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Supplementary Figure from PTEN Loss Contributes to Erlotinib Resistance in EGFR-Mutant Lung Cancer by Activation of Akt and EGFR

Clinical resistance to epidermal growth factor receptor (EGFR) inhibition in lung cancer has been linked to the emergence of the EGFR T790M resistance mutation or amplification of MET. Additional mechanisms contributing to EGFR inhibitor resistance remain elusive. By applying combined analyses of gene expression, copy number, and biochemical analyses of EGFR inhibitor responsiveness, we identified homozygous loss of PTEN to segregate EGFR-dependent and EGFR-independent cells. We show that in EGFR-dependent cells, PTEN loss partially uncouples mutant EGFR from downstream signaling and activates EGFR, thereby contributing to erlotinib resistance. The clinical relevance of our findings is supported by the observation of PTEN loss in 1 out of 24 primary EGFR-mutant non–small cell lung cancer (NSCLC) tumors. These results suggest a novel resistance mechanism in EGFR-mutant NSCLC involving PTEN loss. [Cancer Res 2009;69(8):3256–61]

Supplementary Materials & Methods and Figure Legend from PTEN Loss Contributes to Erlotinib Resistance in EGFR-Mutant Lung Cancer by Activation of Akt and EGFR

Supplementary Table from PTEN Loss Contributes to Erlotinib Resistance in EGFR-Mutant Lung Cancer by Activation of Akt and EGFR

Objective Benzodiazepines have been reported to cause photosensitivity reactions. We characterized the clinical presentation and diagnosis of benzodiazepine-associated photosensitivity and adjudicated these cases for a causal association with benzodiazepines. Methods A literature search on PubMed's "MeSH" search feature and CINAHL (1964 to 2019) was performed using search terms: benzodiazepine, photosensitivity, and photosensitivity disorders/chemically induced. We applied the Naranjo scale, a standardized causality assessment algorithm, to identified cases. Results We identified 8 published cases, with 50% of patients being female with a mean age of 46.3 years. Alprazolam, tetrazepam, clobazam, and clorazepate induced phototoxic reactions. Chlordiazepoxide induced one photoallergic reaction. Photosensitivity occurred between 1-3 days (37.5%), 7-14 days (25%), and >14 days (25%). Photosensitivity resolved after drug discontinuation within 2 weeks (62.5%). Benzodiazepine rechallenge confirmed photosensitivity in 75% of cases. Photopatch testing was negative in two patients; however, these patients had positive oral provocation testing. However, an oral photoprovocation test, an ideal diagnostic test, was not administered to several patients. Despite these challenges, the Naranjo scale identified 5 cases as definite benzodiazepine-induced photosensitivity. Conclusion Five benzodiazepines induced photosensitivity reactions. Five patients showed a definite association with the Naranjo scale. Reporting to pharmacovigilance databases may help identify other benzodiazepines causing photosensitivity reactions.

Mucosal and skin cancers are associated with infections by human papillomaviruses (HPV). The manner how viral oncoproteins hijack the host cell metabolism to meet their own energy demands and how this may contribute to tumorigenesis is poorly understood. We now show that the HPV oncoprotein E7 of HPV8, HPV11 and HPV16 directly interact with the beta subunit of the mitochondrial ATP-synthase (ATP5B), which may therefore represent a conserved feature across different HPV genera. By measuring both glycolytic and mitochondrial activity we observed that the association of E7 with ATP5B was accompanied by reduction of glycolytic activity. Interestingly, there was a drastic increase in spare mitochondrial respiratory capacity in HPV8-E7 and an even more profound increase in HPV16-E7 expressing cells. In addition, we could show that ATP5B levels were unchanged in betaHPV positive skin cancers. However, comparing HPV-positive and HPV-negative oropharyngeal squamous cell carcinomas (OPSCC) we noticed that, while ATP5B expression levels did not correlate with patient overall survival in HPV-negative OPSCC, there was a strong correlation within the HPV16-positive OPSCC patient group. These novel findings provide evidence that HPV targets the host cell energy metabolism important for viral life cycle and HPV-mediated tumorigenesis.

