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Background: Structural racism may drive the constellation of structural determinants that increase racialized disparities in the risk for Alzheimer's disease related dementias (ADRD). Structural racism via adverse policing increases exposure to negative police encounters that produce heightened vigilance, anxiety, and depressed mood in persons racialized as Black. Seminal research suggests high‐police contact and disparities in Black‐White incarceration are positively associated with risk for other health conditions. It is feasible that cumulative stress from anticipatory and recurrent police encounters disrupts the body's homeostasis leading to accelerated cognitive aging. Method: We used US county‐level incarceration data to compute the Black‐White difference in prison and jail rates for US counties between 1995‐2005 (succeeding the 1994 Crime Bill). We then averaged the decade and linked said data by county to individual‐level health data for participants racialized as Black >50 years in the Health and Retirement Study (N = 2,300) who completed the core interview between 2006‐18 (mean observation of 3.4 per participant). Cognitive function was assessed using a 27‐item global cognitive score from the modified Telephone Interview for Cognitive Status. A mixed effects model was used to estimate the cognitive effect of a one‐unit change in incarceration (1,000 additional persons racialized as Black compared to White) with covariates of age at baseline, gender, education, and living arrangement. Result: Greater Black‐White 10‐year difference in prison population was significantly associated with worse 2006 cognitive function (β ‐1.08, SE.45, 95% CI ‐1.96,‐.22). The adjusted model was significant for Black‐White difference in prison population with cognitive decline starting in 2006 (β.011, SE.006, 95% CI ‐.001,.023). The Black‐White difference in jail population was not significant. Conclusion: Ten‐year Black‐White disparities in prison population are associated with cognitive decline among people racialized as Black starting one year later. While the 1994 Crime Bill is a decades‐old federal policy, it put into place a fiscal infrastructure which local governments continue to use to fund prisons, increase average prison time, and implement adverse policing quotas. These findings suggest structural racism via adverse policing is meaningful to explore in the context of ADRD. [ABSTRACT FROM AUTHOR]

Background: Seminal studies on exposure to life course social determinants of health, such as neighborhood racial segregation and neighborhood poverty, suggest detrimental associations with poorer cognitive function. We aimed to test the opposite by examining the relationship between self‐reported exposure to health‐promoting neighborhood environments over the life course and cognitive function among older adults. Method: Participants were persons living without dementia at three US Alzheimer's Disease Research Centers (University of California, Davis in Sacramento (UCD); Washington University in Saint Louis (WU); and Wake Forest University in Winston‐Salem (WFU)). An ancillary study (K01AG063895, PI: Besser) included the Life Course Sociodemographics and Neighborhood Questionnaire (LSNEQ) comprised of indices like neighborhood measures of socioeconomic status (NSES), walking and biking frequency, and greenness from childhood, midlife, and late life. LSNEQ data were linked with late‐life cognitive test z‐scores (Animals and Vegetables Category Fluency, Trail Making Parts A and B) from the National Alzheimer's Coordinating Center Uniform Data Set. Multivariable linear mixed effects models tested associations between the LSNEQ index scores (composite values over childhood and mid‐ and late‐life) and baseline and longitudinal change in cognitive function controlling for demographics, Center, and baseline global Clinical Dementia Rating (0 or 0.5). Result: The sample (n = 322) included 65% women, 17% Black, 76% White, and 7% other/mixed racialized group participants and was, on average, 70±7 years old and followed for 2.5±3.2 years. Life Course NSES was lower for UCD (mean = 12.7, SD = 3.5) versus WU (mean = 13.9, SD = 3.2) and WFU (mean = 14.3, SD = 3.2). Life Course Neighborhood Walking and Biking frequency did not differ by Center. Life Course Neighborhood Greenness differed across Centers, and was lowest for WU (mean = 4.8, SD = 1.3) and highest for WFU (mean = 5.6; SD = 1.2). In multivariable analyses, greater Life Course Neighborhood Walking and Biking was associated with higher baseline Trail A scores (estimate = 0.83, 95% CI = 0.08‐1.58) and slower decline on Animals over time (estimate = 0.024, 95% CI = 0.002‐0.045). Greater Life Course Neighborhood Greenness was associated with slower decline on Vegetables over time (estimate = 0.035, 95% CI = 0.001‐0.069). Conclusion: These preliminary findings suggest self‐reported, life course neighborhood exposures and behaviors (i.e., greenness and neighborhood walking/biking) may be associated with better cognition and slower decline in later life. [ABSTRACT FROM AUTHOR]

