Integrated safety analysis of filgotinib in patients with moderate-to-severe rheumatoid arthritis over a treatment duration of up to 8.3 years.

OBJECTIVES: To update the long-term safety profile of filgotinib, a Janus kinase-1 preferential inhibitor, in patients with moderate-to-severe rheumatoid arthritis. METHODS: Data from seven trials were integrated (NCT01888874, NCT01894516, NCT02889796, NCT02873936, NCT02886728, NCT02065700 and NCT03025308). Patients received once-daily filgotinib 100 mg or 200 mg. Exposure-adjusted incidence rates (EAIRs)/100 patient-years of exposure (PYE) were calculated for treatment-emergent adverse events (TEAEs). Post hoc analyses assessed patients aged <65 and ≥65 years. RESULTS: Patients (N=3691) received filgotinib for a median (maximum) of 3.8 (8.3) years (12 541 PYE). Rates of TEAEs of interest: serious infections, malignancies, major adverse cardiovascular events (MACE) and venous thromboembolism were stable over time and comparable between doses. In the overall population, numerically lower EAIR (95% CI)/100 PYE of herpes zoster was observed for filgotinib 100 mg versus 200 mg (1.1 (0.8 to 1.5) vs 1.5 (1.2 to 1.8)). Incidence of serious infections, herpes zoster, MACE, malignancies and all-cause mortality was higher in patients aged ≥65 versus <65 years. In patients aged ≥65 years, EAIRs (95% CI)/100 PYE for non-melanoma skin cancer (NMSC) (0.4 (0.1 to 1.1) vs 1.4 (0.8 to 2.2)), malignancies excluding NMSC (1.0 (0.5 to 1.9) vs 2.0 (1.3 to 2.9)) and all-cause mortality (1.3 (0.7 to 2.2) vs 1.6 (1.0 to 2.5)) were numerically lower for filgotinib 100 mg versus 200 mg. CONCLUSIONS: In the overall population, TEAEs of interest were stable over time and similar between filgotinib 100 mg and 200 mg dose groups, except for herpes zoster. A dose-dependent relationship between malignancies and all-cause mortality was suggested in patients ≥65 years old.

Galactose-modified iNKT cell agonists stabilized by an induced fit of CD1d prevent tumour metastasis.

Invariant natural killer T (iNKT) cells are known to have marked immunomodulatory capacity due to their ability to produce copious amounts of effector cytokines. Here, we report the structure and function of a novel class of aromatic α-galactosylceramide structurally related glycolipids with marked Th1 bias in both mice and men, leading to superior tumour protection in vivo. The strength of the Th1 response correlates well with enhanced lipid binding to CD1d as a result of an induced fit mechanism that binds the aromatic substitution as a third anchor, in addition to the two lipid chains. This induced fit is in contrast to another Th1-biasing glycolipid, α-C-GalCer, whose CD1d binding follows a conventional key-lock principle. These findings highlight the previously unexploited flexibility of CD1d in accommodating galactose-modified glycolipids and broaden the range of glycolipids that can stimulate iNKT cells. We speculate that glycolipids can be designed that induce a similar fit, thereby leading to superior and more sustained iNKT cell responses in vivo.

Analysis of the Nutritional Composition of Ready-to-Use Meat Alternatives in Belgium.

BACKGROUND: The interest in meat alternatives has increased over the years as people embrace more varied food choices because of different reasons. This study aims to analyse the nutritional composition of ready-to-use meat alternatives and compare them with meat (products). METHODS: Nutritional composition values were collected in 2022 of all ready-to-use meat alternatives in Belgian supermarkets, as well as their animal-based counterparts. A one-sample t-test was performed to test the nutritional composition of ready-to-use meat alternatives against norm values, while an independent samples t-test was used to make the comparison with meat. RESULTS: Minced meat and pieces/strips/cubes scored favourably on all norm values. Cheeseburgers/schnitzels, nut/seed burgers and sausages contained more than 10 g/100 g total fat. The saturated fat and salt content was lower than the norm value in each category. Legume burgers/falafel contained less than 10 g/100 g protein. Vegetarian/vegan minced meat and bacon contained fewer calories, total and saturated fat, and more fibre compared to their animal-based counterparts. CONCLUSIONS: Minced meat and pieces/strips/cubes came out as the most favourable categories regarding nutritional composition norm values. Vegetarian/vegan steak came out the least favourable compared to steak, while vegetarian/vegan minced meat and vegetarian/vegan bacon came out the most favourable compared to their animal-based counterparts.

