Dimethyl fumarate modulates neutrophil extracellular trap formation in a glutathione- and superoxide-dependent manner.

BACKGROUND: Neutrophil (polymorphonuclear) granulocytes (PMN) have been shown to contribute to the pathogenesis of psoriasis by releasing interleukin-17 and LL37-DNA complexes via neutrophil extracellular traps (NETs), webs of chromatin strands decorated with antimicrobial peptides, in psoriatic skin. Fumaderm® , a fumaric acid ester (FAE) formulation consisting of different FAE salts, has been successfully used to treat psoriasis for decades. Most recently, FAE treatment was reported to inhibit NET formation in murine epidermolysis bullosa acquisita. OBJECTIVES: To elucidate the effect of FAE treatment on human psoriasis and healthy donor NET formation. RESULTS: Among the compounds present in the FAE formulation, dimethyl fumarate (DMF) pretreatment of human psoriasis and healthy donor PMN resulted in a consistent inhibitory effect on NET formation in response to phorbol 12-myristate 13-acetate but not to platelet activating factor and ionomycin. This effect was l-glutathione (GSH) dependent and involved a decrease in reactive oxygen species (ROS) production, a key event in NET formation. In contrast, G-protein-coupled signalling and protein synthesis were not involved. Monomethyl fumarate (MMF) was found to slightly reduce ROS production without affecting NET formation. CONCLUSIONS: We report DMF as a potent, stimulus-specific, GSH- and ROS-dependent modulator of NET formation. Our results support the notion that modulation of NET formation contributes to the beneficial effects of FAEs in a variety of inflammatory conditions.

Fungal Pathogens in CF Airways: Leave or Treat?

Chronic airway infection plays an essential role in the progress of cystic fibrosis (CF) lung disease. In the past decades, mainly bacterial pathogens, such as Pseudomonas aeruginosa, have been the focus of researchers and clinicians. However, fungi are frequently detected in CF airways and there is an increasing body of evidence that fungal pathogens might play a role in CF lung disease. Several studies have shown an association of fungi, particularly Aspergillus fumigatus and Candida albicans, with the course of lung disease in CF patients. Mechanistically, in vitro and in vivo studies suggest that an impaired immune response to fungal pathogens in CF airways renders them more susceptible to fungi. However, it remains elusive whether fungi are actively involved in CF lung disease pathologies or whether they rather reflect a dysregulated airway colonization and act as microbial bystanders. A key issue for dissecting the role of fungi in CF lung disease is the distinction of dynamic fungal-host interaction entities, namely colonization, sensitization or infection. This review summarizes key findings on pathophysiological mechanisms and the clinical impact of fungi in CF lung disease.

Treatment de-escalation in HPV-positive oropharyngeal carcinoma: ongoing trials, critical issues and perspectives.

Due to the generally poor prognosis of head and neck squamous cell carcinoma (HNSCC), treatment has been intensified, these last decades, leading to an increase of serious side effects. High-risk human papillomavirus (HR-HPV) infection has been recently etiologically linked to a subset of oropharyngeal squamous cell carcinoma (OPSCC), which is on the increase. These tumors are different, at the clinical and molecular level, when compared to tumors caused by traditional risk factors. Additionally, their prognosis is much more favorable which has led the medical community to consider new treatment strategies. Indeed, it is possible that less intensive treatment regimens could achieve similar efficacy with less toxicity and improved quality of life. Several clinical trials, investigating different ways to de-escalate treatment, are currently ongoing. In this article, we review these main approaches, discuss the rationale behind them and the issues raised by treatment de-escalation in HPV-positive OPSCC.

Screening in asymptomatic SDHx mutation carriers: added value of ¹8F-FDG PET/CT at initial diagnosis and 1-year follow-up.

PURPOSE: Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of (18)F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population. METHODS: The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by (18)F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. (123)I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year. RESULTS: At initial work-up, an imaging abnormality was found in eight subjects (27%). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with (18)F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutaion and two were considered false-positive. The tumour detection rate was 100% for (18)F-FDG PET/CT and conventional imaging, 80% for SRS and 60% for (123)I-MIBG scintigraphy. Overall, disease was detected in 4% of the subjects at the 1-year follow-up. CONCLUSION: (18)F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if (18)F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination that does not expose the patient to radiation should be used.

Neutrophilic myeloid-derived suppressor cells in cord blood modulate innate and adaptive immune responses.