Background: Structural racism has concentrated Americans racialized as Black in under‐resourced and disinvested neighborhoods. These same Americans experience higher rates of Alzheimer's disease and related dementias (ADRD). Differences in socioeconomic opportunities structured by racism is a potential contributor to ADRD disparities. To investigate this hypothesis, we tested how life‐course exposure to area‐level measures of structural racism relate to late‐life cognitive test performance. Method: We computed the Black‐White disparity in land ownership and value, residential and occupational segregation, and income, employment, and poverty at the county‐level using US Census data from 1930‐2010. We aggregated these data to the state‐level then created four unidimensional measures by life‐course period (Before‐Birth 1930‐50, Childhood 1960‐70, Adulthood 1980‐2000, Midlife 2010). We linked state‐ and life‐course‐period‐level data with individual‐level demographic and cognitive data from the US Health and Retirement Study. We included participants racialized as Black and born 1954‐59 (N = 1,172). We measured cognitive performance from repeated measures of the 27‐item global cognitive score from the modified Telephone Interview for Cognitive Status during 2010‐18 (average follow up of 4.1 years). Mixed effects models were used to test associations of life‐course‐period‐specific state‐level structural socioeconomic racism and cognitive change. Covariates were age, gender, education, Living arrangement, and year of death. Result: Participants racialized as Black who lived in places with higher levels of area‐level structural socioeconomic racism experienced lower levels of cognition at baseline and at varying time points in the six‐year period—compared to those in places with lower structural socioeconomic racism. The effects of the life‐course‐period‐specific state‐level structural socioeconomic racism exposure on the slope were in the expected direction but not statistically different from zero (‐.02, SE 0.25, ‐.51, 4.7). Conclusion: Among participants racialized as Black in the HRS born during 1954‐59, effects of exposure to state‐level structural racism varied according to life course period of exposure. These findings reveal the utility of examining the impact of racist U.S. policies enacted in the past and present that influence health over time. In addition to exploring the epigenetic and in utero exposures that may contribute to ADRD risk later in life. [ABSTRACT FROM AUTHOR]

Background: Minoritized groups experience higher stress due to structural racism and discrimination. These exposures have been linked to lower cognitive test scores and inflammation is a potential biological pathway underlying this association. Yet studies with multiple inflammatory markers in diverse populations remain limited. Method: We assessed 635 community‐dwelling adults (mean age = 54.5, SD = 11; 66% women; 67% Latinx, 33% non‐Latinx Black) from the Offspring Cohort. We characterized peripheral inflammation using principal component analysis on 33 serum inflammatory markers. Discrimination was ascertained by the Everyday and Major Discrimination Scales. Episodic memory was measured using the Selective Reminding Test and working memory by the Digit Span Test. Linear models stratified by racialized/ethnic group tested the cross‐sectional relationship between inflammation and memory adjusting for age, sex, and diabetes. Further, we examined if relationship between discrimination and memory (adjusted for age, gender, and education) was attenuated when inflammation was added. Due to smaller sample size, the magnitude of associations corresponding to change in cognitive score associated with >1 year of chronological age, rather than statistical significance, was used to highlight important associations. Result: Two inflammatory factors were derived, with component 1 including FGF2, Fractalkine, GM‐CSF, IFNg, IL13, MCP3, TNFa, and TNFb, and Component 2 including IFNa2, IL1b, IL1ra, IL5, IL9, and MIP1a. Among Spanish‐speaking participants racialized as Latinx, both inflammatory factors were associated with lower memory scores. Only the first factor was associated with lower memory for English‐speaking participants racialized as Latinx. For participants racialized as Black, only the second factor associated with lower memory. Among Spanish‐speaking Latinx, Everyday Discrimination was associated with lower working memory. Everyday Discrimination was associated with lower episodic memory among Black respondents; this association was attenuated by 20% with inclusion of the inflammatory factor 1 in the models. Several associations that were opposite to hypothesized relationships were observed. Conclusion: Elevated peripheral inflammation was associated with worse memory among individuals racialized as Black and Latinx. Our results indicate peripheral inflammation may contribute to disparities in cognition and may be one of the ways in which disadvantage due to structural racism and discrimination is embodied among minoritized groups in the United States. [ABSTRACT FROM AUTHOR]

