (n = 372 including 79 HCC cases), a validation cohort of alcohol-associated cirrhosis (n = 355 including 132 HCC cases), and a cohort of cirrhosis due to nonalcoholic steatohepatitis (NASH) (n = 145 including 62 HCC cases) were genotyped for the TLR5 rs5744174 and rs5744168 polymorphisms. Chemokine levels were measured by ELISA in patients' sera and supernatants of flagellin-stimulated healthy monocytes. RESULTS: Frequency of the TLR5 rs5744174 TT genotype was similar in healthy controls (33%), controls with alcohol abuse (34%), and patients with alcohol-associated cirrhosis in the discovery (28%), validation (33%), and NASH cohort (31%). The TT genotype was enriched in patients with versus without HCC in the discovery, validation, and NASH cohort (41% vs 25%; 39% vs 29%; 40% vs 24%; p < .05 each). This genotype remained a risk factor for HCC (OR = 1.9; p = .01) after multivariate correction for age, gender, diabetes, and carriage of the PNPLA3 148M variant. Interleukin-8 induction in monocytes from healthy controls and serum levels of interleukin-8 and CXCL1 from cirrhotic patients with the TT genotype were significantly increased versus C allele carriers. CONCLUSION: The TLR5 rs5744174 polymorphism, affecting immune response to flagellin, is linked to occurrence of HCC in cirrhosis caused by steatohepatitis.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Carcinoma Hepatocelular/genética , Predisposición Genética a la Enfermedad , Humanos , Cirrosis Hepática/genética , Neoplasias Hepáticas/genética , Enfermedad del Hígado Graso no Alcohólico/genética , Polimorfismo de Nucleótido Simple , Receptor Toll-Like 5/genética
7.
Arch Toxicol ; 95(9): 3001-3013, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34241659

RESUMEN

The liver is one of the most sexually dimorphic organs. The hepatic metabolic pathways that are subject to sexual dimorphism include xenobiotic, amino acid and lipid metabolism. Non-alcoholic fatty liver disease and hepatocellular carcinoma are among diseases with sex-dependent prevalence, progression and outcome. Although male and female livers differ in their abilities to metabolize foreign compounds, including drugs, sex-dependent treatment and pharmacological dynamics are rarely applied in all relevant cases. Therefore, it is important to consider hepatic sexual dimorphism when developing new treatment strategies and to understand the underlying mechanisms in model systems. We isolated primary hepatocytes from male and female C57BL6/N mice and examined the sex-dependent transcriptome, proteome and extracellular metabolome parameters in the course of culturing them for 96 h. The sex-specific gene expression of the general xenobiotic pathway altered and the female-specific expression of Cyp2b13 and Cyp2b9 was significantly reduced during culture. Sex-dependent differences of several signaling pathways increased, including genes related to serotonin and melatonin degradation. Furthermore, the ratios of male and female gene expression were inversed for other pathways, such as amino acid degradation, beta-oxidation, androgen signaling and hepatic steatosis. Because the primary hepatocytes were cultivated without the influence of known regulators of sexual dimorphism, these results suggest currently unknown modulatory mechanisms of sexual dimorphism in vitro. The large sex-dependent differences in the regulation and dynamics of drug metabolism observed during cultivation can have an immense influence on the evaluation of pharmacodynamic processes when conducting initial preclinical trials to investigate potential new drugs.


Asunto(s)
Hepatocitos/metabolismo , Metaboloma/fisiología , Proteoma/fisiología , Transcriptoma/fisiología , Animales , Hidrocarburo de Aril Hidroxilasas/genética , Sistema Enzimático del Citocromo P-450/genética , Familia 2 del Citocromo P450/genética , Femenino , Regulación de la Expresión Génica/fisiología , Masculino , Melatonina/metabolismo , Ratones , Ratones Endogámicos C57BL , Serotonina/metabolismo , Caracteres Sexuales , Factores Sexuales , Transducción de Señal/fisiología , Esteroide Hidroxilasas/genética
8.
Am J Pathol ; 189(5): 1091-1104, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30794807

