1. |
- Armandi, Angelo, et al.
(author)
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Serum ferritin levels can predict long-term outcomes in patients with metabolic dysfunction-associated steatotic liver disease
- 2024
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In: Gut. - : BMJ PUBLISHING GROUP. - 0017-5749 .- 1468-3288.
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Journal article (peer-reviewed)abstract
- Objective Hyperferritinaemia is associated with liver fibrosis severity in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), but the longitudinal implications have not been thoroughly investigated. We assessed the role of serum ferritin in predicting long-term outcomes or death. Design We evaluated the relationship between baseline serum ferritin and longitudinal events in a multicentre cohort of 1342 patients. Four survival models considering ferritin with confounders or non-invasive scoring systems were applied with repeated five-fold cross-validation schema. Prediction performance was evaluated in terms of Harrell's C-index and its improvement by including ferritin as a covariate. Results Median follow-up time was 96 months. Liver-related events occurred in 7.7%, hepatocellular carcinoma in 1.9%, cardiovascular events in 10.9%, extrahepatic cancers in 8.3% and all-cause mortality in 5.8%. Hyperferritinaemia was associated with a 50% increased risk of liver-related events and 27% of all-cause mortality. A stepwise increase in baseline ferritin thresholds was associated with a statistical increase in C-index, ranging between 0.02 (lasso-penalised Cox regression) and 0.03 (ridge-penalised Cox regression); the risk of developing liver-related events mainly increased from threshold 215.5 mu g/L (median HR=1.71 and C-index=0.71) and the risk of overall mortality from threshold 272 mu g/L (median HR=1.49 and C-index=0.70). The inclusion of serum ferritin thresholds (215.5 mu g/L and 272 mu g/L) in predictive models increased the performance of Fibrosis-4 and Non-Alcoholic Fatty Liver Disease Fibrosis Score in the longitudinal risk assessment of liver-related events (C-indices>0.71) and overall mortality (C-indices>0.65). Conclusions This study supports the potential use of serum ferritin values for predicting the long-term prognosis of patients with MASLD.
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2. |
- Dutta, Tanmoy, 1998, et al.
(author)
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Mitochondrial amidoxime-reducing component 1 p.Ala165Thr increases protein degradation mediated by the proteasome.
- 2024
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In: Liver international. - 1478-3223. ; 44:5, s. 1219-1232
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Journal article (peer-reviewed)abstract
- Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global health concern with no effective and specific drug treatment available. The rs2642438 minor allele in mitochondrial amidoxime-reducing component 1 (MARC1) results in an aminoacidic substitution (p.Ala165Thr) and associates with protection against MASLD. However, the mechanisms behind this protective effect are unknown. In this study, we examined the consequences of this aminoacidic substitution on protein stability and subcellular localization.We overexpressed the human MARC1 A165 (wild-type) or 165T (mutant) invivo in mice and invitro in human hepatoma cells (HepG2 and HuH-7), generated several mutants at position 165 by insitu mutagenesis and then examined protein levels. We also generated HepG2 cells stably overexpressing MARC1 A165 or 165T to test the effect of this substitution on MARC1 subcellular localization.MARC1 165T overexpression resulted in lower protein levels than A165 both invivo and invitro. Similarly, any mutant at position 165 showed lower protein levels compared to the wild-type protein. We showed that the 165T mutant protein is polyubiquitinated and its degradation is accelerated through lysine-48 ubiquitin-mediated proteasomal degradation. We also showed that the 165T substitution does not affect the MARC1 subcellular localization.This study shows that alanine at position 165 in MARC1 is crucial for protein stability, and the threonine substitution at this position leads to a hypomorphic protein variant due to lower protein levels. Our result supports the notion that lowering hepatic MARC1 protein level may be a successful therapeutic strategy for treating MASLD.
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3. |
- Grimaudo, Stefania, et al.
(author)
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NR1H4 rs35724 G>C variant modulates liver damage in nonalcoholic fatty liver disease.