What benefit-risk trade-offs are acceptable to rheumatoid arthritis patients during treatment selection? Evidence from a multicountry choice experiment.

OBJECTIVE: Understanding preferences of patients with rheumatoid arthritis (RA) can facilitate tailored patient-centric care. This study elicited trade-offs that patients with RA were willing to make during treatment selection. METHODS: Patients with RA completed an online discrete choice experiment, consisting of a series of choices between hypothetical treatments. Treatment attributes were selected based on literature review and qualitative patient interviews. Eligible patients were ≥18 years old, diagnosed with RA, receiving systemic disease-modifying antirheumatic drug therapy, and residents of Europe or USA. Male patients were oversampled for subgroup analyses. Data were analysed using a correlated mixed logit model. RESULTS: Of 2090 participants, 42% were female; mean age was 45.2 years (range 18-83). Estimated effects were significant for all attributes (p<0.001) but varied between patients. Average relative attribute importance scores revealed different priorities (p<0.001) between males and females. While reducing pain and negative effect on semen parameters was most important to males, females were most concerned by risk of blood clots and serious infections. No single attribute explained treatment preferences by more than 30%. Preferences were also affected by patients' age: patients aged 18-44 years placed less importance on frequency and mode of treatment administration (p<0.05) than older age groups. Patients were willing to accept higher risk of serious infections and blood clots in exchange for improvements in pain, daily activities or administration convenience. However, acceptable trade-offs varied between patients (p<0.05). CONCLUSION: Treatment preferences of patients with RA were individual-specific, but driven by benefits and risks, with no single attribute dominating the decision-making.

Comparison of trichostatin A and valproic acid treatment regimens in a mouse model of kidney fibrosis.

Histone deacetylase (HDAC) inhibitors are promising new compounds for the therapy of fibrotic diseases. In this study we compared the effect of two HDAC inhibitors, trichostatin A and valproic acid, in an experimental model of kidney fibrosis. In mice, doxorubicin (adriamycin) can cause nephropathy characterized by chronic proteinuria, glomerular damage and interstitial inflammation and fibrosis, as seen in human focal segmental glomerulosclerosis. Two treatment regimens were applied, treatment was either started prior to the doxorubicin insult or delayed until a significant degree of proteinuria and fibrosis was present. Pre-treatment of trichostatin A significantly hampered glomerulosclerosis and tubulointerstitial fibrosis, as did the pre-treatment with valproic acid. In contrast, the development of proteinuria was only completely inhibited in the pre-treated valproic acid group, and not in the pre-treated trichostatin A animals. In the postponed treatment with valproic acid, a complete resolution of established doxorubicin-induced proteinuria was achieved within three days, whereas trichostatin A could not correct proteinuria in such a treatment regimen. However, both postponed regimens have comparable efficacy in maintaining the kidney fibrosis to the level reached at the start of the treatments. Moreover, not only the process of fibrosis, but also renal inflammation was attenuated by both HDAC inhibitors. Our data confirm a role for HDACs in renal fibrogenesis and point towards a therapeutic potential for HDAC inhibitors. The effect on renal disease progression and manifestation can however be different for individual HDAC inhibitors.

Impact of COVID-19 pandemic on the management of patients with RA: a survey of rheumatologists in six European countries.

Objective: We aimed to describe, from the perspective of rheumatologists in Europe, how the coronavirus disease 2019 (COVID-19) pandemic has impacted their management of people with RA and the continuing medical education of physicians. Methods: Rheumatologists participating in the Adelphi RA Disease Specific ProgrammeTM in six European countries were contacted in August and September 2020 for a telephone survey. Rheumatologists were asked seven attitudinal questions on changes to patient management, prescription behaviour and continuing education owing to COVID-19. Results were summarized with descriptive statistics. Results: The telephone survey was completed by 284 rheumatologists. The most commonly reported changes to patient management were increased utilization of video/telephone consultations (66.5% of respondents), fewer visits (58.5%) and limiting physical contact (58.1%). Furthermore, 67.9% of rheumatologists who indicated that prescribing behaviour had changed switched their patients to self-administered medication, and 60.7% reported not starting patients on targeted synthetic DMARDs, biologic originator DMARDs or biosimilar DMARDs. In total, 57.6% of rheumatologists believed that changes in management would persist. Rheumatologists reported that 38.0% of patients expressed concerns about how COVID-19 would impact treatment, including access to treatment and the risk of infection. The biggest impact on rheumatologist education was a switch to online training and conferences. Conclusion: All countries saw changes in patient management and prescribing behaviour, including the rapid uptake of telemedicine. It is important that the international rheumatology community learns from these experiences to prepare better for future pandemics and to address ongoing rheumatologist shortages.