RESUMEN

Hepatoblastoma (HB), the most common pediatric primary liver neoplasm, shows nuclear localization of ß-catenin and yes-associated protein 1 (YAP1) in almost 80% of the cases. Co-expression of constitutively active S127A-YAP1 and ΔN90 deletion-mutant ß-catenin (YAP1-ΔN90-ß-catenin) causes HB in mice. Because heterogeneity in downstream signaling is being identified owing to mutational differences even in the ß-catenin gene alone, we investigated if co-expression of point mutants of ß-catenin (S33Y or S45Y) with S127A-YAP1 led to similar tumors as YAP1-ΔN90-ß-catenin. Co-expression of S33Y/S45Y-ß-catenin and S127A-YAP1 led to activation of Yap and Wnt signaling and development of HB, with 100% mortality by 13 to 14 weeks. Co-expression with YAP1-S45Y/S33Y-ß-catenin of the dominant-negative T-cell factor 4 or dominant-negative transcriptional enhanced associate domain 2, the respective surrogate transcription factors, prevented HB development. Although histologically similar, HB in YAP1-S45Y/S33Y-ß-catenin, unlike YAP1-ΔN90-ß-catenin HB, was glutamine synthetase (GS) positive. However, both ΔN90-ß-catenin and point-mutant ß-catenin comparably induced GS-luciferase reporter in vitro. Finally, using a previously reported 16-gene signature, it was shown that YAP1-ΔN90-ß-catenin HB tumors exhibited genetic similarities with more proliferative, less differentiated, GS-negative HB patient tumors, whereas YAP1-S33Y/S45Y-ß-catenin HB exhibited heterogeneity and clustered with both well-differentiated GS-positive and proliferative GS-negative patient tumors. Thus, we demonstrate that ß-catenin point mutants can also collaborate with YAP1 in HB development, albeit with a distinct molecular profile from the deletion mutant, which may have implications in both biology and therapy.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Biomarcadores de Tumor/metabolismo , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Mutación , Factores de Transcripción/metabolismo , beta Catenina/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Apoptosis , Biomarcadores de Tumor/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Ratones , Pronóstico , Factores de Transcripción/genética , Células Tumorales Cultivadas , Proteínas Señalizadoras YAP , beta Catenina/genética
9.
J Hepatol ; 70(6): 1192-1202, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30711403

RESUMEN

BACKGROUND & AIMS: The mammalian circadian clock controls various aspects of liver metabolism and integrates nutritional signals. Recently, we described Hedgehog (Hh) signaling as a novel regulator of liver lipid metabolism. Herein, we investigated crosstalk between hepatic Hh signaling and circadian rhythm. METHODS: Diurnal rhythms of Hh signaling were investigated in liver and hepatocytes from mice with ablation of Smoothened (SAC-KO) and crossbreeds with PER2::LUC reporter mice. By using genome-wide screening, qPCR, immunostaining, ELISA and RNAi experiments in vitro we identified relevant transcriptional regulatory steps. Shotgun lipidomics and metabolic cages were used for analysis of metabolic alterations and behavior. RESULTS: Hh signaling showed diurnal oscillations in liver and hepatocytes in vitro. Correspondingly, the level of Indian Hh, oscillated in serum. Depletion of the clock gene Bmal1 in hepatocytes resulted in significant alterations in the expression of Hh genes. Conversely, SAC-KO mice showed altered expression of clock genes, confirmed by RNAi against Gli1 and Gli3. Genome-wide screening revealed that SAC-KO hepatocytes showed time-dependent alterations in various genes, particularly those associated with lipid metabolism. The clock/hedgehog module further plays a role in rhythmicity of steatosis, and in the response of the liver to a high-fat diet or to differently timed starvation. CONCLUSIONS: For the first time, Hh signaling in hepatocytes was found to be time-of-day dependent and to feed back on the circadian clock. Our findings suggest an integrative role of Hh signaling, mediated mainly by GLI factors, in maintaining homeostasis of hepatic lipid metabolism by balancing the circadian clock. LAY SUMMARY: The results of our investigation show for the first time that the Hh signaling in hepatocytes is time-of-day dependent, leading to differences not only in transcript levels but also in the amount of Hh ligands in peripheral blood. Conversely, Hh signaling is able to feed back to the circadian clock.


