| 1. |
- van Leeuwen, F., et al.
(författare)
-
Gaia Data Release 1 : Open cluster astrometry: Performance, limitations, and future prospects
- 2017
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601
-
Tidskriftsartikel (refereegranskat)abstract
- Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
|
|
| 2. |
- Molinaro, Angela, et al.
(författare)
-
Insulin-Driven PI3K-AKT Signaling in the Hepatocyte Is Mediated by Redundant PI3Kα and PI3Kβ Activities and Is Promoted by RAS.
- 2019
-
Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 29:6
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphatidylinositol-3-kinase (PI3K) activity is aberrant in tumors, and PI3K inhibitors are investigated as cancer therapeutics. PI3K signaling mediates insulin action in metabolism, but the role of PI3K isoforms in insulin signaling remains unresolved. Defining the role of PI3K isoforms in insulin signaling is necessary for a mechanistic understanding of insulin action and to develop PI3K inhibitors with optimal therapeutic index. We show that insulin-driven PI3K-AKT signaling depends on redundant PI3Kα and PI3Kβ activities, whereas PI3Kδ and PI3Kγ are largely dispensable. We have also found that RAS activity promotes AKT phosphorylation in insulin-stimulated hepatocytes and that promotion of insulin-driven AKT phosphorylation by RAS depends on PI3Kα. These findings reveal the detailed mechanism by which insulin activates AKT, providing an improved mechanistic understanding of insulin signaling. This improved model for insulin signaling predicts that isoform-selective PI3K inhibitors discriminating between PI3Kα and PI3Kβ should bedosed below their hyperglycemic threshold to achieve isoform selectivity.
|
|
| 3. |
- Al-Dury, Samer, et al.
(författare)
-
Propranolol-induced hallucinations mimicking encephalopathy in a patient with liver cirrhosis
- 2021
-
Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 56:7, s. 829-831
-
Tidskriftsartikel (refereegranskat)abstract
- Hepatic encephalopathy (HE) is a frequent complication of liver cirrhosis, which is mostly characterized by psychomotor slowing. However, psychotic symptoms such as visual and olfactory hallucinations may sometimes also be present. In contrast, auditory hallucinations are uncommon in chronic liver disease. In this case report, we present a patient with liver cirrhosis due to excessive alcohol consumption who presented to the emergency department with disorientation and signs of infection. Initial assessment led to the diagnosis acute on chronic liver failure exacerbated by infection leading to encephalopathy. The patient was admitted and successfully treated with antibiotics, Lactulose and Rifaximin. Gastroscopy showed varices without bleeding stigmata and Propranolol 20 mg was initiated as primary prophylaxis. Upon follow-up, the patient was clinically stable but had developed visual and auditory hallucinations which raised the suspicion that HE was not the cause. CT scan of the brain was unremarkable and the hallucinations were considered to be caused by Propranolol and disappeared shortly after switching to Carvedilol.
|
|
| 4. |
- Amadeo, Marcia, et al.
(författare)
-
Information-Centric Networking for the Internet of Things : Challenges and Opportunities
- 2016
-
Ingår i: IEEE Network. - 0890-8044 .- 1558-156X. ; 30:2, s. 92-100
-
Tidskriftsartikel (refereegranskat)abstract
- In view of evolving the Internet infrastructure, ICN is promoting a communication model that is fundamentally different from the traditional IP address-centric model. The ICN approach consists of the retrieval of content by (unique) names, regardless of origin server location (i.e., IP address), application, and distribution channel, thus enabling in-network caching/replication and content-based security. The expected benefits in terms of improved data dissemination efficiency and robustness in challenging communication scenarios indicate the high potential of ICN as an innovative networking paradigm in the IoT domain. IoT is a challenging environment, mainly due to the high number of heterogeneous and potentially constrained networked devices, and unique and heavy traffic patterns. The application of ICN principles in such a context opens new opportunities, while requiring careful design choices. This article critically discusses potential ways toward this goal by surveying the current literature after presenting several possible motivations for the introduction of ICN in the context of IoT. Major challenges and opportunities are also highlighted, serving as guidelines for progress beyond the state of the art in this timely and increasingly relevant topic.
|
|
| 5. |
- Bényei, Eszter, et al.
(författare)
-
The additional value of the combined use of EUS and ERCP for the evaluation of unclear biliary strictures
- 2024
-
Ingår i: Scandinavian Journal of Gastroenterology. - 0036-5521 .- 1502-7708.
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Assessing unclear biliary strictures is challenging. We analyzed the diagnostic performance of radiology, EUS, and ERCP. Methods: All patients referred for EUS and ERCP to assess an unclear biliary stricture were prospectively included. The data from radiology, EUS, ERCP, and tissue sampling were recorded. The diagnostic modalities were analyzed separately and in combination, with a focus on PSC. Results: Between 2013 and 2020, 78 patients were included; 31% had PSC. A cholangioscopy was not performed in this study. The final diagnosis indicated that the biliary stricture was benign in 62% of the patients and malignant in 38%. The differences among the modalities were numerical, not significant. The modalities showed an accuracy between 78 and 83% in all the patients and between 75 and 83% in the patients with PSC. The combination of radiology and EUS showed the highest sensitivity of 94% in all the patients and a sensitivity of 100% in PSC. Tissue sampling showed the highest specificity of 93% in all patients and 89% in PSC. In 22 cases with combined EUS, ERCP, and tissue sampling, the accuracy, sensitivity, and specificity were 82%, 70%, and 92%, respectively. Minor differences were observed between the intention-to-diagnose analysis and the per-protocol analysis. Adverse events were recorded in 4% of cases. Conclusion: The combination of EUS and ERCP with tissue sampling seems to be useful and safe for excluding malignancy in unclear biliary strictures. In cases with a reduced suspicion of malignancy, radiology with an EUS may be sufficient.
|
|
| 6. |
- Bernardi, Anna, et al.
(författare)
-
Multivalent glycoconjugates as anti-pathogenic agents
- 2013
-
Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 0306-0012 .- 1460-4744. ; 42:11, s. 4709-4727
-
Forskningsöversikt (refereegranskat)abstract
- Multivalency plays a major role in biological processes and particularly in the relationship between pathogenic microorganisms and their host that involves protein-glycan recognition. These interactions occur during the first steps of infection, for specific recognition between host and bacteria, but also at different stages of the immune response. The search for high-affinity ligands for studying such interactions involves the combination of carbohydrate head groups with different scaffolds and linkers generating multivalent glycocompounds with controlled spatial and topology parameters. By interfering with pathogen adhesion, such glycocompounds including glycopolymers, glycoclusters, glycodendrimers and glyconanoparticles have the potential to improve or replace antibiotic treatments that are now subverted by resistance. Multivalent glycoconjugates have also been used for stimulating the innate and adaptive immune systems, for example with carbohydrate-based vaccines. Bacteria present on their surfaces natural multivalent glycoconjugates such as lipopolysaccharides and S-layers that can also be exploited or targeted in anti-infectious strategies.
|
|
| 7. |
- Braadland, P. R., et al.
