Impaired Hepatic Vitamin A Metabolism in NAFLD Mice Leading to Vitamin A Accumulation in Hepatocytes

BACKGROUND & AIMS: Systemic retinol (vitamin A) homeostasis is controlled by the liver, involving close collaboration between hepatocytes and hepatic stellate cells (HSCs). Genetic variants in retinol metabolism (PNPLA3 and HSD17B13) are associated with non-alcoholic fatty liver disease (NAFLD) and disease progression. Still, little mechanistic details are known about hepatic vitamin A metabolism in NAFLD, which may affect carbohydrate and lipid metabolism, inflammation, oxidative stress and the development of fibrosis and cancer, e.g. all risk factors of NAFLD. METHODS: Here, we analyzed vitamin A metabolism in 2 mouse models of NAFLD; mice fed a high-fat, high-cholesterol (HFC) diet and Leptin(ob) mutant (ob/ob) mice. RESULTS: Hepatic retinol and retinol binding protein 4 (RBP4) levels were significantly reduced in both mouse models of NAFLD. In contrast, hepatic retinyl palmitate levels (the vitamin A storage form) were significantly elevated in these mice. Transcriptome analysis revealed a hyperdynamic state of hepatic vitamin A metabolism, with enhanced retinol storage and metabolism (upregulated Lrat, Dgat1, Pnpla3, Raldh's and RAR/RXR-target genes) in fatty livers, in conjunction with induced hepatic inflammation (upregulated Cd68, Tnf alpha, Nos2, Il1 beta, 11-6) and fibrosis (upregulated Colla1, Acta2, Tgf beta, Timp1). Autofluorescence analyses revealed prominent vitamin A accumulation in hepatocytes rather than HSC in HFC-fed mice. Palmitic acid exposure increased Lrat mRNA levels in primary rat hepatocytes and promoted retinyl palmitate accumulation when co-treated with retinol, which was not detected for similarly-treated primary rat HSCs. CONCLUSION: NAFLD leads to cell type-specific rearrangements in retinol metabolism leading to vitamin A accumulation in hepatocytes. This may promote disease progression and/or affect therapeutic approaches targeting nuclear receptors

Rapid and Sustained Effect of Dupilumab on Work Productivity in Patients with Difficult-to-treat Atopic Dermatitis:Results from the Dutch BioDay Registry

Dupilumab treatment improves signs, symptoms, and quality of life in patients with moderate-to-severe atopic dermatitis. This study evaluated the impact of dupilumab treatment on absenteeism, presenteeism, and related costs in a large multi-centre cohort of adult patients with difficult-to-treat atopic dermatitis in daily practice. Patients treated with dupilumab participating in the Dutch BioDay Registry reporting employment were included. Absenteeism, presenteeism, and related costs at baseline and during follow-up were calculated using the Work Productivity and Activity Impairment questionnaire. A total of 218 adult patients with moderate-to-severe atopic dermatitis were included. Total work impairment reduced significantly from baseline (35.5%) to week 52 (11.5%), p &lt; 0.001. Median weekly productivity losses reduced significantly from baseline (€379.8 (140.7-780.8)) to week 52 (€0.0 (0.0-211.0), p &lt; 0.001). In this study, dupilumab treatment demonstrated a significant improvement in work productivity and reduction in associated costs in a large cohort of patients with difficult-to-treat atopic dermatitis in daily practice.</p

Early and Long-Term Effects of Dupilumab Treatment on Circulating T-Cell Functions in Patients with Moderate-to-Severe Atopic Dermatitis

Dupilumab, a mAb targeting IL-4 receptor alpha (IL-4Rα), markedly improves disease severity in patients with atopic dermatitis. However, the effect of IL-4Rα blockade on dynamics of circulating skin-homing T cells, which are crucial players in the pathologic mechanism of atopic dermatitis, has not been studied yet. In addition, it remains unknown whether dupilumab treatment induces long-lasting T- and B-cell polarization. Therefore, we studied the short- and long-term effects of dupilumab treatment on IL-4Rα expression and T-cell cytokine production within total and skin-homing (cutaneous lymphocyte antigen+/CCR4+) subpopulations in patients with moderate-to-severe atopic dermatitis. Dupilumab treatment completely blocked IL-4Rα expression and signal transducer and activator of transcription 6 phosphorylation in CD19+ B cells and CD4+ T cells within 2 hours of administration and through week 52. Although no change in the proportion of skin-homing T-cell subsets was found, dupilumab treatment significantly decreased the percentage of proliferating (Ki67+) and T helper type 2 and T helper type 22 cytokine-producing skin-homing CD4+ T cells at week 4. No evidence of general T helper type cell skewing following a year of dupilumab treatment was found. In summary, dupilumab treatment rapidly and stably inhibited IL-4Rα, which was accompanied by a strong early functional immunological effect specifically on skin-homing T cells without affecting overall T helper type cell skewing in the long term

Dupilumab shows long-term effectiveness in a large cohort of treatment-refractory atopic dermatitis patients in daily practice:52-Week results from the Dutch BioDay registry