Neonates show an impaired anti-microbial host defence, but the underlying immune mechanisms are not understood fully. Myeloid-derived suppressor cells (MDSCs) represent an innate immune cell subset characterized by their capacity to suppress T cell immunity. In this study we demonstrate that a distinct MDSC subset with a neutrophilic/granulocytic phenotype (Gr-MDSCs) is highly increased in cord blood compared to peripheral blood of children and adults. Functionally, cord blood isolated Gr-MDSCs suppressed T cell proliferation efficiently as well as T helper type 1 (Th1), Th2 and Th17 cytokine secretion. Beyond T cells, cord blood Gr-MDSCs controlled natural killer (NK) cell cytotoxicity in a cell contact-dependent manner. These studies establish neutrophilic Gr-MDSCs as a novel immunosuppressive cell subset that controls innate (NK) and adaptive (T cell) immune responses in neonates. Increased MDSC activity in cord blood might serve as key fetomaternal immunosuppressive mechanism impairing neonatal host defence. Gr-MDSCs in cord blood might therefore represent a therapeutic target in neonatal infections.

RADseq underestimates diversity and introduces genealogical biases due to nonrandom haplotype sampling.

Reduced representation genome-sequencing approaches based on restriction digestion are enabling large-scale marker generation and facilitating genomic studies in a wide range of model and nonmodel systems. However, sampling chromosomes based on restriction digestion may introduce a bias in allele frequency estimation due to polymorphisms in restriction sites. To explore the effects of this nonrandom sampling and its sensitivity to different evolutionary parameters, we developed a coalescent-simulation framework to mimic the biased recovery of chromosomes in restriction-based short-read sequencing experiments (RADseq). We analysed simulated DNA sequence datasets and compared known values from simulations with those that would be estimated using a RADseq approach from the same samples. We compare these 'true' and 'estimated' values of commonly used summary statistics, π, θ(w), Tajima's D and F(ST). We show that loci with missing haplotypes have estimated summary statistic values that can deviate dramatically from true values and are also enriched for particular genealogical histories. These biases are sensitive to nonequilibrium demography, such as bottlenecks and population expansion. In silico digests with 102 completely sequenced Drosophila melanogaster genomes yielded results similar to our findings from coalescent simulations. Though the potential of RADseq for marker discovery and trait mapping in nonmodel systems remains undisputed, our results urge caution when applying this technique to make population genetic inferences.

Natural variation of the Y chromosome suppresses sex ratio distortion and modulates testis-specific gene expression in Drosophila simulans.

X-linked sex-ratio distorters that disrupt spermatogenesis can cause a deficiency in functional Y-bearing sperm and a female-biased sex ratio. Y-linked modifiers that restore a normal sex ratio might be abundant and favored when a X-linked distorter is present. Here we investigated natural variation of Y-linked suppressors of sex-ratio in the Winters systems and the ability of these chromosomes to modulate gene expression in Drosophila simulans. Seventy-eight Y chromosomes of worldwide origin were assayed for their resistance to the X-linked sex-ratio distorter gene Dox. Y chromosome diversity caused males to sire ∼63% to ∼98% female progeny. Genome-wide gene expression analysis revealed hundreds of genes differentially expressed between isogenic males with sensitive (high sex ratio) and resistant (low sex ratio) Y chromosomes from the same population. Although the expression of about 75% of all testis-specific genes remained unchanged across Y chromosomes, a subset of post-meiotic genes was upregulated by resistant Y chromosomes. Conversely, a set of accessory gland-specific genes and mitochondrial genes were downregulated in males with resistant Y chromosomes. The D. simulans Y chromosome also modulated gene expression in XXY females in which the Y-linked protein-coding genes are not transcribed. The data suggest that the Y chromosome might exert its regulatory functions through epigenetic mechanisms that do not require the expression of protein-coding genes. The gene network that modulates sex ratio distortion by the Y chromosome is poorly understood, other than that it might include interactions with mitochondria and enriched for genes expressed in post-meiotic stages of spermatogenesis.

The role of matrix metalloproteinases in cystic fibrosis lung disease.

Significant airway remodelling is a major component of the increased morbidity and mortality observed in cystic fibrosis (CF) patients. These airways feature ongoing leukocytic inflammation and unrelenting bacterial infection. In contrast to acute bacterial pneumonia, CF infection is not cleared efficiently and the ensuing inflammatory response causes tissue damage. This structural damage is mainly a result of free proteolytic activity released by infiltrated neutrophils and macrophages. Major proteases in this disease are serine and matrix metalloproteases (MMPs). While the role of serine proteases, such as elastase, has been characterised in detail, there is emerging evidence that MMPs could play a key role in the pathogenesis of CF lung disease. This review summarises studies linking MMPs with CF lung disease and discusses the potential value of MMPs as future therapeutic targets in CF and other chronic lung diseases.

Novel method to process cystic fibrosis sputum for determination of oxidative state.

