| 1. |
- Donati, Benedetta, et al.
(author)
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Telomerase reverse transcriptase germline mutations and hepatocellular carcinoma in patients with nonalcoholic fatty liver disease.
- 2017
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In: Cancer medicine. - : Wiley. - 2045-7634. ; 6:8, s. 1930-1940
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Journal article (peer-reviewed)abstract
- In an increasing proportion of cases, hepatocellular carcinoma (HCC) develops in patients with nonalcoholic fatty liver disease (NAFLD). Mutations in telomerase reverse transcriptase (hTERT) are associated with familial liver diseases. The aim of this study was to examine telomere length and germline hTERT mutations as associated with NAFLD-HCC. In 40 patients with NAFLD-HCC, 45 with NAFLD-cirrhosis and 64 healthy controls, peripheral blood telomere length was evaluated by qRT-PCR and hTERT coding regions and intron-exon boundaries sequenced. We further analyzed 78 patients affected by primary liver cancer (NAFLD-PLC, 76 with HCC). Enrichment of rare coding mutations (allelic frequency <0.001) was evaluated by Burden test. Functional consequences were estimated in silico and by over-expressing protein variants in HEK-293 cells. We found that telomere length was reduced in individuals with NAFLD-HCC versus those with cirrhosis (P=0.048) and healthy controls (P=0.0006), independently of age and sex. We detected an enrichment of hTERT mutations in NAFLD-HCC, that was confirmed when we further considered a larger cohort of NAFLD-PLC, and was more marked in female patients (P=0.03). No mutations were found in cirrhosis and local controls, and only one in 503 healthy Europeans from the 1000 Genomes Project (allelic frequency=0.025 vs. <0.001; P=0.0005). Mutations with predicted functional impact, including the frameshift Glu113Argfs*79 and missense Glu668Asp, cosegregated with liver disease in two families. Three patients carried missense mutations (Ala67Val in homozygosity, Pro193Leu and His296Pro in heterozygosity) in the N-terminal template-binding domain (P=0.037 for specific enrichment). Besides Glu668Asp, the Ala67Val variant resulted in reduced intracellular protein levels. In conclusion, we detected an association between shorter telomeres in peripheral blood and rare germline hTERT mutations and NAFLD-HCC.
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| 2. |
- Dongiovanni, Paola, et al.
(author)
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Protein phosphatase 1 regulatory subunit 3B gene variation protects against hepatic fat accumulation and fibrosis in individuals at high risk of nonalcoholic fatty liver disease.
- 2018
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In: Hepatology communications. - : Ovid Technologies (Wolters Kluwer Health). - 2471-254X. ; 2:6, s. 666-675
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Journal article (peer-reviewed)abstract
- Nonalcoholic fatty liver disease (NAFLD) is a major cause of liver damage and has a strong genetic component. The rs4841132 G>A variant, modulating the expression of protein phosphatase 1 regulatory subunit 3B (PPP1R3B), which is involved in glycogen synthesis, has been reported to reduce the risk of NAFLD but at the same time may favor liver disease by facilitating glycogen accumulation. The aim of this study was to assess the impact of rs4841132 on development of histologic steatosis and fibrosis in 1,388 European individuals in a liver biopsy cohort, on NAFLD hepatocellular carcinoma in a cross-sectional Italian cohort (n = 132 cases), and on liver disease at the population level in the United Kingdom Biobank cohort. We investigated the underlying mechanism by examining the impact of the variant on gene expression profiles. In the liver biopsy cohort, the rs4841132 minor A allele was associated with protection against steatosis (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42-0.95; P = 0.03) and clinically significant fibrosis (OR, 0.35; 95% CI, 0.14-0.87; P = 0.02) and with reduced circulating cholesterol (P = 0.02). This translated into protection against hepatocellular carcinoma development (OR, 0.22; 95% CI, 0.07-0.70; P = 0.01). At the population level, the rs4841132 variation was not associated with nonalcoholic or nonviral diseases of the liver but was associated with lower cholesterol (P = 1.7 × 10-8). In individuals with obesity, the A allele protecting against steatosis was associated with increased PPP1R3B messenger RNA expression and activation of lipid oxidation and with down-regulation of pathways related to lipid metabolism, inflammation, and cell cycle. Conclusion: The rs4841132 A allele is associated with protection against hepatic steatosis and fibrosis in individuals at high risk of NAFLD but not in the general population and against dyslipidemia. The mechanism may be related to modulation of PPP1R3B expression and hepatic lipid metabolism. (Hepatology Communications 2018;2:666-675).
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| 3. |
- Dongiovanni, Paola, et al.
(author)
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Statin use and nonalcoholic steatohepatitis in at risk individuals.
- 2015
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In: Journal of hepatology. - : Elsevier BV. - 1600-0641 .- 0168-8278. ; 63:3, s. 705-712
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Journal article (peer-reviewed)abstract
- Excess hepatic free cholesterol contributes to the pathogenesis of nonalcoholic steatohepatitis, and statins reduce cholesterol synthesis. Aim of this study was to assess whether statin use is associated with histological liver damage related to steatohepatitis.
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| 4. |
- 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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| 5. |
- Mancina, Rosellina Margherita, et al.
(author)
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PSD3 downregulation confers protection against fatty liver disease.
- 2022
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In: Nature metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 4:1, s. 60-75
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Journal article (peer-reviewed)abstract
- Fatty liver disease (FLD) is a growing health issue with burdening unmet clinical needs. FLD has a genetic component but, despite the common variants already identified, there is still a missing heritability component. Using a candidate gene approach, we identify a locus (rs71519934) at the Pleckstrin and Sec7 domain-containing 3 (PSD3) gene resulting in a leucine to threonine substitution at position 186 of the protein (L186T) that reduces susceptibility to the entire spectrum of FLD in individuals at risk. PSD3 downregulation by short interfering RNA reduces intracellular lipid content in primary human hepatocytes cultured in two and three dimensions, and in human and rodent hepatoma cells. Consistent with this, Psd3 downregulation by antisense oligonucleotides in vivo protects against FLD in mice fed a non-alcoholic steatohepatitis-inducing diet. Thus, translating these results to humans, PSD3 downregulation might be a future therapeutic option for treating FLD.
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| 6. |
- 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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| 7. |
- 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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| 8. |
- Sasidharan, Kavitha, et al.
(author)
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IL32 downregulation lowers triglycerides and type I collagen in di-lineage human primary liver organoids.
- 2024
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In: Cell reports. Medicine. - 2666-3791. ; 5:1
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Journal article (peer-reviewed)abstract
- Steatotic liver disease (SLD) prevails as the most common chronic liver disease yet lack approved treatments due to incomplete understanding of pathogenesis. Recently, elevated hepatic and circulating interleukin 32 (IL-32) levels were found in individuals with severe SLD. However, the mechanistic link between IL-32 and intracellular triglyceride metabolism remains to be elucidated. We demonstrate invitro that incubation with IL-32β protein leads to an increase in intracellular triglyceride synthesis, while downregulation of IL32 by small interfering RNA leads to lower triglyceride synthesis and secretion in organoids from human primary hepatocytes. This reduction requires the upregulation of Phospholipase A2 group IIA (PLA2G2A). Furthermore, downregulation of IL32 results in lower intracellular type I collagen levels in di-lineage human primary hepatic organoids. Finally, we identify a genetic variant of IL32 (rs76580947) associated with lower circulating IL-32 and protection against SLD measured by non-invasive tests. These data suggest that IL32 downregulation may be beneficial against SLD.
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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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