PAX4 preserves endoplasmic reticulum integrity preventing beta cell degeneration in a mouse model of type 1 diabetes mellitus

[Aims/hypothesis]: A strategy to enhance pancreatic islet functional beta cell mass (BCM) while restraining inflammation, through the manipulation of molecular and cellular targets, would provide a means to counteract the deteriorating glycaemic control associated with diabetes mellitus. The aims of the current study were to investigate the therapeutic potential of such a target, the islet-enriched and diabetes-linked transcription factor paired box 4 (PAX4), to restrain experimental autoimmune diabetes (EAD) in the RIP-B7.1 mouse model background and to characterise putative cellular mechanisms associated with preserved BCM. [Methods]: Two groups of RIP-B7.1 mice were genetically engineered to: (1) conditionally express either PAX4 (BPTL) or its diabetes-linked mutant variant R129W (mutBPTL) using doxycycline (DOX); and (2) constitutively express luciferase in beta cells through the use of RIP. Mice were treated or not with DOX, and EAD was induced by immunisation with a murine preproinsulin II cDNA expression plasmid. The development of hyperglycaemia was monitored for up to 4 weeks following immunisation and alterations in the BCM were assessed weekly by non-invasive in vivo bioluminescence intensity (BLI). In parallel, BCM, islet cell proliferation and apoptosis were evaluated by immunocytochemistry. Alterations in PAX4- and PAX4R129W-mediated islet gene expression were investigated by microarray profiling. PAX4 preservation of endoplasmic reticulum (ER) homeostasis was assessed using thapsigargin, electron microscopy and intracellular calcium measurements. [Results]: PAX4 overexpression blunted EAD, whereas the diabetes-linked mutant variant PAX4R129W did not convey protection. PAX4-expressing islets exhibited reduced insulitis and decreased beta cell apoptosis, correlating with diminished DNA damage and increased islet cell proliferation. Microarray profiling revealed that PAX4 but not PAX4R129W targeted expression of genes implicated in cell cycle and ER homeostasis. Consistent with the latter, islets overexpressing PAX4 were protected against thapsigargin-mediated ER-stress-related apoptosis. Luminal swelling associated with ER stress induced by thapsigargin was rescued in PAX4-overexpressing beta cells, correlating with preserved cytosolic calcium oscillations in response to glucose. In contrast, RNA interference mediated repression of PAX4-sensitised MIN6 cells to thapsigargin cell death. [Conclusions/interpretation]: The coordinated regulation of distinct cellular pathways particularly related to ER homeostasis by PAX4 not achieved by the mutant variant PAX4R129W alleviates beta cell degeneration and protects against diabetes mellitus. The raw data for the RNA microarray described herein are accessible in the Gene Expression Omnibus database under accession number GSE62846

Efficient Calculation of the 3-D Rectangular Waveguide Green’s Functions Derivatives by the Ewald Method

In this contribution, the Ewald method has efficiently been applied to accelerate the computation of the rectangular waveguide Green’s functions derivatives. Based on previous works, we have outlined new approximation formulae that avoid the evaluation of computationally expensive complementary error functions of complex argument, needed by the Ewald method. This is possible when the internal medium of the rectangular waveguide is homogeneous and lossless. On the other hand, different convergence numerical studies have been carried out, showing a similar convergence rate for computing the original Green’s functions and their derivatives. Moreover, we have checked that the computational time is only slightly increased for obtaining the derivatives as compared to the original Green’s functions, after the application of these new techniques. The new derived expressions are useful for the evaluation of electromagnetic fields, the characterization of dielectric materials and step discontinuities between rectangular waveguides, and the analysis of rectangular cavities using integral equation formulations. For validation, the electric field produced by a surface electric current density with a rectangular pulse distribution has been evaluated, using the new proposed expressions. These results have been compared to simulations provided by a full-wave finite elements commercial software to verify their correctness, exhibiting a good agreement

Association between physiological stress and skin temperature response after a half marathon