(författare)
-
Suppression of bile acid synthesis as a tipping point in the disease course of primary sclerosing cholangitis
- 2022
-
Ingår i: Jhep Reports. - : Elsevier BV. - 2589-5559. ; 4:11
-
Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Farnesoid X receptor (FXR) agonists and fibroblast growth factor 19 (FGF19) analogues suppress bile acid synthesis and are being investigated for their potential therapeutic efficacy in cholestatic liver diseases. We investigated whether bile acid synthesis associated with outcomes in 2 independent populations of people with primary sclerosing cholangitis (PSC) not receiving such therapy.Methods: Concentrations of individual bile acids and 7a-hydroxy-4-cholesten-3-one (C4) were measured in blood samples from 330 patients with PSC attending tertiary care hospitals in the discovery and validation cohorts and from 100 healthy donors. We used a predefined multivariable Cox proportional hazards model to evaluate the prognostic value of C4 to predict liver transplantation-free survival and evaluated its performance in the validation cohort. Results: The bile acid synthesis marker C4 was negatively associated with total bile acids. Patients with fully suppressed bile acid synthesis had strongly elevated total bile acids and short liver transplantation-free survival. In multivariable models, a 50% reduction in C4 corresponded to increased hazards for liver transplantation or death in both the discovery (adjusted hazard ratio [HR] = 1.24, 95% CI 1.06-1.43) and validation (adjusted HR = 1.23, 95% CI 1.03-1.47) cohorts. Adding C4 to established risk scores added value to predict future events, and predicted survival probabilities were well calibrated externally. There was no discernible impact of ursodeoxycholic acid treatment on bile acid synthesis.Conclusions: Bile acid accumulation-associated suppression of bile acid synthesis was apparent in patients with advanced PSC and associated with reduced transplantation-free survival. In a subset of the patients, bile acid synthesis was likely suppressed beyond a tipping point at which any further pharmacological suppression may be futile. Implications for patient stratification and inclusion criteria for clinical trials in PSC warrant further investigation.Lay summary: We show, by measuring the level of the metabolite C4 in the blood from patients with primary sclerosing cholangitis (PSC), that low production of bile acids in the liver predicts a more rapid progression to severe disease. Many people with PSC appear to have fully suppressed bile acid production, and both established and new drugs that aim to reduce bile acid production may therefore be futile for them. We propose C4 as a test to find those likely to respond to these treatments.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 8. |
- Burza, M. A., et al.
(författare)
-
The 35-year odyssey of beta blockers in cirrhosis: any gender difference in sight?
- 2017
-
Ingår i: Pharmacological Research. - : Elsevier BV. - 1043-6618. ; 119, s. 20-26
-
Tidskriftsartikel (refereegranskat)abstract
- Cirrhosis is the end-stage of chronic liver disease and leads to the development of portal hypertension and its complications such as esophagogastric varices. Non-selective beta blockers (NSBB) are the keystone for the treatment of portal hypertension since the 1980s and, over the decades, several studies have confirmed their beneficial effect on the prevention of variceal (re)bleeding. Pharmacological studies showed effects of gender, sex hormones, oral contraceptives, and pregnancy on cytochrome P450 (CYPs) enzymes that metabolise NSBB, suggesting that gender differences might exist in the effect of NSBB. In this review, we focused on the 35-year knowledge about the use of beta blockers in cirrhosis and potential gender differences. We specifically examined the role of NSBB in pre-primary, primary and secondary prophylaxis of variceal bleeding, compared two commonly used NSBB (i.e., Propranolol and Carvedilol), and present the current controversies about the window of treatment in advanced cirrhosis with a specific focus on gender differences in NSBB effects. NSBB are not currently recommended in pre-primary prophylaxis of varices mainly because of lack of proven efficacy. On the other hand, NSBB are strongly recommended in patient with cirrhosis as primary (as alternative to endoscopic band ligation, EBL) and secondary prophylaxis (in addition to EBL) of variceal bleeding. To date, no studies have focused specifically on the effect of gender on NSBB treatment Data extrapolated from clinical studies show that gender was neither a risk factor for the development of varices nor associated with a different response to treatment in primary or secondary prophylaxis. According to the available guidelines, no different, gender-based treatment for portal hypertension is recommended. (C) 2017 Elsevier Ltd. All rights reserved.
|
|
| 9. |
- Cammarota, G., et al.
(författare)
-
European consensus conference on faecal microbiota transplantation in clinical practice
- 2017
-
Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 66:4, s. 569-580
-
Tidskriftsartikel (refereegranskat)abstract
- Faecal microbiota transplantation (FMT) is an important therapeutic option for Clostridium difficile infection. Promising findings suggest that FMT may play a role also in the management of other disorders associated with the alteration of gut microbiota. Although the health community is assessing FMT with renewed interest and patients are becoming more aware, there are technical and logistical issues in establishing such a non-standardised treatment into the clinical practice with safety and proper governance. In view of this, an evidence-based recommendation is needed to drive the practical implementation of FMT. In this European Consensus Conference, 28 experts from 10 countries collaborated, in separate working groups and through an evidence-based process, to provide statements on the following key issues: FMT indications; donor selection; preparation of faecal material; clinical management and faecal delivery and basic requirements for implementing an FMT centre. Statements developed by each working group were evaluated and voted by all members, first through an electronic Delphi process, and then in a plenary consensus conference. The recommendations were released according to best available evidence, in order to act as guidance for physicians who plan to implement FMT, aiming at supporting the broad availability of the procedure, discussing other issues relevant to FMT and promoting future clinical research in the area of gut microbiota manipulation. This consensus report strongly recommends the implementation of FMT centres for the treatment of C. difficile infection as well as traces the guidelines of technicality, regulatory, administrative and laboratory requirements.
|
|
| 10. |
- Cornillet, Martin, et al.
(författare)
-
The Swedish initiative for the study of Primary sclerosing cholangitis (SUPRIM)
- 2024
-
Ingår i: eClinicalMedicine. - : ELSEVIER. - 2589-5370. ; 70
-
Tidskriftsartikel (refereegranskat)abstract
- Background Despite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well -characterised prospective resources is an important contributing factor to the current situation. Methods We here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10 -year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011-April 2016). Findings Out of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided. Interpretation We envision the SUPRIM cohort as an open -access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040. Funding This work was supported by the Swedish Cancer Society, Stockholm County Council, and the Cancer Research Funds of Radiumhemmet. Copyright (c) 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 11. |
- Cornillet, Martin, et al.
