| 1. |
- Ovadia, C., et al.
(författare)
-
Ursodeoxycholic acid enriches intestinal bile salt hydrolase-expressing Bacteroidetes in cholestatic pregnancy
- 2020
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Ursodeoxycholic acid (UDCA) treatment can reduce itch and lower endogenous serum bile acids in intrahepatic cholestasis of pregnancy (ICP). We sought to determine how it could influence the gut environment in ICP to alter enterohepatic signalling. The gut microbiota and bile acid content were determined in faeces from 35 pregnant women (14 with uncomplicated pregnancies and 21 with ICP, 17 receiving UDCA). Faecal bile salt hydrolase activity was measured using a precipitation assay. Serum fibroblast growth factor 19 (FGF19) and 7α-hydroxy-4-cholesten-3-one (C4) concentrations were measured following a standardised diet for 21 hours. Women with a high ratio of Bacteroidetes to Firmicutes were more likely to be treated with UDCA (Fisher’s exact test p = 0.0178) than those with a lower ratio. Bile salt hydrolase activity was reduced in women with low Bacteroidetes:Firmicutes. Women taking UDCA had higher faecal lithocholic acid (p < 0.0001), with more unconjugated bile acids than women with untreated ICP or uncomplicated pregnancy. UDCA-treatment increased serum FGF19, and reduced C4 (reflecting lower bile acid synthesis). During ICP, UDCA treatment can be associated with enrichment of the gut microbiota with Bacteroidetes. These demonstrate high bile salt hydrolase activity, which deconjugates bile acids enabling secondary modification to FXR agonists, enhancing enterohepatic feedback via FGF19. © 2020, The Author(s).
|
|
| 2. |
- Clifford, B. L., et al.
(författare)
-
FXR activation protects against NAFLD via bile-acid-dependent reductions in lipid absorption
- 2021
-
Ingår i: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 33:8
-
Tidskriftsartikel (refereegranskat)abstract
- FXR agonists are used to treat non-alcoholic fatty liver disease (NAFLD), in part because they reduce hepatic lipids. Here, we show that FXR activation with the FXR agonist GSK2324 controls hepatic lipids via reduced absorption and selective decreases in fatty acid synthesis. Using comprehensive lipidomic analyses, we show that FXR activation in mice or humans specifically reduces hepatic levels of mono-and polyunsaturated fatty acids (MUFA and PUFA). Decreases in MUFA are due to FXR-dependent repression of Scd1, Dgat2, and Lpin1 expression, which is independent of SHP and SREBP1c. FXR-dependent decreases in PUFAs are mediated by decreases in lipid absorption. Replenishing bile acids in the diet prevented decreased lipid absorption in GSK2324-treated mice, suggesting that FXR reduces absorption via decreased bile acids. We used tissue-specific FXR KO mice to show that hepatic FXR controls lipogenic genes, whereas intestinal FXR controls lipid absorption. Together, our studies establish two distinct pathways by which FXR regulates hepatic lipids.
|
|
| 3. |
|
|
| 4. |
- Johnsson, Jesper, et al.
(författare)
-
Functional outcomes associated with varying levels of targeted temperature management after out-of-hospital cardiac arrest — An INTCAR2 registry analysis
- 2020
-
Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 146, s. 229-236
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA) has been recommended in international guidelines since 2005. The TTM-trial published in 2013 showed no difference in survival or neurological outcome for patients randomised to 33 °C or 36 °C, and many hospitals have changed practice. The optimal utilization of TTM is still debated. This study aimed to analyse if a difference in temperature goal was associated with outcome in an unselected international registry population. Methods: This is a retrospective observational study based on a prospective registry — the International Cardiac Arrest Registry 2. Patients were categorized as receiving TTM in the lower range at 32–34 °C (TTM-low) or at 35–37 °C (TTM-high). Primary outcome was good functional status defined as cerebral performance category (CPC) of 1–2 at hospital discharge and secondary outcome was adverse events related to TTM. A logistic regression model was created to evaluate the independent effect of temperature by correcting for clinical and demographic factors associated with outcome. Results: Of 1710 patients included, 1242 (72,6%) received TTM-low and 468 (27,4%) TTM-high. In patients receiving TTM-low, 31.3% survived with good outcome compared to 28.8% in the TTM-high group. There was no significant association between temperature and outcome (p = 0.352). In analyses adjusted for baseline differences the OR for a good outcome with TTM-low was 1.27, 95% CI (0.94–1.73). Haemodynamic instability leading to discontinuation of TTM was more common in TTM-low. Conclusions: No significant difference in functional outcome at hospital discharge was found in patients receiving lower- versus higher targeted temperature management.
|
|
| 5. |
- 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.
|
|
| 6. |
|
|
