Coexisting cancer stem cells with heterogeneous gene amplifications, transcriptional profiles, and malignancy are isolated from single glioblastomas.

Glioblastoma (GBM) is known as an intractable, highly heterogeneous tumor encompassing multiple subclones, each supported by a distinct glioblastoma stem cell (GSC). The contribution of GSC genetic and transcriptional heterogeneity to tumor subclonal properties is debated. In this study, we describe the systematic derivation, propagation, and characterization of multiple distinct GSCs from single, treatment-naive GBMs (GSC families). The tumorigenic potential of each GSC better correlates with its transcriptional profile than its genetic make-up, with classical GSCs being inherently more aggressive and mesenchymal more dependent on exogenous growth factors across multiple GBMs. These GSCs can segregate and recapitulate different histopathological aspects of the same GBM, as shown in a paradigmatic tumor with two histopathologically distinct components, including a conventional GBM and a more aggressive primitive neuronal component. This study provides a resource for investigating how GSCs with distinct genetic and/or phenotypic features contribute to individual GBM heterogeneity and malignant escalation.

Comparative evaluation using PRO of an algorithm of one-stage immediate alloplastic breast reconstruction versus two-stage reconstruction.

BACKGROUND: One-stage direct-to-implant (DTI) immediate breast reconstruction has proven to be an oncologically safe technique, but there are some conditions that do not allow its performance. The introduction of new surgical techniques and the recent COVID-19 pandemic have pushed us to introduce a breast reconstruction algorithm in our clinical practice. This allows a one-stage immediate reconstruction for all patients, regardless of their anatomical characteristics, the type of implants used, and the need for postoperative radiotherapy. METHODS: A total of 40 patients were recruited and divided into two cohorts, 20 patients underwent immediate one-stage breast reconstruction in the period between October 2019 and January 2021, and 20 patients completed the two-stage reconstructive process in the period prior to October 2019. During the follow-up at 6 months, all patients who had completed the reconstructive process filled out the Breast-Q Reconstruction Module Pre and Postoperative scales questionnaire. The outcomes of the questionnaires were compared between the two cohorts, and statistical analysis was carried out using SPSS Statistics 20 (IBM Corporation, Armonk, NY, USA). RESULTS: The analysis of patient-reported outcomes showed that patients from the one-stage group reported better outcomes in all items evaluated. We did not find statistically significant differences concerning the rate of complications and length of hospital stay between the two groups. CONCLUSIONS: The analysis of the results shows that the outcomes reported by patients who completed breast reconstruction according to our algorithm are statistically better than those with the two-stage technique.

Aberrant L-Fucose Accumulation and Increased Core Fucosylation Are Metabolic Liabilities in Mesenchymal Glioblastoma.

Glioblastoma (GBM) is a common and deadly form of brain tumor in adults. Dysregulated metabolism in GBM offers an opportunity to deploy metabolic interventions as precise therapeutic strategies. To identify the molecular drivers and the modalities by which different molecular subgroups of GBM exploit metabolic rewiring to sustain tumor progression, we interrogated the transcriptome, the metabolome, and the glycoproteome of human subgroup-specific GBM sphere-forming cells (GSC). L-fucose abundance and core fucosylation activation were elevated in mesenchymal (MES) compared with proneural GSCs; this pattern was retained in subgroup-specific xenografts and in subgroup-affiliated human patient samples. Genetic and pharmacological inhibition of core fucosylation significantly reduced tumor growth in MES GBM preclinical models. Liquid chromatography-mass spectrometry (LC-MS)-based glycoproteomic screening indicated that most MES-restricted core-fucosylated proteins are involved in therapeutically relevant GBM pathological processes, such as extracellular matrix interaction, cell adhesion, and integrin-mediated signaling. Selective L-fucose accumulation in MES GBMs was observed using preclinical minimally invasive PET, implicating this metabolite as a potential subgroup-restricted biomarker.Overall, these findings indicate that L-fucose pathway activation in MES GBM is a subgroup-specific dependency that could provide diagnostic markers and actionable therapeutic targets. SIGNIFICANCE: Metabolic characterization of subgroup-specific glioblastoma (GBM) sphere-forming cells identifies the L-fucose pathway as a vulnerability restricted to mesenchymal GBM, disclosing a potential precision medicine strategy for targeting cancer metabolism.