(författare)
-
The Swedish initiative for the study of Primary sclerosing cholangitis (SUPRIM)
- 2024
-
Ingår i: eClinicalMedicine. - : Elsevier. - 2589-5370. ; 70
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundDespite more than 50 years of research and parallel improvements in hepatology and oncology, there is still today neither a treatment to prevent disease progression in primary sclerosing cholangitis (PSC), nor reliable early diagnostic tools for the associated hepatobiliary cancers. Importantly, the limited understanding of the underlying biological mechanisms in PSC and its natural history not only affects the identification of new drug targets but implies a lack of surrogate markers that hampers the design of clinical trials and the evaluation of drug efficacy. The lack of easy access to large representative well-characterised prospective resources is an important contributing factor to the current situation.MethodsWe here present the SUPRIM cohort, a national multicentre prospective longitudinal study of unselected PSC patients capturing the representative diversity of PSC phenotypes. We describe the 10-year effort of inclusion and follow-up, an intermediate analysis report including original results, and the associated research resource. All included patients gave written informed consent (recruitment: November 2011–April 2016).FindingsOut of 512 included patients, 452 patients completed the five-year follow-up without endpoint outcomes. Liver transplantation was performed in 54 patients (10%) and hepatobiliary malignancy was diagnosed in 15 patients (3%). We draw a comprehensive landscape of the multidimensional clinical and biological heterogeneity of PSC illustrating the diversity of PSC phenotypes. Performances of available predictive scores are compared and perspectives on the continuation of the SUPRIM cohort are provided.InterpretationWe envision the SUPRIM cohort as an open-access collaborative resource to accelerate the generation of new knowledge and independent validations of promising ones with the aim to uncover reliable diagnostics, prognostic tools, surrogate markers, and new treatment targets by 2040.
|
|
| 12. |
|
|
| 13. |
- Ferri, F., et al.
(författare)
-
Donor small-droplet macrovesicular steatosis affects liver transplant outcome in HCV-negative recipients
- 2019
-
Ingår i: Canadian Journal of Gastroenterology. - : Hindawi Limited. - 0835-7900 .- 2291-2789 .- 2291-2797. ; 2019
-
Tidskriftsartikel (refereegranskat)abstract
- - Background. No data are available on liver transplantation (LT) outcome and donor liver steatosis, classified as large droplet macrovesicular (Ld-MaS), small-droplet macrovesicular (Sd-MaS), and true microvesicular (MiS), taking into account the recipient Hepatitis C virus (HCV) status. Aim. We investigate the impact of allograft steatosis reclassified according to the Brunt classification on early graft function and survival after LT. Methods. We retrospectively reviewed 204 consecutive preischemia biopsies of grafts transplanted in our center during the period 2001-2011 according to recipient HCV status. Results. The median follow-up after LT was 7.5 years (range: 0.0-16.7). In negative recipients (n=122), graft loss was independently associated with graft Sd-MaS, in multivariable Cox regression models comprehending only pre-/intraoperative variables (HR=1.03, 95%CI=1.01-1.05; P=0.003) and when including indexes of early postoperative graft function (HR=1.04, 95%CI=1.02-1.06; P=0.001). Graft Sd-MaS>15% showed a risk for graft loss > 2.5-folds in both the models. Graft Sd-MaS>15% was associated with reduced graft ATP content and, only in HCV-recipients, with higher early post-LT serum AST peaks. Conclusions. In HCV-negative recipients, allografts with >15% Sd-MaS have significantly reduced graft survival and show low ATP and higher AST peaks in the immediate posttransplant period. Donors with >15% Sd-MaS have significantly higher BMI, longer ICU stays, and lower PaO2. © 2019 Flaminia Ferri et al.
|
|
| 14. |
- Ferri, F., et al.
(författare)
-
The Propensity of the Human Liver to Form Large Lipid Droplets Is Associated with PNPLA3 Polymorphism, Reduced INSIG1 and NPC1L1 Expression and Increased Fibrogenetic Capacity
- 2021
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:11
-
Tidskriftsartikel (refereegranskat)abstract
- In nonalcoholic steatohepatitis animal models, an increased lipid droplet size in hepatocytes is associated with fibrogenesis. Hepatocytes with large droplet (Ld-MaS) or small droplet (Sd-MaS) macrovesicular steatosis may coexist in the human liver, but the factors associated with the predominance of one type over the other, including hepatic fibrogenic capacity, are unknown. In pre-ischemic liver biopsies from 225 consecutive liver transplant donors, we retrospectively counted hepatocytes with Ld-MaS and Sd-MaS and defined the predominant type of steatosis as involving >= 50% of steatotic hepatocytes. We analyzed a donor Patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 polymorphism, hepatic expression of proteins involved in lipid metabolism by RT-PCR, hepatic stellate cell (HSC) activation by alpha-SMA immunohistochemistry and, one year after transplantation, histological progression of fibrosis due to Hepatitis C Virus (HCV) recurrence. Seventy-four livers had no steatosis, and there were 98 and 53 with predominant Ld-MaS and Sd-MaS, respectively. In linear regression models, adjusted for many donor variables, the percentage of steatotic hepatocytes affected by Ld-MaS was inversely associated with hepatic expression of Insulin Induced Gene 1 (INSIG-1) and Niemann-Pick C1-Like 1 gene (NPC1L1) and directly with donor PNPLA3 variant M, HSC activation and progression of post-transplant fibrosis. In humans, Ld-MaS formation by hepatocytes is associated with abnormal PNPLA3-mediated lipolysis, downregulation of both the intracellular cholesterol sensor and cholesterol reabsorption from bile and increased hepatic fibrogenesis.
|
|
| 15. |
- Jaeger, Julius W., et al.
(författare)
-
Microbiota modulation by dietary oat beta-glucan prevents steatotic liver disease progression
- 2024
-
Ingår i: JHEP Reports. - 2589-5559. ; 6:3
-
Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Changes in gut microbiota in metabolic dysfunction-associated steatotic liver disease (MASLD) are important drivers of disease progression towards fibrosis. Therefore, reversing microbial alterations could ameliorate MASLD progression. Oat beta-glucan, a non-digestible polysaccharide, has shown promising therapeutic effects on hyperlipidemia associated with MASLD, but its impact on gut microbiota and most importantly MASLD-related fibrosis remains unknown. Methods: We performed detailed metabolic phenotyping, including assessments of body composition, glucose tolerance, and lipid metabolism, as well as comprehensive characterization of the gut-liver axis in a western-style diet (WSD)-induced model of MASLD and assessed the effect of a beta-glucan intervention on early and advanced liver disease. Gut microbiota were modulated using broad-spectrum antibiotic treatment. Results: Oat beta-glucan supplementation did not affect WSD-induced body weight gain or glucose intolerance and the metabolic phenotype remained largely unaffected. Interestingly, oat beta-glucan dampened MASLD-related inflammation, which was associated with significantly reduced monocyte-derived macrophage infiltration and fibroinflammatory gene expression, as well as strongly reduced fibrosis development. Mechanistically, this protective effect was not mediated by changes in bile acid composition or signaling, but was dependent on gut microbiota and was lost upon broad-spectrum antibiotic treatment. Specifically, oat beta-glucan partially reversed unfavorable changes in gut microbiota, resulting in an expansion of protective taxa, including Ruminococcus, and Lactobacillus followed by reduced translocation of Toll-like receptor ligands. Conclusions: Our findings identify oat beta-glucan as a highly efficacious food supplement that dampens inflammation and fibrosis development in diet-induced MASLD. These results, along with its favorable dietary profile, suggest that it may be a cost-effective and well-tolerated approach to preventing MASLD progression and should be assessed in clinical studies. Impact and Implications: Herein, we investigated the effect of oat beta-glucan on the gut-liver axis and fibrosis development in a mouse model of metabolic dysfunction-associated steatotic liver disease (MASLD). Beta-glucan significantly reduced inflammation and fibrosis in the liver, which was associated with favorable shifts in gut microbiota that protected against bacterial translocation and activation of fibroinflammatory pathways. Together, oat beta-glucan may be a cost-effective and well-tolerated approach to prevent MASLD progression and should be assessed in clinical studies.