The vasculature represents a highly plastic compartment, capable of switching from a quiescent to an active proliferative state during angiogenesis. Metabolic reprogramming in endothelial cells (ECs) thereby is crucial to cover the increasing cellular energy demand under growth conditions. Here we assess the impact of mitochondrial bioenergetics on neovascularisation, by deleting cox10 gene encoding an assembly factor of cytochrome c oxidase (COX) specifically in mouse ECs, providing a model for vasculature-restricted respiratory deficiency. We show that EC-specific cox10 ablation results in deficient vascular development causing embryonic lethality. In adult mice induction of EC-specific cox10 gene deletion produces no overt phenotype. However, the angiogenic capacity of COX-deficient ECs is severely compromised under energetically demanding conditions, as revealed by significantly delayed wound-healing and impaired tumour growth. We provide genetic evidence for a requirement of mitochondrial respiration in vascular endothelial cells for neoangiogenesis during development, tissue repair and cancer., During angiogenesis the vasculature switches from a quiescent to a proliferative state. Here the authors show that mitochondrial respiration in endothelial cells controls angiogenesis during development, tumour growth and tissue repair.

The transition between quiescence and activation in neural stem and progenitor cells (NSPCs) is coupled to reversible changes in energy metabolism with key implications for life-long NSPC self-renewal and neurogenesis. How this metabolic plasticity is ensured between NSPC activity states is unclear. We found that a state-dependent rewiring of the mitochondrial proteome by the peptidase YME1L is required to preserve NSPC self-renewal in the adult brain. YME1L-mediated proteome rewiring regulates the rate of fatty acid oxidation (FAO) for replenishing Krebs cycle intermediates and dNTP precursors, which are required to sustain NSPC amplification. Yme1l deletion irreversibly shifts the metabolic profile of NSPCs away from a FAO-dependent state resulting in defective self-renewal, premature differentiation and NSPC pool depletion. Our results disclose an important role for YME1L in coordinating the switch between metabolic states of NSPCs and suggest that NSPC fate is regulated by compartmentalized changes in protein network dynamics.

Maintaining the architecture, size and composition of an intact stem cell (SC) compartment is crucial for tissue homeostasis and regeneration throughout life. In mammalian skin, elevated expression of the anti‐apoptotic Bcl‐2 protein has been reported in hair follicle (HF) bulge SCs (BSCs), but its impact on SC function is unknown. Here, we show that systemic exposure of mice to the Bcl‐2 antagonist ABT‐199/venetoclax leads to the selective loss of suprabasal BSCs (sbBSCs), thereby disrupting cyclic HF regeneration. RNAseq analysis shows that the pro‐apoptotic BH3‐only proteins BIM and Bmf are upregulated in sbBSCs, explaining their addiction to Bcl‐2 and the marked susceptibility to Bcl‐2 antagonism. In line with these observations, conditional knockout of Bcl‐2 in mouse epidermis elevates apoptosis in BSCs. In contrast, ectopic Bcl‐2 expression blocks apoptosis during HF regression, resulting in the accumulation of quiescent SCs and delaying HF growth in mice. Strikingly, Bcl‐2‐induced changes in size and composition of the HF bulge accelerate tumour formation. Our study identifies a niche‐instructive mechanism of Bcl‐2‐regulated apoptosis response that is required for SC homeostasis and tissue regeneration, and may suppress carcinogenesis., Anti‐apoptotic Bcl‐2 protein function is required to maintain a hair follicle subpopulation of stem cells in murine skin. Blocking cell death by Bcl‐2 overexpression affects the hair follicle stem cell niche and hair follicle regeneration.

Children with mitochondrial diseases often present with slow growth and short stature, but the underlying mechanism remains unclear. In this study, Holzer et al. provide in vivo evidence that mitochondrial respiratory chain dysfunction induces cartilage degeneration coincident with altered metabolism, impaired extracellular matrix formation, and cell death at the cartilage–bone junction., In childhood, skeletal growth is driven by transient expansion of cartilage in the growth plate. The common belief is that energy production in this hypoxic tissue mainly relies on anaerobic glycolysis and not on mitochondrial respiratory chain (RC) activity. However, children with mitochondrial diseases causing RC dysfunction often present with short stature, which indicates that RC activity may be essential for cartilage-mediated skeletal growth. To elucidate the role of the mitochondrial RC in cartilage growth and pathology, we generated mice with impaired RC function in cartilage. These mice develop normally until birth, but their later growth is retarded. A detailed molecular analysis revealed that metabolic signaling and extracellular matrix formation is disturbed and induces cell death at the cartilage–bone junction to cause a chondrodysplasia-like phenotype. Hence, the results demonstrate the overall importance of the metabolic switch from fetal glycolysis to postnatal RC activation in growth plate cartilage and explain why RC dysfunction can cause short stature in children with mitochondrial diseases.