Background: Racialization is the process of grouping individuals into "races" based on phenotypic characteristics, assigning value to these groups, and disproportionately treating them. Racial health disparities may capture the differential impact of racialization, and subsequently, discrimination on these groups. In a longitudinal study of C‐reactive protein (CRP), a marker of systemic inflammation, we explored trajectories of inflammation between non‐Hispanic Black vs non‐Hispanic White participants and tested if persistent inflammation mediated the racial disparity in cognitive function. Methods: In the US Health and Retirement Study (n = 4,719 adults aged >50), we used three repeated CRP and global cognitive measures at baseline (2006 or 2008), at year 4 (2010 or 2012), and year 8 (2014 or 2016). In multivariable generalized estimating equation models, we compared changes in cognitive function between non‐Hispanic Black vs non‐Hispanic White participants as a function of sustained elevated levels of CRP (all time points >3 vs. ≤3mg/L). We decomposed the racial disparity in cognitive function onto 1) the mediated effect due to elevated CRP, and 2) the portion attributable to the interaction between race and CRP. Results: The average age at baseline was 68.8 years. Non‐Hispanic Black participants (n = 599) had 24% higher CRP at year 4 and 18% higher at year 8, relative to non‐Hispanic White participants (n = 4,120). Non‐Hispanic Black participants with elevated CRP had 2.9 (95% CI: ‐3.2, ‐2.7) lower points on the global cognitive assessment than non‐Hispanic White participants. In a randomized analogue model, we found that 4% (95% CI: 1%, 6%) of the racial disparity in cognitive function was mediated by sustained elevated CRP, and 14% (95%CI: 5%, 23%) attributable to the interaction between race and sustained elevated CRP. Conclusions: Systemic inflammation mediates racialized disparities in cognitive function. The effect of persistent elevated levels of systemic inflammation on cognition differs when individuals are racialized as non‐Hispanic Black had they been racialized and treated as non‐Hispanic White. [ABSTRACT FROM AUTHOR]

The article focuses on understanding the role of social determinants on clinical trial participation and trust. Topics discussed include the Michael J. Fox Foundation for Parkinson's Research (MJFF) aims to speed clinical research by removing obstacles that stand in the way of drug development; and the Foundation gathers insights from a wide range of stakeholders and uses these perspectives to enhance clinical trial processes from start to finish.

Background: Racism is a social determinant of health that operates at multiple levels ‐ interpersonal, institutional, structural ‐ producing stress and limiting access to resources that have dire biopsychosocial effects for historically marginalized communities. Research on older adults suggests interpersonal and structural racism, separately, are associated with worse cognition and may be an underlying reason for racial/ethnic disparities in cognitive aging. An evidence gap remains on how multilevel racism influences cognition throughout the life‐course. Method: We assessed 942 middle‐aged community‐dwelling adults (mean age = 55, SD = 11; 64% women; 19% non‐Latinx White; 23% non‐Latinx Black; 55% Latinx). Daily interpersonal racism was ascertained by the Everyday Discrimination (ED) scale, institutional racism by the Major Discrimination (MD) Scale, and structural racism in early life was measured by residential segregation of the census block group in which parents of our respondents lived. Our outcomes were derived from a neuropsychological evaluation with the Digit Span assessing attention and working memory, and delayed recall from the Selective Reminding Test capturing episodic memory. Two fluency measures (animal and letter) were also studied. The relationship between multilevel racism indicators and cognition was estimated using age‐adjusted linear regression models. Additional models were stratified by racialized/ethnic group and added education as a covariate. Result: Exposure to multilevel racism varied across racialized/ethnic group. Non‐Latinx Black respondents scored highest on interpersonal racism, second highest on institutional racism, and were more likely to grow up in segregated residential areas with higher proportion of other Black residents. Exposure to interpersonal (Figure A) and institutional racism (Figure B) was associated with lower memory scores and these associations were driven by non‐Latinx Black respondents. Structural racism was associated with lower episodic memory in the full sample. Conclusion: Our findings indicate that multilevel racism related to cognition and due to higher exposure among marginalized groups may be a substantial driver of racial/ethnic disparities in cognitive health. In future, additive and multiplicative effects of our exposures will be examined. [ABSTRACT FROM AUTHOR]

