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181
result(s) for
"Lamb, John G."
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Pro-inflammatory effects of inhaled Great Salt Lake dust particles
by
Lamb, John G.
,
Venosa, Alessandro
,
Reilly, Christopher A.
in
Air Pollutants - toxicity
,
Air pollution
,
Animals
2025
Background
Climate change and human activities have caused the drying of marine environments around the world. An example is the Great Salt Lake in Utah, USA which is at a near record low water level. Adverse health effects have been associated with exposure to windblown dust originating from dried lakebed sediments, but mechanistic studies evaluating the health effects of these dusts are limited.
Results
Monitoring data and images highlight the impact of local crustal and Great Salt Lake sediment dusts on the Salt Lake Valley/Wasatch front airshed. Great Salt Lake sediment and derived PM
< 3.1
(quasi-PM
2.5
or qPM
2.5
) contained metals/salts, natural and anthropogenic chemicals, and bacteria. Exposure of mice via inhalation and oropharyngeal aspiration caused neutrophilia, increased expression of mRNA for
Il6
,
Cxcl1
,
Cxcl2
, and
Muc5ac
in the lungs, and increased IL6 and CXCL1 in bronchoalveolar lavage. Inhaled GSLD qPM
2.5
caused a greater neutrophilic response than coal fly ash qPM
2.5
and was more cytotoxic to human airway epithelial cells (HBEC3-KT) in vitro. Pro-inflammatory biomarker mRNA induction was replicated in vitro using HBEC3-KT and differentiated monocyte-derived (macrophage-like) THP-1 cells. In HBEC3-KT cells,
IL6
and
IL8
(the human analogue of
Cxcl1
and
Cxcl2
) mRNA induction was attenuated by ethylene glycol-bis(β-aminoethyl ether)-N, N,N′,N’-tetraacetic acid (EGTA) and ruthenium red (RR) co-treatment, and by TRPV1 and TRPV3 antagonists, but less by the Toll-like Receptor-4 (TLR4) inhibitor TAK-242 and deferoxamine. Accordingly, GSLD qPM
2.5
activated human TRPV1 as well as other human TRP channels. Dust from the Salton Sea playa (SSD qPM
2.5
) also stimulated
IL6
and
IL8
mRNA expression and activated TRPV1 in vitro, but inhibition by TRPV1 and V3 antagonists was dose dependent. Alternatively, responses of THP-1 cells to the Great Salt Lake and Salton Sea dusts were partially mediated by TLR4 as opposed to TRPV1. Finally, “humanized”
Trpv1
N606D
mice exhibited greater neutrophilia than C57Bl/6 mice following GSLD qPM
2.5
inhalation.
Conclusions
Dust from the GSL playa and similar dried lakebeds may affect human respiratory health via activation of TRPV1, TRPV3, TLR4, and oxidative stress.
Journal Article
Mushroom Ganoderma lucidum Prevents Colitis-Associated Carcinogenesis in Mice
by
Lamb, John G.
,
Sandusky, George E.
,
Jiang, Jiahua
in
Aberration
,
Aminopyridines - toxicity
,
Animal tissues
2012
Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice.
Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue.
Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.
Journal Article
Impact of CYP3A5 Polymorphisms on Pediatric Asthma Outcomes
by
Lamb, John G.
,
Reilly, Christopher A.
,
Stone, Bryan L.
in
Adolescent
,
Adrenal Cortex Hormones - administration & dosage
,
Adrenal Cortex Hormones - pharmacokinetics
2024
Genetic variation among inhaled corticosteroid (ICS)-metabolizing enzymes may affect asthma control, but evidence is limited. This study tested the hypothesis that single-nucleotide polymorphisms (SNPs) in Cytochrome P450 3A5 (CYP3A5) would affect asthma outcomes. Patients aged 2–18 years with persistent asthma were recruited to use the electronic AsthmaTracker (e-AT), a self-monitoring tool that records weekly asthma control, medication use, and asthma outcomes. A subset of patients provided saliva samples for SNP analysis and participated in a pharmacokinetic study. Multivariable regression analysis adjusted for age, sex, race, and ethnicity was used to evaluate the impact of CYP3A5 SNPs on asthma outcomes, including asthma control (measured using the asthma symptom tracker, a modified version of the asthma control test or ACT), exacerbations, and hospital admissions. Plasma corticosteroid and cortisol concentrations post-ICS dosing were also assayed using liquid chromatography–tandem mass spectrometry. Of the 751 patients using the e-AT, 166 (22.1%) provided saliva samples and 16 completed the PK study. The e-AT cohort was 65.1% male, and 89.6% White, 6.0% Native Hawaiian, 1.2% Black, 1.2% Native American, 1.8% of unknown race, and 15.7% Hispanic/Latino; the median age was 8.35 (IQR: 5.51–11.3) years. CYP3A5*3/*3 frequency was 75.8% in White subjects, 50% in Native Hawaiians and 76.9% in Hispanic/Latino subjects. Compared with CYP3A5*3/*3, the CYP3A5*1/*x genotype was associated with reduced weekly asthma control (OR: 0.98; 95% CI: 0.97–0.98; p < 0.001), increased exacerbations (OR: 6.43; 95% CI: 4.56–9.07; p < 0.001), and increased asthma hospitalizations (OR: 1.66; 95% CI: 1.43–1.93; p < 0.001); analysis of 3/*3, *1/*1 and *1/*3 separately showed an allelic copy effect. Finally, PK analysis post-ICS dosing suggested muted changes in cortisol concentrations for patients with the CYP3A5*3/*3 genotype, as opposed to an effect on ICS PK. Detection of CYP3A5*3/3, CYPA35*1/*3, and CYP3A5*1/*1 could impact inhaled steroid treatment strategies for asthma in the future.
