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Bataller, R.

Publications and source records attributed to Bataller, R..

5 recordsLinked to original sources

Alpha diversity analysis of hepatic transcriptome reveals novel pathways inalcohol-related hepatitis

Next generation sequencing can identify novel gene expression patterns in disease. Beyond differentially expressed genes analysis, we investigated the ability of within-population diversity (-diversity) of the transcriptome to reveal new biological information in alcohol-related liver disease (ALD), comparing Differential Shannon diversity (DSD) to transcriptome heterogeneity changes. RNA sequencing data from normal livers and patients with early silent ALD and severe AH were analyzed. -diversity indices and Percent Shannon Diversity of a gene, which refers to this genes contribution to total Shannon entropy were calculated. Ingenuity pathway analysis identified canonical pathways determined by differentially expressed genes (DEG) and DSD approaches. ALD significantly decreased hepatic transcriptome -diversity correlating with increased relative contribution of select genes. These changes were driven by lower abundance gene expression loss. DEG and DSD analyses showed overlapping genes and canonical pathways, but DSD also identified novel genes and pathways not highlighted by DEG. Importantly, DSD more effectively identified differences between preclinical ALD and AH severity stages. ALD decreases hepatic transcriptome heterogeneity, favoring pathways associated with organ damage or damage response. Preclinical and clinical ALD led to differential heterogeneity patterns that may provide new disease insights. DSD analysis identified enriched pathways missed by standard DEG analyses, potentially yielding novel insight into disease mechanisms and biomarkers. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=53 SRC="FIGDIR/small/681263v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@d2d3a3org.highwire.dtl.DTLVardef@14496a8org.highwire.dtl.DTLVardef@1ff0dfeorg.highwire.dtl.DTLVardef@1efa8f3_HPS_FORMAT_FIGEXP M_FIG C_FIG

systems biology↗

Calpain-4 Knockdown Modulates Cholesterol Metabolism and LXRα Nuclear Localization in Alcohol-Related Liver Disease

Background & AimsEthanol affects lipid metabolism through multiple pathways, leading to fatty liver development in most ALD patients. Recent studies have highlighted the role of calpain, a calcium-dependent protease, in liver inflammation and fibrosis. Calpain activity is regulated by its essential subunit, Capns1, (calpain-4, Capn4), which stabilizes and modulates the activity of its catalytic isoforms, calpain-1 and calpain-2. This study investigated calpains impact on lipid metabolism in ALD. Approach & ResultsSix-week-old C57Bl6/J mice were injected with rAAV8 vectors encoding Capn4 shRNA or control vectors. After four weeks, mice underwent a 10-day period of ad libitum ethanol consumption, followed by a single gavaged ethanol administration on day 11. Following Capn4 knockdown, microvesicular steatosis was attenuated. While triglycerides and free fatty acids levels showed no significant changes, cholesterol levels were significantly reduced in the ethanol (EtOH) group with Capn4 knockdown. Cpt1a expression increased significantly in the EtOH group with Capn4 knockdown. Western blot analysis revealed increased Cleaved-HMGCR to Pro-HMGCR ratio in Capn4 knockdown mice, suggesting reduced HMGCR activity and suppressed cholesterol biosynthesis. LXR expression was mainly increased in the cytoplasm in the EtOH group, and following Capn4 knockdown, it was relocalized to the nucleus via its activation. In addition, RNA sequencing analysis suggests that Capn4 knockdown contributes to the reprogramming of ethanol-induced disruptions in metabolic and homeostatic pathways, primarily those involving cholesterol metabolism. ConclusionsFurther investigation into the relationship between Capn4 and cholesterol biosynthesis proteins may provide insights into using calpain inhibitors as a therapeutic approach for alcohol-related hepatitis.

molecular biology↗

Patient-derived liver biopsy organoids enable precision alcohol-associated liver disease modeling

Background & AimsAlcohol-associated liver disease (ALD) is a major cause of liver disease worldwide with scarce therapeutic options. Animal models poorly recapitulate advanced ALD precluding the development of new treatments. Organoids have emerged as a powerful human-based preclinical tool. However, current patient-derived liver organoids fail to recapitulate the epithelial heterogeneity and its generation requires liver surgical resections, thus limiting personalized disease modeling. Here, we report the development of organoids from liver needle biopsies (b-Orgs) from patients with ALD. Methodsb-Orgs were generated from tru-cut biopsies from patients at early (n=28) and advanced (n=34) stages of ALD. b-Orgs were characterized by immunofluorescence, bulk and single cell RNA-sequencing and compared to parental tissues. b-Orgs were used to model ALD progression, identify pathogenic drivers, induce alcohol-associated hepatitis (AH) and evaluate response to prednisolone. ResultsPhenotypic and functional analysis of b-Orgs showed hepatocyte- enriched features. Single-cell RNA-sequencing revealed a heterogeneous cell composition comprising hepatocyte, biliary and progenitor populations, mirroring the epithelial landscape found in patients with advanced ALD. Moreover, b-Orgs preserved disease-stage features and allowed to identify the association of ELF3 with cell plasticity and disease progression. Finally, stimulation of b-Orgs with drivers of ALD induced pathophysiological features of alcohol-associated hepatitis, including ROS production, lipid accumulation, inflammation and decreased cell proliferation, which were mitigated in response to prednisolone. Conclusions Overall, we provide a human-based model that recapitulates epithelial complexity and patient specific features, allowing to identify drivers of cell plasticity and expanding organoid-based liver disease modeling for personalized medicine. Impact and implications Here, we describe the generation of biopsy-derived organoids (b-Orgs) from patients with liver disease. b-Orgs reproduce the liver epithelial cell composition found in patients liver tissue and are efficiently generated from different stages of the disease, providing a platform for patient- tailored disease modeling and drug testing.

