• Allele-specific differences in transcriptome, miRNome, and mitochondrial function in two hypertrophic cardiomyopathy mouse models

      Vakrou, Styliani; Fukunaga, Ryuya; Foster, D Brian; Sorensen, Lars; Liu, Yamin; Guan, Yufan; Woldemichael, Kirubel; Pineda-Reyes, Roberto; Liu, Ting; Tardiff, Jill C; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2018-03-22)
      Hypertrophic cardiomyopathy (HCM) stems from mutations in sarcomeric proteins that elicit distinct biophysical sequelae, which in turn may yield radically different intracellular signaling and molecular pathologic profiles. These signaling events remain largely unaddressed by clinical trials that have selected patients based on clinical HCM diagnosis, irrespective of genotype. In this study, we determined how two mouse models of HCM differ, with respect to cellular/mitochondrial function and molecular biosignatures, at an early stage of disease. We show that hearts from young R92W-TnT and R403Q-αMyHC mutation–bearing mice differ in their transcriptome, miRNome, intracellular redox environment, mitochondrial antioxidant defense mechanisms, and susceptibility to mitochondrial permeability transition pore opening. Pathway analysis of mRNA-sequencing data and microRNA profiles indicate that R92W-TnT mutants exhibit a biosignature consistent with activation of profibrotic TGF-β signaling. Our results suggest that the oxidative environment and mitochondrial impairment in young R92W-TnT mice promote activation of TGF-β signaling that foreshadows a pernicious phenotype in young individuals. Of the two mutations, R92W-TnT is more likely to benefit from anti–TGF-β signaling effects conferred by angiotensin receptor blockers and may be responsive to mitochondrial antioxidant strategies in the early stage of disease. Molecular and functional profiling may therefore serve as aids to guide precision therapy for HCM.
    • Arginine metabolic control of airway inflammation

      Asosingh, Kewal; Lauruschkat, Chris D; Alemagno, Mario; Frimel, Matthew; Wanner, Nicholas; Weiss, Kelly; Kessler, Sean; Meyers, Deborah A; Bennett, Carole; Xu, Weiling; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2020-01-30)
      Inducible nitric oxide synthase (iNOS) and arginase-2 (ARG2) share a common substrate, arginine. Higher expression of iNOS and exhaled NO are linked to airway inflammation in patients. iNOS deletion in animal models suggests that eosinophilic inflammation is regulated by arginine metabolism. Moreover, ARG2 is a regulator of Th2 response, as shown by the development of severe eosinophilic inflammation in ARG2(-/-) mice. However, potential synergistic roles of iNOS and ARG2 in asthma have not been explored. Here, we hypothesized that arginine metabolic fate via iNOS and ARG2 may govern airway inflammation. In an asthma cohort, ARG2 variant genotypes were associated with arginase activity. ARG2 variants with lower arginase activity, combined with levels of exhaled NO, identified a severe asthma phenotype. Airway inflammation was present in WT, ARG2(-/-), iNDS(-/-), and ARG2(-/-)/iNOS(-/-) mice but was greatest in ARG2(-/-). Eosinophilic and neutrophilic infiltration in the ARG2(-/-) mice was abrogated in ARG2(-/-)/iNOS(-/-) animals. Similarly, angiogenic airway remodeling was greatest in ARG2(-/- )mice. Cytokines driving inflammation and remodeling were highest in lungs of asthmatic ARG2(-/-) mice and lowest in the iNOS(-/-). ARG2 metabolism of arginine suppresses inflammation, while iNOS metabolism promotes airway inflammation, supporting a central role for arginine metabolic control of inflammation.
    • Chronic immune barrier dysregulation among women with a history of violence victimization

      Swaims-Kohlmeier, Alison; Haddad, Lisa B; Li, Zheng-Rong Tiger; Brookmeyer, Kathryn A; Baker, James M; Widom, Cathy Spatz; Lamousin, James C; Chi, Kai-Hua; Chen, Cheng Y; Kersh, Ellen N; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2019-05-16)
      We explored the association between violence victimization and increased risk for acquiring sexually transmitted infections (STIs) in women by measuring cellular immune barrier properties from the female reproductive tract. STI-negative participants reporting repeated prior victimization occurrences through the lifetime trauma and victimization history (LTVH) instrument were more likely to exhibit alterations in barrier homeostasis and the composition of critical immune mediators irrespective of demographic parameters or presence of bacterial vaginosis. By combining cellular data with mixed-effect linear modeling, we uncovered differences in local T cells, MHCII+ antigen-presenting cells, and epithelial cells indicative of altered trafficking behavior, increased immunosuppressive function, and decreased barrier integrity at sites of STI exposure that correlate most strongly with LTVH score. These data evidence a biological link between a history of violence victimization and risk of STI acquisition through immune dysregulation in the female reproductive tract.
    • The effect of BPIFA1/SPLUNC1 genetic variation on its expression and function in asthmatic airway epithelium