The use of complementary and alternative medicine (CAM) therapies continues to rise worldwide. The cultural importance of various CAM techniques and systems cannot be overlooked. As data become available on the use and adverse events, misuse, adulterations, toxicities and interactions of various dietary supplements (DS) and other CAM therapies, the clinician can piece together appropriate patient care approaches. Reporting mechanisms in many countries continue to be sporadic and inconsistent. Information may be biased or inaccurate in the public domain, causing consumer distrust of healthcare provider guidance. As with any therapeutic decision-making, the patient/consumer should be included in the process and given evidence-based information to weigh the risks and benefits for the individual's needs. Healthcare providers should familiarize themselves with CAM practices and the benefits and associated risks to best care for their patient populations. In this review of the current literature from January through December 2019, the adverse effects of herbal dietary supplements (HDS) are organized as affecting different physiological systems. Systematic reporting and monitoring of AEs from mind/body therapies are extremely limited though reported as found. The full impact caused by side effects (SE) of various CAM therapies may be underappreciated due to this lack of complete data.

Objective Zolpidem is associated with sleep-related eating disorder (SRED). We compiled case reports and performed a descriptive study to identify etiology and aggravating factors. Methods A literature search on PubMed's MeSH search feature, CINAHL, and SciFinder was performed using search terms “Zolpidem,” “Feeding and Eating Disorders/chemically induced,” “Dyssomnias,” “sleep eating disorder,” and “sleep-related eating disorder.” Three reviewers examined all English and Spanish citations and extracted pertinent information. A narrative synthesis of the evidence was prepared. Results We identified 40 case reports of which 65% were female, and the mean age was 53 years. SRED onset was most commonly seen with daily zolpidem doses of 10 mg or higher (95% of patients). Prior medical history included obstructive sleep apnea (OSA) (35%), depression (32.5%), and restless leg syndrome (RLS) (25%). Even with controlled RLS and OSA, SRED developed in some patients. All patients had either partial or full amnesia with compulsive eating. Onset of SRED occurred as early as the first dose to after 9 years of use. SRED symptoms occurred nightly in 57.5% of patients. Discontinuation of zolpidem resolved SRED in all patients (n = 36). Conclusion SRED associated with zolpidem can occur with any dose, but was most common with higher doses of zolpidem. Therefore, prescribers should initiate lower doses of zolpidem. Interestingly, many patients had underlying disorders known to affect sleep (RLS, OSA, depression). Although it is recommended to control these underlying disorders prior to initiating zolpidem, SRED may still occur. Zolpidem discontinuation resolved all cases of SRED., Graphical abstract Image 1, Highlights • Sleep-Related Eating Disorder (SRED) can occur with any dose of zolpidem. • Patients most vulnerable include females receiving higher doses of zolpidem. • SRED is more common with underlying disorders known to affect sleep. • Discontinuation of zolpidem resolves SRED.

The spliceosomal B complex-specific protein Prp38 forms a complex with the intrinsically unstructured proteins MFAP1 and Snu23. Our binding and crystal structure analyses show that MFAP1 and Snu23 contact Prp38 via ER/K motif-stabilized single α helices, which have previously been recognized only as rigid connectors or force springs between protein domains. A variant of the Prp38-binding single α helix of MFAP1, in which ER/K motifs not involved in Prp38 binding were mutated, was less α-helical in isolation and showed a reduced Prp38 affinity, with opposing tendencies in interaction enthalpy and entropy. Our results indicate that the strengths of single α helix-based interactions can be tuned by the degree of helix stabilization in the unbound state. MFAP1, Snu23, and several other spliceosomal proteins contain multiple regions that likely form single α helices via which they might tether several binding partners and act as intermittent scaffolds that facilitate remodeling steps during assembly of an active spliceosome.

