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Background Air pollution has been linked to neurodegenerative diseases, including Alzheimer’s disease (AD), and the underlying neuroimmune mechanisms remain poorly understood. TREM2 is a myeloid cell membrane receptor that is a key regulator of disease-associated microglia (DAM) cells, where loss-of-function TREM2 mutations are associated with an increased risk of AD. At present, the basic function of TREM2 in neuroinflammation is a point of controversy. Further, the impact of air pollution on TREM2 and the DAM phenotype is largely unknown. Using diesel exhaust (DE) as a model of urban air pollution exposure, we sought to address its impact on TREM2 expression, the DAM phenotype, the association of microglia with the neurovasculature, and the role of TREM2 in DE-induced neuroinflammation. Methods WYK rats were exposed for 4 weeks to DE (0, 50, 150, 500 μg/m3) by inhalation. DE particles (DEP) were administered intratracheally once (600 μg/mouse) or 8 times (100 μg/mouse) across 28 days to male mice (Trem2+/+, Trem2−/−, PHOX+/+, and PHOX−/−). Results Rats exposed to DE exhibited inverted-U patterns of Trem2 mRNA expression in the hippocampus and frontal cortex, while TREM2 protein was globally diminished, indicating impaired TREM2 expression. Analysis of DAM markers Cx3Cr1, Lyz2, and Lpl in the frontal cortex and hippocampus showed inverted-U patterns of expression as well, supporting dysregulation of the DAM phenotype. Further, microglial-vessel association decreased with DE inhalation in a dose-dependent manner. Mechanistically, intratracheal administration of DEP increased Tnf (TNFα), Ncf1 (p47PHOX), and Ncf2 (p67PHOX) mRNA expression in only Trem2+/+ mice, where Il1b (IL-1β) expression was elevated in only Trem2−/− mice, emphasizing an important role for TREM2 in DEP-induced neuroinflammation. Conclusions Collectively, these findings reveal a novel role for TREM2 in how air pollution regulates neuroinflammation and provides much needed insight into the potential mechanisms linking urban air pollution to AD.

The evolution of oxygenic photosynthesis was one of the most transformative evolutionary events in Earth’s history, leading eventually to the oxygenation of Earth’s atmosphere and, consequently, the evolution of aerobic respiration. Previous work has shown that the terminal electron acceptors (complex IV) of aerobic respiration likely evolved after the evolution of oxygenic photosynthesis. However, complex I of the respiratory complex chain can be involved in anaerobic processes and, therefore, may have pre-dated the evolution of oxygenic photosynthesis. If so, aerobic respiration may have built upon respiratory chains that pre-date the rise of oxygen in Earth’s atmosphere. The Melainabacteria provide a unique opportunity to examine this hypothesis because they contain genes for aerobic respiration but likely diverged from the Cyanobacteria before the evolution of oxygenic photosynthesis. Here, we examine the phylogenies of translated complex I sequences from 44 recently published Melainabacteria metagenome assembled genomes and genomes from other Melainabacteria, Cyanobacteria, and other bacterial groups to examine the evolutionary history of complex I. We find that complex I appears to have been present in the common ancestor of Melainabacteria and Cyanobacteria, supporting the idea that aerobic respiration built upon respiratory chains that pre-date the evolution of oxygenic photosynthesis and the rise of oxygen.

Introduction: Delirium occurs frequently in adults undergoing hematopoietic cell transplantation, with significant associated morbidity. Little is known about the burden of delirium in children in the peri-transplant period. This study was designed to determine delirium rates, define risk factors (demographic and treatment related), and establish feasibility of multi-institutional bedside screening for delirium in children undergoing hematopoietic cell transplant.Methods: This is a multi-institutional point prevalence study. All subjects were prospectively screened for delirium twice daily using the Cornell Assessment of Pediatric Delirium over a 10-day period. De-identified data, including basic demographics and daily characteristics, were extracted from the electronic medical record.Results: Eleven North American institutions were included, 106 children were enrolled, and 883 hospital days were captured. Delirium screening was successfully completed on more than 98% of the study days. Forty-eight children (45%) developed delirium over the course of the 10-day study. Children were diagnosed with delirium on 161/883 study days, for an overall delirium rate of 18% per day. Higher delirium rates were noted in children Conclusion: Delirium was a frequent occurrence in our study cohort, with identifiable risk factors. Delirium screening is highly feasible in the pediatric hematopoietic cell transplant patient population. A large-scale prospective longitudinal study following children throughout their transplant course is urgently needed to fully describe the epidemiology of pediatric delirium, explore the effects of delirium on patient outcomes, and establish guidelines to prevent and treat delirium in the peri-transplant period.