An anti-inflammatory selective glucocorticoid receptor modulator preserves osteoblast differentiation.

Glucocorticoids (GCs) are in widespread use to treat inflammatory bone diseases, such as rheumatoid arthritis (RA). Their anti-inflammatory efficacy, however, is accompanied by deleterious effects on bone, leading to GC-induced osteoporosis (GIO). These effects include up-regulation of the receptor activator of NF-κB ligand/osteoprotegerin (RANKL/OPG) ratio to promote bone-resorbing osteoclasts and include inhibition of bone-forming osteoblasts. We previously identified suppression of osteoblast differentiation by the monomer glucocorticoid receptor (GR) via the inhibition of Il11 expression as a crucial mechanism for GIO. Here we show that the GR-modulating substance compound A (CpdA), which does not induce GR dimerization, still suppresses proinflammatory cytokines in fibroblast-like synovial cells from patients with RA and in osteoblasts. In contrast to the full GR agonist dexamethasone, it does not unfavorably alter the RANKL/OPG ratio and does not affect Il11 expression and subsequent STAT3 phosphorylation in these cells. Notably, while dexamethasone inhibits osteoblast differentiation, CpdA does not affect osteoblast differentiation in vitro and in vivo. We describe here for the first time that selective GR modulators can act against inflammation, while not impairing osteoblast differentiation.

Valproic acid attenuates proteinuria and kidney injury.

Inhibitors of histone deacetylase (HDAC) have anti-inflammatory and antifibrotic effects in several organs and tissues, but their effect on the progression of renal disease is unknown. Here, we studied the effect of valproic acid in adriamycin-induced nephropathy in mice. Administration of valproic acid before kidney injury prevented the development of proteinuria and the onset of glomerulosclerosis. Even after postponing treatment until the peak of adriamycin-induced proteinuria, valproic acid rapidly decreased the quantity of proteinuria and attenuated the progression of renal disease. Valproic acid abrogated the decrease in glomerular acetylation observed during adriamycin-induced nephropathy. Furthermore, valproic acid attenuated the significant upregulation of profibrotic and proinflammatory genes, the deposition of collagen, and the infiltration of macrophages into the kidney. Valproic acid decreased glomerular apoptosis and proliferation induced by adriamycin. Ultrastructural studies further supported the protective effect of valproic acid on podocytes in this model. Taken together, these data suggest that HDACs contribute to the pathogenesis of renal disease and that HDAC inhibitors may have therapeutic potential in CKD.

Treat-to-target in rheumatoid arthritis: a real-world study of the application and impact of treat-to-target within the wider context of patient management, patient centricity and advanced therapy use in Europe.

BACKGROUND: While treat-to-target (T2T) is endorsed for the management of rheumatoid arthritis (RA), data on the degree of implementation in clinical practice are limited. This study investigated the use of T2T for RA in a real-world setting across Europe. METHODS: The Adelphi RA Disease-Specific Programme was a point-in-time survey of rheumatologists and their consulting patients with RA conducted between January and October 2020 in Belgium, France, Germany, Italy, Spain and the UK. Rheumatologists completed an attitudinal survey, and a record form for their next 10-12 consulting patients, who were invited to voluntarily complete a patient-reported questionnaire. Data collected included clinical characteristics, treatment patterns and attitudes towards T2T. RESULTS: Overall, 316 rheumatologists provided data for 3120 patients, of whom 1108 completed the questionnaire. While 86.1% of rheumatologists estimated using T2T principles in clinical practice, only 66.6% of patients were reported by their physician to be managed using a T2T approach. Achieving disease remission was the most commonly reported treatment goal identified by rheumatologists (79.7%), followed by symptom control (47.8%) and reducing impact on quality of life (44.5%). 40.8% of rheumatologists and their patients were in agreement that a treatment goal had been set. When there was agreement on treatment goals, we observed better patient satisfaction, engagement and treatment success. CONCLUSIONS: Despite recommendations, the T2T approach in RA appears to be suboptimally implemented in clinical practice. This highlights the importance of patient-centricity in the decision-making process to define meaningful targets and select appropriate treatments to improve disease outcomes.

