Mitochondrial ROS promotes susceptibility to infection via gasdermin D-mediated necroptosis.

Although mutations in mitochondrial-associated genes are linked to inflammation and susceptibility to infection, their mechanistic contributions to immune outcomes remain ill-defined. We discovered that the disease-associated gain-of-function allele Lrrk2G2019S (leucine-rich repeat kinase 2) perturbs mitochondrial homeostasis and reprograms cell death pathways in macrophages. When the inflammasome is activated in Lrrk2G2019S macrophages, elevated mitochondrial ROS (mtROS) directs association of the pore-forming protein gasdermin D (GSDMD) to mitochondrial membranes. Mitochondrial GSDMD pore formation then releases mtROS, promoting a switch to RIPK1/RIPK3/MLKL-dependent necroptosis. Consistent with enhanced necroptosis, infection of Lrrk2G2019S mice with Mycobacterium tuberculosis elicits hyperinflammation and severe immunopathology. Our findings suggest a pivotal role for GSDMD as an executer of multiple cell death pathways and demonstrate that mitochondrial dysfunction can direct immune outcomes via cell death modality switching. This work provides insights into how LRRK2 mutations manifest or exacerbate human diseases and identifies GSDMD-dependent necroptosis as a potential target to limit Lrrk2G2019S-mediated immunopathology.

De novo identification of CD4+ T cell epitopes.

CD4+ T cells recognize peptide antigens presented on class II major histocompatibility complex (MHC-II) molecules to carry out their function. The remarkable diversity of T cell receptor sequences and lack of antigen discovery approaches for MHC-II make profiling the specificities of CD4+ T cells challenging. We have expanded our platform of signaling and antigen-presenting bifunctional receptors to encode MHC-II molecules presenting covalently linked peptides (SABR-IIs) for CD4+ T cell antigen discovery. SABR-IIs can present epitopes to CD4+ T cells and induce signaling upon their recognition, allowing a readable output. Furthermore, the SABR-II design is modular in signaling and deployment to T cells and B cells. Here, we demonstrate that SABR-IIs libraries presenting endogenous and non-contiguous epitopes can be used for antigen discovery in the context of type 1 diabetes. SABR-II libraries provide a rapid, flexible, scalable and versatile approach for de novo identification of CD4+ T cell ligands from single-cell RNA sequencing data using experimental and computational approaches.

The Aconitate Decarboxylase 1/Itaconate Pathway Modulates Immune Dysregulation and Associates with Cardiovascular Disease Markers and Disease Activity in Systemic Lupus Erythematosus.

The Krebs cycle enzyme aconitate decarboxylase 1 (ACOD1) mediates itaconate synthesis in monocytes and macrophages. Previously, we reported that administration of 4-octyl itaconate to lupus-prone mice abrogated immune dysregulation and clinical features. In this study, we explore the role of the endogenous ACOD1/itaconate pathway in the development of TLR7-induced lupus (imiquimod [IMQ] model). We found that, in vitro, ACOD1 was induced in mouse bone marrow-derived macrophages and human monocyte-derived macrophages following TLR7 stimulation. This induction was partially dependent on type I IFN receptor signaling and on specific intracellular pathways. In the IMQ-induced mouse model of lupus, ACOD1 knockout (Acod1-/-) displayed disruptions of the splenic architecture, increased serum levels of anti-dsDNA and proinflammatory cytokines, and enhanced kidney immune complex deposition and proteinuria, when compared with the IMQ-treated wild-type mice. Consistent with these results, Acod1-/- bone marrow-derived macrophages treated in vitro with IMQ showed higher proinflammatory features. Furthermore, itaconate serum levels in systemic lupus erythematosus patients were decreased compared with healthy individuals, in association with disease activity and specific perturbed cardiometabolic parameters. These findings suggest that the ACOD1/itaconate pathway plays important immunomodulatory and vasculoprotective roles in systemic lupus erythematosus, supporting the potential therapeutic role of itaconate analogs in autoimmune diseases.

The nuclear receptor Nurr1 is preferentially expressed in human pro-inflammatory macrophages and limits their inflammatory profile.