In many arid regions, the reuse of wastewater is an economic option for crop irrigation. To avoid health risks for consumers, pathogens must be eliminated prior to application. Slow sand filtration (SSF) represents an effective low-tech treatment technology for pathogen removal from water. To further improve the time-space yield of SSF, innovative filter configurations were investigated regarding the removal of the pathogen indicators Escherichia coli , enterococci, Clostridium perfringens spores, somatic and F-specific RNA coliphages as well as heterotrophic bacteria. A standard filter ( N ), a recirculating filter ( R ), a static cascade ( N + N ) and a rotating cascade ( C ) were tested at high and low hydraulic loading rates, two recirculation rates and two rotation frequencies. Results showed that only C and N + N concurrently complied with European standards for E. coli and enterococci, achieving mean log removal of 2.7-4.7 and 2.1-2.4, respectively. The best performance was reached by C with weekly rotation; N + N may be a promising, technically simpler alternative. The crucial role of biological removal mechanisms for E. coli and enterococci elimination was indicated by (i) the increased efficiency of the standard SSF N after 1½ years of operation and (ii) the positive impact of several Schmutzdecke layers. C. perfringens spore removal performance was good for all SSFs. Considerable sorption of spores was indicated by decreased efficiency in N and C at long operation times. Somatic coliphages were reduced to concentrations close to the detection limit, while F-specific RNA coliphage removal was ∼1.1 log. Removal of heterotrophic bacteria was generally limited.

Background:IgG4-related disease (IgG4-RD) is a polymorphic autoimmune disease leading to tumourous swelling and/or fibrosis of affected organs. Riedel’s thyroiditis is – besides chronic periaortitis, Mikulicz Syndrome and many others – an organ manifestation of IgG4-RD that has been thought to be an independent disease for a long time. About 40% of patients have single organ IgG4-RD while the others suffer from multisystemic disease [1].Objectives:Glucocorticoids, sometimes combined with other immunosuppressives are the standard treatment of IgG4-RD, in some situations (e.g. mechanical complications or suspected malignancy) surgery may be necessary but little is known about the management of fully resected single-organ IgG4-RD [1].Methods:We report a case of single-organ IgG4-RD (Riedel’s thyroiditis) after complete resection and perform a brief review of the literature to guide clinical management in this situation.Results:A woman (51 y) with pre-existing Hashimoto’s thyroiditis (thyroid peroxidase antibody positive) developed a rapidly growing struma with very firm consistency (not allowing fine needle biopsy). Besides slightly increased C-reactive protein (5,3 mg/l) there was no laboratory sign suggestive for IgG4-RD (normal serum IgG4, complement, eosinophils and IgE). Within 4 months the patient suffered from hoarseness and progredient dyspnea. Surgical thyroidectomy was performed and histopathology revealed IgG4-related Riedel’s thyroiditis with extensive (storiform) fibrosis, a dense lymphoplasmacytic infiltrate, obliterative phlebitis, eosinophilia and 13 IgG4-positive plasma cells per high power field.After referral to our department a comprehensive work-up showed no signs of other manifestations of IgG4-RD. Treatment with glucocorticoids is clearly recommended for patients with symptomatic IgG4-RD in an international consensus statement, whereas “watchful waiting” may be appropriate in some cases of asymptomatic or mild disease. While some highly fibrotic lesions may not respond well to glucocorticoids and may require surgical intervention, no clear guidance is available for the management of fully resected single organ IgG4-RD [2].A brief review of the literature revealed that few cases of single-organ IgG4-RD remaining in remission after resection without medical treatment have been reported e.g. IgG4-related cholecystitis, autoimmune-pancreatitis, tumours of the intestinal tract, lung, thymus, meninges, paravertebral space and others [3–9].After discussion of the options with the patient no systemic immunosuppression was given under close follow up without signs of relapse in clinical examinations, laboratory or imaging during the first 6 months.Conclusion:Limited evidence from case reports suggests that a “watchful waiting” strategy without systemic immunosuppressive treatment may be reasonable in some cases of single-organ IgG4-RD after the affected organ was completely resected (e.g. due to mechanical complications or suspected malignoma). However, close follow-up monitoring should be applied due to the risk of relapse or development of new organ manifestations.References:[1]Brito-Zerón et al.Best Pract. Res. Clin. Rheumatol.2016[2]Khosroshahi et al.Arthritis Rheumatol.2015[3]Takahashi et al.Surg. Case Rep.2015[4]Akbari et al.ACG Case Rep. J.2018[5]Oda et al.Thorac. Cancer2019[6]Nambirajan et al.Childs Nerv. Syst. ChNS Off. J. Int. Soc. Pediatr. Neurosurg.2019[7]Uchida et al.Asian J. Endosc. Surg.2018[8]Hart et al.Mod. Pathol. Off. J. U. S. Can. Acad. Pathol. Inc2015[9]Kim et al.Tuberc. Respir. Dis.2014Disclosure of Interests:Jan Schirmer: None declared, Marcus Seeger: None declared, Dominik Schulte Paid instructor for: Ferring, Speakers bureau: Amgen, Astra Zeneca, Braun, Fresenius, Ipsen, Johnson & Johnson, Lilly, MSD, Novartis, Novo Nordisk, Sanofi, Matthias Laudes Speakers bureau: Roche, Sanofi, Chugai, Stefan Schreiber Consultant of: AbbVie, Arena, BMS, Biogen, Celltrion, Celgene, IMAB, Gilead, MSD, Mylan, Pfizer, Fresenius, Janssen, Takeda, Theravance, provention Bio, Protagonist and Falk, Bimba F. Hoyer: None declared