OBJECTIVE: The objective of this study was to determine the association between skin temperature response and the physiological stress after a half marathon. APPROACH: Seventeen runners were measured 48 h before, 24 h before, 24 h after and 48 h after completing a half marathon. The measurements on each day of testing included blood markers (creatine kinase [CK] and glutamate oxaloacetate transaminase [GOT]), perception of pain and fatigue (using a visual analogue scale), skin temperature (using infrared thermography), and jump performance (using countermovement jump test). MAIN RESULTS: CK (p     1.0) increased 24 h after the half marathon, whereas jump performance decreased (p   <  0.01 and ES  =  0.4). No increase of skin temperature was observed in the tests after the competition and no regression model was able to predict physiological stress using skin temperature. Only a bivariate correlation was observed between the 24 h variation (pre-24 h) of CK and the skin temperature of the posterior upper limb (p   =  0.04 and r  =  0.5), and between the 48 h variation (pre-48 h) of pain perceived and the skin temperature of the knee (p   <  0.01 and r  =  0.6). SIGNIFICANCE: In conclusion, follow-up on basal skin temperatures does not seem to be an adequate method to detect physiological stress after a half marathon. In line with the observed results, we recommend caution when interpreting peaks in basal skin temperature in field sports assessments

Enantiospecific Synthesis of 1,3-Disubstituted Allenes from Propargylic Carbonates through a Borylation-1,2-Elimination Process

An array of enantioenriched vinyl boronates bearing an allylic carbonate moiety have been prepared through selective hydroboration of propargyl carbonates. Treatment of these vinyl boronates with TBAF in THF affords enantioenriched 1,3- disubstituted allenes through a novel 1,2-anti elimination in good yields and high enantiospecificitiesWe thank MINECO (CTQ2016-78779-R) and MICINN (PID2019-107380GB I00) for financial suppor

Soil pyrogenic carbon in southern Amazonia: Interaction between soil, climate, and above-ground biomass

The Amazon forest represents one of the world’s largest terrestrial carbon reservoirs. Here, we evaluated the role of soil texture, climate, vegetation, and distance to savanna on the distribution and stocks of soil pyrogenic carbon (PyC) in intact forests with no history of recent fire spanning the southern Amazonia forest-Cerrado Zone of Transition (ZOT). In 19 one hectare forest plots, including three Amazonian Dark Earth (ADE, terra preta) sites with high soil PyC, we measured all trees and lianas with diameter ≥ 10 cm and analyzed soil physicochemical properties, including texture and PyC stocks. We quantified PyC stocks as a proportion of total organic carbon using hydrogen pyrolysis. We used multiple linear regression and variance partitioning to determine which variables best explain soil PyC variation. For all forests combined, soil PyC stocks ranged between 0.9 and 6.8 Mg/ha to 30 cm depth (mean 2.3 ± 1.5 Mg/ha) and PyC, on average, represented 4.3% of the total soil organic carbon (SOC). The most parsimonious model (based on AICc) included soil clay content and above-ground biomass (AGB) as the main predictors, explaining 71% of soil PyC variation. After removal of the ADE plots, PyC stocks ranged between 0.9 and 3.8 Mg/ha (mean 1.9 ± 0.8 Mg/ha–1) and PyC continued to represent ∼4% of the total SOC. The most parsimonious models without ADE included AGB and sand as the best predictors, with sand and PyC having an inverse relationship, and sand explaining 65% of the soil PyC variation. Partial regression analysis did not identify any of the components (climatic, environmental, and edaphic), pure or shared, as important in explaining soil PyC variation with or without ADE plots. We observed a substantial amount of soil PyC, even excluding ADE forests; however, contrary to expectations, soil PyC stocks were not higher nearer to the fire-dependent Cerrado than more humid regions of Amazonia. Our findings that soil texture and AGB explain the distribution and amount of soil PyC in ZOT forests will help to improve model estimates of SOC change with further climatic warming

