Uncommon BK polyomaviruses detected in allogeneic hematopoietic cell transplant recipients.

The role of viral diversity in the pathogenesis of BK polyomavirus (BKPyV)-associated disease is poorly understood. Here, we report near full-length BKPyV genome sequences from two allogeneic hematopoietic cell transplant recipients infected with BKPyV genotype II, which is uncommon in the USA.

Increased Body Mass Index Augments Endothelial Injury and Clinical Outcomes after Hematopoietic Stem Cell Transplantation.

Higher body mass index (BMI) is characterized as a chronic inflammatory state with endothelial dysfunction. Endothelial injury after allogeneic hematopoietic stem cell transplantation (allo-HSCT) puts patients at risk for such complications as transplantation-associated thrombotic microangiopathy (TA-TMA) and acute graft-versus-host-disease (aGVHD). To evaluate the impact of increased BMI on endothelial injury after allo-HSCT in pediatric and young adult patients, we conducted a retrospective cohort study evaluating 476 consecutive allo-HSCT children and young adult recipients age 0 to 20 years. Our analysis was subdivided based on distinct age categories (<2 years and 2 to 20 years). BMI was considered as a variable but was also expressed in standard deviations from the mean adjusted for age and sex (z-score), based on established criteria from the World Health Organization (age <2 years) and the Centers for Disease Control and Prevention (age 2 to 20 years) to account for differences associated with age. Primary endpoints included the incidences of TA-TMA and aGVHD. Increased BMI z-score was associated with TA-TMA after allo-HSCT in patients age <2 years (median, 18.1; IQR, 17 to 20; P = .006) and in patients age 2 to 20 years (median, 18.7; IQR, 16 to 21.9; P = .02). Higher BMI z-score correlated with TA-TMA risk in both age groups, with a BMI z-score of .9 in the younger cohort and .7 (IQR, -.4 to 1.6; P = .04) in the older cohort. Increased BMI z-score was associated with an increased risk of TA-TMA in a multivariate analysis of the entire cohort (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.05 to 1.37; P = .008). Multivariate analysis also demonstrated that patients with BMI in the 85th percentile or greater had an increased risk of developing TA-TMA compared to those with a lower BMI percentile (OR, 2.66; 95% CI, 1.62 to 4.32; P < .001). Baseline and day +7 ST2 levels were elevated in subjects with TA-TMA compared to those without TA-TMA in both age groups. Baseline sC5b-9 concentration was not correlated with BMI z-score, but sC5b-9 concentration was increased markedly by 7 days post-allo-HSCT in patients age <2 years who later developed TA-TMA compared to those who never developed TA-TMA (P = .001). The median BMI z-score was higher for patients with aGVHD compared to patients without aGVHD (.7 [range, -3.9 to 3.9] versus .2 [range, -7.8 to 5.4]; P = .03). We show that high BMI is associated with augmented risk of endothelial injury after HSCT, specifically TA-TMA. These data identify a high-risk population likely to benefit from early interventions to prevent endothelial injury and prompt treatment of established endothelial injury.

BK Polyomavirus Diversity After Hematopoietic Stem Cell Transplantation.

BK polyomavirus (BKPyV) infection is common after hematopoietic stem cell transplantation (HSCT) and is associated with the development of hemorrhagic cystitis (HC). The role that BKPyV plays in the pathogenesis of HC is not well characterized. We investigated the impact of BKPyV diversity on the development of HC using a previously established cohort of pediatric HSCT patients. There were 147 urine samples with quantifiable BKPyV at month 1 after HSCT; 137 (93.2%) were amplified using our in-house polymerase chain reaction approach and sent for next-generation sequencing. Subtype Ia was most frequent (61.3%), followed by subtype Ib1 (31.4%). The median viral load of subtype Ia samples was higher than for subtype Ib1 at month 1. Across the protein coding regions, APOBEC-induced mutations and signature patterns associated with HC were identified. This is the largest sequencing study of a single cohort of HSCT patients, providing a vast resource of sequence data for future analyses.