BACKGROUND: Induced sputum is the most commonly used method to analyze airway inflammation in cystic fibrosis (CF) patients ex vivo. Due to the complex matrix of the sample material, precise and reliable analysis of sputum constituents depends critically on preanalytical issues. OBJECTIVES: Here we compared the commonly used method for sputum processing by dithiothreitol (DTT) with a novel mechanical method in regard to basal cellular parameters, neutrophil markers and glutathione (GSH) levels. METHODS: Sputum samples from CF patients were processed in parallel with or without the use of DTT. The key improvement of the mechanical method was the processing in many very small aliquots. Cellular and humoral markers were assessed and compared according to Bland-Altman. RESULTS: Total cell count, cell viability, differential cell count, neutrophil elastase levels and flow cytometrically analyzed neutrophil markers (CD63, CD11b, DHR) did not differ between the two methods. Intracellular and extracellular GSH levels were significantly higher in DTT-treated samples (p = 0.002). CONCLUSION: The mechanical sputum-processing method presented had a similar yield of cells and fluids as the conventional DTT method and the advantage of omitting the introduction of reducing agents. This method allows a more reliable analysis of redox-dependent airway inflammation in sputum cells and fluid from CF patients than methods utilizing DTT.

[Alpha-1-blockers (alfuzosin) for obstructive salivary gland diseases]. / Les Alpha-1-Bloquants (alfuzosine) en pathologie salivaire obstructive.

INTRODUCTION: Alpha-blockers are used in urology to treat stenosis and lithiasis. The pathophysiology is similar in salivary glands. We had for aim to assess the safety and effectiveness of an alpha-blocker (Alfuzosin) in patients with ductal stenosis, allergic pseudo-parotitis or sialolithiasis after lithotripsy. PATIENTS AND METHODS: Three hundred and fifty-two patients were included, 194 of whom presented with sialolithiasis fragmented by extracorporeal lithotripsy (112 parotidic and 82 submandibular). Sixty-nine presented with ductal stenosis, and 89 with allergic pseudo-parotitis. This retrospective study lasted 3 years (January 2005 to January 2008) with a mean follow-up of 33 months (18 months to 4 years). Male patients were given 2.5mg tid of the alpha-blocker Alfuzosin and female patients 2.5mg bid for 3 to 24 months. After 6 months and up to 2 years of treatment, patients were assessed every 3 months by US and with a questionnaire on symptoms. RESULTS: Results were similar in male and female patients. Eighty percent of patients with colic-like pain due to stenosis reported a significant improvement after treatment. 78.6% of patients with allergic pseudo-parotitis felt they had improved and noted a sharp decrease of pruritus. Sixty-seven of the patients with residual parotid lithiasis after extracorporeal lithotripsy presented with less ductal lithiasis and fragments were evacuated more rapidly in the two months following lithotripsy. Forty-two percent of the patients treated for residual submandibular lithiasis reported a significant functional improvement and faster evacuation of fragments. Twelve patients out of 352 (3.4%) reported adverse effects. The incidence of orthostatic hypotension was 2.2%. DISCUSSION: A significant improvement of symptoms was observed in patients treated with Alfuzosin for obstructive salivary gland diseases. The drug was well tolerated. These preliminary results are good in terms of effectiveness and inocuity. They should be confirmed with a prospective controlled study.

French consensus on management of head and neck cancer surgery during COVID-19 pandemic.

In the context of the current pandemic, there is a need for specific advice concerning treatment of patients with Head and Neck cancers. The rule is to limit as much as possible the number of patients in order to reduce the risks of contamination by the SARS-Cov-2 virus for both patients and the caregivers, who are particularly exposed in ENT. The aim is to minimize the risk of loss of opportunity for patients and to anticipate the increased number of cancer patients to be treated at the end of the pandemic, taking into account the degree of urgency, the difficulty of the surgery, the risk of contaminating the caregivers (tracheotomy) and the local situation (whether or not the hospital and intensive care departments are overstretched).

Locally unresectable differentiated thyroid cancer: outcomes and perspectives.