Acid mine drainage (AMD) is a global problem in which iron sulfide minerals oxidize and generate acidic, metal-rich water. Bioremediation relies on understanding how microbial communities inhabiting an AMD site contribute to biogeochemical cycling. A number of studies have reported community composition in AMD sites from16S rRNA gene amplicons but it remains difficult to link taxa to function, especially in the absence of closely related cultured species or those with published genomes. Unfortunately, there is a paucity of genomes and cultured taxa from AMD environments. Here, we report 29 novel metagenome assembled genomes from Cabin Branch, an AMD site in the Daniel Boone National Forest, KY, USA. The genomes span 11 bacterial phyla and include one Archaea and include taxa that contribute to carbon, nitrogen, sulfur, and iron cycling. These data reveal overlooked taxa that contribute to carbon fixation in AMD sites as well as uncharacterized Fe(II)-oxidizing bacteria. These data provide additional context for 16S rRNA gene studies, add to our understanding of the taxa involved in biogeochemical cycling in AMD environments, and can inform bioremediation strategies.IMPORTANCEBioremediating acid mine drainage requires understanding how microbial communities influence geochemical cycling of iron and sulfur and biologically important elements like carbon and nitrogen. Research in this area has provided an abundance of 16S rRNA gene amplicon data. However, linking these data to metabolisms is difficult because many AMD taxa are uncultured or lack published genomes. Here, we present metagenome assembled genomes from 29 novel AMD taxa and detail their metabolic potential. These data provide information on AMD taxa that could be important for bioremediation strategies including taxa that are involved in cycling iron, sulfur, carbon, and nitrogen.

Introduction Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds used industrially for a wide variety of applications. These PFAS compounds are very stable and persist in the environment. The PFAS contamination is a growing health issue as these compounds have been reported to impact human health and have been detected in both domestic and global water sources. Contaminated water found on military bases poses a potentially serious health concern for active duty military, their families, and the surrounding communities. Previous detection methods for PFAS in contaminated water samples require expensive and time-consuming testing protocols that limit the ability to detect this important global pollutant. The main objective of this work was to develop a novel detection system that utilizes a biological reporter and engineered bacteria as a way to rapidly and efficiently detect PFAS contamination. Materials and Methods The United States Air Force Academy International Genetically Engineered Machine team is genetically engineering Rhodococcus jostii strain RHA1 to contain novel DNA sequences composed of a propane 2-monooxygenase alpha (prmA) promoter and monomeric red fluorescent protein (mRFP). The prmA promoter is activated in the presence of PFAS and transcribes the mRFP reporter. Results The recombinant R. jostii containing the prmA promoter and mRFP reporter respond to exposure of PFAS by activating gene expression of the mRFP. At 100 µM of perfluorooctanoic acid, the mRFP expression was increased 3-fold (qRT-PCR). Rhodococcus jostii without exposure to PFAS compounds had no mRFP expression. Conclusions This novel detection system represents a synthetic biology approach to more efficiently detect PFAS in contaminated samples. With further refinement and modifications, a similar system could be readily deployed in the field around the world to detect this critical pollutant.

Additional file 1: Table S1. Carbon uptake experiment results.

Additional file 2: Table S2. Mouse Primer Sequences for qPCR. Tumor Necrosis Factor α, TNFα; interleukin 1 β, IL-1β; neutrophil cytosolic factor 1, Ncf1; neutrophil cytosolic factor 2, Ncf2; cytochrome b-245, beta polypeptide, Cybb; glyceraldehyde 3-phosphate dehydrogenase, GAPDH; triggering receptor expressed on myeloid cells 2, Trem2.