|
|
| 16. |
- Jonsson, Hanna, 1979-
(författare)
-
Exploring the structure of oligo- and polysaccharides : Synthesis and NMR spectroscopy studies
- 2010
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A deeper understanding of the diversity of carbohydrates and the many applications of oligo- and polysaccharides found in nature are of high interest. Many of the processes involving carbohydrates affect our everyday life. This thesis is based on six papers all contributing to an extended perspective of carbohydrate property and functionality. An introduction to carbohydrate chemistry together with a presentation of selected carbohydrate synthesis and analysis methods introduces the reader to the research field. The first paper is an NMR spectroscopy reinvestigation of the structures of the O-antigens from the lipopolysaccharides (LPS) of Shigella dysenteriae type 3 and Escherichia coli O124. The repeating units were concluded to be built of identical branched pentasaccharides now with the correct anomeric configurations. Paper II is a structural investigation of the O-antigen from the LPS of E. coli O74 which is built of branched tetrasaccharide repeating units including the uncommon monosaccharide d-Fuc3NAc. Paper III is a conformational study of a rhamnose derivative, using NMR spectroscopy and X-ray crystallography. The benzoyl ester group positioned at C4 prefers an “eclipsed” conformation in the crystal as well as in solution. The use of site-specifically 13C-labeled compounds in conformational studies is discussed in Papers IV and V. The disaccharide α-L-Rhap-(1→2)-α-L-Rhap-OMe was synthesized together with two 13C-isotopologues and studied with NMR spectroscopy to give seven J-couplings related to torsion angles φ and ψ. The trisaccharide α-L-Rhap-(1→2)[α-L-Rhap-(1→3)]-α-L-Rhap-OMe was synthesized with 13C-labeling at two positions which presented a solution to a problem of overlapping signals in the 1H NMR spectrum. The site-specific labeling also facilitated the measurement of two 3JCC and two 2JCH coupling constants. Finally, chapter 6 gives a short introduction to glycosynthase chemistry and discusses the synthesis of α-glycosyl fluorides. A novel cyclic heptasaccharide was synthesized from α-laminariheptaosyl fluoride using a mutant of the enzyme laminarase 16A and subsequently analyzed by NMR spectroscopy.
|
|
| 17. |
- Koh, Ara, et al.
(författare)
-
Microbial Imidazole Propionate Affects Responses to Metformin through p38 gamma-Dependent Inhibitory AMPK Phosphorylation
- 2020
-
Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131. ; 32:4
-
Tidskriftsartikel (refereegranskat)abstract
- Metformin is the first-line therapy for type 2 diabetes, but there are large inter-individual variations in responses to this drug. Its mechanism of action is not fully understood, but activation of AMP-activated protein kinase (AMPK) and changes in the gut microbiota appear to be important. The inhibitory role of microbial metabolites on metformin action has not previously been investigated. Here, we show that concentrations of the microbial metabolite imidazole propionate are higher in subjects with type 2 diabetes taking metformin who have high blood glucose. We also show that metformin-induced glucose lowering is not observed in mice pretreated with imidazole propionate. Furthermore, we demonstrate that imidazole propionate inhibits AMPK activity by inducing inhibitory AMPK phosphorylation, which is dependent on imidazole propionate-induced basal Akt activation. Finally, we identify imidazole propionate-activated p38 gamma as a novel kinase for Akt and demonstrate that p38 gamma kinase activity mediates the inhibitory action of imidazole propionate on metformin.
|
|
| 18. |
- Koh, Ara, et al.
(författare)
-
Microbially Produced Imidazole Propionate Impairs Insulin Signaling through mTORC1
- 2018
-
Ingår i: Cell. - : Elsevier BV. - 0092-8674. ; 175:4
-
Tidskriftsartikel (refereegranskat)abstract
- Interactions between the gut microbiota, diet, and the host potentially contribute to the development of metabolic diseases. Here, we identify imidazole propionate as a microbially produced histidine-derived metabolite that is present at higher concentrations in subjects with versus without type 2 diabetes. We show that imidazole propionate is produced from histidine in a gut simulator at higher concentrations when using fecal microbiota from subjects with versus without type 2 diabetes and that it impairs glucose tolerance when administered to mice. We further show that imidazole propionate impairs insulin signaling at the level of insulin receptor substrate through the activation of p38 gamma MAPK, which promotes p62 phosphorylation and, subsequently, activation of mechanistic target of rapamycin complex 1 (mTORC1). We also demonstrate increased activation of p62 and mTORC1 in liver from subjects with type 2 diabetes. Our findings indicate that the microbial metabolite imidazole propionate may contribute to the pathogenesis of type 2 diabetes.
|
|
| 19. |
- Koopman, N., et al.
(författare)
-
Review article: can bugs be drugs? The potential of probiotics and prebiotics as treatment for non-alcoholic fatty liver disease
- 2019
-
Ingår i: Alimentary Pharmacology & Therapeutics. - : Wiley. - 0269-2813. ; 50:6, s. 628-639
-
Forskningsöversikt (refereegranskat)abstract
- Background Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver condition. A major current research effort is ongoing to find potential strategies to treat NAFLD-non-alcoholic steatohepatitis (NASH), with special attention to the gut microbiota. Multiple animal studies and pilot clinical trials are assessing different gut microbiota modulating strategies such as faecal microbiota transplantation, antibiotics, probiotics, prebiotics and synbiotics. Aim To review the role of microbiota in NAFLD-NASH and determine whether pro- and prebiotics have potential as treatment Methods Information was obtained from critically reviewing literature on PubMed on targeting the gut microbiota in NAFLD. Search terms included NAFLD, NASH, non-alcoholic fatty liver disease, steatohepatitis; combined with microbiome, microbiota, gut bacteria, probiotics and prebiotics. Results Animal studies and the first emerging studies in humans show promising results for both the common probiotics Lactobacillus, Bifidobacterium and Streptococci as for short chain fatty acid (SCFA) butyrate-producing bacteria. Also, prebiotics have positive effects on different mechanisms underlying NAFLD-NASH. Conclusions The most promising strategies thus far developed to alter the microbiome in NAFLD-NASH are probiotics and prebiotics. However, pre- and probiotic treatment of NAFLD-NASH is relatively new and still under development. Actual understanding of the involved mechanisms is lacking and changes in the intestinal microbiota composition after treatment are rarely measured. Furthermore, large clinical trials with comparative endpoints are unavailable. Personalised treatment based on metagenomics gut microbiota analysis will probably be part of the future diagnosis and treatment of NAFLD-NASH.
|
|
| 20. |
- Mancina, Rosellina Margherita, et al.
