Vitamin D deficiency predicts unfavorable disease outcomes in inflammatory bowel disease. Endogenous vitamin D synthesis is affected by seasonal factors including sunlight exposure, raising the ...question whether seasonality determines the risk of vitamin D deficiency and may mask other clinical risk factors.
Univariable and multiple regression analyses were performed in a retrospective cohort of 384 patients to determine risk factors for vitamin D deficiency. Since the observed 25-hydroxyvitamin D 25(OH)D concentrations followed a sinusoidal pattern over the year, all 25(OH)D concentrations were normalized for the predicted variability of the respective day of analysis based on a sinusoidal regression analysis of 25(OH)D test results obtained in more than 86,000 control serum samples.
Vitamin D deficiency was highly prevalent in patients with Crohn's disease or ulcerative colitis (63% and 55%, respectively) and associated with winter/spring seasons. After normalization of 25(OH)D concentrations for the day of analysis, vitamin D deficiency was associated with histories of complications related to inflammatory bowel disease, surgery, smoking and ongoing diarrhea while initial disease manifestation during adulthood, ongoing vitamin D supplementation and diagnosis of ulcerative colitis vs. Crohn's disease appeared to be protective. Multiple regression analyses revealed that vitamin D deficiency was associated with disease activity in Crohn's disease and anemia in ulcerative colitis patients. Only few deficient patients achieved sufficient 25(OH)D concentrations over time. However, increasing 25(OH)D concentrations correlated with improved Crohn's disease activity.
Vitamin D deficiency was highly prevalent in patients with Crohn's disease and ulcerative colitis and dependent on the season of the year. Following normalization for seasonality by sinusoidal regression analysis, vitamin D deficiency was found to be associated with parameters of complicated disease course while increasing 25(OH)D concentrations over time correlated with reduced activity of Crohn's disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Diet-induced obesity can result in the development of a diverse spectrum of cardiovascular and metabolic diseases, including type 2 diabetes, dyslipidemia, non-alcoholic liver steatosis and ...atherosclerotic disease. MicroRNAs have been described to be important regulators of metabolism and disease development.
In the current study, we investigated the effects of ubiquitous miR-100 overexpression on weight gain and the metabolic phenotype in a newly generated transgenic mouse strain under normal chow and high fat diet and used microarray expression analysis to identify new potential target genes of miR-100.
While transgenic overexpression of miR-100 did not significantly affect weight and metabolism under a normal diet, miR-100 overexpressing mice showed a reduced weight gain under a high fat diet compared to wildtype mice, despite an equal calorie intake. This was accompanied by less visceral and subcutaneous fat development and lover serum LDL cholesterol. In addition, transgenic miR-100 mice were more glucose tolerant and insulin sensitive and demonstrated increased energy expenditure under high fat diet feeding. A comprehensive gene expression profiling revealed the differential expression of several genes involved in lipid storage- and metabolism, among them CD36 and Cyp4A14. Our data showed a direct regulation of CD36 by miR-100, leading to a reduced fatty acid uptake in primary hepatocytes overexpressing miR-100 and the downregulation of several downstream mediators of lipid metabolism such as ACC1, FABP4, FAS and PPARγ in the liver.
Our findings demonstrate a protective role of miR-100 in high fat diet induced metabolic syndrome and liver steatosis, partially mediated by the direct repression of CD36 and attenuation of hepatic lipid storage, implicating miR-100 as a possible therapeutic target in liver steatosis.
