| 1. |
- Hellerud, Christina, 1955, et al.
(författare)
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Clinical heterogeneity and molecular findings in five Polish patients with glycerol kinase deficiency: investigation of two splice site mutations with computerized splice junction analysis and Xp21 gene-specific mRNA analysis.
- 2003
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Ingår i: Molecular genetics and metabolism. - 1096-7192. ; 79:3, s. 149-59
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Tidskriftsartikel (refereegranskat)abstract
- Five cases of glycerol kinase deficiency are presented with clinical, biochemical, and genetic results. Two had the glycerol kinase deficiency as part of an Xp21 contiguous gene deletion syndrome-complex form-and three had an isolated form of the enzyme deficiency. In these we found two splice site mutations (IVS1+4A>G, IVS9-1G>T) and one insertion (1393_1394insG). In patients with the complex form, a deletion of the DAX1, GK genes and the distal part of the DMD gene was found. A computerized study was performed to predict the effects of the splice site mutations. It showed that the IVS9-1G>T mutation substantially altered and removed the wild-type site and enhanced a cryptic site seven nucleotides downstream, and that the IVS1+4A>G diminished the strength of the wild-type donor site from strong to leaky. To verify these predictions, we developed an RT-PCR system with gene-specific primers that exclusively amplifies the Xp21 glycerol kinase gene transcript. Identification of individuals at risk is motivated by a need to avoid delay in a correct diagnosis. For reliable identification of heterozygotes for isolated glycerol kinase deficiency, knowledge of the specific mutation in the proband is required. This is easily obtained with the RT-PCR analyses developed in this study.
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| 2. |
- Adori, Csaba, et al.
(författare)
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Disorganization and degeneration of liver sympathetic innervations in nonalcoholic fatty liver disease revealed by 3D imaging
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:30
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Tidskriftsartikel (refereegranskat)abstract
- Hepatic nerves have a complex role in synchronizing liver metabolism. Here, we used three-dimensional (3D) immunoimaging to explore the integrity of the hepatic nervous system in experimental and human nonalcoholic fatty liver disease (NAFLD). We demonstrate parallel signs of mild degeneration and axonal sprouting of sympathetic innervations in early stages of experimental NAFLD and a collapse of sympathetic arborization in steatohepatitis. Human fatty livers display a similar pattern of sympathetic nerve degeneration, correlating with the severity of NAFLD pathology. We show that chronic sympathetic hyperexcitation is a key factor in the axonal degeneration, here genetically phenocopied in mice deficient of the Rac-1 activator Vav3. In experimental steatohepatitis, 3D imaging reveals a severe portal vein contraction, spatially correlated with the extension of the remaining nerves around the portal vein, enlightening a potential intrahepatic neuronal mechanism of portal hypertension. These fundamental alterations in liver innervation and vasculature uncover previously unidentified neuronal components in NAFLD pathomechanisms.
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| 3. |
- Almeida, Francisco C., et al.
(författare)
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APOE genotype dictates lipidomic signatures in primary human hepatocytes
- 2024
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Ingår i: Journal of Lipid Research. - 0022-2275 .- 1539-7262. ; 65:2
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Tidskriftsartikel (refereegranskat)abstract
- Apolipoprotein E (APOE) genetic variants are most notably known for their divergent impact on the risk of developing Alzheimer's disease. While APOE genotype has been consistently shown to modulate lipid metabolism in a variety of cellular contexts, the effect of APOE alleles on the lipidome in hepatocytes is unknown. In this study, we investigated the contribution of APOE alleles to lipidomic profiles of donor -derived primary human hepatocytes from 77 subjects. Lipidomic data obtained by liquid chromatography -mass spectrometry were analyzed across e2/e3, e3/e3, and e3/e4 genotypes to reveal how APOE modulates lipid relative levels over age and between groups. Hepatic APOE concentration, measured by ELISA, was assessed for correlation with lipid abundance in subjects grouped as per APOE genotype and sex. APOE genotype -specific differential lipidomic signatures associated with age for multiple lipid classes but did not differ between sexes. Compared to e2/e3, e3/e4 hepatocytes had higher abundance of acylcarnitines (AC) and acylphosphatidylglycerol (AcylPG) as a class, as well as higher medium and long -chain ACs, AcylPG, phosphatidylglycerol (PG), bis(monoacylglycerol)phosphate (BMP), monoacylglycerol (MG) and diacylglycerol (DG) species. The e3/e4 hepatocytes also exhibited a higher abundance of medium and long -chain ACs compared to the e3/e3 hepatocytes. Only in the e3/e4 hepatocytes, APOE concentration was lower and showed a negative correlation with BMP levels, specifically in females. APOE genotype dictates a differential lipidome in primary human hepatocytes. The lipids involved suggest mitochondrial dysfunction with accompanying alterations in neutral lipid storage, reflective of a general disturbance of free fatty acid metabolism in human hepatocytes with the e4 allele.
