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Found 35038 matches. Displaying 41-50
Rodrigues G, Hoshino A, Kenific CM, Matei IR, Steiner L, Freitas D, Kim HS, Oxley PR, Scandariato I, Casanova-Salas I, Dai JX, Badwe CR, Gril B, Mark MT, Dill BD, Molina H, Zhang HY, Benito-Martin A, Bojmar L, Ararso Y, Offer K, LaPlant Q, Buehring W, Wang HJ, Jiang XR, Lu TM, Liu Y, Sabari JK, Shin SJ, Narula N, Ginter PS, Rajasekhar VK, Healey JH, Meylan E, Costa-Silva B, Wang SE, Rafii S, Altorki NK, Rudin CM, Jones DR, Steeg PS, Peinado H, Ghajar CM, Bromberg J, de Sousa M, Pisapia D, Lyden D
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Tumour exosomal CEMIP protein promotes cancer cell colonization in brain metastasis

NATURE CELL BIOLOGY 2019 NOV; 21(11):1403-1412
The development of effective therapies against brain metastasis is currently hindered by limitations in our understanding of the molecular mechanisms driving it. Here we define the contributions of tumour-secreted exosomes to brain metastatic colonization and demonstrate that pre-conditioning the brain microenvironment with exosomes from brain metastatic cells enhances cancer cell outgrowth. Proteomic analysis identified cell migration-inducing and hyaluronan-binding protein (CEMIP) as elevated in exosomes from brain metastatic but not lung or bone metastatic cells. CEMIP depletion in tumour cells impaired brain metastasis, disrupting invasion and tumour cell association with the brain vasculature, phenotypes rescued by pre-conditioning the brain microenvironment with CEMIP exosomes. Moreover, uptake of CEMIP+ exosomes by brain endothelial and microglial cells induced endothelial cell branching and inflammation in the perivascular niche by upregulating the pro-inflammatory cytokines encoded by Ptgs2, Tnf and Ccl/Cxcl, known to promote brain vascular remodelling and metastasis. CEMIP was elevated in tumour tissues and exosomes from patients with brain metastasis and predicted brain metastasis progression and patient survival. Collectively, our findings suggest that targeting exosomal CEMIP could constitute a future avenue for the prevention and treatment of brain metastasis.
Wang XM, Lu JP, Xie WG, Lu XY, Liang YJ, Li M, Wang ZC, Huang XD, Tang MX, Pfaff DW, Tang YP, Yao P
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Maternal diabetes induces autism-like behavior by hyperglycemia-mediated persistent oxidative stress and suppression of superoxide dismutase 2

Epidemiological studies show that maternal diabetes is associated with an increased risk of autism spectrum disorders (ASDs), although the detailed mechanisms remain unclear. The present study aims to investigate the potential effect of maternal diabetes on autism-like behavior in offspring. The results of in vitro study showed that transient hyperglycemia induces persistent reactive oxygen species (ROS) generation with suppressed superoxide dismutase 2 (SOD2) expression. Additionally, we found that SOD2 suppression is due to oxidative stress-mediated histone methylation and the subsequent dissociation of early growth response 1 (Egr1) on the SOD2 promoter. Furthermore, in vivo rat experiments showed that maternal diabetes induces SOD2 suppression in the amygdala, resulting in autism-like behavior in offspring. SOD2 overexpression restores, while SOD2 knockdown mimics, this effect, indicating that oxidative stress and SOD2 expression play important roles in maternal diabetes-induced autism-like behavior in offspring, while prenatal and postnatal treatment using antioxidants permeable to the blood-brain barrier partly ameliorated this effect. We conclude that maternal diabetes induces autism-like behavior through hyperglycemia-mediated persistent oxidative stress and SOD2 suppression. Here we report a potential mechanism for maternal diabetes-induced ASD.
Zammataro L, Lopez S, Bellone S, Pettinella F, Bonazzoli E, Perrone E, Zhao SM, Menderes G, Altwerger G, Han C, Zeybek B, Bianchi A, Manzano A, Manara P, Cocco E, Buza N, Hui P, Wong S, Ravaggi A, Bignotti E, Romani C, Todeschini P, Zanotti L, Odicino F, Pecorelli S, Donzelli C, Ardighieri L, Angioli R, Raspagliesi F, Scambia G, Choi JM, Dong WL, Bilguvar K, Alexandrov LB, Silasi DA, Huang GS, Ratner E, Azodi M, Schwartz PE, Pirazzoli V, Stiegler AL, Boggon TJ, Lifton RP, Schlessinger J, Santin AD
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Whole-exome sequencing of cervical carcinomas identifies activating ERBB2 and PIK3CA mutations as targets for combination therapy