Chromosome-scale genome assembly of the brown anole (Anolis sagrei), an emerging model species.

Rapid technological improvements are democratizing access to high quality, chromosome-scale genome assemblies. No longer the domain of only the most highly studied model organisms, now non-traditional and emerging model species can be genome-enabled using a combination of sequencing technologies and assembly software. Consequently, old ideas built on sparse sampling across the tree of life have recently been amended in the face of genomic data drawn from a growing number of high-quality reference genomes. Arguably the most valuable are those long-studied species for which much is already known about their biology; what many term emerging model species. Here, we report a highly complete chromosome-scale genome assembly for the brown anole, Anolis sagrei - a lizard species widely studied across a variety of disciplines and for which a high-quality reference genome was long overdue. This assembly exceeds the vast majority of existing reptile and snake genomes in contiguity (N50 = 253.6 Mb) and annotation completeness. Through the analysis of this genome and population resequence data, we examine the history of repetitive element accumulation, identify the X chromosome, and propose a hypothesis for the evolutionary history of fusions between autosomes and the X that led to the sex chromosomes of A. sagrei.

TREM2 drives microglia response to amyloid-ß via SYK-dependent and -independent pathways.

Genetic studies have highlighted microglia as pivotal in orchestrating Alzheimer's disease (AD). Microglia that adhere to Aß plaques acquire a transcriptional signature, "disease-associated microglia" (DAM), which largely emanates from the TREM2-DAP12 receptor complex that transmits intracellular signals through the protein tyrosine kinase SYK. The human TREM2R47H variant associated with high AD risk fails to activate microglia via SYK. We found that SYK-deficient microglia cannot encase Aß plaques, accelerating brain pathology and behavioral deficits. SYK deficiency impaired the PI3K-AKT-GSK-3ß-mTOR pathway, incapacitating anabolic support required for attaining the DAM profile. However, SYK-deficient microglia proliferated and advanced to an Apoe-expressing prodromal stage of DAM; this pathway relied on the adapter DAP10, which also binds TREM2. Thus, microglial responses to Aß involve non-redundant SYK- and DAP10-pathways. Systemic administration of an antibody against CLEC7A, a receptor that directly activates SYK, rescued microglia activation in mice expressing the TREM2R47H allele, unveiling new options for AD immunotherapy.

ß-Galactosylceramidase Deficiency Causes Upregulation of Long Pentraxin-3 in the Central Nervous System of Krabbe Patients and Twitcher Mice.

Globoid cell leukodystrophy (GLD), or Krabbe disease, is a neurodegenerative sphingolipidosis caused by genetic deficiency of lysosomal ß-galactosylceramidase (GALC), characterized by neuroinflammation and demyelination of the central (CNS) and peripheral nervous system. The acute phase protein long pentraxin-3 (PTX3) is a soluble pattern recognition receptor and a regulator of innate immunity. Growing evidence points to the involvement of PTX3 in neurodegeneration. However, the expression and role of PTX3 in the neurodegenerative/neuroinflammatory processes that characterize GLD remain unexplored. Here, immunohistochemical analysis of brain samples from Krabbe patients showed that macrophages and globoid cells are intensely immunoreactive for PTX3. Accordingly, Ptx3 expression increases throughout the course of the disease in the cerebrum, cerebellum, and spinal cord of GALC-deficient twitcher (Galctwi/twi) mice, an authentic animal model of GLD. This was paralleled by the upregulation of proinflammatory genes and M1-polarized macrophage/microglia markers and of the levels of PTX3 protein in CNS and plasma of twitcher animals. Crossing of Galctwi/twi mice with transgenic PTX3 overexpressing animals (hPTX3 mice) demonstrated that constitutive PTX3 overexpression reduced the severity of clinical signs and the upregulation of proinflammatory genes in the spinal cord of P35 hPTX3/Galctwi/twi mice when compared to Galctwi/twi littermates, leading to a limited increase of their life span. However, this occurred in the absence of a significant impact on the histopathological findings and on the accumulation of the neurotoxic metabolite psychosine when evaluated at this late time point of the disease. In conclusion, our results provide the first evidence that PTX3 is produced in the CNS of GALC-deficient Krabbe patients and twitcher mice. PTX3 may exert a protective role by reducing the neuroinflammatory response that occurs in the spinal cord of GALC-deficient animals.