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| 4. |
- Ellis, Ewa C S
(författare)
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Use of primary human hepatocytes for the elucidation of bile acid synthesis
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the present investigation we cultured primary human hepatocytes on matrigel under serum-free conditions and studied bile acid formation. The following observations were made: · The major steroid products excreted from primary human hepatocytes into the culture medium were cholic acid, CA (70%) and chenodeoxycholic acid, CDCA (25%) conjugated with glycine or taurine. This composition is similar to that formed in man under in vivo conditions. · A new alternative pathway from cholesterol to cholic acid was defined in the hepatocytes including 7alpha, 12alpha, 27-trihydroxy-4-cholesten-3 -one, 7alpha,12alpha-dihydroxy-3-oxo-4-cholestenoic acid and 7alpha,12alpha-dihydroxy-3oxo-5beta-cholanoic acid as intermediates. · The oxysterol 24S-hydroxycholesterol (formed in brain) was taken up by hepatocytes and partly metabolised into cholic acid, chenodeoxycholic acid and 5- cholestene-3beta,24S,27-triol. · 27-Hydroxycholesterol, the first product in the acidic pathway was found to be converted into bile acids less efficiently than 7alphahydroxycholesterol. Cheriodeoxycholic acid was found to be the major product. The findings suggest that the acidic pathway is responsible for a minor part of bile acid synthesis in human hepatocytes. · Glycine-conjugated and free bile acids suppressed bile acid synthesis and mRNA levels of cholesterol 7alpha-hydroxylase (CYP7A1) in the order CDCA > DCA > CA > UDCA. mRNA levels of sterol 12alpha-hydroxylase (CYP81B1) and especially sterol 27-hydroxylase (CYP27A1) were suppressed to a much lower degree than CYP7A1. · T3 dose-dependently decreased total bile acid formation in parallel with decreased expression of both CYP7A 1 and CYP8B 1. CA formation was inhibited to a higher degree than CDCA, resulting in a marked decrease in the CA / CDCA ratio. The results are in agreement with a number of previous in vivo studies in humans and emphasize that human hepatocytes cultured as above are suitable for studies on human bile acid formation.
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| 5. |
- Forkel, Marianne, et al.
(författare)
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Composition and functionality of the intrahepatic innate lymphoid cell-compartment in human nonfibrotic and fibrotic livers
- 2017
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 47:8, s. 1280-1294
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Tidskriftsartikel (refereegranskat)abstract
- Human innate lymphoid cells have been described to exist in different organs, with functional deregulation of these cells contributing to several disease states. Here, we performed the first detailed characterization of the phenotype, tissue-residency properties, and functionality of ILC1s, ILC2s, and ILC3s in the human adult and fetal liver. In addition, we investigated changes in the ILC compartment in liver fibrosis. A unique composition of tissue-resident ILCs was observed in nonfibrotic livers as compared with that in mucosal tissues, with NKp44− ILC3s accounting for the majority of total intrahepatic ILCs. The frequency of ILC2s, representing a small fraction of ILCs in nonfibrotic livers, increased in liver fibrosis and correlated directly with the severity of the disease. Notably, intrahepatic ILC2s secreted the profibrotic cytokine IL-13 when exposed to IL-33 and thymic stromal lymphopoetin (TSLP); these cytokines were produced by hepatocytes, hepatic stellate cells (HSCs), and Kupffer cells in response to TLR-3 stimulation. In summary, the present results provide the first detailed characterization of intrahepatic ILCs in human adult and fetal liver. The results indicate a role for ILC2s in human liver fibrosis, implying that targeting ILC2s might be a novel therapeutic strategy for its treatment.
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| 6. |
- Giannisis,, Andreas, et al.
(författare)
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Brain integrity is altered by hepatic APOEε4 in humanized-liver mice
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Liver-generated plasma apolipoprotein E (apoE) does not enter the brain but nonetheless correlates with Alzheimer’s disease (AD) risk and AD biomarker levels. Carriers of APOEε4, the strongest genetic AD risk factor, exhibit lower plasma apoE and altered brain integrity already at mid-life versus non-APOEε4 carriers. Whether altered plasma liver-derived apoE or specifically an APOEε4 liver phenotype promotes brain injury and neurodegeneration is unknown. Here we investigated the brains of Fah-/-, Rag2-/-, Il2rg-/- mice on the Non-Obese Diabetic (NOD) background (FRGN) with humanized-livers of an AD risk-associated APOE ε4/ε4 versus an APOE ε2/ε3 genotype. Reduced endogenous mouse apoE levels in the brains of APOE ε4/ε4 liver mice were accompanied by various changes in markers of synaptic integrity, neuroinflammation, and insulin signaling. Plasma apoE4 levels were associated with unfavorable changes in several of the assessed markers. These results propose a previously unexplored role of the liver in the APOEε4-associated risk neurodegenerative diseases.