MANTA and MANTA-RAy: Rationale and Design of Trials Evaluating Effects of Filgotinib on Semen Parameters in Patients with Inflammatory Diseases.

INTRODUCTION: The phase 2 MANTA and MANTA-RAy studies were developed in consultation with global regulatory authorities to investigate potential impacts of filgotinib, a Janus kinase 1 preferential inhibitor, on semen parameters in men with active inflammatory diseases. Here we describe the methods and rationale for these studies. METHODS AND RATIONALE: The MANTA and MANTA-RAy studies included men (aged 21-65 years) with active inflammatory bowel disease (IBD) and rheumatic diseases, respectively. Participants had no history of reproductive health issues, and the following semen parameter values (≥ 5th percentile of World Health Organization reference values) at baseline: semen volume ≥ 1.5 mL, total sperm/ejaculate ≥ 39 million, sperm concentration ≥ 15 million/mL, sperm total motility ≥ 40% and normal sperm morphology ≥ 30%. Each trial included a 13-week, randomized, double-blind, placebo-controlled period (filgotinib 200 mg vs placebo, up to N = 125 per arm), for pooled analysis of the week-13 primary endpoint (proportion of participants with ≥ 50% decrease from baseline in sperm concentration). All semen assessments were based on two samples (≤ 14 days apart) to minimize effects of physiological variation; stringent standardization processes were applied across assessment sites. From week 13, MANTA and MANTA-RAy study designs deviated owing to disease-specific considerations. All subjects with a ≥ 50% decrease in sperm parameters continued the study in the monitoring phase until reversibility, or up to a maximum of 52 weeks, with standard of care as treatment. Overall conclusions from MANTA and MANTA-RAy will be based on the totality of the data, including secondary/exploratory measures (e.g. sperm motility/morphology, sex hormones, reversibility of any effects on semen parameters). CONCLUSIONS: Despite the complexities, the MANTA and MANTA-RAy studies form a robust trial programme that is the first large-scale, placebo-controlled evaluation of potential impacts of an advanced IBD and rheumatic disease therapy on semen parameters. TRIAL REGISTRATION: EudraCT numbers 2017-000402-38 and 2018-003933-14; ClinicalTrials.gov identifiers NCT03201445 and NCT03926195.

Filgotinib is a treatment for patients with ulcerative colitis and rheumatoid arthritis, and is being studied in other inflammatory diseases. Filgotinib works by blocking Janus kinase 1, an intracellular protein involved in inflammatory signalling processes. We designed the MANTA and MANTA-RAy trials with global health agencies to find out if filgotinib decreases the quality of semen in men with active inflammatory bowel disease (ulcerative colitis or Crohn's disease) (MANTA) or rheumatic disease (rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis or non-radiographic axial spondylitis) (MANTA-RAy). This paper describes the design of the two trials.Patients had normal sperm measurements and could not have had previous reproductive health issues. Nearly 250 patients were included in each trial. In both MANTA and MANTA-RAy, half of the patients were treated with 200 mg of filgotinib once a day for 13 weeks, and the other half with placebo. We determined if any patients had a decrease in number of sperm cells per millilitre (sperm concentration) by at least half after 13 weeks of treatment. We then monitored any patients who had such a decrease in sperm concentration for up to 52 weeks (while they received standard of care treatment) or until the decrease was reversed.The conclusions from the trials will be in a different paper and will be based on all the final data, including changes in sex hormones. This is the first large-scale clinical trial programme to measure the effect of a treatment on sperm in men with inflammatory bowel disease or rheumatic diseases.

Invariant natural killer T cells are natural regulators of murine spondylarthritis.