Percutaneous coronary intervention versus coronary artery bypass graft for left main coronary artery disease: A meta-analysis.

BACKGROUND: The optimal revascularization strategy for patients with left main coronary artery disease is still controversial. This is systematic review and meta-analysis aims to evaluate the outcomes of percutaneous coronary intervention (PCI) with drug-eluting stents compared with coronary artery bypass graft (CABG) for LM disease. METHODS: Online electronic databases were systematically reviewed until January 2020 for randomized trials comparing PCI with drug-eluting stents and CABG. Primary outcomes were: all-cause mortality, myocardial infarction (MI), stroke, and repeated revascularization. Secondary outcomes included periprocedural and nonperiprocedural MI. The period of follow-up included 30 days, 1 year, and 5 years. Odds ratio and 95% confidence interval were calculated with a fixed-effects model. RESULTS: A total of 4595 patients (5 randomized trials) with left main coronary artery disease were included. At 30 days and 1 year, PCI was associated with lower incidence of stroke, higher repeated revascularization, and similar odds of mortality and MI compared with CABG. At 5 years, PCI was associated with higher rates of MI (odds ratio, 1.43; 95% confidence interval, 1.13-1.79; P = .003) and repeat revascularization (odds ratio, 1.89; 95% CI, 1.58-2.26; P < .001) than CABG. PCI was associated with lower periprocedural MI at 30 days, whereas at 5 years PCI was associated with higher nonperiprocedural MI (odds ratio, 2.32; 95% confidence interval, 1.62-3.31; P < .001). Mortality and stroke rate did not differ at 5-year follow-up. CONCLUSIONS: Patients with left main coronary artery disease treated with either PCI or CABG do not show significant difference in early or 5-year mortality. Although CABG was associated with higher stroke rates at 30 days and 1 year, PCI was associated with an increase in MI and need for repeat revascularization at 5 years.

mTORC1 promotes malignant large cell/anaplastic histology and is a targetable vulnerability in SHH-TP53 mutant medulloblastoma.

Medulloblastoma (MB), one of the most malignant brain tumors of childhood, comprises distinct molecular subgroups, with p53 mutant sonic hedgehog-activated (SHH-activated) MB patients having a very severe outcome that is associated with unfavorable histological large cell/anaplastic (LC/A) features. To identify the molecular underpinnings of this phenotype, we analyzed a large cohort of MB developing in p53-deficient Ptch+/- SHH mice that, unexpectedly, showed LC/A traits that correlated with mTORC1 hyperactivation. Mechanistically, mTORC1 hyperactivation was mediated by a decrease in the p53-dependent expression of mTORC1 negative regulator Tsc2. Ectopic mTORC1 activation in mouse MB cancer stem cells (CSCs) promoted the in vivo acquisition of LC/A features and increased malignancy; accordingly, mTORC1 inhibition in p53-mutant Ptch+/- SHH MB and CSC-derived MB resulted in reduced tumor burden and aggressiveness. Most remarkably, mTORC1 hyperactivation was detected only in p53-mutant SHH MB patient samples, and treatment with rapamycin of a human preclinical model phenocopying this subgroup decreased tumor growth and malignancy. Thus, mTORC1 may act as a specific druggable target for this subset of SHH MB, resulting in the implementation of a stringent risk stratification and in the potentially rapid translation of this precision medicine approach into the clinical setting.

Transcatheter valve-in-valve implantation for degenerated bioprosthetic aortic and mitral valves - an update on indications, techniques, and clinical results.