Background: Residential greenspaces such a parks and other areas of natural vegetation are social determinants of health that have been associated with brain health outcomes including Alzheimer's disease and related disorders (ADRD). Greenspace access is associated with reduced risk of ADRD‐related comorbidities and increased participation in risk‐reducing behaviors such as physical activity. Therefore, exposure to greenspace may present an ideal opportunity to encourage risk‐reducing behaviors while intervening on the impact of comorbidities on brain health. Although structural determinants of health such as residential segregation and the built environment may influence these outcomes, racial/ethnic minoritized groups are less likely to live in neighborhoods where physical activity is feasible. Additionally, such groups have elevated risk for comorbidities that may increase risk for ADRD. Yet few known studies have investigated greenspace and brain health by racial/ethnic group. Method: We will include papers previously identified in a published rapid scoping review on greenspace and brain health outcomes (Besser, 2020; n = 22), and will employ the same review methods from that paper to identify additional papers published since February 13, 2020. For each article, we will catalog the racial/ethnic composition of the sample, observed differences between racial/ethnic groups, methods employed, other related findings, as well as guiding theories, conceptual frameworks, and causal mechanisms. Result: We will: 1) examine the extent to which the current literature investigates racial/ethnic differences in greenspace and brain health associations; 2) cover the potential mechanisms relating greenspace to brain health and how these mechanisms may differentially impact individuals based on race/ethnicity; and 3) discuss the methodological issues surrounding the study of racial/ethnic disparities in greenspace‐brain health associations. Lastly, we will describe greenspace characteristics for select existing datasets and cohorts by race/ethnicity to provide context for future investigations using these and similar resources. Conclusion: The goal of this review is to provide a foundation for understanding and a starting point for studies of racial/ethnic differences in greenspace‐brain health associations. [ABSTRACT FROM AUTHOR]

Recurrent infections are a hallmark of STAT3 dominant-negative hyper-IgE syndrome (STAT3 HIES), a rare immunodeficiency syndrome previously known as Jobs syndrome, along with elevated IgE levels and impaired neutrophil function. We have been developing nanoparticles with neutrophil trophism that home to the sites of infection via these first-responder leukocytes, named neutrophil-avid nanocarriers (NANs). Here, we demonstrate that human neutrophils can phagocytose nanogels (NGs), a type of NAN, with enhanced uptake after particle serum opsonization, comparing neutrophils from healthy individuals to those with STAT3 HIES, where both groups exhibit NG uptake; however, the patient group showed reduced phagocytosis efficiency with serum-opsonized NANs. Proteomic analysis of NG protein corona revealed complement components, particularly C3, as predominant in both groups. Difference between groups includes STAT3 HIES samples with higher neutrophil protein and lower acute-phase protein expression. The study suggests that despite neutrophil dysfunction in STAT3 HIES, NANs have potential for directed delivery of cargo therapeutics to improve neutrophil infection clearance., (© 2024 Rubey et al.)