- 2021
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In: Liver international. - : Wiley. - 1478-3231 .- 1478-3223. ; 41:11, s. 2712-2719
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Journal article (peer-reviewed)abstract
- Farnesoid X receptor (FXR) plays a key role in bile acid and lipid homeostasis. Experimental evidence suggests that it can modulate liver damage related to nonalcoholic fatty liver disease (NAFLD). We examined the impact of the NR1H4 rs35724 G>C, encoding for FXR, on liver damage in a large cohort of patients at risk of steatohepatitis.We considered 2,660 consecutive individuals at risk of steatohepatitis with liver histology. The rs35724 G>C polymorphisms were genotyped by TaqMan assays. Gene expression was evaluated by RNASeq in a subset of patients (n=124).The NR1H4 rs35724 CC genotype, after adjusting for clinic-metabolic and genetic confounders and for enrolling centre, was protective against severity of steatosis (GG vs CC OR 0.77, 95% CI 0.62-0.95; P=.01), steatohepatitis (GG vs CC OR 0.62, 95% CI 0.47-0.83; P=.001) and severity of fibrosis (GG vs CC OR 0.83, 95% CI 0.67-0.98; P=.04). The C allele was associated with higher total circulating cholesterol (P=.01). Patients carrying the NR1H4 rs35724 C allele had significantly higher hepatic mRNA levels of FXR and were associated with higher hepatic FGFR4 and Cyp39A1 that are in turn involved in bile acid synthesis.Increased hepatic FXR expression due to the NR1H4 rs35724 C allele is linked to higher serum cholesterol but protects against steatosis, steatohepatitis and liver fibrosis. The translational relevance of these results for patient risk stratification and FXR-targeted therapy warrants further investigation.
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4. |
- Mozes, Ferenc E., et al.
(author)
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Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis
- 2023
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In: The Lancet Gastroenterology & Hepatology. - : ELSEVIER INC. - 2468-1253. ; 8:8, s. 704-713
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Journal article (peer-reviewed)abstract
- Background Histologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD. Methods This was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0-4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score >= 15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0-2 vs F3 vs F4; LSM: <10 vs 10 to <20 vs >= 20 kPa; FIB-4: <1<middle dot>3 vs 1<middle dot>3 to <= 2<middle dot>67 vs >2<middle dot>67; NFS: <-1<middle dot>455 vs -1<middle dot>455 to <= 0<middle dot>676 vs >0<middle dot>676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226.Findings Of 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44<middle dot>7%] were female, median age was 54 years [IQR 44-63), and 1161 [46<middle dot>1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33-91], the composite endpoint was observed in 145 (5<middle dot>8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0<middle dot>0001 for all comparisons). The tAUC at 5 years were 0<middle dot>72 (95% CI 0<middle dot>62-0<middle dot>81) for histology, 0<middle dot>76 (0<middle dot>70-0<middle dot>83) for LSM-VCTE, 0<middle dot>74 (0<middle dot>64-0<middle dot>82) for FIB-4, and 0<middle dot>70 (0<middle dot>63-0<middle dot>80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression.Interpretation Simple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases.
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5. |
- Oveis, Jamialahmadi, et al.
(author)
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Exome-wide Association Study on Alanine Aminotransferase Identifies Sequence Variants in the GPAM and APOE Associated with Fatty Liver Disease.
- 2021
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In: Gastroenterology. - : Elsevier BV. - 1528-0012 .- 0016-5085. ; 160:5
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Journal article (peer-reviewed)abstract
- Fatty liver disease (FLD) is a growing epidemic that is expected to be the leading cause of end-stage liver disease within the next decade. Both environmental and genetic factors contribute to the susceptibility of FLD. Several genetic variants contributing to FLD have been identified in exome-wide association studies. However, there is still a missing hereditability indicating that other genetic variants are yet to be discovered.To find genes involved in FLD, we first examined the association of missense and nonsense variants with alanine aminotransferase (ALT) at an exome-wide level in 425,671 participants from the UK Biobank. We then validated genetic variants with liver fat content in 8,930 participants in whom liver fat measurement was available, and replicated two genetic variants in three independent cohorts comprising 2,621 individuals with available liver biopsy.We identified 190 genetic variants independently associated with ALT after correcting for multiple testing with Bonferroni method. The majority of these variants were not previously associated with this trait. Among those associated, there was a striking enrichment of genetic variants influencing lipid metabolism. We identified the variants rs2792751 in GPAM/GPAT1, the gene encoding glycerol-3-phosphate acyltransferase, mitochondrial, and rs429358 in APOE, the gene encoding apolipoprotein E, as robustly associated with liver fat content and liver disease after adjusting for multiple testing. Both genes affect lipid metabolism in the liver.We identified two novel genetic variants in GPAM and APOE that are robustly associated with steatosis and liver damage. These findings may help to better elucidate the genetic susceptibility to FLD onset and progression.