Abstract
Immune cells must adapt to different environments during the course of an immune response. Here we study the adaptation of CD8
+
T cells to the intestinal microenvironment and how this ...process shapes the establishment of the CD8
+
T cell pool. CD8
+
T cells progressively remodel their transcriptome and surface phenotype as they enter the gut wall, and downregulate expression of mitochondrial genes. Human and mouse intestinal CD8
+
T cells have reduced mitochondrial mass, but maintain a viable energy balance to sustain their function. We find that the intestinal microenvironment is rich in prostaglandin E
2
(PGE
2
), which drives mitochondrial depolarization in CD8
+
T cells. Consequently, these cells engage autophagy to clear depolarized mitochondria, and enhance glutathione synthesis to scavenge reactive oxygen species (ROS) that result from mitochondrial depolarization. Impairing PGE
2
sensing promotes CD8
+
T cell accumulation in the gut, while tampering with autophagy and glutathione negatively impacts the T cell pool. Thus, a PGE
2
-autophagy-glutathione axis defines the metabolic adaptation of CD8
+
T cells to the intestinal microenvironment, to ultimately influence the T cell pool.
Studies using genetically modified mice have revealed fundamental functions of the transcription factor Fos/AP-1 in bone biology, inflammation, and cancer. However, the biological role of the ...Fos-related protein Fra-2 is not well defined in vivo. Here we report an unexpected profibrogenic function of Fra-2 in transgenic mice, in which ectopic expression of Fra-2 in various organs resulted in generalized fibrosis with predominant manifestation in the lung. The pulmonary phenotype was characterized by vascular remodeling and obliteration of pulmonary arteries, which coincided with expression of osteopontin, an AP-1 target gene involved in vascular remodeling and fibrogenesis. These alterations were followed by inflammation; release of profibrogenic factors, such as IL-4, insulin-like growth factor 1, and CXCL5; progressive fibrosis; and premature mortality. Genetic experiments and bone marrow reconstitutions suggested that fibrosis developed independently of B and T cells and was not mediated by autoimmunity despite the marked inflammation observed in transgenic lungs. Importantly, strong expression of Fra-2 was also observed in human samples of idiopathic and autoimmune-mediated pulmonary fibrosis. These findings indicate that Fra-2 expression is sufficient to cause pulmonary fibrosis in mice, possibly by linking vascular remodeling and fibrogenesis, and suggest that Fra-2 has to be considered a contributing pathogenic factor of pulmonary fibrosis in humans.
Autologous haematopoietic stem cell transplantation AHSCT is a therapeutic option for patients with severe, treatment-refractory Crohn's disease CD. The evidence base for AHSCT for CD is limited, ...with one randomised trial ASTIC suggesting benefit. The aim of this study was to evaluate safety and efficacy for patients undergoing AHSCT for CD in Europe, outside the ASTIC trial.
We identified 99 patients in the European Society for Blood and Marrow Transplantation EBMT registry, who were eligible for inclusion. Transplant and clinical outcomes were obtained for 82 patients from 19 centres in seven countries.
Median patient age was 30 years range 20-65. Patients had failed or been intolerant to a median of six lines of drug therapy; 61/82 74% had had surgery. Following AHSCT, 53/78 68% experienced complete remission or significant improvement in symptoms at a median follow-up of 41 months range 6-174; 22/82 27% required no medical therapy at any point post-AHSCT. In patients who had re-started medical therapy at latest follow-up, 57% 24/42 achieved remission or significant symptomatic improvement with therapies to which they had previously lost response or been non-responsive. Treatment-free survival at 1 year was 54%. On multivariate analysis, perianal disease was associated with adverse treatment-free survival (hazard ratio 2.34, 95% confidence interval CI 1.14-4.83, p = 0.02). One patient died due to infectious complications cytomegalovirus disease at Day +56.
In this multicentre retrospective analysis of European centres, AHSCT was relatively safe and appeared to be effective in controlling otherwise treatment-resistant Crohn's disease. Further prospective randomised controlled trials against standard of care are warranted.
