Browsing by Author "Kumar, Rajesh"

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    5-HTP inhibits eosinophilia via intracellular endothelial 5-HTRs; SNPs in 5-HTRs associate with asthmatic lung function
    (Frontiers Media, 2024-05-23) Walker, Matthew T.; Bloodworth, Jeffrey C.; Kountz, Timothy S.; McCarty, Samantha L.; Green, Jeremy E.; Ferrie, Ryan P.; Campbell, Jackson A.; Averill, Samantha H.; Beckman, Kenneth B.; Grammer, Leslie C.; Eng, Celeste; Avila, Pedro C.; Farber, Harold J.; Rodriguez-Cintron, William; Rodriguez-Santana, Jose R.; Serebrisky, Denise; Thyne, Shannon M.; Seibold, Max A.; Burchard, Esteban G.; Kumar, Rajesh; Cook-Mills, Joan M.; Pediatrics, School of Medicine
    Background: Previous research showed that 5-hydroxytryptophan (5HTP), a metabolic precursor of serotonin, reduces allergic lung inflammation by inhibiting eosinophil migration across endothelial monolayers. Objective: It is unknown if serotonin receptors are involved in mediating this 5HTP function or if serotonin receptor (HTR) single nucleotide polymorphisms (SNPs) associate with lung function in humans. Methods: Serotonin receptor subtypes were assessed by qPCR, western blot, confocal microscopy, pharmacological inhibitors and siRNA knockdown. HTR SNPs were assessed in two cohorts. Results: Pharmacological inhibition or siRNA knockdown of the serotonin receptors HTR1A or HTR1B in endothelial cells abrogated the inhibitory effects of 5HTP on eosinophil transendothelial migration. In contrast, eosinophil transendothelial migration was not inhibited by siRNA knockdown of HTR1A or HTR1B in eosinophils. Surprisingly, these HTRs were intracellular in endothelial cells and an extracellular supplementation with serotonin did not inhibit eosinophil transendothelial migration. This is consistent with the inability of serotonin to cross membranes, the lack of selective serotonin reuptake receptors on endothelial cells, and the studies showing minimal impact of selective serotonin reuptake inhibitors on asthma. To extend our HTR studies to humans with asthma, we examined the CHIRAH and GALA cohorts for HTR SNPs that affect HTR function or are associated with behavior disorders. A polygenic index of SNPs in HTRs was associated with lower lung function in asthmatics. Conclusions: Serotonin receptors mediate 5HTP inhibition of transendothelial migration and HTR SNPs associate with lower lung function. These results may serve to aid in design of novel interventions for allergic inflammation.
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    Associations of alpha and gamma-tocopherol during early life with lung function in childhood
    (Elsevier, 2020) Kumar, Rajesh; Ferrie, Ryan; Balmert, Lauren; Kienzi, Matthew; Rifas-Shiman, Sheryl L.; Gold, Diane R.; Sordillo, Joanne E.; Kleinman, Ken; Camargo, Carlos A., Jr.; Litonjua, Augusto A.; Oken, Emily; Cook-Mills, Joan; Pediatrics, School of Medicine
    Background: Tocopherol isoforms may regulate child lung growth and spirometric measures. Objective: Our aim was to determine the extent to which plasma a-tocopherol (a-T) or g-tocopherol (g-T) isoform levels in early childhood or in utero are associated with childhood lung function. Methods: We included 622 participants in the Project Viva cohort who had lung function at a mid-childhood visit (age 6-10 years). Maternal and child tocopherol isoform levels were measured by HPLC at the second trimester and 3 years of age, respectively. Multivariable linear regression models (adjusted for mid-childhood body mass index z scores, maternal education, smoking in pregnancy, and prenatal particulate matter with diameter of <2.5 micrometers (PM2.5) particulate exposure) stratified by tertiles of child g-T level were used to assess the association of a-T levels with FEV1 and forced vital capacity (FVC) percent predicted. Similarly, models stratified by child a-T tertile evaluated associations of g-T levels with lung function. We performed similar analyses with maternal second trimester tocopherol isoform levels. Results: The median maternal second trimester a-T level was 63 mM (interquartile range 5 47-82). The median early-childhood level was 25 mM (interquartile range 5 20-33 mM). In the lowest tertile of early-childhood g-T, children with a higher a-T level (per 10 mM) had a higher mid-childhood FEV1 percent predicted (b 5 3.09; 95% CI 5 0.58-5.59 and a higher FVC percent predicted (b 5 2.77; 95% CI 5 0.47-5.06). This protective association of a-T was lost at higher g-T levels. We did not see any consistent associations of second trimester levels of either a-T or g-T with mid-childhood FEV1 or FVC. Conclusion: When g-T levels were in the lowest tertile, a higher early-childhood a-T level was associated with better lung function at mid-childhood. Second trimester maternal plasma a-T concentration was 3-fold higher than in the adult nonpregnant female population.
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    Cord blood sphingolipids are associated with atopic dermatitis and wheeze in the first year of life
    (Elsevier, 2022) Hoji, Aki; Kumar, Rajesh; Gern, James E.; Bendixsen, Casper G.; Seroogy, Christine M.; Cook-Mills, Joan M.; Pediatrics, School of Medicine
    Background: Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation. Objective: Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort. Methods: We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year. Results: Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life. Conclusion: The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.