Background Real-life data on long-term effectiveness and safety of dupilumab in atopic dermatitis patients are limited. Objective To study 52-week effectiveness and safety of dupilumab in a prospective multicenter cohort of adult patients with treatment-refractory atopic dermatitis. Methods Patients treated with dupilumab and participating in the Dutch BioDay registry were included. Clinical effectiveness and safety were evaluated. Results Two hundred ten atopic dermatitis patients were included. Mean percentage change in Eczema Area and Severity Index score after 16 weeks was –70.0% (standard deviation 33.2%) and further decreased to –76.6% (standard deviation 30.6%) by week 52. A greater than or equal to 75% improvement in the score was achieved by 59.9% of individuals by week 16 and by 70.3% by week 52. The most reported adverse effect was conjunctivitis (34%). Limited patients (17; 8.1%) discontinued dupilumab treatment. Limitations Because of the lack of a control group and observational design, factors of bias may have been induced. Conclusion Treatment with dupilumab resulted in a rapid improvement in clinical outcome measures, and effectiveness further improved during the 52-week follow-up period

Daily Practice Experience of Baricitinib Treatment for Patients with Difficult-to-Treat Atopic Dermatitis:Results from the BioDay Registry

Clinical trials have shown that baricitinib, an oral selective Janus kinase 1/2 inhibitor, is effective for the treatment of moderate-to-severe atopic dermatitis. However, daily practice data are limited. Therefore, this multicentre prospective study evaluated the effectiveness and safety of 16-weeks' treatment with baricitinib in adult patients with moderate-to-severe atopic dermatitis in daily practice. A total of 51 patients from the BioDay registry treated with baricitinib were included and evaluated at baseline and after 4, 8 and 16 weeks of treatment. Effectiveness was assessed using clinician- and patient-reported outcome measurements. Adverse events and laboratory assessments were evaluated at every visit. At week 16, the probability (95% confidence interval) of achieving Eczema Area and Severity Index ≤ 7 and numerical rating scale pruritus ≤ 4 was 29.4% (13.1-53.5) and 20.5% (8.8-40.9), respectively. No significant difference in effectiveness was found between dupilumab non-responders and responders. Twenty-two (43.2%) patients discontinued baricitinib treatment due to ineffectiveness, adverse events or both (31.4%, 9.8% and 2.0%, respectively). Most frequently reported adverse events were nausea (n = 6, 11.8%), urinary tract infection (n = 5, 9.8%) and herpes simplex infection (n = 4, 7.8%). In conclusion, baricitinib can be an effective treatment option for moderate-to-severe atopic dermatitis, including patients with non-responsiveness on dupilumab. However, effectiveness of baricitinib is heterogeneous, which is reflected by the high discontinuation rate in this difficult-to-treat cohort

Identification of Risk Factors for Dupilumab-associated OculaSurface Disease in Patients with Atopic Dermatitis

This study identified risk factors for the development of dupilumab-associated ocular surface disease in patients with moderate-to-severe atopic dermatitis in a large prospective daily practice cohort. Data from the Dutch BioDay Registry were used to assess the risk of developing dupilumab-associated ocular surface di-sease, by performing univariate and multivariate logistic regression analyses. A total of 469 patients were included, of which 152/469 (32.4%) developed dupi-lumab-associated ocular surface disease. Multivariate analysis showed a statistically significant association of the development of dupilumab-associated ocular surface disease with a history of any eye disease (his-tory of self-reported episodic acute allergic conjunctivitis excluded) combined with the use of ophthalmic medication at the start of dupilumab (odds ratio 5.16, 95% confidence interval 2.30–11.56, p < 0.001). In conclusion, a history of any eye disease (history of self-reported episodic acute allergic conjunctivitis ex-cluded) combined with the use of ophthalmic medication at baseline was associated with the development of dupilumab-associated ocular surface disease in patients with atopic dermatitis

NF-kappa B p65 serine 467 phosphorylation sensitizes mice to weight gain and TNF alpha-or diet-induced inflammation

The NF-kappa B family of transcription factors is essential for an effective immune response, but also controls cell metabolism, proliferation and apoptosis. Its broad relevance and the high connectivity to diverse signaling pathways require a tight control of NF-kappa B activity. To investigate the control of NF-kappa B activity by phosphorylation of the NF-kappa B p65 subunit, we generated a knock-in mouse model in which serine 467 (the mouse homolog of human p65 serine 468) was replaced with a non-phosphorylatable alanine (S467A). This substitution caused reduced p65 protein synthesis and diminished TNF alpha-induced expression of a selected group of NF-kappa B dependent genes. Intriguingly, high-fat fed S467A mice displayed increased locomotor activity and energy expenditure, which coincided with a reduced body weight gain. Although glucose metabolism or insulin sensitivity was not improved, diet-induced liver inflammation was diminished in S467A mice. Altogether, this study demonstrates that phosphorylation of p65 serine 467 augment NF-kappa B activity and exacerbates various deleterious effects of overnutrition in mice.</p

A four-domain approach of frailty explored in the Doetinchem Cohort Study.

Accumulation of problems in physical, psychological, cognitive, or social functioning is characteristic for frail individuals. Using a four-domain approach of frailty, this study explored how sociodemographic and lifestyle factors, life events and health are associated with frailty