PROTECTIVE EFFECTS OF HUMANIN-G IN HEMORRHAGIC SHOCK IN FEMALE MICE VIA AMPKα1-INDEPENDENT MECHANISMS.

ABSTRACT: Introduction: Despite therapeutic advances in hemorrhagic shock, mortality from multiple organ failure remains high. We previously showed that the α1 subunit of AMP-activated protein kinase (AMPK), a crucial regulator of mitochondrial function, exerts a protective role in hemorrhagic shock. Humanin is a mitochondrial peptide with cytoprotective properties against cellular stress. Here, we investigated whether AMPKα1 influences systemic levels of endogenous humanin in hemorrhagic shock and whether treatment with the synthetic analog humanin-G affords beneficial effects. Methods: AMPKα1 wild-type (WT) and knockout (KO) female mice were subjected to hemorrhagic shock followed by resuscitation with blood and lactated Ringer's solution. In short-term studies, mice were treated with humanin-G or vehicle and sacrificed at 3 h after resuscitation; in survival studies, mice were treated with PEGylated humanin-G and monitored for 7 days. Results: Compared with the vehicle WT group, KO mice exhibited severe hypotension, cardiac mitochondrial damage, and higher plasma levels of Th17 cytokines but had similar lung injury and similar plasma elevation of endogenous humanin. Treatment with humanin-G improved lung injury, mean arterial blood pressure, and survival in both WT and KO mice, without affecting systemic cytokine or humanin levels. Humanin-G also ameliorated cardiac mitochondrial damage and increased adenosine triphosphate levels in KO mice. Beneficial effects of humanin-G were associated with lung cytoplasmic and nuclear activation of the signal transducer and activator of transcription-3 (STAT3) in AMPKα1-independent manner with marginal or no effects on mitochondrial STAT3 and complex I subunit GRIM-19. Conclusions: Our data indicate that circulating levels of humanin increase during hemorrhagic shock in AMPKα1-independent fashion as a defense mechanism to counteract metabolic derangement and that administration of humanin-G affords beneficial effects through STAT3 activation even in the absence of a functional AMPKα1.

Center volume effect on acute cellular rejection and outcomes in pediatric lung transplant recipients.

BACKGROUND: Acute cellular rejection (ACR) is common after lung transplant (LTx). We sought to determine if transplant center volume affected ACR-related outcomes in children after LTx. METHODS: The United Network for Organ Sharing (UNOS) Registry was queried for patients <18-years-of-age who underwent LTx 1987-2020. Cohorts were children who survived the first-year post transplant and were treated for ACR within that first year (ACR group) and those not treated for ACR (non-ACR). LTx center volume was defined as: high volume center (HVC) (>5LTxs/year), medium volume center (MVC) (>1≤5 LTxs/year), and low volume center (LVC) (≤1LTxs/year). RESULTS: 1320 patients were enrolled into the study; 269 (20.4%) did not experience ACR. The ACR cohort was older (median 14 [11-16] vs 13 [7-16] years, p < 0.001), female (65.3% vs 57.3%, p = 0.016), had cystic fibrosis (62.3% vs 45.5%, p < 0.001), and had a higher lung allocation score (37.3 [34.6-47.8] vs 35.8 [33-42.6], p = 0.029). The ACR cohort trended (p = 0.06) towards lower survival at 5-year (37% vs 47%) and 10-year (25% vs 34%) post-LTx. Among children at HVCs, ACR occurred in 17% of recipients (n = 98/574), compared to 18.5% (n = 73/395) at MVCs and 27% (n = 100/369) at LVCs. Children treated for ACR at HVCs had higher survival than LVCs at 5-years (52% vs 29%) and 10-years (36% vs 15%) (p < 0.001) but similar survival to MVCs at 5-years (52% vs 43%) and 10-years (36% vs 24%) (p = 0.081). No survival differences were detected in MVCs vs LVCs (p = 0.14). CONCLUSIONS: ACR treated within the first post-LTx year influence survival of children. ACR incidence was lowest at higher volume centers whereas post-ACR treatment survival outcomes were also superior.