IL-1β is a cytokine of pivotal importance to the orchestration of inflammatory responses. Synthesized as an inactive pro-cytokine, IL-1β requires proteolytic maturation to gain biological activity. Here, we identify intrinsic apoptosis as a non-canonical trigger of IL-1β maturation. Guided by the discovery of the immunomodulatory activity of vioprolides, cyclic peptides isolated from myxobacteria, we observe IL-1β maturation independent of canonical inflammasome pathways, yet dependent on intrinsic apoptosis. Mechanistically, vioprolides inhibit MCL-1 and BCL2, which in turn triggers BAX/BAK-dependent mitochondrial outer membrane permeabilization (MOMP). Induction of MOMP results in the release of pro-apoptotic factors initiating intrinsic apoptosis, as well as the depletion of IAPs (inhibitors of apoptosis proteins). IAP depletion, in turn, operates upstream of ripoptosome complex formation, subsequently resulting in caspase-8-dependent IL-1β maturation. These results establish the ripoptosome/caspase-8 complex as a pro-inflammatory checkpoint that senses the perturbation of mitochondrial integrity.

Background Immune infiltration is implicated in the development of acquired resistance to anti-angiogenic cancer therapy. We therefore investigated the correlation between neutrophil infiltration in metastasis of colorectal cancer (CRC) patients and survival after treatment with bevacizumab. Our study identifies CD177+ tumour neutrophil infiltration as an adverse prognostic factor for bevacizumab treatment. We further demonstrate that a novel anti-VEGF/anti-Ang2 compound (BI-880) can overcome resistance to VEGF inhibition in experimental tumour models. Methods A total of 85 metastatic CRC patients were stratified into cohorts that had either received chemotherapy alone (n = 39) or combined with bevacizumab (n = 46). Tumour CD177+ neutrophil infiltration was correlated to clinical outcome. The impact of neutrophil infiltration on anti-VEGF or anti-VEGF/anti-Ang2 therapy was studied in both xenograft and syngeneic tumour models by immunohistochemistry. Results The survival of bevacizumab-treated CRC patients in the presence of CD177+ infiltrates was significantly reduced compared to patients harbouring CD177− metastases. BI-880 treatment reduced the development of hypoxia associated with bevacizumab treatment and improved vascular normalisation in xenografts. Furthermore, neutrophil depletion or BI-880 treatment restored treatment sensitivity in a syngeneic tumour model of anti-VEGF resistance. Conclusions Our findings implicate CD177 as a biomarker for bevacizumab and suggest VEGF/Ang2 inhibition as a strategy to overcome neutrophil associated resistance to anti-angiogenic treatment.

We developed a high repetition rate optical parametric chirped-pulse amplification (OPCPA) laser system based on fiber-laser-seeded Innoslab to generate few-cycle pulses around 2 µm with passively stable carrier-envelope phase (CEP) by difference frequency generation (DFG). Incorporating a piezo mirror before the DFG stage permits rapid CEP control. The OPCPA system is seeded by a stable supercontinuum generated in bulk material with the picosecond Innoslab pulses. Few-cycle pulses with durations of 17 fs and energies of over 100 μJ were produced in a single OPCPA stage. Three different nonlinear crystals: BBO, BiBO, and LNB were tested in the final parametric amplifier, and their average power related limitations are addressed.