(författare)
-
A two gene-based risk score predicts alcoholic cirrhosis development in males with at-risk alcohol consumption
- 2019
-
Ingår i: Application of Clinical Genetics. - 1178-704X. ; 12, s. 1-10
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Alcoholic cirrhosis represents 1% of all cause-of-deaths worldwide. Its incidence is higher in males and results from the combination of environmental and genetic factors. Among all the genetic determinants of alcoholic cirrhosis, the patatin-like phospholipase domain protein 3 (PNPLA3) rs738409 represents the most widely validated determinant. Recent cross-sectional studies on alcohol abusers identified transmembrane-6 superfamily member 2 (TM6SF2) rs58542926, membrane bound O-acyltransferase domain containing 7 (MBOAT7) rs641738, and cluster of differentiation 14 (CD14) rs2569190 as new genetic risk factors for alcoholic cirrhosis. We aimed to develop a gene-based risk score to predict the incidence of alcoholic cirrhosis in males with at-risk alcohol consumption. Materials and methods: A total of 416 male at-risk alcohol drinkers were retrospectively examined. The association between alcoholic cirrhosis incidence and PNPLA3, CD14, TM6SF2, and MBOAT7 variants was tested. Age at onset of at-risk alcohol consumption, age, and body mass index (BMI) were included as covariates to determine the prediction score for alcoholic cirrhosis incidence by evaluating time-dependent receiver operating characteristic curves. Results: We found that PNPLA3, CD14, and TM6SF2 were associated with alcoholic cirrhosis prevalence. PNPLA3 and CD14 were also associated with its incidence. The best predictive score formula was (age at onset of at-risk alcohol consumption x 0.1) + (number of CD14 allele T) + (number of PNPLA3 allele M) + (BMI x 0.1). A threshold of 7.27 was identified as cutoff for the predictive risk of alcoholic cirrhosis development in 36 years from the onset of at-risk alcohol consumption with 70.1% sensitivity and 78.7% specificity. Conclusion: We developed the first score for alcoholic cirrhosis prediction that combines clinical and genetic factors.
|
|
| 21. |
- Marschall, Hanns-Ulrich, 1954, et al.
(författare)
-
Why Doesn't Primary Biliary Cholangitis Respond to Immunosuppressive Medications?
- 2017
-
Ingår i: Current hepatology reports. - : Springer Science and Business Media LLC. - 2195-9595. ; 16:2, s. 119-123
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this review is to discuss reasons why immunosuppressive therapy so far failed in Primary Biliry Cholangitis.Even targeted immunosuppressive therapy seems ineffective or potentially harmful.Bile acid-mediated cholangiocyte damage, facilitated by insufficient bicarbonate secretion, seems to attenuate the anti-inflammatory and anti-fibrotic actions of immunosuppressant and immunomodulatory drugs in a clinically significant way.
|
|
| 22. |
- Molinaro, Antonio, et al.
(författare)
-
Bile acid metabolism and FXR-mediated effects in human cholestatic liver disorders
- 2022
-
Ingår i: Biochemical Society Transactions. - : Portland Press Ltd.. - 0300-5127 .- 1470-8752. ; 50:1, s. 361-373
-
Tidskriftsartikel (refereegranskat)abstract
- Intrahepatic cholestasis is the main feature of a group of liver diseases that are characterized by hepatic and systemic accumulation of bile acids due to impaired excretion of bile, based on inflammation of intrahepatic and extrahepatic bile ducts or dysfunction of hepatobiliary transport proteins. The nuclear bile acid sensor farnesoid X receptor (FXR) is central for the regulation of bile acid turnover, including synthesis, hepatic excretion and intestinal and hepatic uptake. Several drugs targeting FXR have been developed for the treatment of cholestatic liver diseases, and so far one of them has been granted conditional approval. In this review, we will discuss the current knowledge and the clinical and experimental data available on agents affecting FXR and bile acid turnover.
|
|
| 23. |
|
|
| 24. |
- Molinaro, Antonio, et al.
(författare)
-
Host–microbiota interaction induces bi-phasic inflammation and glucose intolerance in mice
- 2017
-
Ingår i: Molecular Metabolism. - : Elsevier BV. - 2212-8778. ; 6:11, s. 1371-1380
-
Tidskriftsartikel (refereegranskat)abstract
- Objective Gut microbiota modulates adiposity and glucose metabolism in humans and mice. Here we investigated how colonization of germ-free (GF) mice affects kinetics of adiposity and glucose metabolism. Methods Adiposity and glucose metabolism were evaluated at different time points in ex-GF and antibiotic treated mice after colonization with gut microbiota from a conventionally raised (CONV-R) mouse. Mouse physiology, microbiome configuration, serum cytokine levels, and gene expression for inflammatory markers were performed in different tissues. Results Colonization resulted in a bi-phasic glucose impairment: the first phase occurring within 3 days of colonization (early phase) and the second 14–28 days after colonization (delayed phase). The early phase co-occurred with an inflammatory response and was independent of adiposity, while the delayed phase was mostly ascribed to adipose tissue expansion and inflammation. Importantly, re-colonization of antibiotic treated mice displays only the delayed phase of glucose impairment and adiposity, suggesting that the early phase may be unique to colonization of the immature GF mice gut. Conclusions Our results provide new insights on host–microbiota interaction during colonization of GF mice and the resulting effects on adiposity and glucose metabolism in a time resolved fashion. © 2017 The Authors
|
|
| 25. |
- Molinaro, Antonio, et al.
(författare)
-
Imidazole propionate is increased in diabetes and associated with dietary patterns and altered microbial ecology
- 2020
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Microbiota-host-diet interactions contribute to the development of metabolic diseases. Imidazole propionate is a novel microbially produced metabolite from histidine, which impairs glucose metabolism. Here, we show that subjects with prediabetes and diabetes in the MetaCardis cohort from three European countries have elevated serum imidazole propionate levels. Furthermore, imidazole propionate levels were increased in subjects with low bacterial gene richness and Bacteroides 2 enterotype, which have previously been associated with obesity. The Bacteroides 2 enterotype was also associated with increased abundance of the genes involved in imidazole propionate biosynthesis from dietary histidine. Since patients and controls did not differ in their histidine dietary intake, the elevated levels of imidazole propionate in type 2 diabetes likely reflects altered microbial metabolism of histidine, rather than histidine intake per se. Thus the microbiota may contribute to type 2 diabetes by generating imidazole propionate that can modulate host inflammation and metabolism.
|
|
| 26. |
- Molinaro, Antonio, et al.
(författare)
-
Liver-specific RORα deletion does not affect the metabolic susceptibility to western style diet feeding.