Nurr1 is a member of the orphan nuclear receptor family NR4A (nuclear receptor subfamily 4 group A) that modulates inflammation in several cell lineages, both positively and negatively. Macrophages are key regulators of inflammatory responses, yet information about the role of Nurr1 in human macrophages is scarce. Here we examined Nurr1 expression and activity in steady state and activated human macrophages. Pro- and anti-inflammatory macrophages were generated in vitro by culture of blood monocytes with granulocyte/macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF), respectively. Nurr1 expression was predominant in macrophages with the pro-inflammatory phenotype. Nurr1 activation with the agonists 1,1-bis(3'-indolyl)-1-(p-chlorophenyl) methane (C-DIM12) or isoxazolo-pyridinone 7e (IP7e) did not globally modify the polarization status of pro-inflammatory macrophages, but they decreased their production of TNF, IL-1ß, IL-6, IL-8, IL-12 p40, CCL2, IFN-ß, and reactive oxygen species, with variable potencies. Conversely, Nurr1 deficient macrophages increased the expression of transcripts encoding inflammatory mediators, particularly that of IL6, IFNB1, and CCL2. Mechanistically, endogenous Nurr1 interacted with NF-κB p65 in basal conditions and upon lipopolysaccharide (LPS)-mediated activation. C-DIM12 stabilized those complexes in cells exposed to LPS and concurrently decreased NF-κB transcriptional activity and p65 nuclear translocation. Expression of high levels of Nurr1 was associated with a subset of dermal macrophages that display enhanced levels of TNF and lower expression of the anti-inflammatory marker CD163L1 in skin lesions from patients with bullous pemphigoid (BP), a chronic inflammatory autoimmune blistering disorder. These results suggest that Nurr1 expression is linked with the pro-inflammatory phenotype of human macrophages, both in vivo and in vitro, where it may constitute a brake to attenuate the synthesis of inflammatory mediators.

Neutrophil extracellular traps activate Notch-γ-secretase signaling in hidradenitis suppurativa.

BACKGROUND: Hidradenitis suppurativa (HS) is an inflammatory chronic skin disorder of unknown etiology characterized by inflamed abscess-like nodules and boils resulting in sinus tract formation, tissue scarring, and massive infiltration of neutrophils. Multiple lines of evidence have highlighted the potential association between alterations in the Notch pathway and HS pathogenesis, but the mechanisms remain incompletely characterized. OBJECTIVE: We aimed to elucidate the role of neutrophil extracellular traps in Notch-γ-secretase signaling. METHODS: Twenty-six HS lesional tissues, primary HS macrophages, and skin fibroblasts were interrogated by quantitative PCR, Western blot, and ELISA analyses. γ-Secretase and TNF-α converting enzyme activities were measured in HS skin lesions, macrophages, and skin fibroblasts. Immunofluorescence and RNAscope analyses were performed in HS and control skin. RESULTS: A prominent presence of Notch ligands, Delta-like ligand 4 (DLL4), and Jagged (JAG) 2 were detected at the protein and mRNA levels in HS skin lesion compared to control. Levels of DLL4, JAG1, citrullinated histone H3 DNA, and γ-secretase activity correlated with HS disease severity. Additionally, significantly elevated levels of Notch ligands and γ-secretase activity were found in dissected sinus tracts compared to the rest of HS tissue. Immunofluorescence microscopy of HS skin lesions revealed activation of Notch-1 signaling in macrophages and skin fibroblasts. Neutrophil extracellular traps (NETs) purified from HS patients displayed elevated levels of DLL4. HS NETs activated the Notch pathway in macrophages and dermal fibroblasts isolated from HS patients. HS skin fibroblasts displayed elevated levels of CD90 and DPP4 in association with increased migratory capacity and Notch activation. Inhibition of Notch decreased migratory capacity and profibrotic markers in HS fibroblasts. CONCLUSION: These data support a pathogenic connection between NETs, Notch-γ-secretase activation, and the release of profibrotic molecules that promote dysregulation of macrophages and skin fibroblasts in HS. Unveiling the relevance of these molecular events not only expands our understanding of HS but also opens new venues for the development of targeted therapies to address the fibrotic complications of advanced stages of HS.

No Black Holes from Light.