OBJECTIVE: To investigate the role of invariant natural killer T (iNKT) cells in TNF(DeltaARE/+) mice, an animal model of spondylarthritis (SpA) with both gut and joint inflammation. METHODS: The frequency and activation of iNKT cells were analyzed on mononuclear cells from the lymph nodes and livers of mice, using flow cytometry with alpha-galactosylceramide/CD1d tetramers and quantitative polymerase chain reaction for the invariant V(alpha)14-J(alpha)18 rearrangement. Bone marrow-derived dendritic cells (DCs) were obtained by expansion of primary cells with granulocyte-macrophage colony-stimulating factor followed by coculture with iNKT cell hybridomas, and interleukin-2 release into the cocultures was then measured by enzyme-linked immunosorbent assay (ELISA). Cytokine levels were determined by ELISA or cytometric bead array analyses of freshly isolated DCs and iNKT cells in mixed cocultures. TNF(DeltaARE/+) mice were backcrossed onto J(alpha)18(-/-) and CD1d(-/-) mice, and disease onset was evaluated by clinical scoring, positron emission tomography, and histology. CD1d levels were analyzed on mononuclear cells in paired blood and synovial fluid samples from patients with SpA compared with healthy control subjects. RESULTS: In the absence of iNKT cells, symptoms of gut and joint inflammation in TNF(DeltaARE/+)mice were aggravated. Invariant NKT cells were activated during the course of the disease. This was linked to an enrichment of inflammatory DCs, characterized by high levels of CD1d, particularly at draining sites of inflammation. A similar increase in CD1d levels was observed on DCs from patients with SpA. Inflammatory DCs from TNF(DeltaARE/+) mice stimulated iNKT cells to produce immunomodulatory cytokines, in the absence of exogenous stimulation. Prolonged, continuous exposure, but not short-term exposure, to tumor necrosis factor (TNF) was found to be responsible for the enhanced DC-NKT cell crosstalk. CONCLUSION: This mode of iNKT cell activation represents a natural counterregulatory mechanism for the dampening of TNF-driven inflammation.

Cutting edge: the chemokine receptor CXCR3 retains invariant NK T cells in the thymus.

The current model used to define T cell export from the thymus suggests that emigrating lymphocytes seed the peripheral organs as functionally mature cells. This model holds true for the majority of T cells exported from the thymus with the exception of invariant NK T (iNKT) cells. iNKT cells undergo lineage expansion after positive selection and acquire NK receptor expression once fully mature; yet, the majority of mature iNKT cells are retained in the thymus by an as of yet unidentified mechanism. In this study we demonstrate that mature iNKT cells are retained in the thymus by the chemokine receptor CXCR3. We propose that the expression of CXCR3 ligands in the thymic medullary epithelium promotes the chemotactic retention of mature iNKT thymocytes and prevents leakage of iNKT cells into the peripheral circulation.

Adjustments in Food Choices and Physical Activity during Lockdown by Flemish Adults.

BACKGROUND: On Wednesday 18/03/2020 Belgium was placed in lockdown in order to curb the spread of COVID-19. Lockdown can lead to loneliness, boredom, anger, anxiety and depression, which in turn have an influence on food choices and physical activity (PA). This study aims to map the adjustments in food choices and PA by Flemish adults during lockdown. METHODS: Chi square tests were performed to investigate the relationship between adjustments in food choices, PA and demographic variables. RESULTS: A total of 1.129 respondents filled in the online questionnaire, aged between 18 and 81 years. The healthiest food choices were made by respondents living alone during lockdown, whilst people cohabiting with others increased their PA significantly. Moreover, the dietary adjustments of adults living with children evolved more favourably to healthier choices then those cohousing with other adults. However, respondents living with other adults showed a more favourable pattern regarding adjustments in PA. The strongest increase in sedentary behaviour was observed in students. CONCLUSIONS: This study shows the impact of lockdown on both PA and food choices, where healthier adjustments were observed in PA and respondents were prone to consume unhealthier food.

Application of a new anti-zearalenone monoclonal antibody in different immunoassay formats.