In the normal quiescent vasculature, only 0.01% of endothelial cells (ECs) are proliferating. However, this proportion increases dramatically following the angiogenic switch during tumor growth or wound healing. Recent evidence suggests that this angiogenic switch is accompanied by a metabolic switch. Here, we show that proliferating ECs increasingly depend on mitochondrial oxidative phosphorylation (OxPhos) for their increased energy demand. Under growth conditions, ECs consume three times more oxygen than quiescent ECs and work close to their respiratory limit. The increased utilization of the proton motif force leads to a reduced mitochondrial membrane potential in proliferating ECs and sensitizes to mitochondrial uncoupling. The benzoquinone embelin is a weak mitochondrial uncoupler that prevents neoangiogenesis during tumor growth and wound healing by exhausting the low respiratory reserve of proliferating ECs without adversely affecting quiescent ECs. We demonstrate that this can be exploited therapeutically by attenuating tumor growth in syngenic and xenograft mouse models. This novel metabolic targeting approach might be clinically valuable in controlling pathological neoangiogenesis while sparing normal vasculature and complementing cytostatic drugs in cancer treatment.

The X-linked inhibitor of apoptosis protein (XIAP) is a potent caspase inhibitor, best known for its anti-apoptotic function in cancer. During apoptosis, XIAP is antagonized by SMAC, which is released from the mitochondria upon caspase-mediated activation of BID. Recent studies suggest that XIAP is involved in immune signaling. Here, we explore XIAP as an important mediator of an immune response against the enteroinvasive bacterium Shigella flexneri, both in vitro and in vivo. Our data demonstrate for the first time that Shigella evades the XIAP-mediated immune response by inducing the BID-dependent release of SMAC from the mitochondria. Unlike apoptotic stimuli, Shigella activates the calpain-dependent cleavage of BID to trigger the release of SMAC, which antagonizes the inflammatory action of XIAP without inducing apoptosis. Our results demonstrate how the cellular death machinery can be subverted by an invasive pathogen to ensure bacterial colonization.

The strength of electrical insulation in gaseous compressed SF6 is determined by various parameters, like pressure, polarity, field homogeneity, surface roughness of the electrodes, particulate contamination, and voltage wave shape. The dependence of the involved physical phenomena on accessible design parameters, like e.g. pressure, geometry, is of interest for the prediction of partial discharge inception and breakdown fields. Models for first electron production, streamer inception and leader propagation are presented, which are combined systematically to deduce these fields in technically relevant electrical insulation systems.

Se han estudiado los suelos en cinco areas de muestreo a lo largo de un transecto entre la Depresion Central del Ebro y el Pirineo Central espanol con el fin de detectar un posible gradiente en cuanto a la erosionabilidad y a diferentes parametros hidricos del suelo. El estudio de los suelos de este transecto muestra ciertas similitudes, pudiendo observarse una ligera tendencia a la disminucion de la erosionabilidad desde la Depresion del Ebro hasta el Pirineo Central. La erosionabilidad del material matricial del suelo es, de todas formas, alta en todas las areas estudiadas, siendo moderada de forma significativa por la pedregosidad en las zonas situadas fuera de la Depresion central del Ebro. De los resultados obtenidos se deduce que las diferencias en la produccion de sedimento dependen primordialmente de la cobertura vegetal y de la erosividad de las precipitaciones. Las condiciones hidricas del suelo muestra ser dentro de cada area estudiada mucho mas variable que a lo largo del transecto. Se han llegado a estimar en zonas erosionadas valores de capacidad de retencion de agua disponible extremadamente bajos. De igual forma, todos los suelos muestran conductividades hidraulicas muy bajas en condiciones no saturadas. En consecuencia, las precipitaciones generan una elevada escorrentia, que a su vez erosiona los suelos e impide su recarga hidrica. Del conjunto de caracteristicas fisicas de los suelos entre la depresion Central del Ebro y el Pirineo Central se puede deducir que las capacidades hidraulicas tenderan a deteriorarse a causa de la alta erosividad de la matriz edafica. De este modo, las condiciones para la recuperacion de la cubierta vegetal tras el los cambios de uso del suelo seran cada vez mas adversas

Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in canonical SR proteins. Instead, yeast two-hybrid analyses suggest that the amino-terminal domain is a versatile protein–protein interaction hub that possibly binds 12 other spliceosomal proteins, most of which are recruited at the same stage as Prp38. By quantitative, alanine surface-scanning two-hybrid screens and biochemical analyses we delineated four distinct interfaces on the Prp38 amino-terminal domain. In vitro interaction assays using recombinant proteins showed that Prp38 can bind at least two proteins simultaneously via two different interfaces. Addition of excess Prp38 amino-terminal domain to in vitro splicing assays, but not of an interaction-deficient mutant, stalled splicing at a precatalytic stage. Our results show that human Prp38 is an unusual SR protein, whose amino-terminal domain is a multi-interface protein–protein interaction platform that might organize the relative positioning of other proteins during splicing.

The influence of irradiance on the nitrifying activity in photobioreactors of a bacterial consortium enriched from a wastewater treatment bioreactor was assessed using independent ammonium oxidation kinetic batch tests and respirometric assays. Culture irradiance below 250 μmol m −2 s −1 did not show a significant effect on nitrification activity, while irradiance at 500 and 1250 μmol m −2 s −1 caused a decrease of 20 and 60% in the specific total ammonium nitrogen removal rates and a reduction of 26 and 71% in the specific NO 3 − production rates, respectively. However, no significant influence of irradiance on the affinity constant of NH 4 + oxidation was observed. The increasing nitrite accumulation at higher light intensities suggested a higher light sensitivity of nitrite oxidizers. Additionally, NH 4 + oxidation respirometric assays showed a decrease in the oxygen uptake of 14 and 50% at 500 and 1250 μmol m −2 s −1 , respectively. The experimental determination of the light extinction coefficient (λ) of the nitrifying bacterial consortium (λ = 0.0003 m 2 g −1 ) and of Chlorella sorokiniana (λ = 0.1045 m 2 g −1 ) allowed the estimation of light penetration in algal-bacterial high rate algal ponds, which showed that photoinhibition of nitrifying bacteria can be significantly mitigated in the presence of high density microalgal cultures.

We show that the activity of an ion channel is correlated with the phase state of the lipid bilayer hosting the channel. By measuring unitary conductance, dwell times, and open probability of the K+ channel KcsA as a function of temperature in lipid bilayers composed of POPE and POPG in different relative proportions, we obtain that all those properties show a trend inversion when the bilayer is in the transition region between the liquid-disordered and the solid-ordered phase. These data suggest that the physical properties of the lipid bilayer influence ion channel activity likely via a fine-tuning of its conformations. In a more general interpretative framework, we suggest that other parameters such as pH, ionic strength, and the action of amphiphilic drugs can affect the physical behavior of the lipid bilayer in a fashion similar to temperature changes resulting in functional changes of transmembrane proteins.

Background: In various tumour types, elevated expression of the X-linked inhibitor of apoptosis protein (XIAP) has been observed and XIAP targeting in diverse tumour entities enhanced the susceptibility to chemotherapeutic agents. Therefore, XIAP has been described and reviewed repeatedly as a chemoresistance factor in different tumour entities. However, rather than being an adverse prognostic marker, recent data suggest that elevated XIAP expression may be associated with a favourable clinical outcome. These somewhat conflicting findings, and the fact that in early studies XIAP suppressed apoptosis only when expressed transiently at levels far in excess of its physiological concentration, argue that the function of XIAP as an anti-apoptotic factor in tumour cells is both more complex and diverse than previously appreciated. Methods: To better understand the impact of long-term elevated XIAP expression on resistance to chemotherapy, we generated cell lines stably overexpressing XIAP. The role of mitochondria was examined by stable expression of Bcl2 or stable knockdown of second mitochondria-derived activator of caspase (SMAC) in combination with up- or downregulation of XIAP expression. Results: Our data show that long-term expression of XIAP at concentrations comparable to that in tumour cells (two- to five-fold increase) resulted in little or no resistance towards chemotherapeutic drugs. The XIAP overexpression only in conjunction with stable knockdown of a single XIAP-antagonising factor such as SMAC resulted in severe resistance to cytostatic agents demonstrating XIAP as a potent chemoresistance factor only in cells lacking functional XIAP regulatory circuits. Conclusion: Our results demonstrated that elevated XIAP expression alone cannot serve as a predictive marker of chemoresistance. Our data suggest that in order to predict the impact of XIAP on chemosusceptibility for a given tumour entity, the expression levels and functional states of all XIAP modulators need to be taken into account.