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    Exposure: Staphylococcus aureus skin colonization predisposes to food allergy in the Learning Early about Allergy to Peanut (LEAP) and LEAP-On studies
    (Elsevier, 2019-08) Cook-Mills, Joan M.; Kaplan, Mark H.; Turner, Matthew J.; Kloepfer, Kirsten M.; Kumar, Rajesh; Pediatrics, School of Medicine
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    PrecISE: Precision Medicine in Severe Asthma: An adaptive platform trial with biomarker ascertainment
    (Elsevier, 2021) Israel, Elliot; Denlinger, Loren C.; Bacharier, Leonard B.; LaVange, Lisa M.; Moore, Wendy C.; Peters, Michael C.; Georas, Steve N.; Wright, Rosalind J.; Mauger, David T.; Noel, Patricia; Akuthota, Praveen; Bach, Julia; Bleecker, Eugene R.; Cardet, Juan Carlos; Carr, Tara F.; Castro, Mario; Cinelli, Angeles; Comhair, Suzy A.A.; Covar, Ronina A.; Alexander, Laura Crotty; DiMango, Emily A.; Erzurum, Serpil C.; Fahy, John V.; Fajt, Merritt L.; Gaston, Benjamin M.; Hoffman, Eric A.; Holguin, Fernando; Jackson, Daniel J.; Jain, Sonia; Jarjour, Nizar N.; Ji, Yuan; Kenyon, Nicholas J.; Kosorok, Michael R.; Kraft, Monica; Krishnan, Jerry A.; Kumar, Rajesh; Liu, Andrew H.; Liu, Mark C.; Ly, Ngoc P.; Marquis, M. Alison; Martinez, Fernando D.; Moy, James N.; O’Neal, Wanda K.; Ortega, Victor E.; Peden, David B.; Phipatanakul, Wanda; Ross, Kristie; Smith, Lewis J.; Szefler, Stanley J.; Teague, W. Gerald; Tulchinsky, Abigail F.; Vijayanand, Pandurangan; Wechsler, Michael E.; Wenzel, Sally E.; White, Steven R.; Zeki, Amir A.; Ivanova, Anastasia; Pediatrics, School of Medicine
    Severe asthma accounts for almost half the cost associated with asthma. Severe asthma is driven by heterogeneous molecular mechanisms. Conventional clinical trial design often lacks the power and efficiency to target subgroups with specific pathobiological mechanisms. Furthermore, the validation and approval of new asthma therapies is a lengthy process. A large proportion of that time is taken by clinical trials to validate asthma interventions. The National Institutes of Health Precision Medicine in Severe and/or Exacerbation Prone Asthma (PrecISE) program was established with the goal of designing and executing a trial that uses adaptive design techniques to rapidly evaluate novel interventions in biomarker-defined subgroups of severe asthma, while seeking to refine these biomarker subgroups, and to identify early markers of response to therapy. The novel trial design is an adaptive platform trial conducted under a single master protocol that incorporates precision medicine components. Furthermore, it includes innovative applications of futility analysis, cross-over design with use of shared placebo groups, and early futility analysis to permit more rapid identification of effective interventions. The development and rationale behind the study design are described. The interventions chosen for the initial investigation and the criteria used to identify these interventions are enumerated. The biomarker-based adaptive design and analytic scheme are detailed as well as special considerations involved in the final trial design.
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    The Precision Interventions for Severe and/or Exacerbation-Prone (PrecISE) Asthma Network: an overview of Network organization, procedures and interventions
    (Elsevier, 2022-02) Georas, Steve N.; Wright, Rosalind J.; Ivanova, Anastasia; Israel, Elliot; LaVange, Lisa M.; Akuthota, Praveen; Carr, Tara F.; Denlinger, Loren C.; Fajt, Merritt L.; Kumar, Rajesh; O’Neal, Wanda K.; Phipatanakul, Wanda; Szefler, Stanley J.; Aronica, Mark A.; Bacharier, Leonard B.; Burbank, Allison J.; Castro, Mario; Alexander, Laura Crotty; Bamdad, Julie; Cardet, Juan Carlos; Comhair, Suzy A. A.; Covar, Ronina A.; DiMango, Emily A.; Erwin, Kim; Erzurum, Serpil C.; Fahy, John V.; Gaffin, Jonathan M.; Gaston, Benjamin; Gerald, Lynn B.; Hoffman, Eric A.; Holguin, Fernando; Jackson, Daniel J.; James, John; Jarjour, Nizar N.; Kenyon, Nicholas J.; Khatri, Sumita; Kirwan, John P.; Kraft, Monica; Krishnan, Jerry A.; Liu, Andrew H.; Liu, Mark C.; Marquis, M. Alison; Martinez, Fernando; Mey, Jacob; Moore, Wendy C.; Moy, James N.; Ortega, Victor E.; Peden, David B.; Pennington, Emily; Peters, Michael C.; Ross, Kristie; Sanchez, Maria; Smith, Lewis J.; Sorkness, Ronald L.; Wechsler, Michael E.; Wenzel, Sally E.; White, Steven R.; Zein, Joe; Zeki, Amir A.; Noel, Patricia; Pediatrics, School of Medicine
    Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here we describe the Precision Interventions for Severe and/or Exacerbation Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the U.S. The PrecISE Network was designed to conduct phase II/proof of concept clinical trials of precision interventions in the severe asthma population, and is supported by the National Heart Lung and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the Network will evaluate up to six interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for of severe asthma.