Heat shock protein Hspa13 regulates endoplasmic reticulum and cytosolic proteostasis through modulation of protein translocation.

Most eukaryotic secretory proteins are cotranslationally translocated through Sec61 into the endoplasmic reticulum (ER). Because these proteins have evolved to fold in the ER, their mistargeting is associated with toxicity. Genetic experiments have implicated the ER heat shock protein 70 (Hsp70) Hspa13/STCH as involved in processing of nascent secretory proteins. Herein, we evaluate the role of Hspa13 in protein import and the maintenance of cellular proteostasis in human cells, primarily using the human embryonic kidney 293T cell line. We find that Hspa13 interacts primarily with the Sec61 translocon and its associated factors. Hspa13 overexpression inhibits translocation of the secreted protein transthyretin, leading to accumulation and aggregation of immature transthyretin in the cytosol. ATPase-inactive mutants of Hspa13 further inhibit translocation and maturation of secretory proteins. While Hspa13 overexpression inhibits cell growth and ER quality control, we demonstrate that HSPA13 knockout destabilizes proteostasis and increases sensitivity to ER disruption. Thus, we propose that Hspa13 regulates import through the translocon to maintain both ER and cytosolic protein homeostasis. The raw mass spectrometry data associated with this article have been deposited in the PRIDE archive and can be accessed at PXD033498.

Monitoring Protein Import into the Endoplasmic Reticulum in Living Cells with Proximity Labeling.

The proper trafficking of eukaryotic proteins is essential to cellular function. Genetic, environmental, and other stresses can induce protein mistargeting and, in turn, threaten cellular protein homeostasis. Current methods for measuring protein mistargeting are difficult to translate to living cells, and thus the role of cellular signaling networks in stress-dependent protein mistargeting processes, such as ER pre-emptive quality control (ER pQC), is difficult to parse. Herein, we use genetically encoded peroxidases to characterize protein import into the endoplasmic reticulum (ER). We show that the ERHRP/cytAPEX pair provides good selectivity and sensitivity for both multiplexed protein labeling and for identifying protein mistargeting, using the known ER pQC substrate transthyretin (TTR). Although ERHRP labeling induces formation of detergent-resistant TTR aggregates, this is minimized by using low ERHRP expression, without loss of labeling efficiency. cytAPEX labeling recovers TTR that is mistargeted as a consequence of Sec61 inhibition or ER stress-induced ER pQC. Furthermore, we discover that stress-free activation of the ER stress-associated transcription factor ATF6 recapitulates the TTR import deficiency of ER pQC. Hence, proximity labeling is an effective strategy for characterizing factors that influence ER protein import in living cells.

Efficacy comparison of intraperitoneal anaesthesia and post-operative analgesia regimens in laboratory rats.

INTRODUCTION: Effective and safe anesthesia for rodents has long been a leading concern among biomedical researchers. Intraperitoneal injection constitutes an alternative to inhalant anesthesia. PURPOSE: The aim of this study was to identify a safe, reliable, and effective anesthesia and postoperative analgesia protocol for laboratory rats exposed to painful procedures. MATERIAL AND METHODS: Twenty-seven female Wistar rats in an ongoing study that required surgery were randomized into groups for three different intraperitoneal anesthesia protocols and three different analgesia regimens. The anesthesia groups were (1) medetomidine + ketamine (MK), (2) ketamine + xylacine (KX), and (3) fentanyl + medetomidine (FM). Three analgesia groups were equally distributed among the anesthesia groups: (1) local mepivacaine + oral ibuprofen (MI), (2) oral tramadol + oral ibuprofen (TI), and (3) local tramadol + oral tramadol + + oral ibuprofen (TTI). A core was assigned to measure anesthesia (0-3) and analgesia (0-2) effectiveness; the lower the score, the more effective the treatment. RESULTS: The mean MK score was 0.44 versus 2.00 for FM and 2.33 for KX. Mean score for analgesia on the first postoperative day was TTI (4.66) TI (9.13), and MI (10.14). Mean score 48 hours after surgery was TTI (3.4), TI (6.71), and MI (9.5). These differences were statistically significant. CONCLUSION: MK was shown to be a reliable, safe, and effective method of anesthesia. The TTI analgesia regimen is strongly recommended in light of these results.