Co-occurrence of colistin-resistance genes mcr-1 and mcr-3 among multidrug-resistant Escherichia coli isolated from cattle, Spain, September 2015

Los genes de resistencia a colistina mcr-3 y mcr-1 se detectaron en un aislado de Escherichia coli de heces de ganado en un matadero español en 2015. Las secuencias de ambos genes se hibridaron a la misma banda de plásmidos de aproximadamente 250 kb, aunque la resistencia a la colistina no fue movilizable . El aislado producía betalactamasas de espectro extendido y pertenecía al serotipo O9: H10 y al tipo de secuencia ST533. Aquí informamos un gen mcr-3 detectado en Europa después de informes anteriores de Asia y los Estados Unidos.Colistin resistance genes mcr-3 and mcr-1 have been detected in an Escherichia coli isolate from cattle faeces in a Spanish slaughterhouse in 2015. The sequences of both genes hybridised to same plasmid band of ca 250 kb, although colistin resistance was non-mobilisable. The isolate was producing extended-spectrum beta-lactamases and belonged to serotype O9:H10 and sequence type ST533. Here we report an mcr-3 gene detected in Europe following earlier reports from Asia and the United States.• Ministerio de Economía, Industria y Competitividad. Proyecto AGL2016- 74882-C3 • Ministerio de Agricultura y Pesca (España) y Comunidad Autónoma de Comunidad Autónoma de Madrid. Ayuda S2013 / ABI-2747 • Junta de Extremadura y Fondo Europeo de Desarrollo Regional. Ayuda GR15075 e IB16073 • Fundación para la Ciencia y la Tecnología (Portugal). Ayudas UID / MAR / 04292/2013 • Fundación Tatiana de Guzmán El Bueno (España). Beca doctoral para María del Rocío Iglesias Parro • Instituto Nacional de Agricultura y Alimentación. Investigación y Tecnología (INIA). Beca doctoral para María del Rocío Iglesias Parro • Ministerio de Economía, Industria y Competitividad. Beca FPI2014-020, para Narciso Martín QuijadapeerReviewe

Identification of L. infantum trypanothione synthetase inhibitors with leishmanicidal activity from a (non-biased) in-house chemical library

Redox homeostasis in trypanosomatids is based on the low-molecular-weight trypanothione, an essential dithiol molecule that is synthetized by trypanothione synthetase (TryS) and maintained in its reduced state by trypa- nothione disulfide reductase (TryR). The fact that both enzymes are indispensable for parasite survival and absent in the mammalian hosts makes them ideal drug targets against leishmaniasis. Although many efforts have been directed to developing TryR inhibitors, much less attention has been focused on TryS. The screening of an in-house library of 144 diverse molecules using two parallel biochemical assays allowed us to detect 13 inhibitors of L. infantum TryS. Compounds 1 and 3 were characterized as competitive inhibitors with Ki values in the low micromolar range and plausible binding modes for them were identified by automated ligand docking against refined protein structures obtained through computational simulation of an entire catalytic cycle. The proposed binding site for both inhibitors overlaps the polyamine site in the enzyme and, additionally, 1 also occupies part of the ATP site. Compound 4 behaves as a mixed hyperbolic inhibitor with a Ki of 0.8 μM. The activity of 5 is clearly dependent on the concentration of the polyamine substrate, but its kinetic behavior is clearly not compatible with a competitive mode of inhibition. Analysis of the activity of the six best inhibitors against intracellular amastigotes identified 5 as the most potent leishmanicidal candidate, with an EC50 value of 0.6 μM and a selectivity index of 35.This work has been supported by the Spanish MICINN (Projects PID2019-104070RB-C21 and PID2019-104070RBC22), the Spanish National Research Council (CSIC, Projects CSIC-PIE-201980E100 and CSIC-PIE-201980E028), and the Comunidad de Madrid (PLATESA2-CM ref S-2018/BAA-4370). The MCIN is also acknowledged for the pre- doctoral fellowship to M.A.C.Peer reviewe