We show that it is not possible to concentrate enough light to precipitate the formation of an event horizon. We argue that the dissipative quantum effects coming from the self-interaction of light (such as vacuum polarization) are enough to prevent any meaningful buildup of energy that could create a black hole in any realistic scenario.

Shrinking Devices: Shape-Memory Polymer Fabrication of Micro-and Nanostructured Electrodes.

Since their discovery in the 1940s, shape memory polymers (SMPs) have been used in a broad spectrum of applications for research and industry.[1] SMPs can adopt a temporary shape and promptly return to their original form when submitted to an external stimulus. They have proven useful in fields such as wearable and stretchable electronics,[2] biomedicine,[3] and aerospace..[4] These materials are attractive and unique due to their ability to "remember" a shape after being submitted to elastic deformation. By combining the properties of SMPs with the advantages of electrochemistry, opportunities have emerged to develop structured sensing devices through simple and inexpensive fabrication approaches. The use of electrochemistry for signal transduction provides several advantages, including the translation into inexpensive sensing devices that are relatively easy to miniaturize, extremely low concentration requirements for detection, rapid sensing, and multiplexed detection. Thus, electrochemistry has been used in biosensing,[5] pollutant detection,[6] and pharmacological[7] applications, among others. To date, there is no review that summarizes the literature addressing the use of SMPs in the fabrication of structured electrodes for electrochemical sensing. This review aims to fill this gap by compiling the research that has been done on this topic over the last decade.

Shrinking Devices: Shape-Memory Polymer Fabrication of Micro-and Nanostructured Electrodes.

The front cover artwork is provided by Prof. Jose Moran-Mirabal's group at McMaster University in Hamilton, Ontario, Canada. The image shows a 3D rendering and electron microscopy images of micro/nanostructured electrodes, fabricated through thermal shrinking of a shape memory polymer. Read the full text of the Review at 10.1002/cphc.202300535.

Potential of Pinus radiata, Eucalyptus globulus and Acacia dealbata for the long-term phytostabilization of copper mine tailings.

Many contaminated tailings throughout the world cause environmental and human-health related problems due to air and water drift. Tailing phytostabilization is a promising solution, but only certain plant species may tolerate and grow in these contaminated areas. We analyzed the chemical properties of a vegetated and unvegetated area in a tailing site in Central Chile. In addition, in the vegetated area we analyzed the metals content of roots, stems, and foliage in 41-years old plantations of Pinus radiata, Acacia dealbata, and Eucalyptus globulus (the only three species that survived from a total of 34 species planted), and determined height (H), and diameter at breast height (DBH). The results indicated that, except for pH, Se, Pb, and organic matter, all components (nutrients and metals) were two- to three- fold lower in the vegetated tailing compared to that of the unvegetated tailing. The analysis of plant tissues indicated that Cu was higher in the roots of P. radiata (2,073 mg kg-1) and lower in the stems of the same species (4.1 mg kg-1). However, the ability to take up and transport Cu to the shoots was higher in A. dealbata and lower in P. radiata (bioaccumulation factor of 0.19 and 0.06, respectively).

Here we present results for the first long-term phytostabilization project of copper mine tailings in Chile. From the 34 native and exotic species established in 1980 in a mine tailing disposal site with 1,000 mg Cu kg⁻¹, only the exotic Pinus radiata, Acacia dealbata and Eucalyptus globulus were able to survive and adapt to the tailing conditions the last 41 years. This corroborates their potential for the future phytostabilization of copper mine wastes.

Optical Printing of Single Au Nanostars.

Obtaining arrays of single nanoparticles with three-dimensional complex shapes is still an open challenge. Current nanolithography methods do not allow for the preparation of nanoparticles with complex features like nanostars. In this work, we investigate the optical printing of gold nanostars of different sizes as a function of laser wavelength and power. We found that tuning the laser to the main resonances of the nanostars in the near-infrared makes it possible to avoid nanoparticles reshaping due to plasmonic heating, enabling their deposition at the single particle level and in ordered arrays.

Asynchronous current-induced switching of rare-earth and transition-metal sublattices in ferrimagnetic alloys.