Novel FOXF1-Stabilizing Compound TanFe Stimulates Lung Angiogenesis in Alveolar Capillary Dysplasia.

Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is linked to heterozygous mutations in the FOXF1 (Forkhead Box F1) gene, a key transcriptional regulator of pulmonary vascular development. There are no effective treatments for ACDMPV other than lung transplant, and new pharmacological agents activating FOXF1 signaling are urgently needed. Objectives: Identify-small molecule compounds that stimulate FOXF1 signaling. Methods: We used mass spectrometry, immunoprecipitation, and the in vitro ubiquitination assay to identify TanFe (transcellular activator of nuclear FOXF1 expression), a small-molecule compound from the nitrile group, which stabilizes the FOXF1 protein in the cell. The efficacy of TanFe was tested in mouse models of ACDMPV and acute lung injury and in human vascular organoids derived from induced pluripotent stem cells of a patient with ACDMPV. Measurements and Main Results: We identified HECTD1 as an E3 ubiquitin ligase involved in ubiquitination and degradation of the FOXF1 protein. The TanFe compound disrupted FOXF1-HECTD1 protein-protein interactions and decreased ubiquitination of the FOXF1 protein in pulmonary endothelial cells in vitro. TanFe increased protein concentrations of FOXF1 and its target genes Flk1, Flt1, and Cdh5 in LPS-injured mouse lungs, decreasing endothelial permeability and inhibiting lung inflammation. Treatment of pregnant mice with TanFe increased FOXF1 protein concentrations in lungs of Foxf1+/- embryos, stimulated neonatal lung angiogenesis, and completely prevented the mortality of Foxf1+/- mice after birth. TanFe increased angiogenesis in human vascular organoids derived from induced pluripotent stem cells of a patient with ACDMPV with FOXF1 deletion. Conclusions: TanFe is a novel activator of FOXF1, providing a new therapeutic candidate for treatment of ACDMPV and other neonatal pulmonary vascular diseases.

Changing racial and ethnic differences for lung transplantation in cystic fibrosis.

BACKGROUND: CFTR modulators, especially (elexacaftor/tezacaftor/ivacaftor), have positively impacted the CF population and quickly decreased LTx numbers. However, no study has investigated if this reduction is universal across all races/ethnicities. METHODS: Using the UNOS Registry, we explored the frequency/proportions of LTx in WNH and NW (Black, non-Hispanic/Hispanic-Latino/Asian-non Hispanic/American Indian-Alaskan Native-non-Hispanic/Native Hawaiian/Other Pacific Islander-non-Hispanic/Multiracial) in children and adults with CF in the US. RESULTS: Between 1990 and 2019, the annual mean (±SD) number of LTxs for children with CF was 23.2 (±7.7) compared to 5 in 2020 (p < .001) and in 2021 (p < .001). In adults from 1990 to 2019, the mean (±SD) number of LTxs performed was 144.9 (±73.5), which was significantly higher than 2020 (n = 73; p < .001) and 2021 (n = 45; p < .001). Comparing 1990-2019 to post-2019, the proportion of LTxs performed in both children and adults with CF has decreased from 50.5% (696/1378) to 16.4% (9/55) and from 12.1% (4773/39542) to 2.4% (118/5004), respectively. In WNH pediatric patients, the difference in the percentage of all LTx made up by CF patients between the two eras was 41.2% compared to NW patients where the difference was 11%. Similarly in adults, the difference between the two eras was 10.4% in WNH and 2.4% in NW patients. CONCLUSIONS: The recent reduction in LTx for the CF population has had less impact on the NW population in the US, so the continuation of optimal referrals for this group is needed.

Tissue-localized immune responses in people with cystic fibrosis and respiratory nontuberculous mycobacteria infection.