Asunto(s)
Relojes Circadianos/fisiología , Hígado Graso/etiología , Proteínas Hedgehog/fisiología , Animales , Metabolismo de los Lípidos , Ratones , Ratones Endogámicos C57BL , Proteínas del Tejido Nervioso/fisiología , Transducción de Señal/fisiología , Receptor Smoothened/fisiología , Proteína con Dedos de Zinc GLI1/fisiología , Proteína Gli3 con Dedos de Zinc/fisiología
10.
Diabetologia ; 60(5): 889-899, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28233033

RESUMEN

AIMS/HYPOTHESIS: Recently, hedgehog (Hh) was identified as a crucial player in adipose tissue development and energy expenditure. Therefore, we tested whether Hh ligands are regulated in obesity. Further, we aimed at identifying potential target cells of Hh signalling and studied the functional impact of Hh signalling on adipose tissue inflammation and glucose metabolism. METHODS: Hh ligands and receptors were analysed in adipose tissue or serum from lean and obese mice as well as in humans. To study the impact on adipose tissue inflammation and glucose metabolism, Hh signalling was specifically blocked in myeloid cells using a conditional knockout approach (Lys-Smo -/-). RESULTS: Desert Hh (DHH) and Indian Hh (IHH) are local Hh ligands, whereas Sonic Hh is not expressed in adipose tissue from mice or humans. In mice, obesity leads to a preferential upregulation of Hh ligands (Dhh) and signalling components (Ptch1, Smo and Gli1) in subcutaneous adipose tissue. Further, adipose tissue macrophages are Hh target cells owing to the expression of Hh receptors, such as Patched1 and 2. Conditional knockout of Smo (which encodes Smoothened, a mandatory Hh signalling component) in myeloid cells increases body weight and adipose tissue inflammation and attenuates glucose tolerance, suggesting an anti-inflammatory effect of Hh signalling. In humans, adipose tissue expression of DHH and serum IHH decrease with obesity and type 2 diabetes, which might be explained by the intake of metformin. Interestingly, metformin reduced Dhh and Ihh expression in mouse adipose tissue explants. CONCLUSIONS/INTERPRETATION: Hh signalling in myeloid cells affects adipose tissue inflammation and glucose metabolism and may be a potential target to treat type 2 diabetes.


Asunto(s)
Tejido Adiposo/metabolismo , Peso Corporal/fisiología , Glucosa/metabolismo , Proteínas Hedgehog/metabolismo , Inflamación/metabolismo , Células Mieloides/metabolismo , Tejido Adiposo/inmunología , Animales , Ensayo de Inmunoadsorción Enzimática , Proteínas Hedgehog/sangre , Proteínas Hedgehog/genética , Humanos , Técnicas In Vitro , Inflamación/sangre , Inflamación/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Transducción de Señal/fisiología
11.
Arch Toxicol ; 91(11): 3677-3687, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28560483

RESUMEN

The Hedgehog signaling pathway is known to be involved in embryogenesis, tissue remodeling, and carcinogenesis. Because of its involvement in carcinogenesis, it seems an interesting target for cancer therapy. Indeed, Sonidegib, an approved inhibitor of the Hedgehog receptor Smoothened (Smo), is highly active against diverse carcinomas, but its use is also reported to be associated with several systemic side effects. Our former work in adult mice demonstrated hepatic Hedgehog signaling to play a key role in the insulin-like growth factor axis and lipid metabolism. The current work using mice with an embryonic and hepatocyte-specific Smo deletion describes an adverse impact of the hepatic Hedgehog pathway on female fertility. In female SAC-KO mice, we detected androgenization characterized by a 3.3-fold increase in testosterone at 12 weeks of age based on an impressive induction of steroidogenic gene expression in hepatocytes, but not in the classic steroidogenic organs (ovary and adrenal gland). Along with the elevated level of testosterone, the female SAC-KO mice showed infertility characterized by juvenile reproductive organs and acyclicity. The endocrine and reproductive alterations resembled polycystic ovarian syndrome and could be confirmed in a second mouse model with conditional deletion of Smo at 8 weeks of age after an extended period of 8 months. We conclude that the down-regulation of hepatic Hedgehog signaling leads to an impaired hormonal balance by the induction of steroidogenesis in the liver. These effects of Hedgehog signaling inhibition should be considered when using Hedgehog inhibitors as anti-cancer drugs.