The prognosis of advanced/recurrent cervical cancer patients remains poor. We analyzed 54 fresh-frozen and 15 primary cervical cancer cell lines, along with matched-normal DNA, by whole-exome sequencing (WES), most of which harboring Human-Papillomavirustype-16/18. We found recurrent somatic missense mutations in 22 genes (including PIK3CA, ERBB2, and GNAS) and a widespread APOBEC cytidine deaminase mutagenesis pattern (TON motif) in both adenocarcinoma (ACC) and squamous cell carcinomas (SCCs). Somatic copy number variants (CNVs) identified 12 copy number gains and 40 losses, occurring more often than expected by chance, with the most frequent events in pathways similar to those found from analysis of single nucleotide variants (SNV5), including the ERBB2/PI3K/AKT/mTOR, apoptosis, chromatin remodeling, and cell cycle. To validate specific SNV5 as targets, we took advantage of primary cervical tumor cell lines and xenografts to preclinically evaluate the activity of pan-HER (afatinib and neratinib) and PIK3CA (copanlisib) inhibitors, alone and in combination, against tumors harboring alterations in the ERBB2/PI3K/AKT/mTOR pathway (71%). Tumors harboring ERBB2 (5.8%) domain mutations were significantly more sensitive to single agents afatinib or neratinib when compared to wild-type tumors in preclinical in vitro and in vivo models (P = 0.001). In contrast, pan-HER and PIK3CA inhibitors demonstrated limited in vitro activity and were only transiently effective in controlling in vivo growth of PIK3CA-mutated cervical cancer xenografts. Importantly, combinations of copanlisib and neratinib were highly synergistic, inducing long-lasting regression of tumors harboring alterations in the ERBB2/PI3K/AKT/mTOR pathway. These findings define the genetic landscape of cervical cancer, suggesting that a large subset of cervical tumors might benefit from existing ERBB2/PIK3CA/AKT/mTOR-targeted drugs.
Stemmann H, Freiwald WA
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Evidence for an attentional priority map in inferotemporal cortex

From incoming sensory information, our brains make selections according to current behavioral goals. This process, selective attention, is controlled by parietal and frontal areas. Here, we show that another brain area, posterior inferotemporal cortex (PITd), also exhibits the defining properties of attentional control. We discovered this area with functional magnetic resonance imaging (fMRI) during an attentive motion discrimination task. Single-cell recordings from PITd revealed strong attentional modulation across 3 attention tasks yet no tuning to task-relevant stimulus features, like motion direction or color. Instead, PITd neurons closely tracked the subject's attention state and predicted upcoming errors of attentional selection. Furthermore, artificial electrical PITd stimulation controlled the location of attentional selection without altering feature discrimination. These are the defining properties of a feature-blind priority map encoding the locus of attention. Together, these results suggest area PITd, located strategically to gather information about object properties, as an attentional priority map.
Weber R, Birsoy K
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The Transsulfuration Pathway Makes, the Tumor Takes

CELL METABOLISM 2019 NOV 5; 30(5):845-846
Cells can take up cysteine or synthesize it de novo from methionine, but synthesis alone does not meet the high demands of cancer cells to proliferate. In this issue, Zhu et al. (2019) identify the SAH:SAM ratio, indicative of the cellular methylation state, as limiting for effective cysteine synthesis and the growth of some tumors.
Arshad H, Alfonso JCL, Franke R, Michaelis K, Araujo L, Habib A, Zboromyrska Y, Lucke E, Strungaru E, Akmatov MK, Hatzikirou H, MeyerHermann M, Petersmann A, Nauck M, Bronstrup M, Bilitewski U, Abel L, Sievers J, Vila J, Illig T, Schreiber J, Pessler F
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Decreased plasma phospholipid concentrations and increased acid sphingomyelinase activity are accurate biomarkers for community-acquired pneumonia

BackgroundThere continues to be a great need for better biomarkers and host-directed treatment targets for community-acquired pneumonia (CAP). Alterations in phospholipid metabolism may constitute a source of small molecule biomarkers for acute infections including CAP. Evidence from animal models of pulmonary infections and sepsis suggests that inhibiting acid sphingomyelinase (which releases ceramides from sphingomyelins) may reduce end-organ damage.MethodsWe measured concentrations of 105 phospholipids, 40 acylcarnitines, and 4 ceramides, as well as acid sphingomyelinase activity, in plasma from patients with CAP (n=29, sampled on admission and 4 subsequent time points), chronic obstructive pulmonary disease exacerbation with infection (COPD, n=13) as a clinically important disease control, and 33 age- and sex-matched controls.ResultsPhospholipid concentrations were greatly decreased in CAP and normalized along clinical improvement. Greatest changes were seen in phosphatidylcholines, followed by lysophosphatidylcholines, sphingomyelins and ceramides (three of which were upregulated), and were least in acylcarnitines. Changes in COPD were less pronounced, but also differed qualitatively, e.g. by increases in selected sphingomyelins. We identified highly accurate biomarkers for CAP (AUC <= 0.97) and COPD (AUC <= 0.93) vs. Controls, and moderately accurate biomarkers for CAP vs. COPD (AUC <= 0.83), all of which were phospholipids. Phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins were also markedly decreased in S. aureus-infected human A549 and differentiated THP1 cells. Correlations with C-reactive protein and procalcitonin were predominantly negative but only of mild-to-moderate extent, suggesting that these markers reflect more than merely inflammation. Consistent with the increased ceramide concentrations, increased acid sphingomyelinase activity accurately distinguished CAP (fold change=2.8, AUC=0.94) and COPD (1.75, 0.88) from Controls and normalized with clinical resolution.ConclusionsThe results underscore the high potential of plasma phospholipids as biomarkers for CAP, begin to reveal differences in lipid dysregulation between CAP and infection-associated COPD exacerbation, and suggest that the decreases in plasma concentrations are at least partially determined by changes in host target cells. Furthermore, they provide validation in clinical blood samples of acid sphingomyelinase as a potential treatment target to improve clinical outcome of CAP.
Stein-Thoeringer CK, Nichols KB, Lazrak A, Docampo MD, Slingerland AE, Slingerland JB, Clurman AG, Armijo G, Gomes ALC, Shono Y, Staffas A, da Silva MB, Devlin SM, Markey KA, Bajic D, Pinedo R, Tsakmaklis A, Littmann ER, Pastore A, Taur Y, Monette S, Arcila ME, Pickard AJ, Maloy M, Wright RJ, Amoretti LA, Fontana E, Pham D, Jamal MA, Weber D, Sung AD, Hashimoto D, Scheid C, Xavier JB, Messina JA, Romero K, Lew M, Bush A, Bohannon L, Hayasaka K, Hasegawa Y, Vehreschild MJGT, Cross JR, Ponce DM, Perales MA, Giralt SA, Jenq RR, Teshima T, Holler E, Chao NJ, Pamer EG, Peled JU, van den Brink MRM
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Lactose drives Enterococcus expansion to promote graft-versus-host disease