Additional file 3: Figure S1. Diesel Exhaust Exposure Fails to Affect Markers of Antioxidant System. WKY rats were exposed to diesel exhaust (0, 50, 150, or 500 μg/m3) by inhalation for 4 weeks. Key markers of the endogenous antioxidant system, Nfel2l (NRF2) (A) and Hmox1 (Heme Oxygenase 1) (B) were analyzed by qRT-PCR in the cortex. Data are reported as the mean ± SEM. (n = 7). Figure S2. Diesel Exhaust Exposure Fails to Affect Markers of Blood Brain Barrier Function. WKY rats were exposed to diesel exhaust (0, 50, 150, or 500 μg/m3) by inhalation for 4 weeks. Key markers of the BBB, Aqp4 (Aquaporin-4), Mdr1b (p-Glycoprotein), Icam1 (ICAM-1), and Vcam1 (VCAM-1) were analyzed by qRT-PCR in the hippocampus. Data are reported as the mean ± SEM. (n = 7). Figure S3. Peripherally Administered LPS Increases Microglial Association with the Vasculature at 3 Hours. C57Bl/6 J mice were administered LPS (5 mg/kg, IP) or saline (IP). The changes in the association of microglia cell bodies with the neurovasculature were assessed with confocal images of microglia (IBA-1, green) and vascular endothelial cells (CD31, red) in the hippocampus (3 slices per brain). Representative maximum intensity projection images are shown (A). Quantification of the number of vessel-associated microglia in CA1 hippocampus (B). *p < 0.05 when compared to control. (n = 3). Figure S4. TREM2 Deficiency Does Not Impact Neuroinflammatory Response to Peripherally Administered LPS at 3 Hours. C57Bl/6 J mice were administered LPS (5 mg/kg, IP) or saline (IP). Expression of the pro-inflammatory factors Tnf (A), Il1b (B), and the cytosolic PHOX component Ncf1 (C) were analyzed by qRT-PCR in the cortex. Data are reported as the mean ± SEM. *p < 0.05 when compared to Trem2+/+ control. #p < 0.05 compared between Trem2-/- control. (n = 5-6). Figure S5. Intratracheal DEP Fails to Affect Microglia-Vessel Association in the Cortex. Trem2-/- and Trem2+/+ mice were treated with DEP (100 μg/mouse IT, 2x per week, 4 weeks) or vehicle (IT, 2x per week, 4 weeks). The changes in the association of microglia cell bodies with the neurovasculature were assessed with confocal images of microglia (IBA-1, green) and vascular endothelial cells (CD31, red) in the cortex (4 slices per brain). Representative maximum intensity projection images are shown (A). Quantification of the number of vessel-associated microglia in layer V cortex (B). (n = 3-6). Figure S6. Intratracheal DEP Fails to Affect Microglia-Vessel Association in the Hippocampus. Trem2-/- and Trem2+/+ mice were treated with DEP (100 μg/mouse IT, 2x per week, 4 weeks) or vehicle (IT, 2x per week, 4 weeks). The changes in the association of microglia cell bodies with the neurovasculature were assessed with confocal images of microglia (IBA-1, green) and vascular endothelial cells (CD31, red) in the hippocampus (4 slices per brain). Representative maximum intensity projection images are shown (A). Quantification of the number of vessel-associated microglia in CA1 hippocampus (B). (n = 3-6). Figure S7. Trem2 mRNA is Expressed by Isolated Microglia and Immune Cells in Bronchoalveolar Lavage. C57Bl/6 J mice were treated with DEP (600 μg/mouse IT, single dose) or vehicle (50 μL IT). mRNA levels of Trem2 were measured by qRT-PCR in isolated microglial cells (A) and immune cells collected by bronchoalveolar lavage (B). Data are reported as the mean ± SEM. (n = 3-5). Figure S8. gp91PHOX Fails to Regulate DEP-Induced Neuroinflammation. PHOX-/- or PHOX+/+ control mice were treated with DEP (600 μg/mouse IT, single dose) or vehicle (50 μL IT). mRNA levels were measured by qRT-PCR for Tnf (TNFα) (A,B) and Trem2 (C,D) in the hippocampus (A,C) and cortex (B,D). Data are reported as the mean ± SEM. *p < 0.05, compared with controls. (n = 3-6).

Additional file 1: Table S1. Rat Primer Sequences for qPCR. Tumor Necrosis Factor α, TNFα; lipoprotein lipase, LPL; triggering receptor expressed on myeloid cells 2, TREM2; lysozyme, Lyz2; ionized calcium binding adaptor molecule 1, IBA-1; C-X3-C motif chemokine receptor 1, CX3CR1; glyceraldehyde 3-phosphate dehydrogenase, GAPDH; vascular cell adhesion molecule 1, VCAM-1; intracellular adhesion molecule 1, ICAM-1; aquaporin 4, Aqp4; multidrug resistance protein 1b, Mdr1b.