Monoclonal antibodies against zearalenone (ZEA) were raised in mice according to the hybridoma technology and applied in different immunochemical techniques. More specifically, three formats based on the competitive direct enzyme immunoassay principle were developed: an enzyme-linked immunosorbent assay (ELISA), a flow-through gel-based immunoassay column and a flow-through membrane-based immunoassay. In ELISA, the 50% inhibitory concentration (IC50) was 0.8 ng/mL, and the limit of detection for ZEA standard solutions was 0.1 ng/mL. The antibodies showed a high ZEA (100%) and alpha-zearalenol (alpha-ZOL) (69%) recognition, while cross-reactivities with alpha-zearalanol, zearalanone, beta-zearalenol and beta- zearalanol were 42%, 22%, <1% and <1%, respectively. For standard solutions, a cut-off level at 10 ng/mL could be established for the gel- and membrane-based enzyme immunoassays. Assay time of both non-instrumental tests was 25 min for 10 samples. By including a simple sample extraction procedure, the methods were applied to wheat with IC50s in ELISA of 80 and 120 microg/kg (dilution up to 5% and 15% (v/v) of wheat matrix, respectively). The cut-off level of the gel- and membrane-based immunoassays was established at 100 microg/kg. Potentials and limitations of the developed methods were compared. The possible application for multi-mycotoxin analysis of the ELISA method based on a single monoclonal antibody was investigated. Therefore, principal component analysis and partial least squares regression data modelling were used to separate the immunoassay responses of two cross-reactants (ZEA and alpha-ZOL).

CRBP-I in the renal tubulointerstitial compartment of healthy rats and rats with renal fibrosis.

BACKGROUND: Cellular retinol-binding protein I (CRBP-I), a member of the intracellular lipid-binding protein (iLBP) superfamily, is a specific marker of quiescent stellate cells in the healthy human liver. In the diseased fibrotic/cirrhotic liver, portal and septal myofibroblasts acquire CRBP-I expression, while activated hepatic stellate cells maintain their CRBP-I expression. Here, we investigate the distribution of CRBP-I in the renal cortex of healthy rats and rats with renal fibrosis. METHODS: Kidneys of healthy and adriamycin-treated rats were studied by immunohistochemistry, using antibodies against CRBP-I, desmin, vimentin and alpha-smooth muscle actin (alpha-SMA). Double stainings were done with immunofluorescence. Western blotting was performed to semi-quantify the expression levels of vimentin, desmin, alpha-SMA and CRBP-I. RESULTS: In the normal rat kidney, the convoluted proximal tubular epithelial cells express CRBP-I; no expression is found in the interstitium, nor in the glomeruli. In the adriamycin-induced fibrotic rat kidney, CRBP-I expression diminishes in the convoluted proximal tubular epithelial cells, whereas peritubular myofibroblasts in the interstitium acquire CRBP-I expression. CONCLUSIONS: In the tubulointerstitial compartment of the adriamycin-induced fibrotic rat kidney, CRBP-I is expressed in a different pattern than in the healthy rat kidney. As the convoluted proximal tubular epithelial cells dedifferentiate during fibrosis, CRBP-I expression decreases. Furthermore, de novo expression of CRBP-I is found in activated myofibroblast-like cells in the interstitium of adriamycin-treated rats. CRBP-I is therefore a useful marker to identify a subpopulation of activated/ myodifferentiated fibroblasts in the rat kidney.

Lymphotoxin alpha 1 beta 2: a critical mediator in V alpha 14i NKT cell differentiation.

Lymphotoxin (LT) alpha 1 beta 2, a tumour necrosis factor (TNF) cytokine critically involved in lymphoid organogenesis, is indispensable for the differentiation of V alpha 14i natural killer T (NKT) cells, a lymphocyte subset with important immunoregulatory properties. However, it is not required for the development of conventional T-cells. LT alpha 1 beta 2 signals through the LT beta receptor, which is expressed on non-lymphoid cells. Triggering of this receptor induces a unique signalling cascade leading to the activation of the transcription factor RelB through activation of NF-kappa B inducing kinase. This pathway is required for V alpha 14i NKT cell differentiation as appears from studies in gene-deficient animals. By reciprocal bone marrow chimeras, it was shown that RelB is required in a radiation-resistant host cell or stromal cell for normal V alpha 14i NKT cell development, presumably in the thymic stroma. These stromal cells are not required for the positive selection of these cells but rather play a prominent role in their terminal differentiation. Altogether, these observations underscore the unique developmental requirements of this particular lymphocyte subset.