Granulocytes-Rich Thrombi in Cerebral Large Vessel Occlusion Are Associated with Increased Stiffness and Poorer Revascularization Outcomes

Altres ajuts: acords transformatius de la UABWe aim to identify a profile of intracranial thrombus resistant to recanalization by mechanical thrombectomy (MT) in acute stroke treatment. The first extracted clot of each MT was analyzed by flow cytometry obtaining the composition of the main leukocyte populations: granulocytes, monocytes, and lymphocytes. Demographics, reperfusion treatment, and grade of recanalization were registered. MT failure (MTF) was defined as final thrombolysis in cerebral infarction score IIa or lower and/or need of permanent intracranial stenting as a rescue therapy. To explore the relationship between stiffness of intracranial clots and cellular composition, unconfined compression tests were performed in other cohorts of cases. Thrombi obtained in 225 patients were analyzed. MTF were observed in 30 cases (13%). MTF was associated with atherosclerosis etiology (33.3% vs. 15.9%; p = 0.021) and higher number of passes (3 vs. 2; p < 0.001). Clot analysis of MTF showed higher percentage of granulocytes [82.46 vs. 68.90% p < 0.001] and lower percentage of monocytes [9.18% vs.17.34%, p < 0.001] in comparison to successful MT cases. The proportion of clot granulocytes (aOR 1.07; 95% CI 1.01-1.14) remained an independent marker of MTF. Among thirty-eight clots mechanically tested, there was a positive correlation between granulocyte proportion and thrombi stiffness (Pearson's r = 0.35, p = 0.032), with a median clot stiffness of 30.2 (IQR, 18.9-42.7) kPa. Granulocytes-rich thrombi are harder to capture by mechanical thrombectomy due to increased stiffness, so a proportion of intracranial granulocytes might be useful to guide personalized endovascular procedures in acute stroke treatment. Supplementary Information: The online version contains supplementary material available at 10.1007/s13311-023-01385-1

Thrombectomy within 8 hours after symptom onset in ischemic stroke

BACKGROUND: We aimed to assess the safety and efficacy of thrombectomy for the treatment of stroke in a trial embedded within a population-based stroke reperfusion registry. METHODS: During a 2-year period at four centers in Catalonia, Spain, we randomly assigned 206 patients who could be treated within 8 hours after the onset of symptoms of acute ischemic stroke to receive either medical therapy (including intravenous alteplase when eligible) and endovascular therapy with the Solitaire stent retriever (thrombectomy group) or medical therapy alone (control group). All patients had confirmed proximal anterior circulation occlusion and the absence of a large infarct on neuroimaging. In all study patients, the use of alteplase either did not achieve revascularization or was contraindicated. The primary outcome was the severity of global disability at 90 days, as measured on the modified Rankin scale (ranging from 0 [no symptoms] to 6 [death]). Although the maximum planned sample size was 690, enrollment was halted early because of loss of equipoise after positive results for thrombectomy were reported from other similar trials. RESULTS Thrombectomy reduced the severity of disability over the range of the modified Rankin scale (adjusted odds ratio for improvement of 1 point, 1.7; 95% confidence interval [CI], 1.05 to 2.8) and led to higher rates of functional independence (a score of 0 to 2) at 90 days (43.7% vs. 28.2%; adjusted odds ratio, 2.1; 95% CI, 1.1 to 4.0). At 90 days, the rates of symptomatic intracranial hemorrhage were 1.9% in both the thrombectomy group and the control group (P = 1.00), and rates of death were 18.4% and 15.5%, respectively (P = 0.60). Registry data indicated that only eight patients who met the eligibility criteria were treated outside the trial at participating hospitals. CONCLUSIONS: Among patients with anterior circulation stroke who could be treated within 8 hours after symptom onset, stent retriever thrombectomy reduced the severity of post-stroke disability and increased the rate of functional independence