4-Octyl itaconate reduces influenza A replication by targeting the nuclear export protein CRM1

In recent years, especially since the outbreak of the severe acute respiratory syndrome coronavirus 2 pandemic, the cell-permeable itaconate derivative 4-octyl itaconate (4-OI) has gained traction as a potential antiviral agent. Here, we demonstrate that 4-OI inhibits replication of multiple influenza A viruses (IAV) by restricting nuclear export of viral ribonucleoproteins, a key step in the IAV replication cycle. This nuclear retention is achieved by deactivation and subsequent degradation of chromosomal maintenance 1 protein (CRM1), also known as exportin 1 (XPO1), a host cell protein exploited by IAV during replication. 4-OI-mediated deactivation of CRM1 resulted in the accumulation of the IAV nucleoprotein, the Rev protein of feline immunodeficiency virus, as well as the natural CRM1 cargos p53 and p65, in the nucleus of treated cells. Further mechanism of action studies revealed that, similar to known CRM1 inhibitors, 4-OI modifies a key cysteine in the cargo binding pocket of CRM1 at position 528 through an alkylation reaction called 2,3-dicarboxypropylation. Subsequent studies in a cell line in which the cysteine at position 528 in CRM1 protein was substituted by a serine confirmed that modification of this residue was indeed the cause for the observed inhibitory effect induced by 4-OI on CRM1 function. Overall, this study demonstrated a mechanism through which 4-OI directly interferes with the replication cycle of CRM1-dependent viruses, which contributes to the understanding of the antiviral and anti-inflammatory properties of this multifaceted immuno-metabolite. IMPORTANCE Itaconate derivates, as well as the naturally produced metabolite, have been proposed as antivirals against influenza virus. Here, the mechanism behind the antiviral effects of exogenous 4-octyl itaconate (4-OI), a derivative of itaconate, against the influenza A virus replication is demonstrated. The data indicate that 4-OI targets the cysteine at position 528 of the CRM1 protein, resulting in inhibition of the nuclear export of viral ribonucleoprotein complexes in a similar manner as previously described for other selective inhibitors of nuclear export. These results postulate a mechanism not observed before for this immuno-metabolite derivative. This knowledge is helpful for the development of derivatives of 4-OI as potential antiviral and anti-inflammatory therapeutics.</p

Anti-infliximab antibodies are already detectable in most patients with rheumatoid arthritis halfway through an infusioncycle: an open-label pharmacokinetic cohort study

Contains fulltext : 97636.pdf (publisher's version ) (Open Access)BACKGROUND: This study in patients with rheumatoid arthritis (RA) treated with infliximab describes prospectively the course of (anti)infliximab levels within an infusioncycle to assess at what moment patients develop low/no infliximab trough levels and/or detectable anti-infliximab levels. METHODS: Infliximab treated RA patients were included in this descriptive open-label cohort study. During one infusioncycle (anti-)infliximab levels were assessed just before and one hour after infusion, and subsequently at 50%, 75% and at the end of the infusioncycle (pre-infusion). RESULTS: 27 patients were included. The median infliximab levels decreased from 77.0 mg/l (p25-p75: 65-89) one hour after the infusion to pre-infusion levels of 0.0 mg/l (p25-p75: 0.0-3.1). In 7 (26%) patients pre-infusion anti-infliximab antibodies were detected; these antibodies were already present halfway through the infusioncycle in 5 of the 7 individuals. Patients with detectable pre-infusion anti-infliximab antibodies have significantly more often low/no infliximab levels (< 1 mg/l) halfway trough the infusioncycle (in 5/7 patients) compared to patients without detectable pre-infusion anti-infliximab antibodies (0/20 patients, p < 0.001). CONCLUSIONS: Most anti-infliximab forming patients have detectable anti-infliximab antibodies halfway through an infusioncycle, which implies that these patients are exposed to nontherapeutical infliximab levels during more than halve of their infusion cycle. As none of the patients without anti-infliximab antibodies had no/low-infliximab levels halfway through the infusioncycle, the presence of pre-infusion anti-infliximab antibodies seems a sensitive and specific predictor for no/low infliximab-levels

Reactive community-based self-administered treatment against residual malaria transmission: study protocol for a randomized controlled trial

Background: Systematic treatment of all individuals living in the same compound of a clinical malaria case may clear asymptomatic infections and possibly reduce malaria transmission, where this is focal. High and sustained coverage is extremely important and requires active community engagement. This study explores a communitybased approach to treating malaria case contacts. Methods/design: This is a cluster-randomized trial to determine whether, in low-transmission areas, treating individuals living in the same compound of a clinical malaria case with dihydroartemisinin-piperaquine can reduce parasite carriage and thus residual malaria transmission. Treatment will be administered through the local health system with the approach of encouraging community participation designed and monitored through formative research. The trial goal is to show that this approach can reduce in intervention villages the prevalence of Plasmodium falciparum infection toward the end of the malaria transmission season. Discussion: Adherence and cooperation of the local communities are critical for the success of mass treatment campaigns aimed at reducing malaria transmission. By exploring community perceptions of the changing trends in malaria burden, existing health systems, and reaction to self-administered treatment, this study will develop and adapt a model for community engagement toward malaria elimination that is cost-effective and fits within the existing health system. Trial registration: Clinical trials.gov, NCT02878200. Registered on 25 August 2016