We recently showed that riboflavin is a selected substrate of breast cancer resistance protein (BCRP) over P-glycoprotein (P-gp) and demonstrated its prediction performance in preclinical drug-drug interaction (DDI) studies. The aim of this study was to investigate the suitability of riboflavin to assess BCRP inhibition in humans. First, we assessed the substrate potential of riboflavin toward other major drug transporters using established transfected cell systems. Riboflavin is a substrate for organic anion transporter (OAT)1, OAT3, and multidrug and toxin extrusion protein (MATE)2-K, with uptake ratios ranging from 2.69 to 11.6, but riboflavin is not a substrate of organic anion-transporting polypeptide (OATP)1B1, OATP1B3, organic cation transporter (OCT)2, and MATE1. The effects of BMS-986371, a potent in vitro inhibitor of BCRP ( IC 50 0.40 μ M), on the pharmacokinetics of riboflavin, isobutyryl carnitine, and arginine were then examined in healthy male adults ( N = 14 or 16) after oral administration of methotrexate (MTX) (7.5 mg) and enteric-coated (EC) sulfasalazine (SSZ) (1000 mg) alone or in combination with BMS-986371 (150 mg). Oral administration of BMS-986371 increased the area under the plasma concentration-time curves ( AUC s) of rosuvastatin and immediate-release (IR) SSZ to 1.38- and 1.51-fold, respectively, and significantly increased AUC (0-4h), AUC (0-24h), and C max of riboflavin by 1.25-, 1.14-, and 1.11-fold ( P -values of 0.003, 0.009, and 0.025, respectively) compared with the MTX/SSZ EC alone group. In contrast, BMS-986371 did not significantly influence the AUC (0-24h) and C max values of isobutyryl carnitine and arginine (0.96- to 1.07-fold, respectively; P > 0.05). Overall, these data indicate that plasma riboflavin is a promising biomarker of BCRP that may offer a possibility to assess drug candidate as a BCRP modulator in early drug development. SIGNIFICANCE STATEMENT: Endogenous compounds that serve as biomarkers for clinical inhibition of breast cancer resistance protein (BCRP) are not currently available. This study provides the initial evidence that riboflavin is a promising BCRP biomarker in humans. For the first time, the value of leveraging the substrate of BCRP with acceptable prediction performance in clinical studies is shown. Additional clinical investigations with known BCRP inhibitors are needed to fully validate and showcase the utility of this biomarker., (Copyright © 2024 by The American Society for Pharmacology and Experimental Therapeutics.)

Type II alveolar cells (AT2s) are critical for basic respiratory homeostasis and tissue repair after lung injury. Prior studies indicate that AT2s also express major histocompatibility complex class II (MHCII) molecules, but how MHCII expression by AT2s is regulated and how it contributes to host defense remain unclear. Here we show that AT2s express high levels of MHCII independent of conventional inflammatory stimuli, and that selective loss of MHCII from AT2s in mice results in modest worsening of respiratory virus disease following influenza and Sendai virus infections. We also find that AT2s exhibit MHCII presentation capacity that is substantially limited compared to professional antigen presenting cells. The combination of constitutive MHCII expression and restrained antigen presentation may position AT2s to contribute to lung adaptive immune responses in a measured fashion, without over-amplifying damaging inflammation.

Neutrophils are critical mediators of host defense in pathogen-induced and sterile inflammation. Excessive neutrophil activation has been associated with increased host pathology through collateral organ damage. The beneficial aspects of neutrophil activation, particularly in sterile inflammation, are less well defined. We observed accumulation of nuclear debris in the lungs of neutropenic mice exposed to acid-induced injury compared with wild type. Size analysis of DNA debris showed that neutropenic mice were unable to degrade extracellular DNA fragments. In addition, we found that neutrophils are able to differentially express DNA-degrading and repair-associated genes and proteins. Once neutrophils are at sites of lung inflammation, they are able to phagocytose and degrade extracellular DNA. This neutrophil-dependent DNA degradation occurs in a MyD88-dependent pathway. The increased DNA debris in neutropenic mice was associated with dysregulated alveolar repair and the phenotype is rescued by intratracheal administration of DNase I. Thus, we show a novel mechanism as part of the inflammatory response, in which neutrophils engulf and degrade extracellular DNA fragments and allow for optimal organ repair., (© 2021 by The American Society of Hematology.)