Growth hormone (GH)‐activated signal transducer and activator of transcription 5 (STAT5) and the glucocorticoid (GC)‐responsive glucocorticoid receptor (GR) are important signal integrators in the ...liver during metabolic and physiologic stress. Their deregulation has been implicated in the development of metabolic liver diseases, such as steatosis and progression to fibrosis. Using liver‐specific STAT5 and GR knockout mice, we addressed their role in metabolism and liver cancer onset. STAT5 single and STAT5/GR double mutants developed steatosis, but only double‐mutant mice progressed to liver cancer. Mechanistically, STAT5 deficiency led to the up‐regulation of prolipogenic sterol regulatory element binding protein 1 (SREBP‐1) and peroxisome proliferator activated receptor gamma (PPAR‐γ) signaling. Combined loss of STAT5/GR resulted in GH resistance and hypercortisolism. The combination of both induced expression of adipose tissue lipases, adipose tissue lipid mobilization, and lipid flux to the liver, thereby aggravating STAT5‐dependent steatosis. The metabolic dysfunctions in STAT5/GR compound knockout animals led to the development of hepatic dysplasia at 9 months of age. At 12 months, 35% of STAT5/GR‐deficient livers harbored dysplastic nodules and ∼60% hepatocellular carcinomas (HCCs). HCC development was associated with GH and insulin resistance, enhanced tumor necrosis factor alpha (TNF‐α) expression, high reactive oxygen species levels, and augmented liver and DNA damage parameters. Moreover, activation of the c‐Jun N‐terminal kinase 1 (JNK1) and STAT3 was prominent. Conclusion: Hepatic STAT5/GR signaling is crucial for the maintenance of systemic lipid homeostasis. Impairment of both signaling cascades causes severe metabolic liver disease and promotes spontaneous hepatic tumorigenesis. (HEPATOLOGY 2011;54:1398–1409)
Endoplasmic reticulum (ER) stress due to accumulation of hepatoviral or misfolded proteins is increasingly recognized as an important step in the pathogenesis of inflammatory, toxic, and metabolic ...liver diseases. ER stress results in the activation of several intracellular signaling pathways including Jun N‐terminal kinase (JNK). The AP‐1 (activating protein 1) transcription factor c‐Jun is a prototypic JNK target and important regulator of hepatocyte survival, proliferation, and liver tumorigenesis. Because the functions of c‐Jun during the ER stress response are poorly understood, we addressed this issue in primary hepatocytes and livers of hepatocyte‐specific c‐Jun knockout mice. ER stress was induced pharmacologically in vitro and in vivo and resulted in a rapid and robust induction of c‐Jun protein expression. Interestingly, ER‐stressed hepatocytes lacking c‐Jun displayed massive cytoplasmic vacuolization due to ER distension. This phenotype correlated with exacerbated and sustained activation of canonical ER stress signaling pathways. Moreover, sustained ER stress in hepatocytes lacking c‐Jun resulted in increased cell damage and apoptosis. ER stress is also a strong inducer of macroautophagy, a cell‐protective mechanism of self‐degradation of cytoplasmic components and organelles. Interestingly, autophagosome numbers in response to ER stress were reduced in hepatocytes lacking c‐Jun. To further validate these findings, macroautophagy was inhibited chemically in ER‐stressed wildtype hepatocytes, which resulted in cytoplasmic vacuolization and increased cell damage closely resembling the phenotypes observed in c‐Jun‐deficient cells. Conclusion: Our findings indicate that c‐Jun protects hepatocytes against excessive activation of the ER stress response and subsequent cell death and provide evidence that c‐Jun functionally links ER stress responses and macroautophagy. (HEPATOLOGY 2012)
(1) Background: Tofacitinib is approved in Europe for the treatment of adults with moderately to severely active ulcerative colitis since 2018. Real-world efficacy and safety data are currently ...scarce. (2) Methods: We performed a retrospective multicenter study at three German tertiary outpatient clinics for inflammatory bowel diseases and included all patients who started tofacitinib therapy between August 2018 and March 2020. The primary endpoint was a combined endpoint of steroid-free clinical remission, steroid-free clinical response, or clinical response at week 8. Secondary endpoints were biochemical response at week 8, as well as steroid-free clinical remission, steroid-free clinical response or clinical response at week 24, respectively, adverse events by week 24, and need for colectomy by the end of follow-up. (3) Results: Thirty-eight patients with moderate-to-severe ulcerative colitis were included. Eleven patients (28.9%) achieved steroid-free clinical remission at week 8. Fifty-three percent of the patients were primary non-responders at week 8. Three severe adverse events (pneumonia, hospitalization for aggravation of ulcerative colitis, emergency colectomy due to colon perforation), and 12 adverse events were documented by week 8 of therapy. By the end of follow-up, seven patients (18.4%) had undergone colectomy.