Predictive assessment of ochratoxin A accumulation in grape juice based-medium by Aspergillus carbonarius using neural networks.

AIMS: To study the ability of multi-layer perceptron artificial neural networks (MLP-ANN) and radial-basis function networks (RBFNs) to predict ochratoxin A (OTA) concentration over time in grape-based cultures of Aspergillus carbonarius under different conditions of temperature, water activity (a(w)) and sub-inhibitory doses of the fungicide carbendazim. METHODS AND RESULTS: A strain of A. carbonarius was cultured in a red grape juice-based medium. The input variables to the network were temperature (20-28 degrees C), a(w) (0.94-0.98), carbendazim level (0-450 ng ml(-1)) and time (3-15 days after the lag phase). The output of the ANNs was OTA level determined by liquid chromatography. Three algorithms were comparatively tested for MLP. The lowest error was obtained by MLP without validation. Performance decreased when hold-out validation was accomplished but the risk of over-fitting is also lower. The best MLP architecture was determined. RBFNs provided similar performances but a substantially higher number of hidden nodes were needed. CONCLUSIONS: ANNs are useful to predict OTA level in grape juice cultures of A. carbonarius over a range of a(w), temperature and carbendazim doses. SIGNIFICANCE AND IMPACT OF THE STUDY: This is a pioneering study on the application of ANNs to forecast OTA accumulation in food based substrates. These models can be similarly applied to other mycotoxins and fungal species.

Stem cell-like transcriptional reprogramming mediates metastatic resistance to mTOR inhibition.

Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.

The acetyltransferase Tip60 contributes to mammary tumorigenesis by modulating DNA repair.

The acetyltransferase Tip60/Kat5 acetylates both histone and non-histone proteins, and is involved in a variety of biological processes. By acetylating p53, Tip60 controls p53-dependent transcriptional activity and so is implicated as a tumor suppressor. However, many breast cancers with low Tip60 also show p53 mutation, implying that Tip60 has a tumor suppressor function independent of its acetylation of p53. Here, we show in a p53-null mouse model of sporadic invasive breast adenocarcinoma that heterozygosity for Tip60 deletion promotes mammary tumorigenesis. Low Tip60 reduces DNA repair in normal and tumor mammary epithelial cells, both under resting conditions and following genotoxic stress. We demonstrate that Tip60 controls homologous recombination (HR)-directed DNA repair, and that Tip60 levels correlate inversely with a gene expression signature associated with defective HR-directed DNA repair. In human breast cancer data sets, Tip60 mRNA is downregulated, with low Tip60 levels correlating with p53 mutations in basal-like breast cancers. Our findings indicate that Tip60 is a novel breast tumor suppressor gene whose loss results in genomic instability leading to cancer formation.

Production, crystallization and X-ray characterization of chemically glycosylated hen egg-white lysozyme.

The crystallization of glycoproteins is one of the challenges to be confronted by the crystallographic community in the frame of what is known as glycobiology. The state of the art for the crystallization of glycoproteins is not promising and removal of the carbohydrate chains is generally suggested since they are flexible and a source of heterogeneity. In this paper, the feasibility of introducing glucose into the model protein hen egg-white lysozyme via a post-purification glycosylation reaction that may turn any protein into a model glycoprotein whose carbohydrate fraction can be manipulated is demonstrated.

Shift in rat liver glycolysis control from fed to starved conditions. Flux control coefficients of glucokinase and phosphofructokinase.

The distribution of flux control coefficients of a glycolytic system in starved rat liver has been determined. The flux control coefficient profile in starved conditions is compared with normal fed conditions showing that in the former phosphofructokinase enhances more than 2-fold its flux control coefficient while glucokinase decreases slightly. The results also show that the starved system has a more complex structure probably because of the greater influence on the flux of the reverse substrate cycles and the synthesis and degradation fructose 2,6-bisphosphate reactions.