Alveolar epithelial regeneration is essential for recovery from devastating lung diseases. This process occurs when type II alveolar pneumocytes (AT2 cells) proliferate and transdifferentiate into type I alveolar pneumocytes (AT1 cells). We used genome-wide analysis of chromatin accessibility and gene expression following acute lung injury to elucidate repair mechanisms. AT2 chromatin accessibility changed substantially following injury to reveal STAT3 binding motifs adjacent to genes that regulate essential regenerative pathways. Single-cell transcriptome analysis identified brain-derived neurotrophic factor (Bdnf) as a STAT3 target gene with newly accessible chromatin in a unique population of regenerating AT2 cells. Furthermore, the BDNF receptor tropomyosin receptor kinase B (TrkB) was enriched on mesenchymal alveolar niche cells (MANCs). Loss or blockade of AT2-specific Stat3, Bdnf or mesenchyme-specific TrkB compromised repair and reduced Fgf7 expression by niche cells. A TrkB agonist improved outcomes in vivo following lung injury. These data highlight the biological and therapeutic importance of the STAT3-BDNF-TrkB axis in orchestrating alveolar epithelial regeneration.

Background: Severe traumatic brain injury (TBI) patients are at high risk for early aspiration and pneumonia. How pneumonia impacts neurological recovery after TBI is not well characterized. We hypothesized that, independent of the cerebral injury, pneumonia after TBI delays and worsens neurological recovery and cognitive outcomes., Methods: Fifteen CD1 male mice were randomized to sham craniotomy or severe TBI (controlled cortical impact [CCI] - velocity 6 m/s, depth 1.0 mm) ± intratracheal lipopolysaccharide (LPS-2 mg/kg in 0.1 mL saline) as a pneumonia bioeffector. Neurological functional recovery by Garcia Neurologic Testing (GNT) and body weight loss were recorded daily for 14 days. On Days 6-14, animals underwent Morris Water Maze learning and memory testing with cued trials (platform visible), spatial learning trials (platform invisible, spatial cues present), and probe (memory) trials (platform removed, spatial clues present). Intergroup differences were assessed by the Kruskal-Wallis test with Bonferroni correction (p < 0.05)., Results: Weight loss was greatest in the CCI + LPS group (maximum 24% on Day 3 vs. 8% [Sham], 7% [CCI], both on Day 1). GNT was lowest in CCI + LPS during the first week. Morris Water Maze testing demonstrated greater spatial learning impairment in the CCI + LPS group vs. Sham or CCI counterparts. Cued learning and long-term memory were worse in CCI + LPS and CCI as compared to Sham., Conclusion: A pneumonia bioeffector insult after TBI worsens weight loss and mortality in a rodent model. Not only is spatial learning impaired, but animals are more debilitated and have worse neurologic performance. Understanding the adverse effects of pneumonia on TBI recovery is the first step d patients.

Alveolar type-2 (AT2) cells are necessary for the lung's regenerative response to epithelial insults such as influenza. However, current methods to expand these cells rely on mesenchymal co-culture, complicating the possibility of transplantation following acute injury. Here we developed several mesenchyme-free culture conditions that promote growth of murine AT2 organoids. Transplanting dissociated AT2 organoids into influenza-infected mice demonstrated that organoids engraft and either proliferate as AT2 cells or unexpectedly adopt a basal cell-like fate associated with maladaptive regeneration. Alternatively, transplanted primary AT2 cells also robustly engraft, maintaining their AT2 lineage while replenishing the alveolar type-1 (AT1) cell population in the epithelium. Importantly, pulse oximetry revealed significant increase in blood-oxygen saturation in primary AT2 recipients, indicating that transplanted cells also confer increased pulmonary function after influenza. We further demonstrated that both acid installation and bleomycin injury models are also amenable to AT2 transplantation. These studies provide additional methods to study AT2 progenitor potential, while serving as proof-of-principle for adoptive transfer of alveolar progenitors in potential therapeutic applications., Competing Interests: Competing interestsThe authors declare no competing interests.