Asunto(s)
Proteínas Hedgehog/metabolismo , Infertilidad Femenina/genética , Hígado/metabolismo , Receptor Smoothened/metabolismo , Virilismo/genética , Animales , Femenino , Regulación de la Expresión Génica , Ratones Noqueados , Ratones Transgénicos , Ovario/patología , Transducción de Señal , Receptor Smoothened/genética , Esteroides/metabolismo , Testosterona/sangre , Testosterona/genética
12.
Arch Toxicol ; 89(9): 1579-88, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26233687

RESUMEN

Primary hepatocyte cell cultures are widely used for studying hepatic diseases with alterations in hepatic glucose and lipid metabolism, such as diabetes and non-alcoholic fatty liver disease. Therefore, small interfering RNAs (siRNAs) provide a potent and specific tool to elucidate the signaling pathways and gene functions involved in these pathologies. Although RNA interference (RNAi) in vitro is frequently used in these investigations, the metabolic alterations elucidated by different siRNA delivery strategies have hardly been investigated in transfected hepatocytes. To elucidate the influence of the most commonly used lipid-based transfection reagents on cultured primary hepatocytes, we studied the cytotoxic effects and transfection efficiencies of INTERFERin(®), Lipofectamine(®)RNAiMAX, and HiPerFect(®). All of these transfection agents displayed low cytotoxicity (5.6-9.0 ± 1.3-3.4%), normal cell viability, and high transfection efficiency (fold change 0.08-0.13 ± 0.03-0.05), and they also favored the satisfactory down-regulation of target gene expression. However, when effects on the metabolome and lipidome were studied, considerable differences were observed among the transfection reagents. Cellular triacylglycerides levels were either up- or down-regulated [maximum fold change: INTERFERin(®) (48 h) 2.55 ± 0.34, HiPerFect(®) (24 h) 0.79 ± 0.08, Lipofectamine(®)RNAiMAX (48 h) 1.48 ± 0.21], and mRNA levels of genes associated with lipid metabolism were differentially affected. Likewise, metabolic functions such as amino acid utilization from were perturbed (alanine, arginine, glycine, ornithine, and pyruvate). In conclusion, these findings demonstrate that the choice of non-viral siRNA delivery agent is critical in hepatocytes. This should be remembered, especially if RNA silencing is used for studying hepatic lipid homeostasis and its regulation.


Asunto(s)
Hepatocitos/efectos de los fármacos , Indicadores y Reactivos/administración & dosificación , Lípidos/administración & dosificación , ARN Interferente Pequeño/administración & dosificación , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hepatocitos/metabolismo , Indicadores y Reactivos/química , Indicadores y Reactivos/toxicidad , Lípidos/química , Lípidos/toxicidad , Masculino , Ratones , Ratones Endogámicos C57BL , Interferencia de ARN , ARN Mensajero/metabolismo , Transfección
13.
Cell Commun Signal ; 12: 11, 2014 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-24548465

RESUMEN

BACKGROUND: Hedgehog signaling plays an important role in embryonic development, organogenesis and cancer. In the adult liver, Hedgehog signaling in non-parenchymal cells has been found to play a role in certain disease states such as fibrosis and cirrhosis. However, whether the Hedgehog pathway is active in mature healthy hepatocytes and is of significance to liver function are controversial. FINDINGS: Two types of mice with distinct conditional hepatic deletion of the Smoothened gene, an essential co-receptor protein of the Hedgehog pathway, were generated for investigating the role of Hedgehog signaling in mature hepatocytes. The knockout animals (KO) were inconspicuous and healthy with no changes in serum transaminases, but showed a slower weight gain. The liver was smaller, but presented a normal architecture and cellular composition. By quantitative RT-PCR the downregulation of the expression of Indian hedgehog (Ihh) and the Gli3 transcription factor could be demonstrated in healthy mature hepatocytes from these mice, whereas Patched1 was upregulated. Strong alterations in gene expression were also observed for the IGF axis. While expression of Igf1 was downregulated, that of Igfbp1 was upregulated in the livers of both genders. Corresponding changes in the serum levels of both proteins could be detected by ELISA. By activating and inhibiting the transcriptional output of Hedgehog signaling in cultured hepatocytes through siRNAs against Ptch1 and Gli3, respectively, in combination with a ChIP assay evidence was collected indicating that Igf1 expression is directly dependent on the activator function of Gli3. In contrast, the mRNA level of Igfbp1 appears to be controlled through the repressor function of Gli3, while that of Igfbp2 and Igfbp3 did not change. Interestingly, body weight of the transgenic mice correlated well with IGF-I levels in both genders and also with IGFBP-1 levels in females, whereas it did not correlate with serum growth hormone levels. CONCLUSIONS: Our results demonstrate for the first time that Hedgehog signaling is active in healthy mature mouse hepatocytes and that it has considerable importance for IGF-I homeostasis in the circulation. These findings may have various implications for mouse physiology including the regulation of body weight and size, glucose homeostasis and reproductive capacity.