Journal Article
“Pharm‐Ecology” of Diet Shifting: Biotransformation of Plant Secondary Compounds in Creosote (Larrea tridentata) by a Woodrat Herbivore,Neotoma lepida
by
Haley, Shannon L.
,
Constance, Jonathan E.
,
Franklin, Michael R.
in
Adaptation, Biological - physiology
,
Animal physiology
,
Animals
2008
Diet switching in mammalian herbivores may necessitate a change in the biotransformation enzymes used to process plant secondary compounds (PSCs). We investigated differences in the biotransformation system in the mammalian herbivore,Neotoma lepida, after a radical shift in diet and secondary compound composition. Populations ofN. lepidain the Mojave Desert have evolved over the past 10,000 years to feed on creosote (Larrea tridentata) from an ancestral state of consuming juniper (Juniperus osteosperma). This dietary shift represents a marked change in the dietary composition of PSCs in that creosote leaves are coated with phenolic resin, whereas juniper is high in terpenes but lacks phenolic resin. We quantified the enzyme activity of five major groups of biotransformation enzymes (cytochrome P450s, NAD(P)H:quinone oxidoreductase, glutathione conjugation, sulfation, and glucuronidation) recognized for their importance to mammalian biotransformation for the elimination of foreign compounds. Enzyme activities were compared between populations of Mojave and Great Basin woodrats fed control and creosote diets. In response to creosote, the Mojave population had greater levels of cytochrome P450s (CYP2B, CYP1A) and glutathione conjugation liver enzymes compared with the Great Basin population. Our results suggest that elevated levels of cytochrome P450s and glutathione conjugation enzymes in the Mojave population may be the underlying biotransformation mechanisms that facilitate feeding on creosote.
Journal Article
Xenobiotic Metabolism of Plant Secondary Compounds in Oak (Quercus Agrifolia) by Specialist and Generalist Woodrat Herbivores, Genus Neotoma
by
Franklin, Michael R
,
Dearing, M. Denise
,
Haley, Shannon L
in
anatomy & histology
,
Animal and plant ecology
,
Animal, plant and microbial ecology
2007
The challenge of consuming plant compounds that are recognized to have toxic physiological effects is an unavoidable consequence of an herbivorous diet and requires mechanisms to metabolize and eliminate them after consumption. We took a pharmacological approach to understanding how an oak (Quercus agrifolia) specialist (Neotoma macrotis) and generalist (N. lepida) herbivores process the same dietary toxins. Oak contains polyphenolic compounds considered toxic to most other mammals. N. macrotis includes up to 85% of oak in their diet. N. lepida includes oak as a portion of the diet but is considered a generalist in areas where sympatric with N. macrotis. Xenobiotic metabolizing enzyme activities of N. macrotis and N. lepida were investigated after animals were fed a 70% oak diet and a toxin-free control diet. Biotransformation activities of five major enzymes [cytochrome P450s (CYP), NAD(P)H/quinone oxidoreductase (QOR), UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), and glutathione S-transferase (GST)] and three specific CYP isozymes (CYP1A, CYP2B, and CYP3A) were investigated. The results indicate that, with the exception of CYP2B induction, N. macrotis and N. lepida enzyme activities are not changed by an oak diet. The major differences in enzyme activities were constitutive. The specialist, N. macrotis, had higher constitutive activity of QOR, UGT, and GST. The generalist, N. lepida, had higher constitutive activity levels of CYP1A and SULT.
Journal Article
COMPARISON OF DETOXIFICATION ENZYME mRNAS IN WOODRATS (Neotomalepida) AND LABORATORY RATS
by
Lamb, John G.
,
Dearing, M. Denise
,
Sorensen, Jennifer S.
in
Adaptation, Physiological
,
Animal, plant and microbial ecology
,
Animals
2001
To understand how mammalian herbivores process plant secondary compounds, we examined differences in expression of biotransformation enzyme mRNAs among populations of wild woodrats (Neotoma lepida) and laboratory rats. We compared expression of mRNAs for 10 biotransforming enzymes in five families (CYP, mEH, QOR, GST, and UGT) by using Northern blot analysis. We found significant differences in eight of 10 mRNAs tested. We suggest that the differences in mRNA expression among populations of woodrats and laboratory rats may be due to differences in the secondary compound composition of their diets. Our results provide background for future studies of detoxification strategies in mammalian herbivores that combine pharmacological techniques with an ecological perspective.