Whipple's disease, a rare chronic infectious disorder caused by Tropheryma whipplei, may present with predominant joint manifestations mimicking rheumatoid arthritis (RA).
A retrospective ...single-center cohort study of seven patients was performed. Clinical symptoms were assessed by review of medical charts and Whipple's disease was diagnosed by periodic-acid-Schiff-stain and/or Tropheryma whipplei-specific polymerase-chain-reaction.
Median age at disease onset was 54 years, six patients were male. Median time to diagnosis was 5 years. All patients presented with polyarthritis with a predominantly symmetric pattern. Three had erosive arthritis. Affected joints were: wrists (5/7), metacarpophalangeal joints (MCPs) (5/7), knees (5/7), proximal interphalangeal joints (PIPs) (3/7), hips (2/7), elbow (2/7), shoulder (2/7). All patients had increased C-reactive-protein concentrations, while rheumatoid factor and anti-CCP-antibodies were absent, and were initially (mis)classified as RA-patients according to EULAR/ACR-criteria (median DAS28 4.3). Six patients received antirheumatic treatment consisting of prednisone with methotrexate and/or leflunomide, three were additionally treated with at least one biologic agent (abatacept, adalimumab, etanercept, rituximab, tocilizumab). Most patients showed insufficient treatment response. In all patients Tropheryma whipplei was detected in synovial fluid by polymerase-chain-reaction; in three patients the diagnosis of Whipple's disease was further ascertained by periodic-acid-Schiff-staining. Gastrointestinal symptoms and other extra-articular manifestations were absent, mild or non-specific. Treatment was initiated with trimethoprin/sulfamethoxazole in five and doxycycline/hydroxychloroquine in two patients and had to be adapted in five patients. Finally, all patients had good treatment responses with improvement of arthritis and extra-articular manifestations.
Whipple's disease is rare and can mimic rheumatoid arthritis. Especially patients with seronegative rheumatoid arthritis with a prolonged disease course and insufficient treatment response should be reevaluated for Whipple's disease.
The Wnt/β-Catenin signaling pathway is central for liver functions and frequently deregulated in hepatocellular carcinoma (HCC). Analysis of the early phenotypes and molecular events following ...β-Catenin activation is therefore essential for better understanding HCC pathogenesis. The AP-1 transcription factor c-Jun is a putative β-Catenin target gene and promotes hepatocyte survival, proliferation, and liver tumorigenesis, suggesting that c-Jun may be a key target of β-Catenin signaling in the liver.
To address this issue, the immediate hepatic phenotypes following deletion of the tumor suppressor Apc and subsequent β-Catenin activation were analyzed in mice. The contribution of c-Jun to these phenotypes was dissected in double mutant animals lacking both, Apc and c-Jun. β-Catenin was rapidly activated in virtually all Apc mutant hepatocytes while c-Jun was induced only after several days, suggesting that its expression was rather a secondary event following Apc deletion in the liver. Loss of Apc resulted in increased hepatocyte proliferation, hepatomegaly, deregulated protein metabolism, and premature death. Interestingly, additional deletion of c-Jun did not affect hepatocyte proliferation but resulted in increased liver damage and mortality. This phenotype correlated with impaired expression of hepatoprotective genes such as Birc5, Egfr Igf1 and subsequently deregulated Akt signaling.
These data indicate that c-Jun is not a primary target of β-Catenin signaling in the liver, but rather protects against liver damage, which in turn may promote liver tumorigenesis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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