Nontuberculous mycobacteria (NTM) are an increasingly common cause of respiratory infection in people with cystic fibrosis (PwCF). Relative to those with no history of NTM infection (CF-NTMNEG), PwCF and a history of NTM infection (CF-NTMPOS) are more likely to develop severe lung disease and experience complications over the course of treatment. In other mycobacterial infections (e.g., tuberculosis), an overexuberant immune response causes pathology and compromises organ function; however, since the immune profiles of CF-NTMPOS and CF-NTMNEG airways are largely unexplored, it is unknown which, if any, immune responses distinguish these cohorts or concentrate in damaged tissues. Here, we evaluated lung lobe-specific immune profiles of 3 cohorts (CF-NTMPOS, CF-NTMNEG, and non-CF adults) and found that CF-NTMPOS airways are distinguished by a hyperinflammatory cytokine profile. Importantly, the CF-NTMPOS airway immune profile was dominated by B cells, classical macrophages, and the cytokines that support their accumulation. These and other immunological differences between cohorts, including the near absence of NK cells and complement pathway members, were enriched in the most damaged lung lobes. The implications of these findings for our understanding of lung disease in PwCF are discussed, as are how they may inform the development of host-directed therapies to improve NTM disease treatment.

BK Polyomavirus Subtypes II and IV in Hematopoietic Cell Transplant Recipients.

Symptomatic BK polyomavirus (BKPyV) infections are common and relevant in immunocompromised patients. Here, we present full-length BKPyV genomes from samples from patients who received hematopoietic cell transplants in the United States. These individuals had non-subtype I BKPyV, as determined by amplification, next-generation sequencing, and phylogenetic analysis.

Optimized amplification of BK polyomavirus in urine.

BK polyomavirus (BKPyV) is a ubiquitous pathogen that typically results in asymptomatic infection. However, in immunocompromised individuals, BKPyV viral shedding in the urine can reach 109 copies per mL. These high viral levels within urine provide ideal samples for next-generation sequencing to accurately determine BKPyV genotype and identify mutations associated with pathogenesis. Sequencing data obtained can be further analyzed to better understand and characterize the genetic diversity present in BKPyV. Here, methods are described for the successful extraction of viral DNA from urine and the subsequent amplification methods to prepare a sample for next-generation sequencing.

Bayesian regularization for a nonstationary Gaussian linear mixed effects model.

In omics experiments, estimation and variable selection can involve thousands of proteins/genes observed from a relatively small number of subjects. Many regression regularization procedures have been developed for estimation and variable selection in such high-dimensional problems. However, approaches have predominantly focused on linear regression models that ignore correlation arising from long sequences of repeated measurements on the outcome. Our work is motivated by the need to identify proteomic biomarkers that improve the prediction of rapid lung-function decline for individuals with cystic fibrosis (CF) lung disease. We extend four Bayesian penalized regression approaches for a Gaussian linear mixed effects model with nonstationary covariance structure to account for the complicated structure of longitudinal lung function data while simultaneously estimating unknown parameters and selecting important protein isoforms to improve predictive performance. Different types of shrinkage priors are evaluated to induce variable selection in a fully Bayesian framework. The approaches are studied with simulations. We apply the proposed method to real proteomics and lung-function outcome data from our motivating CF study, identifying a set of relevant clinical/demographic predictors and a proteomic biomarker for rapid decline of lung function. We also illustrate the methods on CD4 yeast cell-cycle genomic data, confirming that the proposed method identifies transcription factors that have been highlighted in the literature for their importance as cell cycle transcription factors.

BK Polyomavirus Genotypes in Two Patients after Hematopoietic Cell Transplant.

BK polyomavirus (BKPyV) infection can lead to nephropathy and hemorrhagic cystitis (HC). We evaluated BKPyV genotypes in two individuals after hematopoietic cell transplant (HCT). The first case developed HC and was infected with genotype Ib-2, while the second did not develop HC and was infected with genotype Ia.