PURPOSE: Differentiated thyroid cancer (DTC) patients with an unresectable primary tumor cannot benefit from curative surgery, and radioiodine treatment for locoregional and distant disease is not possible with the thyroid gland still in place. Due to local invasion, these patients cannot be included in clinical trials, so that treatment options are limited. The aim of this study was to describe the characteristics and the prognosis of patients with these locally unresectable DTC. PATIENTS AND METHODS: A retrospective and multicentric analysis of consecutive cases of unresectable DTC diagnosed between 2000 and 2015 was performed. RESULTS: The study population consisted in 22 patients, 13 females (59%); median age: 77 years (range: 52-91). Thyroid tumors were papillary in six, follicular in seven, Hürthle cell in one and poorly differentiated in eight patients. Patients were treated with external beam radiation therapy (EBRT) (57%), locoregional therapy of distant metastases (41%), cytotoxic chemotherapy (38%) and tyrosine kinase inhibitors (TKIs) (33%). TKI treatment resulted in median disease control duration of 7 months with a grade 3-4 toxicity rate of 44%. Only one patient had a total thyroidectomy after neo-adjuvant EBRT. The 1, 3 and 5-year cumulative survival rate was 81%, 27.7% and 21.5%, respectively. The cause of death was DTC in 11 cases (local progression in 7), and to other causes in 7 cases; no patient died from treatment toxicity. CONCLUSIONS: Clinical trials and approved treatments are lacking for unresectable DTC. TKI treatment may allow prolonged disease control with acceptable toxicity.

Innate immune receptors on neutrophils and their role in chronic lung disease.

Neutrophils, the prototypic cells of the innate immune system, are recruited to infected sites to protect the human body from invading pathogens. To accomplish this function, neutrophils sense pathogens and endogenous damage-associated molecules via innate immune receptors, such as Toll-like receptors (TLRs) and other pattern recognition receptors. This defence function is essential for the pulmonary microenvironment where the host is faced with millions of particles and pathogens inhaled daily. Chronic lung diseases, such as cystic fibrosis or chronic obstructive pulmonary disease are characterized by a neutrophil accumulation and chronic bacterial colonization of the airways. Consequently, insights into the role of TLRs on neutrophils in chronic lung diseases are of high relevance for further diagnostic and therapeutic approaches. Here we summarize and discuss recent advances in the expression, regulation and functional role of TLRs on neutrophils in chronic lung diseases.

Maternally inherited transposon excision in Drosophila simulans.

A mutation in the white gene of Drosophila mauritiana resulting from insertion of the transposable element mariner exhibits genetic instability in germline and somatic cells. The instability is greatly enhanced in the presence of the trans-acting autosomal factor Mos, giving eye-color mosaics with pigmented sectors of tissue on an otherwise peach-colored background. The Mos factor, when introduced into the genome of the sibling species Drosophila simulans, exhibited a dramatic maternal effect on expression of the mosaic phenotype. When D. simulans mosaic females (heterozygous for Mos) were crossed with non-mosaic males, two distinct classes of mosaic offspring occurred, one resulting from a maternal effect in which the non-Mos offspring were nevertheless mosaic. The maternal effect was mediated by a product acting after fertilization, and was expressed to varying extents in different backcross strains.

Population genetics in forensic DNA typing.

Variable number of tandem repeat (VNTR) sequences are used to link defendants with crimes by matching DNA patterns. The probative value of a match is often calculated by multiplying together the estimated frequencies with which each particular VNTR pattern occurs in a reference database. However, this method is liable to potentially serious errors because ethnic subgroups within major racial categories exhibit genetic differences that are maintained by endogamy. The multiplication procedure currently in use can be made scientifically valid only by extensive sampling of VNTR frequency distributions in a variety of ethnic groups, similar to the ethnic studies of various blood groups done in the past. Alternative approaches for dealing with subpopulation heterogeneity are discussed.

Histone transition during spermiogenesis is absent in segregation distorter males of Drosophila melanogaster.

Males homozygous for the segregation distorter chromosome are often sterile or nearly sterile as a result of the dysfunction of virtually all their sperm. Spermatid bundles from such males do not exhibit the normal transition from lysine-rich to arginine-rich histones.

Heritable somatic excision of a Drosophila transposon.

A mutation in the white gene of Drosophila mauritiana that results from insertion of the transposable element mariner is genetically unstable in both germ cells and somatic cells. Somatic instability is indicated by the occurrence of animals having mosaic eyes with patches of pigmented cells on a peach-colored background. Normally uncommon, the frequency of mosaicism is so greatly enhanced in a particular mutant strain that virtually every animal in the strain is an eye-color mosaic. The molecular basis of the mosaicism is the excision of the mariner element from its location in the DNA of the white gene in somatic cells. The phenomenon results from a single dominant genetic factor located in chromosome 3. Genetic control over the excision of transposable elements may play a role in determining the persistence of transposable elements in the genome.

Toward cloning and mapping the genome of Drosophila.

An ultimate goal of Drosophila genetics is to identify and define the functions of all the genes in the organism. Traditional approaches based on the isolation of mutant genes have been extraordinary fruitful. Recent advances in the manipulation and analysis of large DNA fragments have made it possible to develop detailed molecular maps of the Drosophila genome as the initial steps in determining the complete DNA sequence.