Introduction: Aortic and mitral bioprosthesis are the gold standard treatment to replace a pathological native valve. However, bioprostheses are prone to structural valve degeneration, resulting in limited long-term durability. During the past decade, the implantation of transcatheter stent-valves within degenerated aortic and mitral bioprostheses, (the so-called 'valve-in-valve' procedure), represents a valid alternative to redo surgery in patients with high-risk surgical profiles.Areas covered: We reviewed the clinical outcomes and the procedural details of transcatheter aortic and mitral valve-in-valve series according to current published literature and include a practical guide for valve sizing and stent-valve positioning and strategies to prevent complications.Expert opinion: In both aortic and mitral positions meticulous planning is fundamental in these procedures to avoid serious complications including patient prosthesis mismatch, coronary obstruction and left ventricular outflow tract obstruction.

Balloon versus self-expandable transcatheter aortic valve implantation for bicuspid aortic valve stenosis: A meta-analysis of observational studies.

BACKGROUND: There is a rising trend for transcatheter aortic valve implantation (TAVI) in bicuspid aortic stenosis patients. Data on the use of self-expandable (SEV) vs. balloon-expandable (BEV) valves in these patients are scarce. Therefore, we systematically compared clinical outcomes in bicuspid aortic stenosis patients treated with SEV and BEV. METHODS: Data were extracted from PubMed/MEDLINE, EMBASE, CENTRAL/CCTR, ClinicalTrials.gov, SciELO, LILACS, Google Scholar and reference lists of relevant articles. Eight studies published from 2013 to 2020 including a total of 1,080 patients (BEV: n = 620; SEV: n = 460) were selected. Primary endpoints were procedural, 30-day and 1-year mortality. Secondary endpoints were new pacemaker implantation, annular rupture, coronary obstruction, moderate-to-severe paravalvular leak, need of second valve, stroke and acute kidney injury. RESULTS: We found no statistically significant difference in mortality between patients treated with BEV vs. SEV during index procedure, at 30 days and at 1 year. BEVs showed a statistically significant higher risk of annulus rupture (2.5%) in comparison with SEV (0%) (OR 5.81 [95% CI, 3.78-8.92], p < .001). New generation BEVs were also associated with significantly less paravalvular leak when compared to new generation SEVs (OR 0.08 [95% CI, 0.02-0.35], p = .001). CONCLUSIONS: This meta-analysis of observational studies of TAVI for bicuspid valves, showed no difference in short- and mid-term TAVI mortality with BEVs and SEVs. BEVs presented a higher risk of annular rupture in comparison with SEV.

Valve-in-Valve Transcatheter Aortic Valve Replacement Versus Redo Surgical Aortic Valve Replacement: An Updated Meta-Analysis.

OBJECTIVES: The aim of this study was to evaluate early results of valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) versus redo surgical aortic valve replacement (SAVR) for structural valve degeneration (SVD). BACKGROUND: ViV TAVR has been increasingly used for SVD, but it remains unknown whether it produces better or at least comparable results as redo SAVR. METHODS: Observational studies comparing ViV TAVR and redo SAVR were identified in a systematic search of published research. Random-effects meta-analysis was performed, comparing clinical outcomes between the 2 groups. RESULTS: Twelve publications including a total of 16,207 patients (ViV TAVR, n = 8,048; redo SAVR, n = 8,159) were included from studies published from 2015 to 2020. In the pooled analysis, ViV TAVR was associated with lower rates of 30-day mortality overall (odds ratio [OR]: 0.53; 95% confidence interval [CI]: 0.32 to 0.87; p = 0.017) and for matched populations (OR: 0.419; 95% CI: 0.278 to 0.632; p = 0.003), stroke (OR: 0.65; 95% CI: 0.55 to 0.76; p < 0.001), permanent pacemaker implantation (OR: 0.73; 95% CI: 0.22 to 2.43; p = 0.536), and major bleeding (OR: 0.49; 95% CI: 0.26 to 0.93; p = 0.034), as well as with shorter hospital stay (OR: -3.30; 95% CI: -4.52 to -2.08; p < 0.001). In contrast, ViV TAVR was associated with higher rates of myocardial infarction (OR: 1.50; 95% CI: 1.01 to 2.23; p = 0.045) and severe patient-prosthesis mismatch (OR: 4.63; 95% CI: 3.05 to 7.03; p < 0.001). The search revealed an important lack of comparative studies with long-term results. CONCLUSIONS: ViV TAVR is a valuable option in the treatment of patients with SVD because of its lower incidence of post-operative complications and better early survival compared with redo SAVR. However, ViV TAVR is associated with higher rates of myocardial infarction and severe patient-prosthesis mismatch.