      Schaefer, Niccolette; Li, Xingnan; Seibold, Max A; Jarjour, Nizar N; Denlinger, Loren C; Castro, Mario; Coverstone, Andrea M; Teague, W Gerald; Boomer, Jonathan; Bleecker, Eugene R; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2019-04-18)
      Bacterial permeability family member A1 (BPIFA1), also known as short palate, lung, and nasal epithelium clone 1 (SPLUNC1), is a protein involved in the antiinflammatory response. The goal of this study was to determine whether BPIFA1 expression in asthmatic airways is regulated by genetic variations, altering epithelial responses to type 2 cytokines (e.g., IL-13). Nasal epithelial cells from patients with mild to severe asthma were collected from the National Heart, Lung. and Blood Institute Severe Asthma Research Program centers, genotyped for rs750064, and measured for BPIFA1. To determine the function of rs750064, cells were cultured at air-liquid interface and treated with 11-13 with or without recombinant human BPIFA1 (rhBPIFA1). Noncultured nasal cells with the rs750064 CC genotype had significantly less BPIFA1 mRNA expression than the CT and TT genotypes. Cultured CC versus CT and TT cells without stimulation maintained less BPIFA1 expression. With IL-13 treatment, CC genotype cells secreted more eotaxin-3 than CT and TT genotype cells. Also, rhBPIFA1 reduced IL-13-mediated eotaxin-3. BPIFA1 mRNA levels negatively correlated with serum IgE and fractional exhaled nitric oxide. Baseline FEV1% levels were lower in the asthma patients with the CC genotype (n = 1,016). Our data suggest that less BPIFA1 in asthma patients with the CC allele may predispose them to greater eosinophilic inflammation, which could be attenuated by rhBPIFA1 protein therapy.
    • IL-1RA regulates immunopathogenesis during fungal-associated allergic airway inflammation

      Godwin, Matthew S; Reeder, Kristen M; Garth, Jaleesa M; Blackburn, Jonathan P; Jones, MaryJane; Yu, Zhihong; Matalon, Sadis; Hastie, Annette T; Meyers, Deborah A; Steele, Chad; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2019-09-24)
      Severe asthma with fungal sensitization (SAFS) defines a subset of human asthmatics with allergy to 1 or more fungal species and difficult-to-control asthma. We have previously reported that human asthmatics sensitized to fungi have worse lung function and a higher degree of atopy, which was associated with higher IL-1 receptor antagonist (IL-1RA) levels in bronchoalveolar lavage fluid. IL-1RA further demonstrated a significant negative association with bronchial hyperresponsiveness to methacholine. Here, we show that IL-1α and IL-1β are elevated in both bronchoalveolar lavage fluid and sputum from human asthmatics sensitized to fungi, implicating an association with IL-1α, IL-1β, or IL-1RA in fungal asthma severity. In an experimental model of fungal-associated allergic airway inflammation, we demonstrate that IL-1R1 signaling promotes type 1 (IFN-γ, CXCL9, CXCL10) and type 17 (IL-17A, IL-22) responses that were associated with neutrophilic inflammation and increased airway hyperreactivity. Each of these were exacerbated in the absence of IL-1RA. Administration of human recombinant IL-1RA (Kineret/anakinra) during fungal-associated allergic airway inflammation improved airway hyperreactivity and lowered type 1 and type 17 responses. Taken together, these data suggest that IL-1R1 signaling contributes to fungal asthma severity via immunopathogenic type 1 and type 17 responses and can be targeted for improving allergic asthma severity.
    • Increased lipogenesis and impaired β-oxidation predict type 2 diabetic kidney disease progression in American Indians