- 2019
-
Ingår i: Molecular metabolism. - : Elsevier BV. - 2212-8778. ; 23, s. 82-87
-
Tidskriftsartikel (refereegranskat)abstract
- The nuclear receptor superfamily is a potential target for the development of new treatments for obesity and metabolic diseases. Increasing evidence has pointed towards the retinoic acid-related orphan receptor-alpha (RORα) as an important nuclear receptor involved in several biological processes. RORα full body knockout mice display improved metabolic phenotypes on both chow and high fat (60% fat, 20% carbohydrate) diets, but also have severe behavioral abnormalities. Here we investigated the effect of hepatic RORα by generating mice with liver-specific RORα deletion to elucidate the role of this nuclear receptor on host metabolism.8 week-old mice with liver-specific RORα deletion and littermate controls were fed either chow or western-style diets (40% fat, 40% carbohydrate) for 12 weeks. Metabolic phenotyping was performed at the end of the dietary intervention.Here, we show that hepatic RORα deletion does not affect the metabolic susceptibility to either chow or western-style diet in terms of glucose metabolism and adiposity.Our data indicate that liver deletion of RORα does not have a pivotal role in the regulation of hepatic glucose and lipid metabolism on chow or western-style diet.
|
|
| 27. |
- Molinaro, Antonio
(författare)
-
Microbial modulation of metabolic diseases
- 2018
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The gut microbiota, the ensemble of microorganisms living in the gastrointestinal tract, and the host have a mutualist relationship. Alterations of this delicate equilibrium can lead to changes in microbiota composition and/or function leading to the onset of metabolic diseases (e.g., type 2 diabetes and non-alcoholic fatty liver diseases). The current knowledge of host-microbiota interaction, in health and disease, is limited. Here, by using a translational science approach, we were able to identify some of the mechanisms underlying the influence of the microbiota on impaired glucose and lipid metabolism. Specifically: In Paper I, I explored the microbiota-host interaction and its effect on glucose metabolism. Particularly, by performing colonization of germ-free mice, I studied the effect on glucose metabolism over time. I investigated the different molecular mechanisms underlying the impaired metabolic profile induced by the colonization over time. These findings provide fundamental information on how to conduct studies on microbiota and metabolic diseases. In Paper II, I identified a novel microbially-produced molecule, imidazole propionate, which is increased in the portal vein of subjects with type 2 diabetes. I demonstrated causality of this molecule in impaired glucose metabolism by administering it in both in-vivo and in-vitro models. Moreover, I identified molecular targets of imidazole propionate in the insulin signaling cascade, specifically on the insulin receptor substrate proteins, and showed that this effect is mediated by activation of the mTOR complex. In Paper III, I investigated whether the gut microbiota composition and function is altered in subjects with non-alcoholic fatty liver disease. In presence of steatosis, I observed a shift in microbiota composition characterized by increased abundance of bacteria from the oral cavity, ethanol-producing bacteria, and a reduction in butyrate producing bacteria. On a functional level, I observed an enrichment in functions related to metabolic functions and production of lipopolysaccharides in subjects with steatosis. In conclusion, these findings show that the microbiota is an environmental factor that modulates metabolic diseases. Understanding the mechanisms underlying microbial impacts on host metabolism will aid in discovery of novel targets for the treatment of metabolic diseases in humans.
|
|
| 28. |
- Molinaro, Antonio, et al.
(författare)
-
Microbially Produced Imidazole Propionate Is Associated With Heart Failure and Mortality
- 2023
-
Ingår i: JACC: Heart Failure. - 2213-1779 .- 2213-1787. ; 11:7, s. 810-821
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Over the past years, it has become clear that the microbial ecosystem in the gut has a profound capacity to interact with the host through the production of a wide range of bioactive metabolites. The microbially produced metabolite imidazole propionate (ImP) is clinically and mechanistically linked with insulin resistance and type 2 diabetes, but it is unclear how ImP is associated with heart failure. Objectives: The authors aimed to explore whether ImP is associated with heart failure and mortality. Methods: ImP serum measurements in 2 large and independent clinical cohorts of patients (European [n = 1,985] and North American [n = 2,155]) with a range of severity of cardiovascular disease including heart failure. Univariate and multivariate Cox regression analyses were performed to delineate the impact of ImP on 5-year mortality in the North American cohort, independent of other covariates. Results: ImP is independently associated with reduced ejection fraction and heart failure in both cohorts, even after adjusting for traditional risk factors. Elevated ImP was a significant independent predictor of 5-year mortality (for the highest quartile, adjusted HR: 1.85 [95% CI: 1.20-2.88]; P < 0.01). Conclusions: The gut microbial metabolite ImP is increased in individuals with heart failure and is a predictor of overall survival.
|
|
| 29. |
- Molinaro, Antonio, et al.
(författare)
-
Role of Bile Acids in Metabolic Control.
- 2018
-
Ingår i: Trends in endocrinology and metabolism: TEM. - : Elsevier BV. - 1879-3061 .- 1043-2760. ; 29:1, s. 31-41
-
Tidskriftsartikel (refereegranskat)abstract
- Bile acids are endocrine molecules that in addition to facilitating the absorption of fat-soluble nutrients regulate numerous metabolic processes, including glucose, lipid, and energy homeostasis. The signaling actions of bile acids are mediated through specific bile-acid-activated nuclear and membrane-bound receptors. These receptors are not only expressed by tissues within the enterohepatic circulation such as the liver and the intestine, but also in other organs where bile acids mediate their systemic actions. In this review, we discuss bile acid signaling and the interplay with the gut microbiota in the pathophysiology of obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and the role of surgical and pharmacological interventions on bile acid profiles and metabolism.
|
|
| 30. |
- Norén, Åsa, et al.
(författare)
-
Liver Graft Proteomics Reveals Potential Incipient Mechanisms behind Early Renal Dysfunction after Liver Transplantation
- 2022
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 23:19
-
Tidskriftsartikel (refereegranskat)abstract
- Acute kidney injury (AKI) is frequent after liver transplantation (LT) and correlates with later development of chronic kidney disease. Its etiology is multifactorial and combines pre-, intra-, and postoperative factors. Additionally, the liver graft itself seems an important element in the development of AKI, yet the detailed mechanisms remain unclear. We hypothesized that grafts of LT recipients developing significant early AKI may show distinct proteomic alterations, and we set out to identify proteome differences between LT recipients developing moderate or severe AKI (n = 7) and LT recipients without early renal injury (n = 7). Liver biopsies obtained one hour after reperfusion were assessed histologically and using quantitative proteomics. Several cytokines and serum amyloid A2 (SAA2) were analyzed in serum samples obtained preoperatively, 2-4 h, and 20-24 h after graft reperfusion, respectively. LT induced mild histological alterations without significant differences between groups but uniformly altered liver function tests peaking on postoperative day 1, with a trend towards more severe alterations in patients developing AKI. Global quantitative proteomic analysis revealed 136 proteins differing significantly in their expression levels (p < 0.05, FC 20%): 80 proteins had higher and 56 had lower levels in the AKI group. Most of these proteins were related to immune and inflammatory responses, host defense, and neutrophil degranulation. No differences between the studied pro- and anti-inflammatory cytokines or SAA2 between groups were found at any moment. Our results suggest that grafts of LT patients who develop early AKI reveal a distinct proteome dominated by an early yet prominent activation of the innate immunity. These findings support the hypothesis that AKI after LT may be favored by certain graft characteristics.
|
|
| 31. |
- Oldfors Hedberg, Carola, 1969, et al.
(författare)
-
Ribonuclease inhibitor 1 (RNH1) deficiency cause congenital cataracts and global developmental delay with infection-induced psychomotor regression and anemia
- 2023
-
Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438.