SCIENCE 2019 NOV 29; 366(6469):1143-1149
Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.
Galea S, Vaughan RD
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Tendrils of Hope in the Gun Epidemic: A Public Health of Consequence, November 2019

About F, Bibert S, Jouanguy E, Nalpas B, Lorenzo L, Rattina V, Zarhrate M, Hanein S, Munteanu M, Mullhaupt B, Semela D, Semmo N, Casanova JL, Theodorou I, Sultanik P, Poynard T, Pol S, Bochud PY, Cobat A, Abel L, Negro F, Hadengue A, Kaiser L, Rubbia-Brandt L, Moradpour D, Cellerai C, Rickenbach M, Cerny A, Martinetti G, Dufour JF, Gorgievski M, Spicher VM, Heim M, Hirsch H, Helbling B, Regenass S, Malinverni R, Dollenmaier G, Cathomas G, Bousquet L, Ngo Y, Lebray P, Moussalli J, Benhamou Y, Thabut D, Vallet-Pichard A, Fontaine H, Mallet V, Sogni P, Trabut JB, Bourliere M, Delfraissy JF
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Identification of an Endoglin Variant Associated With HCV-Related Liver Fibrosis Progression by Next-Generation Sequencing

FRONTIERS IN GENETICS 2019 NOV 4; 10(?):? Article 1024
Despite the astonishing progress in treating chronic hepatitis C virus (HCV) infection with direct-acting antiviral agents, liver fibrosis remains a major health concern in HCV infected patients, in particular due to the treatment cost and insufficient HCV screening in many countries. Only a fraction of patients with chronic HCV infection develop liver fibrosis. While there is evidence that host genetic factors are involved in the development of liver fibrosis, the common variants identified so far, in particular by genome-wide association studies, were found to have limited effects. Here, we conducted an exome association study in 88 highly selected HCV-infected patients with and without fibrosis. A strategy focusing on TGF-beta pathway genes revealed an enrichment in rare variants of the endoglin gene (ENG) in fibrosis patients. Replication studies in additional cohorts (617 patients) identified one specific ENG variant, Thr5Met, with an overall odds ratio for fibrosis development in carriers of 3.04 (1.39-6.69). Our results suggest that endoglin, a key player in TGF-beta signaling, is involved in HCV-related liver fibrogenesis.
Brohawn SG, Wang WW, Handler A, Campbell EB, Schwarz JR, MacKinnon R
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The mechanosensitive ion channel TRAAK is localized to the mammalian node of Ranvier

ELIFE 2019 NOV 1; 8(?):? Article e50403
TRAAK is a membrane tension-activated K+ channel that has been associated through behavioral studies to mechanical nociception. We used specific monoclonal antibodies in mice to show that TRAAK is localized exclusively to nodes of Ranvier, the action potential propagating elements of myelinated nerve fibers. Approximately 80 percent of myelinated nerve fibers throughout the central and peripheral nervous system contain TRAAK in what is likely an all-nodes or no-nodes per axon fashion. TRAAK is not observed at the axon initial segment where action potentials are first generated. We used polyclonal antibodies, the TRAAK inhibitor RU2 and node clamp amplifiers to demonstrate the presence and functional properties of TRAAK in rat nerve fibers. TRAAK contributes to the 'leak' K+ current in mammalian nerve fiber conduction by hyperpolarizing the resting membrane potential, thereby increasing Na+ channel availability for action potential propagation. We speculate on why nodes of Ranvier contain a mechanosensitive K+ channel.