Ferrimagnetic alloys are model systems for understanding the ultrafast magnetization switching in materials with antiferromagnetically coupled sublattices. Here we investigate the dynamics of the rare-earth and transition-metal sublattices in ferrimagnetic GdFeCo and TbCo dots excited by spin-orbit torques with combined temporal, spatial and elemental resolution. We observe distinct switching regimes in which the magnetizations of the two sublattices either remain synchronized throughout the reversal process or switch following different trajectories in time and space. In the latter case, we observe a transient ferromagnetic state that lasts up to 2 ns. The asynchronous switching of the two magnetizations is ascribed to the master-agent dynamics induced by the spin-orbit torques on the transition-metal and rare-earth sublattices and their weak antiferromagnetic coupling, which depends sensitively on the alloy microstructure. Larger antiferromagnetic exchange leads to faster switching and shorter recovery of the magnetization after a current pulse. Our findings provide insight into the dynamics of ferrimagnets and the design of spintronic devices with fast and uniform switching.

Experimental Activation of Strong Local Passive States with Quantum Information.

Strong local passivity is a property of multipartite quantum systems from which it is impossible to extract energy locally. Surprisingly, if the strong local passive state displays entanglement, it could be possible to locally activate energy density by adding classical communication between different partitions of the system, through so-called "quantum energy teleportation" protocols. Here, we report both the first experimental observation of local activation of energy density on an entangled state and the first realization of a quantum energy teleportation protocol using nuclear magnetic resonance on a bipartite quantum system.

Cancer Cells Hijack Gluconeogenic Enzymes to Fuel Cell Growth.

In this issue and the October 15th issue of Molecular Cell, studies by Montal et al. (2015) and Vincent et al. (2015) report that certain types of cancer cells utilize the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxykinase 2 (PCK2) to reprogram anabolic metabolism and support cell growth.

Comparison of brown adipose tissue activation detected by infrared thermography in men with vs without metabolic syndrome.

BACKGROUND: Brown adipose tissue (BAT) high density of mitochondria and its thermogenic characteristics promote the dissipation of chemical energy in the form of heat, increasing body caloric expenditure, decreasing plasma levels of lipids and glucose (GL). This makes BAT a potential therapeutic target of Metabolic Syndrome (MetS). Position Emission Tomography Scanning (PET-CT) is the gold standard for estimating BAT, but it has several limitations, including high cost and high emission of radiation. On the other hand, Infrared Thermography (IRT) is considered a simpler, cheaper and non-invasive method to detect BAT. OBJECTIVE: The aim of this study was to compare BAT activation through IRT and cold stimulation in men diagnosed without and with MetS. METHODS: Sample of 124 (35.3 ± 9.4 years old) men was evaluated of body composition, anthropometric measurements and dual X-ray absorptiometry (DXA) hemodynamics, biochemical tests and body skin temperature acquisition. The Student t-test with subsequent effect size by (d) Cohen and two-way repeated measures ANOVA with Tukey post-hoc comparisons were conducted. Level of significance was p < 0.05. RESULTS: There was significant interaction between group factor (MetS) vs group moment (BAT activation) in supraclavicular skin temperatures right side (maximum (F(1,122) = 10.4, p < 0.002, η2 = 0.062), mean (F(1.122) = 13.0, p < 0.001, η2 = 0.081) and minimal (F(1,122) = 7.9, p < 0.006, η2 = 0.052)) and left side maximum (F(1,122) = 7.7, p < 0.006, η2 = 0.048), mean (F(1.122) = 13.0, p < 0.037, η2 = 0.007) and minimal (F(1,122) = 9.8, p < 0.002, η2 = 0.012)). The MetS risk factor group didn't present significant increase of SCV temperature BAT after cold stimulation. CONCLUSION: Men diagnosed with MetS risk factors seem to activate less BAT, when exposed to cold stimulation, compared to group without MetS risk factor.

Isolation of Hepatic and Adipose-Tissue-Derived Extracellular Vesicles Using Density Gradient Separation and Size Exclusion Chromatography.