Background: Recessive dystrophic epidermolysis bullosa (RDEB) is a severe systemic genodermatosis lacking therapies beyond supportive care for its extensive, life-limiting manifestations. Objectives: To report the safety and preliminary responses of 10 patients with RDEB to bone marrow transplant (BMT) with post-transplant cyclophosphamide (PTCy BMT) after reduced-intensity conditioning with infusions of immunomodulatory donor-derived mesenchymal stromal cells (median follow-up 16 months). Methods: BMT toxicities, donor blood and skin engraftment, skin biopsies, photographic and dynamic assessments of RDEB disease activity were obtained at intervals from pre-BMT to 1 year post-BMT. Results: Related donors varied from haploidentical (n = 6) to human leucocyte antigen (HLA)-matched (n = 3), with one HLA-matched unrelated donor. Transplant complications included graft failure (n = 3; two pursued a second PTCy BMT), veno-occlusive disease (n = 2), posterior reversible encephalopathy (n = 1) and chronic graft-versus-host disease (n = 1; this patient died). In the nine ultimately engrafted patients, median donor chimerism at 180 days after transplant was 100% in peripheral blood and 27% in skin. Skin biopsies showed stable (n = 7) to improved (n = 2) type VII collagen protein expression by immunofluorescence and gain of anchoring fibril components (n = 3) by transmission electron microscopy. Early signs of clinical response include trends toward reduced body surface area of blisters/erosions from a median of 49·5% to 27·5% at 100 days after BMT (P = 0·05), with parental measures indicating stable quality of life. Conclusions: PTCy BMT in RDEB provides a means of attaining immunotolerance for future donor-derived cellular grafts (ClinicalTrials.gov identifier NCT02582775). What's already known about this topic?. Severe, generalized recessive dystrophic epidermolysis bullosa (RDEB) is marked by great morbidity and early death. No cure currently exists for RDEB. Bone marrow transplant (BMT) is the only described systemic therapy for RDEB. What does this study add?. The first description of post-transplant cyclophosphamide (PTCy) BMT for RDEB. PTCy was well tolerated and provided excellent graft-versus-host disease prophylaxis, replacing long courses of calcineurin inhibitors in patients receiving human leucocyte antigen-matched sibling BMT. What is the translational message?. The PTCy BMT platform permits identification of a suitable related donor for most patients and for subsequent adoptive transfer of donor nonhaematopoietic cells after establishment of immunological tolerance.

BACKGROUND AND AIMS: Adolescents with conduct and substance use problems are at increased risk for premature mortality, but the extent to which these risk factors reflect family- or individual-level differences and account for shared or unique variance is unknown. This study examined common and independent contributions to mortality hazard in adolescents ascertained for conduct disorder (CD) and substance use disorder (SUD), their siblings and community controls, hypothesizing that individual differences in CD and SUD severity would explain unique variation in mortality risk beyond that due to clinical/control status and demographic factors. DESIGN: Mortality analysis in a prospective study (Genetics of Antisocial Drug Dependence Study) that began in 1993. Multi-site sample recruited in San Diego, California and Denver, Colorado, USA. PARTICIPANTS: A total of 1463 clinical probands were recruited through the juvenile correctional system, court-mandated substance abuse treatment programs and correctional schools, along with 1399 of their siblings, and 904 controls. MEASUREMENTS: Mortality and cause-of-death were assessed via National Death Index search (released October, 2017). FINDINGS: There were 104 deaths documented among 3766 (1168 female) adolescents and young adults (average age 16.79 years at assessment, 32.69 years at death/censoring). Mortality hazard for clinical probands and their siblings was 4.99 times greater than that of controls (95% confidence interval = 2.40-10.40; P

Introduction: Six-minute walk distance (6MWD) is a widely used surrogate for exercise capacity in patients both pre- and post-lung transplant. Multiple factors have been suggested to influence exercise capacity. Research Questions: This study sought to determine the change in exercise capacity over time and factors that influence long-term exercise capacity. Design: Data were collected prospectively on lung transplant recipients from 1 center. The 6MWD was measured preoperatively and at the 6- and 12-month clinic visits postoperatively. The Enright equation was used to calculate patients’ percentage predicted 6MWD. The change in 6MWD over time was calculated, and multiple factors affecting 6MWD were analyzed, including predictors of 6MWD at 6 and 12 months posttransplant. Results: Sixty lung transplant recipients were enrolled. Significant improvement in 6MWD was found between pretransplant and hospital discharge and between hospital discharge and 6 months posttransplant. The percentage predicted 6MWD improved significantly from pretransplant to 6 months and to 12 months posttransplant. Factors associated with 6MWD were sex, diagnosis, graft type, and age. Factors predicting long-term exercise capacity included 6MWD at referral, pretransplant, and hospital discharge; pulmonary diagnosis; and type of transplant. Conclusion: The 6MWD provided useful information about patients’ exercise capacity during phases of lung transplantation. The percentage predicted for each patient was found to be a more valuable measure than absolute 6MWD. Intensive, individualized training posttransplant is essential to optimize exercise capacity for this population