Asunto(s)
Proteínas Hedgehog/metabolismo , Hepatocitos/metabolismo , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Factor I del Crecimiento Similar a la Insulina/metabolismo , Transducción de Señal , Animales , Células Cultivadas , Femenino , Proteínas Hedgehog/genética , Homeostasis , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 1 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Hígado/irrigación sanguínea , Hígado/citología , Hígado/metabolismo , Masculino , Ratones , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Receptores Patched , Receptor Patched-1 , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptor Smoothened , Proteína Gli3 con Dedos de Zinc
14.
Pathogens ; 13(9)2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39339010

RESUMEN

Background: Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir for the treatment of chronic hepatitis B (CHB) that has shown a favourable renal safety profile while offering suppression of HBV DNA similar to tenofovir disoproxil fumarate (TDF). We aimed to study changes in markers of HBV replication and renal function in a real-world setting in European patients. Methods: In our prospective single-arm, non-interventional observational study, HBeAg-positive and HBeAg-negative patients with chronic HBV mono-infection receiving TAF as their first or following line treatment were enrolled. HBV DNA, HBsAg, markers of bone metabolism, and renal function were determined at baseline and every consecutive 3 months. Results: A total of 50 patients (70% male) were included. The mean duration of TAF treatment was 18 (3-36) months. In 20 patients with detectable HBV DNA at baseline, median serum levels of HBV DNA log10 changed from 2.33 (0.766-6.47) to 1.04 IU/mL at the end of observation and became undetectable in 11 patients. Median HBsAg log10 decreased from 3.37 (0.88-5.10) to 2.39 (1.52-4.19) IU/mL. During the entire observation period, the renal function parameters remained stable in patients with normal renal function and even in those with renal dysfunction. Mild adverse events were reported by 14 patients (28%). Conclusions: TAF was a safe and effective treatment, also in patients with decreased renal function.

15.
Commun Biol ; 7(1): 104, 2024 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-38228886

RESUMEN

Glucose homeostasis is maintained by hormones secreted from different cell types of the pancreatic islets and controlled by manifold input including signals mediated through G protein-coupled receptors (GPCRs). RNA-seq analyses revealed expression of numerous GPCRs in mouse and human pancreatic islets, among them Gpr116/Adgrf5. GPR116 is an adhesion GPCR mainly found in lung and required for surfactant secretion. Here, we demonstrate that GPR116 is involved in the somatostatin release from pancreatic delta cells using a whole-body as well as a cell-specific knock-out mouse model. Interestingly, the whole-body GPR116 deficiency causes further changes such as decreased beta-cell mass, lower number of small islets, and reduced pancreatic insulin content. Glucose homeostasis in global GPR116-deficient mice is maintained by counter-acting mechanisms modulating insulin degradation. Our data highlight an important function of GPR116 in controlling glucose homeostasis.


Asunto(s)
Islotes Pancreáticos , Humanos , Animales , Ratones , Islotes Pancreáticos/metabolismo , Somatostatina/metabolismo , Insulina/metabolismo , Pulmón/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Ratones Noqueados , Glucosa/metabolismo
16.
J Cancer Res Clin Oncol ; 150(2): 81, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38319485