Synthesis of "sugar-rods" with phytohemagglutinin cross-linking properties by using the palladium-catalyzed Sonogashira reaction

A palladium-catalyzed Sonogashira reaction has been applied for the syntheses of divalent "sugar-rods" which exhibited excellent lectin cross-linking properties. The procedure, which involves a tetrakis(triphenylphosphine)palladium-catalyzed cross-coupling reaction between an alkyne and a halogen-bearing sp2-carbon in DMF at 60 degrees C, is very efficient and the dimeric or heterobifunctional "sugar-rods" (8-13, 15-17) were isolated in 65-100% yields. Dimers 8a and 15a were both shown to form insoluble cross-linked lattices when mixed with the tetrameric plant lectin from Canavalia ensiformis (Concavalin A, Con A). Moreover, the relative inhibitory properties of the synthetic dimannosides were determined by means of the hemagglutination of rabbit erythrocytes, whereby dimer 15a was shown to be 20-fold more potent than monomeric methyl alpha-D-mannopyranoside.

1,3-dipolar cycloadditions as a tool for the preparation of multivalent structures.

The construction of multivalent structures such as sugar heterodimers, glycoclusters, calix sugars, multicalixarenes, and glycocyclodextrins is designed by using 1,3-dipolar cycloaddition as a versatile and efficient tool which allows the creation of heterocyclic bridges between the different units that are coupled.

Effects of high-dose ipratropium bromide and oral aminophylline on spirometry and exercise tolerance in COPD.

Exercise tolerance in chronic obstructive pulmonary disease (COPD) patients treated with oral aminophylline may be different from those treated with high-dose inhaled ipratropium bromide. The purpose of this study was to compare the effects of therapeutic doses of oral aminophylline with high-dose ipratropium bromide on spirometry and exercise tolerance. The study was conducted on three consecutive days in a double-blind, randomized, crossover fashion. Baseline studies obtained on each study day included vital signs, simple spirometry and a symptom-limited maximal cardiopulmonary stress test, after which patients received one of the following treatments on each day: Treatment 1, inhaled ipratropium (total dose of 144 micrograms) with placebo tablets; Treatment 2, inhaled placebo with oral aminophylline (400 mg); Treatment 3, inhaled placebo and placebo tablets. Simple spirometry was repeated at 60 and 120 min after baseline. Vital signs and cardiopulmonary stress testing was repeated at 120 min. Eighteen patients were enrolled in the study, and 17 of these completed the study. There was a significant (P < 0.05) increase in both forced expiratory volume in 1 s (FEV1), from 0.75 (0.21) to 0.92 (0.3), and forced vital capacity (FVC), from 1.8 (0.79) to 2.11 (0.84), with high-dose ipratropium despite prior beta-agonist therapy. Lack of improvement in exercise capacity was noted with ipratropium despite improvement in spirometry. These results suggest that elderly patients with severe COPD may have exercise limitation that is not directly dependent on severity of airflow obstruction. Ipratropium bromide and aminophylline demonstrated no acute effects on exercise capacity.

Carbohydrate components for modified anthracyclines: synthesis of derivatives of 3-amino-3,4,6-trideoxy-L-lyxo- and -L-xylo-hexose, and attempts at fluorination of C-2.

Two new trideoxyglycosides, methyl 3,4,6-trideoxy-3-nitro-alpha-L-lyxo-hexopyranoside (7) and its alpha-L-arabino isomer, as well as the known alpha-L-xylo isomer (15), were synthesized from methyl 3,6-dideoxy-3-nitro-alpha-L-glucopyranoside (1) by methods involving elimination and reduction processes in mesylates prepared from 1. Catalytic hydrogenation of 7 and 15 gave the new and the known aminodeoxyglycosides, respectively, both of which were N-(trifluoroacetyl)ated and sub-subsequently O-(trifluoromethylsulfonyl)ated. Various attempts to effect displacement by fluoride ion in the N-protected 2-triflates so obtained, and also in a related 3-azido-2-triflate, were unsuccessful as far as fluorination at C-2 was concerned. Among other products, two new 2-enopyranosides resulting from elimination of triflic acid were obtained.