Many lung diseases, such as the acute respiratory distress syndrome (ARDS), display significant regional heterogeneity with patches of severely injured tissue adjacent to apparently healthy tissue. Current mouse models that aim to mimic ARDS generally produce diffuse injuries that cannot reproducibly generate ARDS's regional heterogeneity. This deficiency prevents the evaluation of how well therapeutic agents reach the most injured regions and precludes many regenerative medicine studies since it is not possible to know which apparently healing regions suffered severe injury initially. Finally, these diffuse injury models must be relatively mild to allow for survival, as their diffuse nature does not allow for residual healthy lung to keep an animal alive long enough for many drug and regenerative medicine studies. To solve all of these deficiencies in current animal models, we have created a simple and reproducible technique to selectively induce lung injury in specific areas of the lung. Our technique, catheter-in-catheter selective lung injury (CICSLI), involves guiding an inner catheter to a particular area of the lung and delivering an injurious agent mixed with nanoparticles (fluorescently and/or radioactively labeled) that can be used days later to track the location and extent of where the initial injury occurred. Furthermore, we demonstrate that CICSLI can produce a more severe injury than diffuse models, yet has much higher survival since CICSLI intentionally leaves lung regions undamaged. Collectively, these attributes of CICSLI will allow investigators to better study how drugs act within heterogeneous lung pathologies and how regeneration occurs in severely damaged lung tissue, thereby aiding the development of new therapies for ARDS and other heterogenous lung diseases., Competing Interests: Outside the preparation of the present manuscript, JSB has received a grant from Insmed (https://www.insmed.com/), entitled “Pulmonary endothelium-targeted liposomes for the treatment of ARDS.” The funds from that grant were not used to fund any component related to this manuscript. While that grant does not call for the use of the catheter-in-catheter selective lung injury (CICSLI) ARDS animal models employed in the current manuscript, the grant and manuscript are both focused on ARDS, and both employ mouse models of the disease. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Inflamed organs display marked spatial heterogeneity of inflammation, with patches of inflamed tissue adjacent to healthy tissue. To investigate how nanocarriers (NCs) distribute between such patches, we created a mouse model that recapitulates the spatial heterogeneity of the inflammatory lung disease ARDS. NCs targeting the epitope PECAM strongly accumulated in the lungs, but were shunted away from inflamed lung regions due to hypoxic vasoconstriction (HVC). In contrast, ICAM-targeted NCs, which had lower whole-lung uptake than PECAM/NCs in inflamed lungs, displayed markedly higher NC levels in inflamed regions than PECAM/NCs, due to increased regional ICAM. Regional HVC, epitope expression, and capillary leak were sufficient to predict intra-organ of distribution of NCs, antibodies, and drugs. Importantly, these effects were not observable with traditional spatially-uniform models of ARDS, nor when examining only whole-organ uptake. This study underscores how examining NCs' intra-organ distribution in spatially heterogeneous animal models can guide rational NC design., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Alveolar epithelial regeneration is essential for resolution of the acute respiratory distress syndrome (ARDS). Although neutrophils have traditionally been considered mediators of epithelial damage, recent studies suggest they promote type II pneumocyte (AT2) proliferation, which is essential for regenerating alveolar epithelium. These studies did not, however, evaluate this relationship in an in vivo model of alveolar epithelial repair following injury. To determine whether neutrophils influence alveolar epithelial repair in vivo, we developed a unilateral acid injury model that creates a severe yet survivable injury with features similar to ARDS. Mice that received injections of the neutrophil-depleting Ly6G antibody had impaired AT2 proliferation 24 and 72 h after acid instillation, which was associated with decreased reepithelialization and increased alveolar protein concentration 72 h after injury. As neutrophil depletion itself may alter the cytokine response, we questioned the contribution of neutrophils to alveolar epithelial repair in neutropenic granulocyte-colony stimulating factor (G-CSF)-/- mice. We found that the loss of G-CSF recapitulated the neutrophil response of Ly6G-treated mice and was associated with defective alveolar epithelial repair, similar to neutrophil-depleted mice, and was reversed by administration of exogenous G-CSF. To approach the mechanisms, we employed an unbiased protein analysis of bronchoalveolar lavage fluid from neutrophil-depleted and neutrophil-replete mice 12 h after inducing lung injury. Pathway analysis identified significant differences in multiple signaling pathways that may explain the differences in epithelial repair. These data emphasize an important link between the innate immune response and tissue repair in which neutrophils promote alveolar epithelial regeneration., (Copyright © 2016 the American Physiological Society.)