cell biology↗

Hepatocyte Dedifferentiation Profiling In Alcohol-Related Liver Disease Identifies CXCR4 As A Driver Of Cell Reprogramming

Background and AimsLoss of hepatocyte identity is associated with impaired liver function in alcohol-related hepatitis (AH). In this context, hepatocyte dedifferentiation gives rise to cells with a hepatobiliary (HB) phenotype expressing biliary and hepatocytes markers and showing immature features. However, the mechanisms and the impact of hepatocyte dedifferentiation in liver disease are poorly understood. MethodsHB cells and ductular reaction (DR) cells were quantified and microdissected from liver biopsies from patients with alcohol-related liver disease (ALD). Hepatocyte- specific overexpression or deletion of CXCR4, and CXCR4 pharmacological inhibition were assessed in mouse liver injury. Patient-derived and mouse organoids were generated to assess plasticity. ResultsHere we show that HB and DR cells are increased in patients with decompensated cirrhosis and AH, but only HB cells correlate with poor liver function and patients outcome. Transcriptomic profiling of HB cells revealed the expression of biliary-specific genes and a mild reduction of hepatocyte metabolism. Functional analysis identified pathways involved in hepatocyte reprogramming, inflammation, stemness and cancer gene programs. CXCR4 pathway was highly enriched in HB cells, and correlated with disease severity and hepatocyte dedifferentiation. In vitro, CXCR4 was associated with biliary phenotype and loss of hepatocyte features. Liver overexpression of CXCR4 in chronic liver injury decreased hepatocyte specific gene expression profile and promoted liver injury. CXCR4 deletion or its pharmacological inhibition ameliorated hepatocyte dedifferentiation and reduced DR and fibrosis progression. ConclusionsThis study shows the association of hepatocyte dedifferentiation with disease progression and poor outcome in AH. Moreover, the transcriptomic profiling of HB cells revealed CXCR4 as a new driver of hepatocyte-to-biliary reprogramming and as a potential therapeutic target to halt hepatocyte dedifferentiation in AH. Lay summaryHere we describe that hepatocyte dedifferentiation is associated with disease severity and a reduced synthetic capacity of the liver. Moreover, we identify the CXCR4 pathway as a driver of hepatocyte dedifferentiation and as a therapeutic target in alcohol-related hepatitis.

cell biology↗

Ceramide synthase 6 (CerS6) promotes alcohol-induced fatty liver by promoting metabolic dysfunction and upregulating lipid droplet-associated proteins

ObjectiveAlcohol-associated liver disease (ALD) is the leading cause of liver-related mortality worldwide. Current strategies to manage ALD largely focus on advanced stage disease, however, metabolic changes such as glucose intolerance are apparent at the earliest stage of alcoholic steatosis and increase the risk of disease progression. Ceramides impair insulin signaling and accumulate in ALD, and metabolic pathways involving ceramide synthase 6 (CerS6) are perturbed in ALD during hepatic steatosis. In this study, we aimed to investigate the role of CerS6 in ALD development. MethodsC57BL/6 WT and CerS6 KO mice of both sexes were fed either a Lieber-DeCarli control (CON) or 15% ethanol (EtOH) diet for 6 weeks. In vivo metabolic tests including glucose and insulin tolerance tests (GTT and ITT) were performed. The mice were euthanized, and liver histology and lipid levels in serum and liver were measured. For in vitro studies, CerS6 was deleted in human hepatocytes and were incubated with EtOH and/or C16:0-ceramides. RNAseq analysis was performed in mice and in liver from patients with different stages of ALD and diseased controls. ResultsAfter six weeks on an EtOH diet, CerS6 KO mice had reduced body weight, food intake, and %fat mass compared to WT mice. Male (but not female) EtOH-fed KO mice showed significantly higher O2 consumption, CO2 production, respiratory exchange ratio, and energy expenditure (P<0.05 for all) during the dark period compared to EtOH-fed WT mice. In response to EtOH, WT mice developed mild hepatic steatosis, while steatosis was alleviated in KO mice as determined by H&E and ORO staining. KO mice showed significantly decreased long-chain ceramide species, especially C16:0 ceramides, in the serum and liver tissues compared to WT mice. CerS6 deletion decreased serum TG and NEFA only in male not female mice. CerS6 deletion improved glucose tolerance and insulin resistance in EtOH-fed mice of both sexes. RNAseq analysis revealed that 74 genes are significantly upregulated and 66 genes are downregulated by CerS6 deletion in EtOH-fed male mice, with key network pathways including TG biosynthetic process, positive regulation of lipid localization, and fat cell differentiation. Similar to RNAseq results, absence of CerS6 significantly decreased mRNA expression of lipid droplet associated proteins in EtOH-fed mice. In vitro, EtOH stimulation significantly increased PLIN2 protein expression in VL-17A cells while CerS6 deletion inhibited EtOH-mediated PLIN2 upregulation. C16:0-ceramide treatment significantly increased PLIN2 protein expression compared to CON. Importantly, progression of ALD in humans was associated with increased CerS6 hepatic expression. ConclusionsOur findings demonstrate that CerS6 deletion attenuates EtOH-induced weight gain and hepatic steatosis and improves glucose homeostasis in mice fed an EtOH diet. Notably, we unveil that CerS6 plays a major role as a regulator of lipid droplet biogenesis in alcoholic intra-hepatic lipid droplet formation. Together, our data suggest that CerS6 may be targeted for treatment for early stage ALD.

pathology↗