      Afshinnia, Farsad; Nair, Viji; Lin, Jiahe; Rajendiran, Thekkelnaycke M; Soni, Tanu; Byun, Jaeman; Sharma, Kumar; Fort, Patrice E; Gardner, Thomas W; Looker, Helen C; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2019-11-01)
      BACKGROUND. In this study, we identified the lipidomic predictors of early type 2 diabetic kidney disease (DKD) progression, which are currently undefined. METHODS. This longitudinal study included 92 American Indians with type 2 diabetes. Serum lipids (406 from 18 classes) were quantified using mass spectrometry from baseline samples when iothalamate-based glomerular filtration rate (GFR) was at least 90 mL/min. Affymetrix GeneChip Array was used to measure renal transcript expression. DIM progression was defined as at least 40% decline in GFR during follow-up. RESULTS. Participants had a mean age of 45 +/- 9 years and median urine albumin/creatinine ratio of 43 (interquartile range 11-144). The 32 progressors had significantly higher relative abundance of polyunsaturated triacylglycerols (TAGs) and a lower abundance of C16-C 2 0 acylcarnitines (ACs) ( P< 0.001). In a Cox regression model, the main effect terms of unsaturated free fatty acids and phosphatidylethanolamines and the interaction terms of C16-C20 ACs and short-low-double-bond TAGs by categories of albuminuria independently predicted DKD progression. Renal expression of acetyl-CoA carboxylase-encoding gene (ACACIA) correlated with serum diacylglycerols in the glomerular compartment (r = 0.36, and P = 0.006) and with low-double-bond TAGs in the tubulointerstitial compartment (r = 0.52. and P < 0.001). CONCLUSION. Collectively, the findings reveal a previously unrecognized link between lipid markers of impaired mitochondria beta-oxidation and enhanced lipogenesis and DKD progression in individuals with preserved GFR. Renal acetyl-CoA carboxylase activation accompanies these lipidomic changes and suggests that it may be the underlying mechanism linking lipid abnormalities to DKD progression.
    • Modulation of subsets of cardiac B lymphocytes improves cardiac function after acute injury

      Adamo, Luigi; Staloch, Lora J; Rocha-Resende, Cibele; Matkovich, Scot J; Jiang, Wenlong; Bajpai, Geetika; Weinheimer, Carla J; Kovacs, Attila; Schilling, Joel D; Barger, Philip M; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2018-06-07)
      Despite the long-standing recognition that the immune response to acute myocardial injury contributes to adverse left ventricular (LV) remodeling, it has not been possible to effectively target this clinically. Using 2 different in vivo models of acute myocardial injury, we show that pirfenidone confers beneficial effects in the murine heart through an unexpected mechanism that depends on cardiac B lymphocytes. Naive hearts contained a large population of CD19+CD11b–CD23–CD21–IgD+IgMlo lymphocytes, and 2 smaller populations of CD19+CD11b+ B1a and B1b cells. In response to tissue injury, there was an increase in neutrophils, monocytes, macrophages, as well as an increase in CD19+ CD11b– B lymphocytes. Treatment with pirfenidone had no effect on the number of neutrophils, monocytes, or macrophages, but decreased CD19+CD11b– lymphocytes. B cell depletion abrogated the beneficial effects of pirfenidone. In vitro studies demonstrated that stimulation with lipopolysaccharide and extracts from necrotic cells activated CD19+ lymphocytes through a TIRAP-dependent pathway. Treatment with pirfenidone attenuated this activation of B cells. These findings reveal a previously unappreciated complexity of myocardial B lymphocytes within the inflammatory infiltrate triggered by cardiac injury and suggest that pirfenidone exerts beneficial effects in the heart through a unique mechanism that involves modulation of cardiac B lymphocytes.
    • A porcine model of neurofibromatosis type 1 that mimics the human disease

      White, Katherine A; Swier, Vicki J; Cain, Jacob T; Kohlmeyer, Jordan L; Meyerholz, David K; Tanas, Munir R; Uthoff, Johanna; Hammond, Emily; Li, Hua; Rohret, Frank A; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2018-06-21)
      Loss of the NF1 tumor suppressor gene causes the autosomal dominant condition, neurofibromatosis type 1 (NF1). Children and adults with NF1 suffer from pathologies including benign and malignant tumors to cognitive deficits, seizures, growth abnormalities, and peripheral neuropathies. NF1 encodes neurofibromin, a Ras-GTPase activating protein, and NF1 mutations result in hyperactivated Ras signaling in patients. Existing NF1 mutant mice mimic individual aspects of NF1, but none comprehensively models the disease. We describe a potentially novel Yucatan miniswine model bearing a heterozygotic mutation in NF1 (exon 42 deletion) orthologous to a mutation found in NF1 patients. NF1(+/ex42del) miniswine phenocopy the wide range of manifestations seen in NF1 patients, including cafe au lait spots, neurofibromas, axillary freckling, and neurological defects in learning and memory. Molecular analyses verified reduced neurofibromin expression in swine NF1(+/ex42del) fibroblasts, as well as hyperactivation of Ras, as measured by increased expression of its downstream effectors, phosphorylated ERK1/2, SIAH, and the checkpoint regulators p53 and p21. Consistent with altered pain signaling in NF1, dysregulation of calcium and sodium channels was observed in dorsal root ganglia expressing mutant NF1. Thus, these NF1(+/ex42del) miniswine recapitulate the disease and provide a unique, much-needed tool to advance the study and treatment of NF1.
    • Prostatic compensation of the vitamin D axis in African American men