Viral proteins mimic host protein structure and function to redirect cellular processes and subvert innate defenses. Small basic proteins compact and regulate both viral and cellular DNA genomes. Nucleosomes are the repeating units of cellular chromatin and play an important part in innate immune responses. Viral-encoded core basic proteins compact viral genomes, but their impact on host chromatin structure and function remains unexplored. Adenoviruses encode a highly basic protein called protein VII that resembles cellular histones. Although protein VII binds viral DNA and is incorporated with viral genomes into virus particles, it is unknown whether protein VII affects cellular chromatin. Here we show that protein VII alters cellular chromatin, leading us to hypothesize that this has an impact on antiviral responses during adenovirus infection in human cells. We find that protein VII forms complexes with nucleosomes and limits DNA accessibility. We identified post-translational modifications on protein VII that are responsible for chromatin localization. Furthermore, proteomic analysis demonstrated that protein VII is sufficient to alter the protein composition of host chromatin. We found that protein VII is necessary and sufficient for retention in the chromatin of members of the high-mobility-group protein B family (HMGB1, HMGB2 and HMGB3). HMGB1 is actively released in response to inflammatory stimuli and functions as a danger signal to activate immune responses. We showed that protein VII can directly bind HMGB1 in vitro and further demonstrated that protein VII expression in mouse lungs is sufficient to decrease inflammation-induced HMGB1 content and neutrophil recruitment in the bronchoalveolar lavage fluid. Together, our in vitro and in vivo results show that protein VII sequesters HMGB1 and can prevent its release. This study uncovers a viral strategy in which nucleosome binding is exploited to control extracellular immune signaling.

Unlabelled: Among several single-nucleotide polymorphisms (SNPs) that correlate with fibrosis progression in chronic HCV, an SNP in the antizyme inhibitor (AzI) gene is most strongly associated with slow fibrosis progression. Our aim was to identify the mechanism(s) underlying this observation by exploring the impact of the AzI SNP on hepatic stellate cell (HSC) activity. Seven novel AZIN1 splice variants ("SV2-8") were cloned by polymerase chain reaction from the LX2 human HSC line. Expression of a minigene in LX2 containing the AZIN1 slow-fibrosis SNP yielded a 1.67-fold increase in AZIN1 splice variant 2 (AZIN1 SV2) messenger RNA (mRNA) (P = 0.05). In healthy human leukocytes, the SNP variant also correlated with significantly increased SV2 mRNA. Cells (293T) transfected with short hairpin RNA (shRNA) complementary to the exonic splicing chaperone SRp40 expressed 30% less SRp40 (P = 0.044) and 43% more AzI SV2 (P = 0.021) than control shRNA-expressing cells, mimicking the effect of the sequence variant. LX2 cells transfected with AZIN1 full-length complementary DNA expressed 35% less collagen I mRNA (P = 0.09) and 18% less α-smooth muscle actin mRNA (P = 0.09). Transient transfection of AZIN1 SV2 complementary DNA into LX2 cells reduced collagen I gene expression by 64% (P = 0.001) and α-smooth muscle actin by 43% (P = 0.005) compared to vector-transfected controls, paralleling changes in protein expression. Both AZIN1 and AZIN-SV2 mRNAs are detectable in normal human liver and reduced in HCV cirrhotic livers. The AZIN1-SV2 acts via a polyamine-independent pathway, as it neither interacts with antizyme nor affects the ability of AZIN1 lacking this variant to neutralize antizyme., Conclusion: An SNP variant in the AZIN1 gene leads to enhanced generation of a novel alternative splice form that modifies the fibrogenic potential of HSCs., (Copyright © 2011 American Association for the Study of Liver Diseases.)

The tumor suppressor Kruppel-like factor 6 (KLF6) is frequently inactivated in hepatocellular carcinoma (HCC). To unearth downstream transcriptional targets of KLF6, cDNA microarray analysis of whole liver was compared between KLF6+/+ and KLF6+/- mice. Pituitary tumor transforming gene 1 (PTTG1), an oncogene, was the most up-regulated transcript in KLF6+/- liver. In human HCCs, KLF6 mRNA was significantly decreased, associated with increased PTTG1. In HepG2, KLF6 transcriptionally repressed PTTG1 by direct promoter interaction. Whereas KLF6 downregulation by siRNA increased HepG2 proliferation, siRNA to PTTG1 was anti-proliferative. PTTG1 downregulation represents a novel tumor suppressor pathway of KLF6., (Copyright (c) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)