RESUMEN

PURPOSE: The GALAD score and the BALAD-2 score are biomarker-based scoring systems used to detect hepatocellular carcinoma (HCC). Both incorporate levels of alpha-fetoprotein (AFP), lens culinaris agglutinin-reactive AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP). Our objective was to examine the relationship between the GALAD score as well as the BALAD-2 score and treatment response to transarterial or systemic treatments in patients with HCC. METHODS: A total of 220 patients with HCC treated with either transarterial (n = 121) or systemic treatments (n = 99; mainly Sorafenib) were retrospectively analyzed. The GALAD score and the BALAD-2 score were calculated based on AFP-L3, AFP, and DCP levels measured in serum samples collected before treatment. The results were correlated with 3-month treatment efficacy based on radiologic mRECIST criteria. RESULTS: The GALAD score showed a strong correlation with BCLC stage (p < 0.001) and total tumor diameter before treatment (p < 0.001).The GALAD score at baseline was significantly lower in patients with a 3-month response to transarterial (p > 0.001) than in refractory patients. Among patients receiving systemic treatment, the median BALAD-2 score at baseline showed a strong association with response at month 3 (p < 0.001). In the transarterial treatment group, the GALAD score (AUC = 0.715; p < 0.001) as well as the BALAD score (AUC = 0.696; p < 0.001) were associated with overall survival, hereby outperforming AFP, AFP-L3 and DCP. CONCLUSION: The GALAD score as well as the BALAD-2 score hold significant promise as a prognostic tool for patients with early or intermediate-stage HCC who are undergoing transarterial or systemic treatments.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamiento farmacológico , alfa-Fetoproteínas , Estudios Retrospectivos , Neoplasias Hepáticas/tratamiento farmacológico , Sorafenib
17.
J Anat ; 222(3): 358-71, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23171225

RESUMEN

Endocrine cells are evident at an early stage in bovine pancreatic development when the pancreas still consists of primitive epithelial cords. At this stage, the endocrine cells are interspersed between the precursor cells destined to form the ductulo-acinar trees of later exocrine lobules. We here demonstrate that, in bovine fetuses of crown rump length ≥ 11 cm, the endocrine cells become increasingly segregated from the developing exocrine pancreas by assembly into two units that differ in histogenesis, architecture, and fate. Small numbers of 'perilobular giant islets' are distinguishable from larger numbers of 'intralobular small islets'. The two types of islets arise in parallel from the ends of the ductal tree. Aside from differences in number, location, and size, the giant and small islets differ in cellular composition (predominantly insulin-synthesising cells vs. mixtures of endocrine cells), morphology (epithelial trabeculae with gyriform and rosette-like appearance vs. compact circular arrangements of endocrine cells), and in their relationships to intrapancreatic ganglia and nerves. A further difference becomes apparent during the antenatal period; while the 'interlobular small islets' persist in the pancreata of calves and adult cattle, the perilobular giant islets are subject to regression, characterised by involution of the parenchyma, extensive haemorrhage, leukocyte infiltration (myeloid and T-cells) and progressive fibrotic replacement. In conclusion, epithelial precursor cells of the ductolo-acinar tree may give rise to populations of pancreatic islets with different histomorphology, cellular composition and fates. This should be taken into account when using these cells for the generation of pancreatic islets for transplantation therapy.


Asunto(s)
Islotes Pancreáticos/embriología , Animales , Bovinos , Células Endocrinas/citología , Células Gigantes/citología , Inmunohistoquímica , Islotes Pancreáticos/citología , Páncreas/anatomía & histología , Páncreas/embriología
18.
Sci Rep ; 13(1): 23001, 2023 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-38155157

RESUMEN

Small intestinal bacterial overgrowth and compositional changes of intestinal microbiota are pathomechanistic factors in liver cirrhosis leading to bacterial translocation and infectious complications. We analyzed the quantity and composition of duodenal bacterial DNA (bactDNA) in relation to bactDNA in blood and ascites of patients with liver cirrhosis. Duodenal fluid and corresponding blood and ascites samples from 103 patients with liver cirrhosis were collected. Non-liver disease patients (n = 22) served as controls. BactDNA was quantified by 16S-rRNA gene-based PCR. T-RFLP and 16S-rRNA amplicon sequencing were used to analyze bacterial composition. Duodenal bacterial diversity in cirrhosis was distinct to controls showing significantly higher abundances of Streptococcus, Enterococcus and Veillonella. Patients with bactDNA positive ascites revealed reduced spectrum of core microbiota with Streptococcus as key player of duodenal community and higher prevalence of Granulicatella proving presence of cirrhosis related intestinal dysbiosis. Regarding duodenal fluid bactDNA quantification, no significant differences were found between patients with cirrhosis and controls. Additionally, percentage of subjects with detectable bactDNA in blood did not differ between patients and controls. This study evaluated the diversity of bacterial DNA in different body specimens with potential implications on understanding how intestinal bacterial translocation may affect infectious complications in cirrhosis.