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6. |
- Pennisi, Grazia, et al.
(author)
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ANGPTL3 Downregulation Increases Intracellular Lipids by Reducing Energy Utilization.
- 2024
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In: Arteriosclerosis, Thrombosis and Vascular Biology. - 1079-5642. ; 44:5, s. 1086-1097
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Journal article (peer-reviewed)abstract
- ANGPTL3 (angiopoietin-like protein 3) is a circulating protein with a key role in maintaining lipoprotein homeostasis. A monoclonal antibody against ANGPTL3 is an approved and well-tolerated treatment to reduce lipoproteins in familial hypercholesterolemia homozygotes. However, the reduction of hepatic ANGPTL3 synthesis using an antisense oligonucleotide unexpectedly resulted in a dose-dependent increase in liver lipid content and circulating transaminases, resulting in the termination of the clinical trial. Meanwhile, the use of silencing RNAs remains an area of active investigation. Our study sought to investigate whether intracellular downregulation of ANGPTL3 may lead to a primary increase in neutral lipids within the hepatocyte.We downregulated ANGPTL3 by silencing RNA in primary human hepatocytes 3-dimensional spheroids, HepG2/LX-2 3-dimensional spheroids, and in HepG2, Hep3B2, and Huh7 cultured in 2 dimensions.ANGPTL3 downregulation increased neutral lipids in all models investigated. Interestingly, ANGPTL3 induced lower intracellular deiodinase type 1 protein levels resulting in a reduction in beta-oxidation and causing an increase in triglycerides stored in lipid droplets.In conclusion, intracellular ANGPTL3 downregulation by silencing RNA led to an increase in triglycerides content due to a reduction in energy substrate utilization resembling a primary intracellular hepatocyte hypothyroidism.
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7. |
- Pipitone, Rosaria M., et al.
(author)
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Programmed cell death 1 genetic variant and liver damage in nonalcoholic fatty liver disease
- 2023
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In: Liver International. - 1478-3223 .- 1478-3231. ; 43:8, s. 1761-71
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Journal article (peer-reviewed)abstract
- Background and Aims: Programmed cell death 1/programmed cell death-ligand 1 (PD-1/PDL-1) axis has been reported to modulate liver inflammation and progression to hepatocellular carcinoma (HCC) in patients with nonalcoholic fatty liver disease (NAFLD). Here, we examined whether the PDCD1 variation is associated with NAFLD severity in individuals with liver biopsy. Methods: We examined the impact of PDCD1 gene variants on HCC, as robust severe liver disease phenotype in UK Biobank participants. The strongest genetic association with the rs13023138 G>C variation was subsequently tested for association with liver damage in 2889 individuals who underwent liver biopsy for suspected nonalcoholic steatohepatitis (NASH). Hepatic transcriptome was examined by RNA-Seq in a subset of NAFLD individuals (n = 121). Transcriptomic and deconvolution analyses were performed to identify biological pathways modulated by the risk allele. Results: The rs13023138 C>G showed the most robust association with HCC in UK Biobank (p = 5.28E-4, OR = 1.32, 95% CI [1.1, 1.5]). In the liver biopsy cohort, rs13023138 G allele was independently associated with severe steatosis (OR 1.17, 95% CI 1.02-1.34; p =.01), NASH (OR 1.22, 95% CI 1.09-1.37; p <.001) and advanced fibrosis (OR 1.26, 95% CI 1.06-1.50; p =.007). At deconvolution analysis, rs13023138 G>C allele was linked to higher hepatic representation of M1 macrophages, paralleled by upregulation of pathways related to inflammation and higher expression of CXCR6. Conclusions: The PDCD1 rs13023138 G allele was associated with HCC development in the general population and with liver disease severity in patients at high risk of NASH.
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8. |
- Salomone, Federico, et al.