Adoptive transfer of tumor-specific cytolytic T lymphocytes (CTL) results in target cell lysis by activating the intrinsic apoptotic cell death program. Not surprisingly, deregulation of the apoptotic machinery is one of the central mechanisms by which tumor cells escape immune destruction despite specific CTL recognition. Here we show that treatment with the proteasome inhibitor bortezomib sensitizes previously resistant tumor cells for cytolytic T-cell attack. Human T cells were redirected toward melanoma cells by engineered expression of an immunoreceptor with binding specificity for high molecular weight–melanoma-associated antigen. Established melanoma cell lines as well as primary melanoma cells from tumor biopsies, which are notoriously resistant toward T-cell lysis, became sensitive upon bortezomib treatment. Detailed analysis of the underlying molecular mechanism revealed that bortezomib treatment induced mitochondrial accumulation of NOXA, which potentiated the release of mitochondrial second mitochondria-derived activator of caspase (SMAC) in response to CTL effector functions, including caspase-8 and granzyme B. Our data indicate that proteasome inhibition increases the sensitivity of tumor cells toward cytolytic T-cell attack by NOXA-mediated enhancement of mitochondrial SMAC release. Cancer Res; 70(5); 1825–34

Abscess formation associated with secondary peritonitis causes severe morbidity and can be fatal. Formation of abscesses requires the presence of CD4+ T-cells. Zwitterionic polysaccharides (ZPSs) represent a novel class of immunomodulatory bacterial antigens that stimulate CD4+ T-cells in a major histocompatibility complex (MHC) class II-dependent manner. The capsular polysaccharide Sp1 of Streptococcus pneumoniae serotype 1 possesses a zwitterionic charge with free amino groups and promotes T-cell-dependent abscess formation in an experimental mouse model. So far, nothing is known about the function of Interleukin (IL)-6 in intraperitoneal abscess formation. Here, we demonstrate that macrophages and dendritic cells (DCs), the most prevalent professional antigen-presenting cells involved in the formation of abscesses, secrete Interleukin (IL)-6 and are incorporated in the abscess capsule. Sp1 inhibits apoptosis of CD4 + T-cells and causes IL-17 expression by CD4+ T-cells in an IL-6-dependent manner. Abrogation of the Sp1-induced pleiotropic effects of IL-6 in IL-6-deficient mice and mice treated with an IL-6-specific neutralizing antibody results in significant inhibition of abscess formation. The data delineate the essential role of IL-6 in the linkage of innate and adaptive immunity in polysaccharide-mediated abscess formation.

Supported lipid bilayers composed of 1-palmitoyl-2-oleoyl-phosphatidylethanolamine (POPE) and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) were assembled by the vesicle fusion technique on mica and studied by temperature-controlled atomic force microscopy. The role of different physical parameters on the main phase transition was elucidated. Both mixed (POPE/POPG 3:1) and pure POPE bilayers were studied. By increasing the ionic strength of the solution and the incubation temperature, a shift from a decoupled phase transition of the two leaflets, to a coupled transition, with domains in register, was obtained. The observed behavior points to a modulation of the substrate/bilayer and interleaflet coupling induced by the environment and preparation conditions of supported lipid bilayers. The results are discussed in view of the role of different interactions in the system. The influence of the substrate on the lipid bilayers, in terms of interleaflet coupling, can also help us in understanding the possible effect that submembrane elements like the cytoskeleton might have on the structure and dynamics of biomembranes.

Today's academic librarian is frequently called upon to function as a subject specialist, with or without advanced degrees in other disciplines. One method of monitoring trends within a given field is to study its literature; another is to attend conferences in the discipline. Discipline-specific conference attendance by academic librarians provides opportunities to interact with faculty in their disciplines that result in an increased communication with faculty, improved reference expertise, and more focused collection development. This paper describes the Texas A&M University Libraries' support for conference attendance and examples of the resulting benefits.