Acute carnosine and ß-alanine supplementation increase the compensated part of the ventilation versus work rate relationship during a ramp incremental cycle test in physically active men.

BACKGROUND: Chronic supplementation with carnosine and ß-alanine (Carn-ßA) has been proposed to improve muscle contractility and reduce muscle fatigue mainly through an increase in intracellular pH buffering capacity. However, the acute ergogenic effects of Carn-ßA supplementation are poorly investigated. This study aimed at evaluating the acute effects of a single Carn-ßA supplementation on the cardiorespiratory and metabolic response during a ramp cycle-ergometric test. METHODS: This randomized, double-blind, placebo-controlled study, involved 10 healthy males (age: 22.2±1.9 years, body mass: 72.5±7.9 kg, stature: 1.72±0.08 m, Body Mass Index: 24.47±1.91 kg/m2, mean±standard deviation). All the participants performed two maximal incremental ramp tests on a cycle ergometer, with a prior randomized assumption of 2.5 g L-carnosine plus 2.5 g ß-alanine (Carn-ßA) or placebo (PLA). During exercise, gas exchange parameters were measured breath-by-breath, heart rate was monitored by electrocardiography and rate perceived exertion was determined on Borg scales. From the ramp test, peak cardiorespiratory and metabolic parameters and ventilatory thresholds (VT1 and VT2) were calculated offline. RESULTS: No differences between the experimental conditions emerged at peak exercise. However, despite acute Carn-ßA supplementation did not affect the single ventilatory thresholds, the compensated portion of the ramp test (i.e. the difference between VT2 and VT1) was significantly larger (P=0.043) in Carn-ßA. CONCLUSIONS: These findings demonstrate a positive effect of acute Carn-ßA supplementation on the compensated part of the exercise. This should be taken into account by nutritionists and athletes searching for nutritional supplements, when a quick effect based on an acute dose is required.

The Swiss STAR trial - an evaluation of target groups for sexually transmitted infection screening in the sub-sample of women.

OBJECTIVES: In Switzerland, universal health insurance does not cover any routine testing for sexually transmitted infections (STIs), not even in individuals at high risk, and extra-genital swabbing is not standard of care. We compared STI prevalence in a multicentre prospective observational cohort of multi-partner women with/without sex work and evaluated associated risk factors. MATERIALS AND METHODS: Between January 2016 and June 2017, we offered free STI testing to women with multiple  sexual partners (three or more in the previous 12 months), with follow-up examinations every 6 months. We used multiplex polymerase chain-reaction testing (for Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium) for pooled swabs (pharynx, urethra/vagina, anus), and antibody tests for human immunodeficiency virus (HIV) and Treponema pallidum at every visit, and for hepatitis B and C at baseline. RESULTS: We screened 490 female sex workers (FSWs), including 17 trans women, and 92 other multi-partner women. More than half reported a steady partner. Previously undiagnosed HIV was found in 0.2% vs 0.0%, respectively, and T. pallidum antibodies in 5.9% vs 0.0%. STIs requiring antibiotic treatment comprised: active syphilis 1.2% vs 0.0%; N. gonorrhoeae 4.9% vs 0.0%; C. trachomatis 6.3% vs 5.4%, T. vaginalis 10.4% vs 0.0%; M. genitalium 6.7% vs 6.5%. One in four FSWs vs one in nine other women had one or more of these STIs at baseline. 15.8% vs 3.8% had a history of hepatitis B, 45.5% vs 22.8% had no immunity (HBs-AB <10 IU/l). Two FSWs had hepatitis C virus antibodies (0.4%) without concurrent HIV infection. Non-condom-use (last three months) for anal/vaginal sex was not associated with STIs. Independent risk factors were group sex (adjusted odds ratio [aOR] 2.1, 95% confidence interval [CI] 1.1–4.0), age less than 25 (aOR 3.7, 95% CI 1.6–8.9), and being active in sex work for less than 1 year (aOR 2.7, 95% CI 1.3–5.3). CONCLUSION: HIV and HCV do not appear to pose a major public health problem among FSWs in Switzerland, whereas vaccination against HBV should be promoted. FSWs showed high rates of STIs requiring treatment to reduce transmission to clients and/or steady partners. FSWs should be offered low-cost or free STI screening as a public health priority.

