Negative regulation of EGFR signalling by the human folliculin tumour suppressor protein

Germline mutations in the Folliculin (FLCN) tumour suppressor gene result in fibrofolliculomas, lung cysts and renal cancers, but the precise mechanisms of tumour suppression by FLCN remain elusive. Here we identify Rab7A, a small GTPase important for endocytic trafficking, as a novel FLCN interacting protein and demonstrate that FLCN acts as a Rab7A GTPase-activating protein. FLCN-/- cells display slower trafficking of epidermal growth factor receptors (EGFR) from early to late endosomes and enhanced activation of EGFR signalling upon ligand stimulation. Reintroduction of wild-type FLCN, but not tumour-associated FLCN mutants, suppresses EGFR signalling in a Rab7A-dependent manner. EGFR signalling is elevated in FLCN-/- tumours and the EGFR inhibitor afatinib suppresses the growth of human FLCN-/- cells as tumour xenografts. The functional interaction between FLCN and Rab7A appears conserved across species. Our work highlights a mechanism explaining, at least in part, the tumour suppressor function of FLCN

XEN 45 Gel Stent Implantation in Open Angle Glaucoma : 5-Year Results of a Prospective Study

Précis: XEN 45 Gel Stent is safe and effective for 3 years. The study results provide useful insight into the outcome of XEN 45 Gel Stent surgery over 5 years in daily clinical practice. Purpose: To evaluate 5-year outcomes of XEN 45 gel stent implantation (XEN) in patients with open angle glaucoma. Methods: This is a prospective, single-center, interventional study. XEN implantation either alone (XEN) or combined with phacoemulsification (Phaco + XEN) was performed on 170 consecutive eyes (126 patients) with uncontrolled intraocular pressure (IOP) or disease progression despite medical treatment. “Complete” surgical success at 60 months was defined as unmedicated IOP ≤15 mm Hg and a relative IOP reduction ≥20% from medicated baseline, while “qualified” success allowed fewer ocular hypotensive medications than at baseline. Other definitions of success with various IOP targets were also analyzed. Secondary outcomes included mean IOP and IOP-lowering medication changes and rates of reoperations. Results: Mean age was 78.1±9.2 years, and 70.3% were female. Mean medicated IOP decreased from 19.8±7.7 mm Hg [19.6±7.1 (XEN) vs. 19.8±7.0 mm Hg (Phaco+XEN)] at baseline to 12.6±3.1 mm Hg [12.5± 3.1 (XEN) vs. 12.6±3.1 (Phaco+XEN)] at 5 years (−37.0%; P &lt; 0.001). Medications decreased from 2.0±1.3 [2.0±1.3 (XEN) vs. 2.0±1.3 (Phaco+XEN)] to 0.8±1.1 [0.8±1.1 (XEN) vs. 0.8±1.1 (Phaco + XEN)] (−60%; P &lt;0.001). Needling was performed in 84 eyes (49%), and 19.4% underwent a secondary surgical intervention. Complete success at 3 years was a strong predictor of success at 5 years (odds ratio: 3.06, P &lt;0.01), while needling was associated with higher rates of failure (odds ratio: 3.6, P &lt;0.01). Conclusions: At 5 years, XEN gel stent implantation was a safe procedure and achieved clinically meaningful IOP and medication reduction. Success at 3 years is a predictor of success at 5 years. Needling correlates with higher failure rates.</p

Immediate and delayed effects of subchronic Paraquat exposure during an early differentiation stage in 3D-rat brain cell cultures

Xenobiotic exposure is a risk factor in the etiology of neurodegenerative disease. It was recently hypothesized that restricted exposure during brain development could predispose for a neurodegenerative disease later in life. As neuroinflammation contributes to progressive neurodegeneration, it is suspected that neurodevelopmental xenobiotic exposure could elicit a neuroinflammatory process, which over time may assume a detrimental character. We investigated the neurotoxic effects of paraquat (PQ) in three-dimensional whole rat brain cell cultures, exposed during an early differentiation stage, comparing immediate effects—directly post exposure—with long-term effects, 20 days after interrupted PQ-administration. Adverse effects and neuroinflammatory responses were assessed by measuring changes in gene- and protein-expression as well as by determining cell morphology changes. Differentiating neural cultures were highly susceptible to PQ and showed neuronal damage and strong astrogliosis. After the 20-day washout period, neurons partially recovered, whereas astrogliosis persisted, and was accompanied by microglial activation of a neurodegenerative phenotype. Our data shows that immediate and long-term effects of subchronic PQ-exposure differ. Also, PQ-exposure during this window of extensive neuronal differentiation led to a delayed microglial activation, of a character that could promote further pro-inflammatory signals that enable prolonged inflammation, thereby fueling further neurodegeneration

Flying Fox Hemolytic Fever, Description of a New Zoonosis Caused by Candidatus Mycoplasma haemohominis

International audienceBackground : Hemotropic mycoplasmas, previously classified in the genus Eperythrozoon, have been reported as causing human infections in Brazil, China, Japan, and Spain.Methods : In 2017, we detected DNA from Candidatus Mycoplasma haemohominis in the blood of a Melanesian patient from New Caledonia presenting with febrile splenomegaly, weight loss, life-threatening autoimmune hemolytic anemia, and hemophagocytosis. The full genome of the bacterium was sequenced from a blood isolate. Subsequently, we retrospectively (2011–2017) and prospectively (2018–2019) tested patients who had been hospitalized with a similar clinico-biological picture. In addition, as these patients had been in contact with frugivorous bats (authorized under conditions for hunting and eating in New Caledonia), we investigated the role of these animals and their biting flies by testing them for hemotropic mycoplasmas.Results : There were 15 patients found to be infected by this hemotropic mycoplasma. Among them, 4 (27%) died following splenectomy performed either for spontaneous spleen rupture or to cure refractory autoimmune hemolytic anemia. The bacterium was cultivated from the patient’s blood. The full genome of the Neocaledonian Candidatus M. haemohominis strain differed from that of a recently identified Japanese strain. Of 40 tested Pteropus bats, 40% were positive; 100% of collected bat flies Cyclopodia horsfieldi (Nycteribiidae, Diptera) were positive. Human, bat, and dipteran strains were highly similar.Conclusions : The bacterium being widely distributed in bats, Candidatus M. haemohominis, should be regarded as a potential cause of severe infections in humans