-
Tidskriftsartikel (refereegranskat)abstract
- Ribonuclease inhibitor 1, also known as angiogenin inhibitor 1, encoded by RNH1, is a ubiquitously expressed leucine-rich repeat protein, which is highly conserved in mammalian species. Inactivation of rnh1 in mice causes an embryonically lethal anemia, but the exact biological function of RNH1 in humans remains unknown and no human genetic disease has so far been associated with RNH1. Here, we describe a family with two out of seven siblings affected by a disease characterized by congenital cataract, global developmental delay, myopathy and psychomotor deterioration, seizures and periodic anemia associated with upper respiratory tract infections. A homozygous splice-site variant (c.615-2A > C) in RNH1 segregated with the disease. Sequencing of RNA derived from patient fibroblasts and cDNA analysis of skeletal muscle mRNA showed aberrant splicing with skipping of exon 7. Western blot analysis revealed a total lack of the RNH1 protein. Functional analysis revealed that patient fibroblasts were more sensitive to RNase A exposure, and this phenotype was reversed by transduction with a lentivirus expressing RNH1 to complement patient cells. Our results demonstrate that loss-of-function of RNH1 in humans is associated with a multiorgan developmental disease with recessive inheritance. It may be speculated that the infection-induced deterioration resulted from an increased susceptibility toward extracellular RNases and/or other inflammatory responses normally kept in place by the RNase inhibitor RNH1.
|
|
| 32. |
- Oltean, Mihai, 1976, et al.
(författare)
-
The proteomic signature of intestinal acute rejection in the mouse
- 2022
-
Ingår i: Metabolites. - : MDPI AG. - 2218-1989. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Intestinal acute rejection (AR) lacks a reliable non-invasive biomarker and AR surveillance is conducted through frequent endoscopic biopsies. Although citrulline and calprotectin have been suggested as AR biomarkers, these have limited clinical value. Using a mouse model of intestinal transplantation (ITx), we performed a proteome-wide analysis and investigated rejection-related proteome changes that may eventually be used as biomarkers. ITx was performed in allogenic (Balb/C to C57Bl) and syngeneic (C57Bl) combinations. Graft samples were obtained three and six days after transplantation (n = 4/time point) and quantitative proteomic analysis with iTRAQ-labeling and mass spectrometry of whole tissue homogenates was performed. Histology showed moderate AR in all allografts post-transplantation at day six. Nine hundred and thirty-eight proteins with at least three unique peptides were identified in the intestinal grafts. Eighty-six proteins varying by >20% between time points and/or groups had an alteration pattern unique to the rejecting allografts: thirty-seven proteins and enzymes (including S100-A8 and IDO-1) were significantly upregulated whereas forty-nine (among other chromogranin, ornithine aminotransferase, and arginase) were downregulated. Numerous proteins showed altered expression during intestinal AR, several of which were previously identified to be involved in acute rejection, although our results also identified previously unreported proteome changes. The metabolites and downstream metabolic pathways of some of these proteins and enzymes may become potential biomarkers for intestinal AR.
|
|
| 33. |
- Parseus, Ava, et al.
(författare)
-
Microbiota-induced obesity requires farnesoid X receptor
- 2017
-
Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 66:3, s. 429-437
-
Tidskriftsartikel (refereegranskat)abstract
- Objective The gut microbiota has been implicated as an environmental factor that modulates obesity, and recent evidence suggests that microbiota-mediated changes in bile acid profiles and signalling through the bile acid nuclear receptor farnesoid X receptor (FXR) contribute to impaired host metabolism. Here we investigated if the gut microbiota modulates obesity and associated phenotypes through FXR. Design We fed germ-free (GF) and conventionally raised (CONV-R) wild-type and Fxr(-/-) mice a high-fat diet (HFD) for 10 weeks. We monitored weight gain and glucose metabolism and analysed the gut microbiota and bile acid composition, beta-cell mass, accumulation of macrophages in adipose tissue, liver steatosis, and expression of target genes in adipose tissue and liver. We also transferred the microbiota of wild-type and Fxr(-) deficient mice to GF wild-type mice. Results The gut microbiota promoted weight gain and hepatic steatosis in an FXR-dependent manner, and the bile acid profiles and composition of faecal microbiota differed between Fxr(-/-) and wild-type mice. The obese phenotype in colonised wild-type mice was associated with increased beta-cell mass, increased adipose inflammation, increased steatosis and expression of genes involved in lipid uptake. By transferring the caecal microbiota from HFD-fed Fxr(-/-) and wild-type mice into GF mice, we showed that the obesity phenotype was transferable. Conclusions Our results indicate that the gut microbiota promotes diet-induced obesity and associated phenotypes through FXR, and that FXR may contribute to increased adiposity by altering the microbiota composition.
|
|
| 34. |
- Salameh, H., et al.
(författare)
-
PNPLA3 Gene Polymorphism Is Associated With Predisposition to and Severity of Alcoholic Liver Disease
- 2015
-
Ingår i: American Journal of Gastroenterology. - : Ovid Technologies (Wolters Kluwer Health). - 0002-9270. ; 110:6, s. 846-856
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The genetic polymorphism with an isoleucine-to-methionine substitution at position 148 (rs738409 C>G) in the patatin-like phospholipase domain protein 3 (PNPLA3) gene confers risk of steatosis. PNPLA3 polymorphism is shown to be associated with alcoholic liver disease (ALD). We performed a systematic review and meta-analysis to examine association of this genetic polymorphism with ALD spectrum and its severity. METHODS: Medline, Embase, and Cochrane Library were searched for studies on association of PNPLA3 polymorphism and ALD spectrum: alcoholic fatty liver (AFL), alcoholic liver injury (ALI), alcoholic cirrhosis (AC), and hepatocellular carcinoma (HCC). Pooled data are reported as odds ratio (OR) with 95% confidence interval. Heterogeneity was assessed using the I 2 statistics and publication bias using Egger's test and Begg and Mazumdar's test. Individual participant data obtained from five studies were used for subgroup analyses. RESULTS: Among 10 studies included in this pooled analysis, compared with controls, OR for rs738409 CG and GG among ALI patients was 1.45 (1.24-1.69) and 2.22 (1.50-3.28), respectively, compared with CC. Respective OR among AC patients was 2.09 (1.79-2.44) and 3.37 (2.49-4.58) and among AC patients with HCC was 2.87 (1.61-5.10) and 12.41 (6.99-22.03). Data for AFL were inconsistent. Among ALD patients, OR of CG and GG genotypes was 2.62 (1.73-3.97) and 8.45 (2.52-28.37), respectively, for AC compared with fatty liver (FL) patients. Similar OR for AC compared with ALI was 1.98 (1.24-3.17) and 3.86 (1.18-12.60). The OR for CG and GG genotypes among AC patients for HCC occurrence was 1.43 (0.76-2.72) and 2.81 (1.57-5.01), respectively. Individual participant data analysis showed age to predispose to AC among ALI patients. CONCLUSIONS: PNPLA3 genetic polymorphism (rs738409 C>G) is associated with increased risk for the entire spectrum of ALD among drinkers including ALI, AC, and HCC. Studies are needed to clarify association of PNPLA3 polymorphism and steatosis in alcoholics. PNPLA3 gene may potentially be a therapeutic target in ALD.
|
|
| 35. |
- Schneider, K. M., et al.