Cystic Fibrosis Point of Personalized Detection (CFPOPD): An Interactive Web Application.

BACKGROUND: Despite steady gains in life expectancy, individuals with cystic fibrosis (CF) lung disease still experience rapid pulmonary decline throughout their clinical course, which can ultimately end in respiratory failure. Point-of-care tools for accurate and timely information regarding the risk of rapid decline is essential for clinical decision support. OBJECTIVE: This study aims to translate a novel algorithm for earlier, more accurate prediction of rapid lung function decline in patients with CF into an interactive web-based application that can be integrated within electronic health record systems, via collaborative development with clinicians. METHODS: Longitudinal clinical history, lung function measurements, and time-invariant characteristics were obtained for 30,879 patients with CF who were followed in the US Cystic Fibrosis Foundation Patient Registry (2003-2015). We iteratively developed the application using the R Shiny framework and by conducting a qualitative study with care provider focus groups (N=17). RESULTS: A clinical conceptual model and 4 themes were identified through coded feedback from application users: (1) ambiguity in rapid decline, (2) clinical utility, (3) clinical significance, and (4) specific suggested revisions. These themes were used to revise our application to the currently released version, available online for exploration. This study has advanced the application's potential prognostic utility for monitoring individuals with CF lung disease. Further application development will incorporate additional clinical characteristics requested by the users and also a more modular layout that can be useful for care provider and family interactions. CONCLUSIONS: Our framework for creating an interactive and visual analytics platform enables generalized development of applications to synthesize, model, and translate electronic health data, thereby enhancing clinical decision support and improving care and health outcomes for chronic diseases and disorders. A prospective implementation study is necessary to evaluate this tool's effectiveness regarding increased communication, enhanced shared decision-making, and improved clinical outcomes for patients with CF.

Utilizing centralized biorepository samples for biomarkers of cystic fibrosis lung disease severity.

BACKGROUND: Circulating biomarkers reflective of lung disease activity and severity have the potential to improve patient care and accelerate drug development in CF. The objective of this study was to leverage banked specimens to test the hypothesis that blood-based biomarkers discriminate CF children segregated by lung disease severity. METHODS: Banked serum samples were selected from children who were categorized into two extremes of phenotype associated with lung function ('mild' or 'severe') based on CF-specific data and were matched on age, gender, CFTR genotype, and P. aeruginosa infection status. Targeted inflammatory proteins, lipids, and discovery metabolite profiles were measured in these serum samples. RESULTS: The severe cohort, characterized by a lower CF-specific FEV1 percentile, had significantly higher circulating concentrations of high sensitivity C-reactive protein, serum amyloid A, granulocyte colony stimulating factor, and calprotectin compared to the mild cohort. The mild cohort tended to have higher serum linoleic acid concentrations. The metabolite arabitol was lower in the severe cohort while other CF relevant metabolic pathways showed non-significant differences after adjusting for multiple comparisons. A sensitivity analysis to correct for biased estimates that may result from selecting subjects using an extremes of phenotype approach confirmed the protein biomarker findings. CONCLUSIONS: Circulating inflammatory proteins differ in CF children segregated by lung function. These findings serve to demonstrate the value of maintaining centralized, high quality patient derived samples for future research, with linkage to clinical information to answer testable hypotheses in biomarker development.

Clinically-approved CFTR modulators rescue Nrf2 dysfunction in cystic fibrosis airway epithelia.