(author)
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SIRT5 rs12216101 T>G variant is associated with liver damage and mitochondrial dysfunction in patients with non-alcoholic fatty liver disease
- 2024
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In: JOURNAL OF HEPATOLOGY. - 0168-8278 .- 1600-0641. ; 80:1, s. 10-19
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Journal article (peer-reviewed)abstract
- Background & Aims: Sirtuin 5, encoded by the SIRT5 gene, is a NAD+ -dependent deacylase that modulates mitochondrial metabolic processes through post-translational modifications. In this study, we aimed to examine the impact of the SIRT5 rs12216101 T>G non-coding single nucleotide polymorphism on disease severity in patients with non-alcoholic fatty liver disease (NAFLD). Methods: The rs12216101 variant was genotyped in 2,606 consecutive European patients with biopsy-proven NAFLD. Transcriptomic analysis, expression of mitochondrial complexes and oxidative stress levels were measured in liver samples from a subset of bariatric patients. Effects of SIRT5 pharmacological inhibition were evaluated in HepG2 cells exposed to excess free fatty acids. Mitochondrial energetics in vitro were investigated by high-performance liquid chromatography. Results: In the whole cohort, the frequency distribution of SIRT5 rs12216101 TT, TG and GG genotypes was 47.0%, 42.3% and 10.7%, respectively. At multivariate logistic regression analysis adjusted for sex, age >50 years, diabetes, and PNPLA3 rs738409 status, the SIRT5 rs12216101 T>G variant was associated with the presence of non-alcoholic steatohepatitis (odds ratio 1.20, 95% CI 1.03-1.40) and F2-F4 fibrosis (odds ratio 1.18; 95% CI 1.00-1.37). Transcriptomic analysis showed that the SIRT5 rs12216101 T>G variant was associated with upregulation of transcripts involved in mitochondrial metabolic pathways, including the oxidative phosphorylation system. In patients carrying the G allele, western blot analysis confirmed an upregulation of oxidative phosphorylation complexes III, IV, V and consistently higher levels of reactive oxygen species, reactive nitrogen species and malondialdehyde, and lower ATP levels. Administration of a pharmacological SIRT5 inhibitor preserved mitochondrial energetic homeostasis in HepG2 cells, as evidenced by restored ATP/ADP, NAD+/NADH, NADP+/NADPH ratios and glutathione levels. Conclusions: The SIRT5 rs12216101 T>G variant, heightening SIRT5 activity, is associated with liver damage, mitochondrial dysfunction, and oxidative stress in patients with NAFLD. (c) 2023 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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9. |
- Stefania, Grimaudo, et al.
(author)
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PCSK9 rs11591147 R46L Loss-of-Function Variant Protects Against Liver Damage in Individuals with NAFLD.
- 2021
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In: Liver international : official journal of the International Association for the Study of the Liver. - : Wiley. - 1478-3231. ; 41:2, s. 321-332
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Journal article (peer-reviewed)abstract
- The proproteinconvertasesubtilisin/kexin type 9(PCSK9) plays a key role in cholesterol homeostasis, and its inhibition represents an effective therapy to lower LDL-C levels. In this study, we examined the impact of the PCSK9 rs11591147 loss-of-function (LOF) variant on liver damage in a multicenter collection of patients at risk of nonalcoholic steatohepatitis (NASH), in clinical samples and experimental models.We considered 1,874 consecutive individuals at risk of NASH as determined by histology. The SNP rs11591147, encoding for the p.R46L variant of PCSK9,was genotyped by TaqMan assays. We also evaluated 1)PCSK9 mRNA hepatic expression in human liver, and 2)the impact of a NASH-inducing diet in mice with hepatic overexpression of human PCSK9.Carriers of PCSK9 rs11591147 had lower circulating LDL-C levels and were protected against NAFLD (OR0.42; 95%C.I0.22-0.81; P=0.01), NASH (OR0.48;95%C.I.0.26-0.87;P=0.01)and more severe fibrosis (OR0.55; 95%C.I.0.32-0.94; P=0.03) independently of clinical, metabolic and genetic confounding factors. PCSK9 hepatic expression was directly correlated with liver steatosis(P=0.03). Finally, liver-specific overexpression of human PCSK9 in male mice drives NAFLD and fibrosis upon a dietary challenge.In individuals at risk of NASH, PCSK9 was induced with hepatic fat accumulation and PCSK9 rs11591147 LOF variant was protective against liver steatosis, NASH and fibrosis, suggesting PCSK9 inhibition may be a new therapeutic strategy to treat NASH.
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