Endothelial Nitric Oxide Synthase Prevents Heparanase Induction and the Development of Proteinuria.

Endothelial nitric oxide synthase (eNOS) deficiency exacerbates proteinuria and renal injury in several glomerular diseases, but the underlying mechanism is not fully understood. We recently showed that heparanase is essential for the development of experimental diabetic nephropathy and glomerulonephritis, and hypothesize that heparanase expression is regulated by eNOS. Here, we demonstrate that induction of adriamycin nephropathy (AN) in C57BL/6 eNOS-deficient mice leads to an increased glomerular heparanase expression accompanied with overt proteinuria, which was not observed in the AN-resistant wild type counterpart. In vitro, the eNOS inhibitor asymmetric dimethylarginine (ADMA) induced heparanase expression in cultured mouse glomerular endothelial cells. Moreover, ADMA enhanced transendothelial albumin passage in a heparanase-dependent manner. We conclude that eNOS prevents heparanase induction and the development of proteinuria.

Ly49E expression points toward overlapping, but distinct, natural killer (NK) cell differentiation kinetics and potential of fetal versus adult lymphoid progenitors.

Using a new antibody, we found previously that contrary to adult natural killer (NK) cells, fetal NK cells have a unique phenotype, as they exclusively express Ly49E. This can be explained by an intrinsic different NK differentiation potential of fetal versus adult lymphoid progenitors, by immaturity of fetal NK cells or by instability of Ly49E expression. Here, we show that adult progenitor cells were still capable of differentiating into Ly49E-expressing NK cells but at a much lower frequency. Surprisingly, Ly49E expression in vitro did not require stromal cells. Kinetic analysis in vivo showed that Ly49E was expressed early, together with CD94/NKG2 and Ly49G2, followed by Ly49C, and finally Ly49D. Transfer of sorted Ly49E-positive fetal NK cells showed stable Ly49E expression, and later, part of these cells up-regulated other Ly49 members. These data indicate that although there are intrinsic differences, there is no strict fetal and adult wave of NK cell differentiation.

HDAC inhibitors in experimental liver and kidney fibrosis.

Histone deacetylase (HDAC) inhibitors have been extensively studied in experimental models of cancer, where their inhibition of deacetylation has been proven to regulate cell survival, proliferation, differentiation and apoptosis. This in turn has led to the use of a variety of HDAC inhibitors in clinical trials. In recent years the applicability of HDAC inhibitors in other areas of disease has been explored, including the treatment of fibrotic disorders. Impaired wound healing involves the continuous deposition and cross-linking of extracellular matrix governed by myofibroblasts leading to diseases such as liver and kidney fibrosis; both diseases have high unmet medical needs which are a burden on health budgets worldwide. We provide an overview of the potential use of HDAC inhibitors against liver and kidney fibrosis using the current understanding of these inhibitors in experimental animal models and in vitro models of fibrosis.

Class II HDAC inhibition hampers hepatic stellate cell activation by induction of microRNA-29.

BACKGROUND: The conversion of a quiescent vitamin A storing hepatic stellate cell (HSC) to a matrix producing, contractile myofibroblast-like activated HSC is a key event in the onset of liver disease following injury of any aetiology. Previous studies have shown that class I histone deacetylases (HDACs) are involved in the phenotypical changes occurring during stellate cell activation in liver and pancreas. AIMS: In the current study we investigate the role of class II HDACs during HSC activation. METHODS: We characterized the expression of the class II HDACs freshly isolated mouse HSCs. We inhibited HDAC activity by selective pharmacological inhibition with MC1568, and by repressing class II HDAC gene expression using specific siRNAs. RESULTS: Inhibition of HDAC activity leads to a strong reduction of HSC activation markers α-SMA, lysyl oxidase and collagens as well as an inhibition of cell proliferation. Knock down experiments showed that HDAC4 contributes to HSC activation by regulating lysyl oxidase expression. In addition, we observed a strong up regulation of miR-29, a well-known anti-fibrotic miR, upon treatment with MC1568. Our in vivo work suggests that a successful inhibition of class II HDACs could be promising for development of future anti-fibrotic compounds. CONCLUSIONS: In conclusion, the use of MC1568 has enabled us to identify a role for class II HDACs regulating miR-29 during HSC activation.