A facile formation of 2,5-anhydro sugars by ring contraction in methyl hexopyranoside 2-triflates under conditions of nucleophilic displacement.

Reaction of methyl 3,4-O-isopropylidene-2-O-(trifluoromethylsulfonyl)-alpha-L-fucopyr anoside and its beta anomer with a variety of nucleophilic reagents under mild conditions led to displacement of the triflic ester group, with migration of the ring-oxygen atom to C-2 and entry of the nucleophile at C-1, to give good yields of 2,5-anhydro sugar derivatives. Reagents employed were hydrogen fluoride-triethylamine complex, methanol in the presence of sodium hydrogencarbonate, sodium benzoate, sodium azide, potassium thiocyanate, and sodium borohydride. The same type of substitutive ring-contraction also occurred in methyl 4-O-benzyl-3-O-(4-methoxybenzyl)-2-O-(trifluoromethylsulfonyl)-alp ha-L- fucopyranoside and methyl 4,6-dideoxy-3-O-(4-methoxybenzyl)-2-O-(trifluoromethylsulfonyl)-al pha-L-xylo- hexopyranoside. The reaction is discussed in light of a literature survey of the chemical behavior of hexopyranoside 2-sulfonates in general, and 2-triflates in particular. Direct SN2 displacements, eliminations, and such different kinds of rearrangement as have previously been observed with structural analogs were not encountered in the present study. However, there is some precedent, in hexopyranoside 2-triflates, for the facile rearrangement that the four representatives here investigated have been found to undergo. The synthesis of these triflates from L-fucose is described.

Synthesis of 3-amino-2,3,6-trideoxy-2-fluoro-L-talose and -D-allose [(R)-2-fluoro-L-daunosamine and (R)-2-fluoro-D-ristosamine].

The title compounds were synthesized (as methyl glycosides) starting from 1,3,4,6-tetra-O-acetyl-2-deoxy-2-fluoro-beta-D-glucopyranose. Stereoselective methods of glycosylation gave, via the tri-O-acetylglycopyranosyl bromide, the methyl 2-deoxy-2-fluoro-alpha- and -beta-D-glucopyranoside triacetates. Each anomer was O-deacetylated and further transformed into the corresponding, 4,6-O-benzylidenated 3-triflate, and the triflates were converted by azide displacement into the 3-azido-2,3-dideoxy-2-fluoroglycosides having the D-allo configuration. Hanesssian-Hullar reaction then furnished the corresponding 6-bromo-6-deoxy-4-benzoates, which were dehydrobrominated to give the methyl 3-azido-4-O-benzoyl-2,3,6-tri-deoxy-2-fluoro-alpha- and -beta-D-ribo-hex-5-enopyranosides. Debenzoylation of the alpha-anomer, followed by catalytic hydrogenation, led to methyl 3-amino-2,3,6-trideoxy-2-fluoro-beta-L-talopyranoside [methyl (R)-2-fluoro-beta-L-daunosaminide], whereas the same sequence applied to the beta-anomer afforded methyl 3-amino-2,3,6-trideoxy-2-fluoro-beta-D-allopyranoside [methyl (R)-2-fluoro-beta-D-ristosaminide]. The overall yields for these 10-step sequences were 11-12 and 16%, respectively. The 1H- and 13C-n.m.r. data for the new fluoro sugar derivatives are discussed with respect to the dependence of JF,H and JF,C values on molecular geometry and substituent effects.

[Prediction of maximal ventilation during exercise in patients with chronic obstructive pulmonary disease]. / Predicción de la ventilación máxima alcanzada en el esfuerzo en pacientes con enfermedad pulmonar obstructiva crónica.