Asunto(s)
Ascitis , Líquido Ascítico , Humanos , Ascitis/complicaciones , ADN Bacteriano/análisis , Líquido Ascítico/microbiología , Cirrosis Hepática/complicaciones , Bacterias/genética , Fibrosis , ARN Ribosómico 16S/genética
19.
JHEP Rep ; 5(4): 100684, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36879887

RESUMEN

Background & Aims: Progression of alcohol-associated liver disease (ALD) is driven by genetic predisposition. The rs13702 variant in the lipoprotein lipase (LPL) gene is linked to non-alcoholic fatty liver disease. We aimed at clarifying its role in ALD. Methods: Patients with alcohol-associated cirrhosis, with (n = 385) and without hepatocellular carcinoma (HCC) (n = 656), with HCC attributable to viral hepatitis C (n = 280), controls with alcohol abuse without liver damage (n = 366), and healthy controls (n = 277) were genotyped regarding the LPL rs13702 polymorphism. Furthermore, the UK Biobank cohort was analysed. LPL expression was investigated in human liver specimens and in liver cell lines. Results: Frequency of the LPL rs13702 CC genotype was lower in ALD with HCC in comparison to ALD without HCC both in the initial (3.9% vs. 9.3%) and the validation cohort (4.7% vs. 9.5%; p <0.05 each) and compared with patients with viral HCC (11.4%), alcohol misuse without cirrhosis (8.7%), or healthy controls (9.0%). This protective effect (odds ratio [OR] = 0.5) was confirmed in multivariate analysis including age (OR = 1.1/year), male sex (OR = 3.0), diabetes (OR = 1.8), and carriage of the PNPLA3 I148M risk variant (OR = 2.0). In the UK Biobank cohort, the LPL rs13702 C allele was replicated as a risk factor for HCC. Liver expression of LPL mRNA was dependent on LPL rs13702 genotype and significantly higher in patients with ALD cirrhosis compared with controls and alcohol-associated HCC. Although hepatocyte cell lines showed negligible LPL protein expression, hepatic stellate cells and liver sinusoidal endothelial cells expressed LPL. Conclusions: LPL is upregulated in the liver of patients with alcohol-associated cirrhosis. The LPL rs13702 high producer variant confers protection against HCC in ALD, which might help to stratify people for HCC risk. Impact and implications: Hepatocellular carcinoma is a severe complication of liver cirrhosis influenced by genetic predisposition. We found that a genetic variant in the gene encoding lipoprotein lipase reduces the risk for hepatocellular carcinoma in alcohol-associated cirrhosis. This genetic variation may directly affect the liver, because, unlike in healthy adult liver, lipoprotein lipase is produced from liver cells in alcohol-associated cirrhosis.

20.
Cells ; 11(10)2022 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-35626717

RESUMEN

The Hedgehog signaling pathway regulates many processes during embryogenesis and the homeostasis of adult organs. Recent data suggest that central metabolic processes and signaling cascades in the liver are controlled by the Hedgehog pathway and that changes in hepatic Hedgehog activity also affect peripheral tissues, such as the reproductive organs in females. Here, we show that hepatocyte-specific deletion of the Hedgehog pathway is associated with the dramatic expansion of adipose tissue in mice, the overall phenotype of which does not correspond to the classical outcome of insulin resistance-associated diabetes type 2 obesity. Rather, we show that alterations in the Hedgehog signaling pathway in the liver lead to a metabolic phenotype that is resembling metabolically healthy obesity. Mechanistically, we identified an indirect influence on the hepatic secretion of the fibroblast growth factor 21, which is regulated by a series of signaling cascades that are directly transcriptionally linked to the activity of the Hedgehog transcription factor GLI1. The results of this study impressively show that the metabolic balance of the entire organism is maintained via the activity of morphogenic signaling pathways, such as the Hedgehog cascade. Obviously, several pathways are orchestrated to facilitate liver metabolic status to peripheral organs, such as adipose tissue.


Asunto(s)
Proteínas Hedgehog , Resistencia a la Insulina , Tejido Adiposo/metabolismo , Animales , Femenino , Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas Hedgehog/metabolismo , Resistencia a la Insulina/fisiología , Hígado/metabolismo , Ratones
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