(författare)
-
Gut microbiota depletion exacerbates cholestatic liver injury via loss of FXR signalling
- 2021
-
Ingår i: Nature Metabolism. - : Springer Science and Business Media LLC. - 2522-5812. ; 3:9, s. 1228-1241
-
Tidskriftsartikel (refereegranskat)abstract
- Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease of unknown aetiology for which there are no approved therapeutic options. Patients with PSC display changes in gut microbiota and in bile acid (BA) composition; however, the contribution of these alterations to disease pathogenesis remains controversial. Here we identify a role for microbiota-dependent changes in BA synthesis that modulates PSC pathophysiology. In a genetic mouse model of PSC, we show that loss of microbiota-mediated negative feedback control of BA synthesis results in increased hepatic BA concentrations, disruption of bile duct barrier function and, consequently, fatal liver injury. We further show that these changes are dependent on decreased BA signalling to the farnesoid X receptor, which modulates the activity of the rate-limiting enzyme in BA synthesis, CYP7A1. Moreover, patients with advanced stages of PSC show suppressed BA synthesis as measured by serum C4 levels, which is associated with poor disease prognosis. Our preclinical data highlight the microbiota-dependent dynamics of BA metabolism in cholestatic liver disease, which could be important for future therapies targeting BA and gut microbiome interactions, and identify C4 as a potential biomarker to functionally stratify patients with PSC and predict disease outcomes. Patients with primary sclerosing cholangitis (PSC), a chronic cholestatic liver disease, display changes in the gut microbiota and in bile acid composition. Schneider, Candels and colleagues identify a role for microbiota-dependent regulation of bile acid synthesis through farnesoid X receptor signalling, which is relevant for PSC disease progression.
|
|
| 36. |
- Schoonejans, Josca M., et al.
(författare)
-
Serum bile acid measurements in women of European and South Asian ethnicity with or without gestational diabetes mellitus: A cohort study
- 2024
-
Ingår i: BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND GYNAECOLOGY. - 1470-0328 .- 1471-0528.
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Investigation of serum bile acid profiles in pregnancies complicated by gestational diabetes mellitus (GDM) in a multi-ethnic cohort of women who are lean or obese. Design: Prospective cohort study. Setting: UK multicentre study. Population: Fasting serum from participants of European or South Asian self-reported ethnicity from the PRiDE study, between 23 and 31 weeks of gestation. Methods: Bile acids were measured using ultra-performance liquid chromatography-tandem mass spectrometry. Log-transformed data were analysed using linear regression in STATA/IC 15.0. Main outcome measures: Total bile acids (TBAs), C4, fasting glucose and insulin. Results: The TBAs were 1.327-fold (1.105-1.594) increased with GDM in European women (P = 0.003). Women with GDM had 1.162-fold (1.002-1.347) increased levels of the BA synthesis marker C4 (P = 0.047). In South Asian women, obesity (but not GDM) increased TBAs 1.522-fold (1.193-1.942, P = 0.001). Obesity was associated with 1.420-fold (1.185-1.702) increased primary/secondary BA ratio (P < 0.001) related to 1.355-fold (1.140-1.611) increased primary BA concentrations (P = 0.001). TBAs were positively correlated with fasting glucose (P = 0.039) in all women, and with insulin (P = 0.001) and the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (P = 0.001) in women with GDM. Conclusions: Serum BA homeostasis in late gestation depends on body mass index and GDM in ethnicity-specific ways. This suggests ethnicity-specific aetiologies may contribute to metabolic risk in European and South Asian women, with the relationship between BAs and insulin resistance of greater importance in European women. Further studies into ethnicity-specific precision medicine for GDM are required.
|
|
| 37. |
- Silipo, Alba, et al.
(författare)
-
NMR Spectroscopic Analysis Reveals Extensive Binding Interactions of Complex Xyloglucan Oligosaccharides with the Cellvibrio japonicus Glycoside Hydrolase Family 31 a-Xylosidase
- 2012
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 18:42, s. 13395-13404
-
Tidskriftsartikel (refereegranskat)abstract
- The study of the interaction of glycoside hydrolases with their substrates is fundamental to diverse applications in medicine, food and feed production, and biomass-resource utilization. Recent molecular modeling of the a-xylosidase CjXyl31A from the soil saprophyte Cellvibrio japonicus, together with protein crystallography and enzyme-kinetic analysis, has suggested that an appended PA14 protein domain, unique among glycoside hydrolase family 31 members, may confer specificity for large oligosaccharide fragments of the ubiquitous plant polysaccharide xyloglucan (J. Larsbrink, A. Izumi, F. M. Ibatullin, A. Nakhai, H. J. Gilbert, G. J. Davies, H. Brumer, Biochem. J. 2011, 436, 567580). In the present study, a combination of NMR spectroscopic techniques, including saturation transfer difference (STD) and transfer NOE (TR-NOE) spectroscopy, was used to reveal extensive interactions between CjXyl31A active-site variants and xyloglucan hexa- and heptasaccharides. The data specifically indicate that the enzyme recognizes the entire cello-tetraosyl backbone of the substrate and product in positive enzyme subsites and makes further significant interactions with internal pendant a-(1?6)-linked xylosyl units. As such, the present analysis provides an important rationalization of previous kinetic data on CjXyl31A and unique insight into the role of the PA14 domain, which was not otherwise obtainable by protein crystallography.
|
|
| 38. |
- Sjöland, Wilhelm, et al.
(författare)
-
Absence of gut microbiota reduces neonatal survival and exacerbates liver disease in Cyp2c70-deficient mice with a human-like bile acid composition
- 2023
-
Ingår i: Clinical Science. - 0143-5221. ; 137:13, s. 995-1011
-
Tidskriftsartikel (refereegranskat)abstract
- Mice with deletion of Cyp2c70 have a human-like bile acid composition, display age-and sex-dependent signs of hepatobiliary disease and can be used as a model to study interactions between bile acids and the gut microbiota in cholestatic liver disease. In the present study, we rederived Cyp2c70-/- mice as germ-free (GF) and colonized them with a human or a mouse microbiota to investigate whether the presence of a microbiota can be protective in cholangiopathic liver disease associated with Cyp2c70-deficiency. GF Cyp2c70-/- mice showed reduced neonatal survival, liver fibrosis, and distinct cholangiocyte proliferation. Colonization of germ-free breeding pairs with a human or a mouse microbiota normalized neonatal survival of the offspring, and particularly colonization with mouse microbiota from a conventionally raised mouse improved the liver phenotype at 6-10 weeks of age. The improved liver phenotype in conventionalized (CD) Cyp2c70-/- mice was associated with increased levels of tauro-ursodeoxycholic acid (TUDCA) and UDCA, resulting in a more hydrophilic bile acid profile compared with GF and humanized Cyp2c70-/- mice. The hydrophobicity index of biliary bile acids of CD Cyp2c70-/- mice was associated with changes in gut microbiota, liver weight, liver transaminases, and liver fibrosis. Hence, our results indicate that neonatal survival of Cyp2c70-/- mice seems to depend on the establishment of a gut microbiota at birth, and the improved liver phenotype in CD Cyp2c70-/- mice may be mediated by a larger proportion of TUDCA/UDCA in the circulating bile acid pool and/or by the presence of specific bacteria.
|
|