Frequency and Interrelations of Risk Factors for Chronic Low Back Pain in a Primary Care Setting

INTRODUCTION: Many risk factors have been identified for chronic low back pain (cLBP), but only one study evaluated their interrelations. We aimed to investigate the frequency of cLBP risk factors and their interrelations in patients consulting their general practitioners (GPs) for cLBP. METHODS: A cross-sectional, descriptive, national survey was performed. 3000 GPs randomly selected were asked to include at least one patient consulting for cLBP. Demographic, clinical characteristics and the presence of cLBP risk factors were recorded. The frequency of each cLBP risk factor was calculated and multiple correspondence analysis (MCA) was performed to study their interrelations. RESULTS: A total of 2068 GPs (68.9%) included at least 1 patient, for 4522 questionnaires analyzed. In the whole sample of patients, the 2 risk factors most commonly observed were history of recurrent LBP (72.1%) and initial limitation of activities of daily living (66.4%). For working patients, common professional risk factors were beliefs, that LBP was due to maintaining a specific posture at work (79.0%) and frequent heavy lifting at work (65.5%). On MCA, we identified 3 risk-factor dimensions (axes) for working and nonworking patients. The main dimension for working patients involved professional risk factors and among these factors, patients' job satisfaction and job recognition largely contribute to this dimension. DISCUSSION: Our results shed in light for the first time the interrelation and the respective contribution of several previously identified cLBP risk factors. They suggest that risk factors representing a "work-related" dimension are the most important cLBP risk factors in the working population

Epigenetic Repression of RARRES1 Is Mediated by Methylation of a Proximal Promoter and a Loss of CTCF Binding

The cis-acting promoter element responsible for epigenetic silencing of retinoic acid receptor responder 1 (RARRES1) by methylation is unclear. Likewise, how aberrant methylation interplays effectors and thus affects breast neoplastic features remains largely unknown.We first compared methylation occurring at the sequences (-664~+420) flanking the RARRES1 promoter in primary breast carcinomas to that in adjacent benign tissues. Surprisingly, tumor cores displayed significantly elevated methylation occurring solely at the upstream region (-664~-86), while the downstream element (-85~+420) proximal to the transcriptional start site (+1) remained largely unchanged. Yet, hypermethylation at the former did not result in appreciable silencing effect. In contrast, the proximal sequence displayed full promoter activity and methylation of which remarkably silenced RARRES1 transcription. This phenomenon was recapitulated in breast cancer cell lines, in which methylation at the proximal region strikingly coincided with downregulation. We also discovered that CTCF occupancy was enriched at the unmethylayed promoter bound with transcription-active histone markings. Furthermore, knocking-down CTCF expression hampered RARRES1 expression, suggesting CTCF positively regulated RARRES1 transcription presumably by binding to unmethylated promoter poised at transcription-ready state. Moreover, RARRES1 restoration not only impeded cell invasion but also promoted death induced by chemotherapeutic agents, denoting its tumor suppressive effect. Its role of attenuating invasion agreed with data generated from clinical specimens revealing that RARRES1 was generally downregulated in metastatic lymph nodes compared to the tumor cores.This report delineated silencing of RARRES1 by hypermethylation is occurring at a proximal promoter element and is associated with a loss of binding to CTCF, an activator for RARRES1 expression. We also revealed the tumor suppressive roles exerted by RARRES1 in part by promoting breast epithelial cell death and by impeding cell invasion that is an important property for metastatic spread

Demographic, clinical and antibody characteristics of patients with digital ulcers in systemic sclerosis: data from the DUO Registry

OBJECTIVES: The Digital Ulcers Outcome (DUO) Registry was designed to describe the clinical and antibody characteristics, disease course and outcomes of patients with digital ulcers associated with systemic sclerosis (SSc). METHODS: The DUO Registry is a European, prospective, multicentre, observational, registry of SSc patients with ongoing digital ulcer disease, irrespective of treatment regimen. Data collected included demographics, SSc duration, SSc subset, internal organ manifestations, autoantibodies, previous and ongoing interventions and complications related to digital ulcers. RESULTS: Up to 19 November 2010 a total of 2439 patients had enrolled into the registry. Most were classified as either limited cutaneous SSc (lcSSc; 52.2%) or diffuse cutaneous SSc (dcSSc; 36.9%). Digital ulcers developed earlier in patients with dcSSc compared with lcSSc. Almost all patients (95.7%) tested positive for antinuclear antibodies, 45.2% for anti-scleroderma-70 and 43.6% for anticentromere antibodies (ACA). The first digital ulcer in the anti-scleroderma-70-positive patient cohort occurred approximately 5 years earlier than the ACA-positive patient group. CONCLUSIONS: This study provides data from a large cohort of SSc patients with a history of digital ulcers. The early occurrence and high frequency of digital ulcer complications are especially seen in patients with dcSSc and/or anti-scleroderma-70 antibodies