In recent years, the study of extracellular vesicles (EVs) in the context of various diseases has dramatically increased due to their diagnostic and therapeutic potential. Typically, EVs are isolated in vitro from the cell culture of primary cells or cell lines or from bodily fluids. However, these cell culture methods do not represent the whole complexity of an in vivo microenvironment, and bodily fluids contain a high heterogeneous population of vesicles since they originate from different tissues. This highlights the need to develop new methods to isolate EVs directly from tissue samples. In the present study, we established a protocol for isolating EVs from hepatic and adipose tissue of mice, using a combination of ultracentrifugation and iodixanol-sucrose density gradient separation. EV isolation was confirmed with EV protein marker enrichment in Western blot assays, total protein quantification, and transmission electron microscopy. Regarding the liver tissue, we additionally implemented size exclusion chromatography (SEC) to further increase the purity grade of the EVs. The successful isolation of EVs from tissue samples will allow us to uncover a more precise molecular composition and functions, as well as their role in intercellular communication in an in vivo microenvironment.

C-reactive protein postoperative values to predict clinically relevant postoperative pancreatic fistula after distal pancreatectomy.

INTRODUCTION: despite significant medical and technological advances, the incidence of postoperative pancreatic fistula (POPF) after distal pancreatectomy (DP) is reported to be between 3-45 %. The main objective of this study was to analyze the early post-surgical risk factors for developing POPF after DP. MATERIAL AND METHODS: a retrospective observational study was performed on a prospective basis of patients undergoing DP in a tertiary hospital from January 2011 to December 2021. Sociodemographic, preoperative analytical, tumor-related and postoperative complications variables were analyzed. RESULTS: of the 52 patients analyzed, 71.8 % of the sample had postoperative drains amylase elevation. However, 25.7 % of the total had grade-B and/or grade-C POPF. Univariate logistic regression with the variables studied showed the following as risk factors for B-C or clinically relevant POPF: amylase values in drainage at the 5th postoperative day (POD) (p = 0.097; 1.01 [1-1.01]), preoperative BMI (p = 0.015; 1.27 [1.04-1.55]) and C-reactive protein (CRP) value at the 3rd POD (p = 0.034; 1.01 [1.01-1.02]). The ROC curve of CRP value at the 3rd POD showed an area under the curve of 0.764 (95 % CI: 0.6-0.93) and the best cut-off point was 190 mg/l (sensitivity 89 % and specificity 67 %). CONCLUSIONS: CRP value at the 3rd POD is a predictive factor for POPF after DP. Early detection of patients at risk of POPF based on these characteristics could have an impact on their postoperative management.

Electrochemical Nano-Roughening of Gold Microstructured Electrodes for Enhanced Sensing in Biofluids.

A key challenge for sensor miniaturization is to create electrodes with smaller footprints, while maintaining or increasing sensitivity. In this work, the electroactive surface of gold electrodes was enhanced 30-fold by wrinkling followed by chronoamperometric (CA) pulsing. Electron microscopy showed increased surface roughness in response to an increased number of CA pulses. The nanoroughened electrodes also showed excellent fouling resistance when submerged in solutions containing bovine serum albumin. The nanoroughened electrodes were used for electrochemical detection of Cu2+ in tap water and of glucose in human blood plasma. In the latter case, the nanoroughened electrodes allowed highly sensitive enzyme-free sensing of glucose, with responses comparable to those of two commercial enzyme-based sensors. We anticipate that this methodology to fabricate nanostructured electrodes can accelerate the development of simple, cost-effective, and high sensitivity electrochemical platforms.

Association of the dysfunctional placentation endotype of prematurity with bronchopulmonary dysplasia: a systematic review, meta-analysis and meta-regression.