      Richards, Zachary; Batai, Ken; Farhat, Rachael; Shah, Ebony; Makowski, Andrew; Gann, Peter H; Kittles, Rick; Nonn, Larisa; Univ Arizona, Coll Med, Dept Surg, Div Urol (AMER SOC CLINICAL INVESTIGATION INC, 2017-01-26)
      BACKGROUND. African American (AA) men are disproportionately affected by both prostate cancer (PCa) and vitamin D deficiency compared with European American (EA) men. Vitamin D deficiency is linked to increased PCa aggressiveness and mortality. Therefore, it has been hypothesized that vitamin D deficiency may contribute to the PCa disparity between AA and EA men. METHODS. We studied a cross sectional group of 60 PCa patients (AA, n = 31; EA, n = 29) who underwent radical prostatectomy. Vitamin D metabolites 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured in the serum and tissue by uHPLC-MS-MS. Tissue was laser capture microdissected, and gene expression was quantified by microarray. DNA isolated from whole blood was genotyped for West African ancestry markers and vitamin D-related SNPs. RESULTS. Serum concentrations of 25(OH)D were lower in AAs, but concentrations of 1,25(OH)2D in the prostate tissue were higher compared with EAs. Expression of the vitamin D receptor was higher in prostate tissue from AAs. Expression of the extracellular receptor of vitamin D binding protein, LRP2, was positively associated with West African ancestry and inversely associated with tissue 25(OH)D concentrations in AAs. CONCLUSIONS. The relationships between vitamin D binding protein LRP2 and vitamin D metabolites suggest that the prohormone is actively transported into the prostate, followed by intraprostatic conversion to the active hormone, rather than passive diffusion. These findings support the presence of a compensatory response in prostate tissue to vitamin D deficiency in AAs and reveal a previously unknown complexity involving tissue distribution of vitamin D metabolites. FUNDING. Department of Defense Prostate Cancer Research Program Idea Award for Disparities Research PC121923 (LN and RK) and the NIH 1R01MD007105 (RK).
    • Sialylation of MUC4β N-glycans by ST6GAL1 orchestrates human airway epithelial cell differentiation associated with type-2 inflammation

      Zhou, Xiuxia; Kinlough, Carol L; Hughey, Rebecca P; Jin, Mingzhu; Inoue, Hideki; Etling, Emily; Modena, Brian D; Kaminski, Naftali; Bleecker, Eugene R; Meyers, Deborah A; et al. (AMER SOC CLINICAL INVESTIGATION INC, 2019-03-07)
      Although type-2-induced (T2-induced) epithelial dysfunction is likely to profoundly alter epithelial differentiation and repair in asthma, the mechanisms for these effects are poorly understood. A role for specific mucins, heavily N-glycosylated epithelial glycoproteins, in orchestrating epithelial cell fate in response to T2 stimuli has not previously been investigated. Levels of a sialylated MUC4 beta isoform were found to be increased in airway specimens from asthmatic patients in association with T2 inflammation. We hypothesized that IL-13 would increase sialylation of MUC4 beta, thereby altering its function and that the beta-galactoside alpha-2,6-sialyltransferase 1 (ST6GAL1) would regulate the sialylation. Using human biologic specimens and cultured primary human airway epithelial cells (HAECs), we demonstrated that IL-13 increases ST6GAL1-mediated sialylation of MUC4 beta and that both were increased in asthma, particularly in sputum supernatant and/or fresh isolated HAECs with elevated T2 biomarkers. ST6GAL1-induced sialylation of MUC4 beta altered its lectin binding and secretion. Both ST6GAL1 and MUC4 beta inhibited epithelial cell proliferation while promoting goblet cell differentiation. These in vivo and in vitro data provide strong evidence for a critical role for ST6GAL1-induced sialylation of MUC4 beta in epithelial dysfunction associated with T2-high asthma, thereby identifying specific sialylation pathways as potential targets in asthma.