The Swiss STAR trial - an evaluation of target groups for sexually transmitted infection screening in the sub-sample of men.

OBJECTIVES: In Switzerland, universal health insurance does not cover any routine testing for sexually transmitted infections (STIs), not even in individuals at high risk, and extra-genital swabbing is not standard of care. We determined the prevalence and incidence of human immunodeficiency virus (HIV), viral hepatitis and non-viral STIs in a multicentre prospective observational cohort of multi-partner men who have sex with men (MSM) and other men. MATERIALS AND METHODS: Between January 2016 and June 2017, we offered free STI testing to all men with multiple  sexual partners (three or more in the previous 12 months), with follow-up examinations every 6 months. We used multiplex polymerase chain-reaction testing (for Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Mycoplasma genitalium) on pooled swabs (pharynx, urethra/vagina, anus), and antibody tests for HIV and Treponema pallidum at every visit, and for hepatitis B/C at baseline. RESULTS: We screened 779 multi-partner MSM and 92 other men. Previously undiagnosed HIV was found in 0.5% vs 0.0%, respectively and T. pallidum antibodies in 15.3% vs 1.1%. STIs requiring antibiotic treatment comprised: active syphilis 1.7% vs 0.0%; N. gonorrhoeae 10.3% vs 0.0%; C. trachomatis 8.7% vs 1.1%. One in four MSM versus 1 in 100 other multi-partner men had any of these three STIs at baseline. 10.4% vs 1.3% had a history of hepatitis B, 31.9% vs 47.3% had no immunity (HBs-AB <10 IU/l). Ten MSM had HCV antibodies (1.4%), with 8 out of the 10 being MSM with HIV; HCV seroprevalence was 0.3% among HIV-negative MSM. In MSM, incidence of the three bacterial STIs was 25.5 per year over 333 person years of follow-up, HIV incidence was 0.3%. Non-condom-use (in the last 3 months) for anal/vaginal sex was not associated with STIs. Independent risk factors were sex with men (adjusted odds ratio [aOR] 16.4) and the number of sexual partners (aOR 2.3 for >20). CONCLUSION: Among MSM, but not among other multi-partner men, STIs, mostly asymptomatic, are common. Given the high risk of onward transmission, low-cost or free routine screening of multi-partner MSM is a public health priority.

Author Correction: Human and mouse single-nucleus transcriptomics reveal TREM2-dependent and TREM2-independent cellular responses in Alzheimer's disease.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Fractional flow reserve-guided multivessel angioplasty in myocardial infarction: three-year follow-up with cost benefit analysis of the Compare-Acute trial.

AIMS: The Compare-Acute trial showed superiority of fractional flow reserve (FFR)-guided acute complete revascularisation compared to culprit-only treatment in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD) at one year. The aim of this study was to investigate the outcome at three years, together with cost analysis of this strategy. METHODS AND RESULTS: After primary percutaneous coronary intervention (PCI), 885 patients with STEMI and MVD were randomised (1:2 ratio) to FFR-guided complete revascularisation (295 patients) or infarct-related artery (IRA)-only treatment (590 patients). After 36 months, the primary endpoint (composite of death, myocardial infarction, revascularisation, stroke) occurred significantly less frequently in the FFR-guided complete revascularisation group: 46/295 patients (15.6%) versus 178/590 patients (30.2%) (HR 0.46, 95% CI: 0.33-0.64; p<0.001). This benefit was driven mainly by the reduction of revascularisations in the follow-up (12.5% vs 25.2%; HR 0.45, 95% CI: 0.31-0.64; p<0.001). Cost analysis shows benefit of the FFR-guided complete revascularisation strategy, which can reduce the cost per patient by up to 21% at one year (8,150€ vs 10,319€) and by 22% at three years (8,653€ vs 11,100€). CONCLUSIONS: In patients with STEMI and MVD, FFR-guided complete revascularisation is more beneficial in terms of outcome and healthcare costs compared to IRA-only revascularisation at 36 months.