BACKGROUND: Antenatal pathological conditions are key in the pathogenesis of bronchopulmonary dysplasia (BPD). Pathophysiological pathways or endotypes leading to prematurity and perinatal lung injury can be clustered into two groups: infection and dysfunctional placentation, which include hypertensive disorders of pregnancy (HDP) and intrauterine growth restriction (IUGR). We conducted a systematic review of observational studies exploring the association between the dysfunctional placentation endotype and BPD. METHODS: MEDLINE, Embase and Web of Science databases were searched up to February 2020 for studies reporting data on the diagnosis of HDP, IUGR or small for gestational age (SGA) and BPD risk. BPD was classified as BPD28 (supplemental oxygen on day 28), BPD36 (oxygen at 36 weeks postmenstrual age), severe BPD (≥ 30% oxygen or mechanical ventilation), BPD36/death and BPD-associated pulmonary hypertension. RESULTS: Of 6319 studies screened, 211 (347 963 infants) were included. Meta-analysis showed an association between SGA/IUGR and BPD36 (OR 1.56, 95% CI 1.37 to 1.79), severe BPD (OR 1.82, 95% CI 1.36 to 2.29) and BPD/death (OR 1.91, 95% CI 1.55 to 2.37). Exposure to HDP was not associated with BPD but was associated with decreased odds of BPD/death (OR 0.77, 95% CI 0.64 to 0.94). Both HDP (OR 1.41, 95% CI 1.10 to 1.80) and SGA/IUGR (OR 2.37, 95% CI 1.86 to 3.02) were associated with BPD-associated pulmonary hypertension. CONCLUSION: When placental vascular dysfunction is accompanied by fetal growth restriction or being born SGA, it is associated with an increased risk of developing BPD and pulmonary hypertension. The placental dysfunction endotype of prematurity is strongly associated with the vascular phenotype of BPD. PROSPERO REGISTRATION NUMBER: Review protocol was registered in PROSPERO database (ID=CRD42018086877).

Impact of different COVID-19 waves on kidney replacement therapy epidemiology and mortality: REMER 2020.

BACKGROUND: Kidney replacement therapy (KRT) confers the highest risk of death from coronavirus disease 2019 (COVID-19). However, most data refer to the early pandemic waves. Whole-year analysis compared with prior secular trends are scarce. METHODS: We present the 2020 REMER Madrid KRT registry, corresponding to the Spanish Region hardest hit by COVID-19. RESULTS: In 2020, KRT incidence decreased 12% versus 2019, while KRT prevalence decreased by 1.75% for the first time since records began and the number of kidney transplants (KTs) decreased by 16%. Mortality on KRT was 10.2% (34% higher than the mean for 2008-2019). The 2019-2020 increase in mortality was larger for KTs (+68%) than for haemodialysis (+24%) or peritoneal dialysis (+38%). The most common cause of death was infection [n = 419 (48% of deaths)], followed by cardiovascular [n = 200 (23%)]. Deaths from infection increased by 167% year over year and accounted for 95% of excess deaths in 2020 over 2019. COVID-19 was the most common cause of death (68% of infection deaths, 33% of total deaths). The bulk of COVID-19 deaths [209/285 (73%)] occurred during the first COVID-19 wave, which roughly accounted for the increased mortality in 2020. Being a KT recipient was an independent risk factor for COVID-19 death. CONCLUSIONS: COVID-19 negatively impacted the incidence and prevalence of KRT, but the increase in KRT deaths was localized to the first wave of the pandemic. The increased annual mortality argues against COVID-19 accelerating the death of patients with short life expectancy and the temporal pattern of COVID-19 mortality suggests that appropriate healthcare may improve outcomes.

Flexible multiplex PCR to detect SARS-CoV-2, coronavirus OC43 and influenza A virus in nasopharyngeal swab samples.

INTRODUCTION: Quantitative reverse transcription PCR (RT-qPCR) is the leading tool to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given that it will almost certainly continue to coexist with other respiratory viruses in the coming years, our study aimed to design a multiplex PCR system not affected by supplier outages and with reduced cost compared to the existing commercially available kits. METHODS AND RESULTS: In this study, combinations of four primers/probe sets were used to construct a flexible RT-qPCR assay which is capable of discriminating between SARS-CoV-2 and the seasonal human coronavirus HCoV-OC43, or even influenza A virus. Additionally, the human RPP30 gene was used as an internal control. To demonstrate the robustness of the assay, it was applied to a collection of 150 clinical samples. The results showed 100% sensitivity and specificity compared to the automatized system used at the hospital and were better when indeterminate samples were analysed. CONCLUSIONS: This study provides an efficient method for the simultaneous detection of SARS-CoV-2, HCoV-OC43 and influenza A virus, and its efficacy has been tested on clinical samples showing outstanding results. SIGNIFICANCE AND IMPACT OF THE STUDY: The multiplex RT-qPCR design offers an accessible and economical alternative to commercial detection kits for hospitals and laboratories with limited economic resources or facing situations of supply shortage.