To analyze the validity of baseline lung function parameters as predictors of maximal exercise ventilation (VEmax) in patients with chronic obstructive pulmonary disease (COPD), we studied 33 stable patients (FEV1 43.6 +/- 16.8%, FEV1/FVC% 48.4 +/- 9.2, FRC 156.8 +/- 32.7% and RV 212 +/- 53.9%). The sample was later divided into 3 groups based on severity of disease (severe, moderate or mild) in order to determine whether ability to predict VEmax increased with airways obstruction (FEV1 26.9 +/- 4.9%, 40.2 +/- 3.5% and 63.9 +/- 10%, respectively). The patients underwent lung function testing at rest and after a progressive stress test, with the maximal reading taken with the subject on a tread mill. We found greater correlation between VEmax and RV, FEV1 and FRC (r = -0.77, 0.75 and -0.74, respectively); the correlation was stronger in patients with severe COPD, in whom FEV1 was under 35% of the predicted value (r = -0.88, 0.753 and -0.83, respectively). Correlation decreased or disappeared with less functional impairment. Prediction of VEmax was more reliable with equations that employed FEV1 accompanied by data reflecting degree of insufflation, RV or FRC (VEmax = 45.2 +/- 8.98 x FEV1 - 5.07 x RV; r2 = 0.72) than with equations based on FEV1 alone (VEmax = 14.79 + 15.03 x FEV1; r2 = 0.56). We therefore conclude that ventilatory limitation during exercise in patients with COPD is better defined by considering parameters related to lung insufflation along with those reflecting degree of expiratory obstruction, given that the former affect the greater or lesser efficacy of muscles under stress.(ABSTRACT TRUNCATED AT 250 WORDS)

[Outpatient emergency care in pneumology. A method to alleviate pressure of hospital emergency services]. / Atención urgente extrahospitalaria en neumología. Un método para aliviar la presión asistencial de servicios de urgencias hospitalarios.

We analyze the result of using a pneumological rapid-attention facility for diagnosis and immediate treatment of patients with respiratory symptoms arriving at the emergency room of University Hospital Virgen del Rocío in Seville (Spain). In the first six months the outpatient service saw 321 patients (male/female ratio 2.6), most of whom were between 55 and 75 years of age and had never before seen a pneumologist (83.4%). Dyspnea was the most common respiratory symptom named (by 35% of patients), and acute exacerbation of chronic obstructive pulmonary disease was the most usual diagnosis (in 19.1%). Only 21 (7%) were admitted to the hospital. We that creating the outpatient unit effectively met a societal need for rapid diagnosis and treatment of patients with respiratory complaints in the area served by our hospital emergency service.

[Listeriosis in the adult. Revision of 10 cases]. / Listeriosis en el adulto. Revisión de 10 casos.

Listeria monocytogenes is still a very rare opportunist infection in immunosuppressive patients. The clinical-epidemiological and therapeutic characteristics in 10 patients with infection produced by LM are reported--four of them had primary bacteriemia, three patients had a meningeal involvement, there were two patients with spontaneous bacterial peritonitis and one suffered from abdominal access. All of the patients had underlying disorders favouring the infection. Sepsis and meningeal syndrome were the most common presenting forms. Ampicillin was the most used antibiotic. The overall mortality was 40%.

[Familial study of patients with hereditary hemorrhagic telangiectasia]. / Estudio familiar de pacientes con telangiectasia hemorrágica hereditaria.

Rendu-Osler-Weber's disease or Hereditary Hemorrhagic Telangiectasia (HTT) is an autosomal dominant hereditary clinical entity characterized by the presence of telangiectasias on skin, mucous membranes and internal organs. The incidence of hepatic, pulmonary or cerebral complications justifies an early diagnostic. A familiar study of patients previously diagnosed of HTT in our hospital was made, establishing a protocol for the identification of asymptomatic or pauci-symptomatic cases. Fourteen patients were studied: 6 with a previous diagnostic, and 8 familiar contacts. Penetrance was of 85%. Epistaxis (80%) and telangiectasias on skin were the most frequent clinical findings. The visceral lesions found were gastrointestinal (28%), hepatic (15%), urological (15%) and pulmonary (7%). All patients were included in an hepatitis B virus vaccination program. It was also made a morphological study with Werhoeff's staining of the elastic layer, that allowed to distinguish both arterial and venous alterations.