Cystic Fibrosis (CF) is a multi-organ progressive genetic disease caused by loss of functional cystic fibrosis transmembrane conductance regulator (CFTR) channel. Previously, we identified a significant dysfunction in CF cells and model mice of the transcription factor nuclear-factor-E2-related factor-2 (Nrf2), a major regulator of redox balance and inflammatory signaling. Here we report that approved F508del CFTR correctors VX809/VX661 recover diminished Nrf2 function and colocalization with CFTR in CF human primary bronchial epithelia by proximity ligation assay, immunoprecipitation, and immunofluorescence, concordant with CFTR correction. F508del CFTR correctors induced Nrf2 nuclear translocation, Nrf2-dependent luciferase activity, and transcriptional activation of target genes. Rescue of Nrf2 function by VX809/VX661 was dependent on significant correction of F508del and was blocked by inhibition of corrected channel function, or high-level shRNA knockdown of CFTR or F508del-CFTR. Mechanistically, F508del-CFTR modulation restored Nrf2 phosphorylation and its interaction with the coactivator CBP. Our findings demonstrate that sufficient modulation of F508del CFTR function corrects Nrf2 dysfunction in CF.

Simvastatin inhibits protein isoprenylation in the brain.

Evidence suggests that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, may reduce the risk of Alzheimer's disease (AD). Statin action in patients with AD, as in those with heart disease, is likely to be at least partly independent of the effects of statins on cholesterol. Statins can alter cellular signaling and protein trafficking through inhibition of isoprenylation of Rho, Cdc42, and Rab family GTPases. The effects of statins on protein isoprenylation in vivo, particularly in the central nervous system, are poorly studied. We utilized two-dimensional gel electrophoresis approaches to directly monitor the levels of isoprenylated and non-isoprenylated forms of Rho and Rab family GTPases. We report that simvastatin significantly inhibits RhoA and Rab4, and Rab6 isoprenylation at doses as low as 50nM in vitro. We also provide the first in vivo evidence that statins inhibit the isoprenylation of RhoA in the brains of rats and RhoA, Cdc42, and H-Ras in the brains of mice treated with clinically relevant doses of simvastatin.

Biomarkers for cystic fibrosis drug development.

PURPOSE: To provide a review of the status of biomarkers in cystic fibrosis drug development, including regulatory definitions and considerations, a summary of biomarkers in current use with supportive data, current gaps, and future needs. METHODS: Biomarkers are considered across several areas of CF drug development, including cystic fibrosis transmembrane conductance regulator modulation, infection, and inflammation. RESULTS: Sweat chloride, nasal potential difference, and intestinal current measurements have been standardized and examined in the context of multicenter trials to quantify CFTR function. Detection and quantification of pathogenic bacteria in CF respiratory cultures (e.g.: Pseudomonas aeruginosa) are commonly used in early phase antimicrobial clinical trials, and to monitor safety of therapeutic interventions. Sputum (e.g.: neutrophil elastase, myeloperoxidase, calprotectin) and blood biomarkers (e.g.: C reactive protein, calprotectin, serum amyloid A) have had variable success in detecting response to inflammatory treatments. CONCLUSIONS: Biomarkers are used throughout the drug development process in CF, and many have been used in early phase clinical trials to provide proof of concept, detect drug bioactivity, and inform dosing for later-phase studies. Advances in the precision of current biomarkers, and the identification of new biomarkers with 'omics-based technologies, are needed to accelerate CF drug development.

Capturing the Direct Binding of CFTR Correctors to CFTR by Using Click Chemistry.

Cystic fibrosis (CF) is a lethal genetic disease caused by the loss or dysfunction of the CF transmembrane conductance regulator (CFTR) channel. F508del is the most prevalent mutation of the CFTR gene and encodes a protein defective in folding and processing. VX-809 has been reported to facilitate the folding and trafficking of F508del-CFTR and augment its channel function. The mechanism of action of VX-809 has been poorly understood. In this study, we sought to answer a fundamental question underlying the mechanism of VX-809: does it bind CFTR directly in order to exert its action? We synthesized two VX-809 derivatives, ALK-809 and SUL-809, that possess an alkyne group and retain the rescue capacity of VX-809. By using Cu(I) -catalyzed click chemistry, we provide evidence that the VX-809 derivatives bind CFTR directly in vitro and in cells. Our findings will contribute to the elucidation of the mechanism of action of CFTR correctors and the design of more potent therapeutics to combat CF.