Human and mouse single-nucleus transcriptomics reveal TREM2-dependent and TREM2-independent cellular responses in Alzheimer's disease.

Glia have been implicated in Alzheimer's disease (AD) pathogenesis. Variants of the microglia receptor triggering receptor expressed on myeloid cells 2 (TREM2) increase AD risk, and activation of disease-associated microglia (DAM) is dependent on TREM2 in mouse models of AD. We surveyed gene-expression changes associated with AD pathology and TREM2 in 5XFAD mice and in human AD by single-nucleus RNA sequencing. We confirmed the presence of Trem2-dependent DAM and identified a previously undiscovered Serpina3n+C4b+ reactive oligodendrocyte population in mice. Interestingly, remarkably different glial phenotypes were evident in human AD. Microglia signature was reminiscent of IRF8-driven reactive microglia in peripheral-nerve injury. Oligodendrocyte signatures suggested impaired axonal myelination and metabolic adaptation to neuronal degeneration. Astrocyte profiles indicated weakened metabolic coordination with neurons. Notably, the reactive phenotype of microglia was less evident in TREM2-R47H and TREM2-R62H carriers than in non-carriers, demonstrating a TREM2 requirement in both mouse and human AD, despite the marked species-specific differences.

DNA threads released by activated CD4+ T lymphocytes provide autocrine costimulation.

The extrusion of DNA traps contributes to a key mechanism in which innate immune cells clear pathogens or induce sterile inflammation. Here we provide evidence that CD4+ T cells, a critical regulator of adaptive immunity, release extracellular threads of DNA on activation. These DNA extrusions convey autocrine costimulatory signals to T lymphocytes and can be detected in lymph nodes isolated during the priming phase of experimental autoimmune encephalomyelitis (EAE), a CD4+ T cell-driven mouse model of multiple sclerosis. Pharmacologic inhibition of mitochondrial reactive oxygen species (mtROS) abolishes the extrusion of DNA by CD4+ T cells, reducing cytokine production in vitro and T cell priming against myelin in vivo. Moreover, mtROS blockade during established EAE markedly ameliorates disease severity, dampening autoimmune inflammation of the central nervous system. Taken together, these experimental results elucidate a mechanism of intrinsic immune costimulation mediated by DNA threads released by activated T helper cells, and identify a potential therapeutic target for such disorders as multiple sclerosis, neuromyelitis optica, and CD4+ T cell-mediated disorders.

Physiological and technical commitment during a 300-m in-line skating trial in athletes of different age categories.

BACKGROUND: This study investigated the differences in strength, technique and time performance in in-line skaters of three age categories during a 300-meter trial. Possible correlations among these variables were also assessed. METHODS: Thirty-six elite in-line skaters (Cadets, Juniors and Seniors, N.=12 each; 14±1, 16±1, and 24±6 years of age, respectively) performed a 300-m trial on an outdoor oval track. Total time (Ttot), 100-m fractions and duration of each skating technique (initial acceleration phase, straight push and cross-over) were recorded. A squat jump (SJ) was performed before and after the trial. Heart rate, blood lactate concentration ([La-]) and rate of perceived exertion (RPE) were collected before, during and at the end of the trial. RESULTS: Ttot was longer and SJ lower in Cadets compared to the other groups. Seniors employed the cross-over technique for a longer period than the straight push technique, compared to Juniors and Cadets. Ttot correlated negatively with SJ in Seniors. The number of significant correlations between skating techniques' duration and both Ttot and SJ increased with age category. No differences among groups were found for heart rate, [La-] and RPE. CONCLUSIONS: With increasing age category, leg strength appeared to be the more related aspect to skating performance. To improve 300-m in-line skating performance, trainers should pay particular attention to the enhancement of leg strength and cross-over skating technique.