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| 7. |
- Giannisis, Andreas, et al.
(författare)
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Brain integrity is altered by hepatic APOE ε4 in humanized-liver mice
- 2022
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Ingår i: Molecular Psychiatry. - : Springer Science and Business Media LLC. - 1359-4184 .- 1476-5578. ; 27:8, s. 3533-3543
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Tidskriftsartikel (refereegranskat)abstract
- Liver-generated plasma apolipoprotein E (apoE) does not enter the brain but nonetheless correlates with Alzheimer’s disease (AD) risk and AD biomarker levels. Carriers of APOEε4, the strongest genetic AD risk factor, exhibit lower plasma apoE and altered brain integrity already at mid-life versus non-APOEε4 carriers. Whether altered plasma liver-derived apoE or specifically an APOEε4 liver phenotype promotes neurodegeneration is unknown. Here we investigated the brains of Fah−/−, Rag2−/−, Il2rg−/− mice on the Non-Obese Diabetic (NOD) background (FRGN) with humanized-livers of an AD risk-associated APOE ε4/ε4 versus an APOE ε2/ε3 genotype. Reduced endogenous mouse apoE levels in the brains of APOE ε4/ε4 liver mice were accompanied by various changes in markers of synaptic integrity, neuroinflammation and insulin signaling. Plasma apoE4 levels were associated with unfavorable changes in several of the assessed markers. These results propose a previously unexplored role of the liver in the APOEε4-associated risk of neurodegenerative disease.
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| 8. |
- Gustafson, Elisabet
(författare)
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Thromboinflammation : in a Model of Hepatocyte Transplantation
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hepatocyte transplantation is an attractive method for the treatment of metabolic liver disease and acute liver failure. The clinical application of this method has been hampered by a large initial loss of transplanted cells.This thesis has identified and characterized an instant blood-mediated inflammatory reaction (IBMIR), which is a thromboinflammatory response from the innate immunity that may partly explain the observed loss of cells. In vitro perifusion experiments were performed and established that hepatocytes in contact with blood activate the complement and coagulation systems and induce clot formation in conjunction with the recruitment of neutrophils. Within an hour, the hepatocytes were surrounded by platelets and entrapped in a clot infiltrated by neutrophils. Furthermore, hepatocytes expressed tissue factor (TF), and the reactions were shown to be initiated through the TF pathway. Monitoring of hepatocyte transplantation in vivo revealed activation of the same parameters as were noted in vitro.For the first time, von Willebrand factor (vWF) was identified on the hepatocyte surface, being demonstrated by flow cytometry and confocal microscopy. mRNA for vWF was also confirmed in hepatocytes. Complex formation between platelets and hepatocytes was also identified. Addition of antibodies targeting the binding site for vWF on the platelets reduced the complex formation.Two different strategies, systemic and local intervention, were applied to diminish the thromboinflammation elicited from the hepatocytes in contact with ABO-matched blood. Systemic inhibition with LMW-DS, in a clinically applicable dose, was found to be superior in controlling the IBMIR in vitro when compared to heparin. Cryopreserved hepatocytes elicited the IBMIR to the same extent as did fresh hepatocytes, and the IBMIR was equally well controlled with LMW-DS in both cryopreserved and fresh cells.Hepatocytes were coated with two layers of immobilized heparin in an attempt to protect the cells from the IBMIR. In vitro perifusion experiments showed heparinized hepatocytes triggered a significantly lower degree of IBMIR.
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| 9. |
- Hildebrandt, Franziska, 1994-, et al.
(författare)
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Spatial Transcriptomics to define transcriptional patterns of zonation and structural components in the mouse liver
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Reconstruction of heterogeneity through single cell transcriptional profiling has greatly advanced our understanding of the spatial liver transcriptome in recent years. However, global transcriptional differences across lobular units remain elusive in physical space. Here, we apply Spatial Transcriptomics to perform transcriptomic analysis across sectioned liver tissue. We confirm that the heterogeneity in this complex tissue is predominantly determined by lobular zonation. By introducing novel computational approaches, we enable transcriptional gradient measurements between tissue structures, including several lobules in a variety of orientations. Further, our data suggests the presence of previously transcriptionally uncharacterized structures within liver tissue, contributing to the overall spatial heterogeneity of the organ. This study demonstrates how comprehensive spatial transcriptomic technologies can be used to delineate extensive spatial gene expression patterns in the liver, indicating its future impact for studies of liver function, development and regeneration as well as its potential in pre-clinical and clinical pathology. Global transcriptional differences across lobular units in the liver remain unknown. Here the authors perform spatial transcriptomics of liver tissue to delineate transcriptional differences in physical space, confirm lobular zonation along transcriptional gradients and suggest the presence of previously uncharacterized structures within liver tissue.
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| 10. |
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