Journal Article
Sites of Extra Hepatic Metabolism, Part I: The Airways and Lung
2019
Metabolic processes in the lung are often studied using whole-lung homogenates. These studies are plentiful in the scientific literature and have been reasonably helpful to evaluate the overall metabolic capacity of the lung. Xenobiotic metabolism in respiratory tissues can be examined by comparing the chemical classes that are metabolized or by focusing on the enzymes responsible for the biotransformations. Prostaglandin endoperoxide synthases or cyclooxygenases prostaglandin-endoperoxide synthases 1/Prostaglandin H synthase and prostaglandin-endoperoxide synthases 2/Prostaglandin H synthase are another important group of xenobiotic metabolizing enzymes present in the lung. The flavin-containing monooxygenases are another class of xenobiotic metabolizing enzymes. The chapter provides an overview of the metabolic enzymes that exist in respiratory tissues and to distinguish metabolism of drugs in this organ system from other anatomical regions that also participate to a greater or lesser extent in the metabolism of xenobiotics.
Book Chapter
Etrolizumab as induction therapy for ulcerative colitis: a randomised, controlled, phase 2 trial
by
Tang, Meina T
,
Sandborn, William J
,
Williams, Marna
in
Adult
,
Antibodies, Monoclonal - administration & dosage
,
Antibodies, Monoclonal - therapeutic use
2014
Etrolizumab is a humanised monoclonal antibody that selectively binds the β7 subunit of the heterodimeric integrins α4β7 and αEβ7. We aimed to assess etrolizumab in patients with moderately-to-severely active ulcerative colitis.
In this double-blind, placebo-controlled, randomised, phase 2 study, patients with moderately-to-severely active ulcerative colitis who had not responded to conventional therapy were recruited from 40 referral centres in 11 countries. Eligible patients (aged 18–75 years; Mayo Clinic Score [MCS] of 5 of higher [or ≥6 in USA]; and disease extending 25 cm or more from anal verge) were randomised (1:1:1) to one of two dose levels of subcutaneous etrolizumab (100 mg at weeks 0, 4, and 8, with placebo at week 2; or 420 mg loading dose [LD] at week 0 followed by 300 mg at weeks 2, 4, and 8), or matching placebo. The primary endpoint was clinical remission at week 10, defined as MCS of 2 or less (with no individual subscore of >1), analysed in the modified intention-to-treat population (mITT; all randomly assigned patients who had received at least one dose of study drug, had at least one post-baseline disease-activity assessment, and had a centrally read screening endoscopic subscore of ≥2). This study is registered with ClinicalTrials.gov, number NCT01336465.
Between Sept 2, 2011, and July 11, 2012, 124 patients were randomly assigned, of whom five had a endoscopic subscore of 0 or 1 and were excluded from the mITT population, leaving 39 patients in the etrolizumab 100 mg group, 39 in the etrolizumab 300 mg plus LD group, and 41 in the placebo group for the primary analyses. No patients in the placebo group had clinical remission at week 10, compared with eight (21% [95% CI 7–36]) patients in the etrolizumab 100 mg group (p=0·0040) and four (10% [0·2–24]) patients in the 300 mg plus LD group (p=0·048). Adverse events occurred in 25 (61%) of 41 patients in the etrolizumab 100 mg group (five [12%] of which were regarded as serious), 19 (48%) of 40 patients in the etrolizumab 300 mg plus LD group (two [5%] serious), and 31 (72%) of 43 patients in the placebo group (five [12%] serious).
Etrolizumab was more likely to lead to clinical remission at week 10 than was placebo. Therefore, blockade of both α4β7 and αEβ7 might provide a unique therapeutic approach for the treatment of ulcerative colitis, and phase 3 studies have been planned.
Genentech.
Journal Article
A genome-wide association study of serum proteins reveals shared loci with common diseases
2022
With the growing number of genetic association studies, the genotype-phenotype atlas has become increasingly more complex, yet the functional consequences of most disease associated alleles is not understood. The measurement of protein level variation in solid tissues and biofluids integrated with genetic variants offers a path to deeper functional insights. Here we present a large-scale proteogenomic study in 5,368 individuals, revealing 4,035 independent associations between genetic variants and 2,091 serum proteins, of which 36% are previously unreported. The majority of both
cis
- and
trans
-acting genetic signals are unique for a single protein, although our results also highlight numerous highly pleiotropic genetic effects on protein levels and demonstrate that a protein’s genetic association profile reflects certain characteristics of the protein, including its location in protein networks, tissue specificity and intolerance to loss of function mutations. Integrating protein measurements with deep phenotyping of the cohort, we observe substantial enrichment of phenotype associations for serum proteins regulated by established GWAS loci, and offer new insights into the interplay between genetics, serum protein levels and complex disease.
Circulating proteins have been linked to many conditions, and understanding their genetic control can lead to understanding of disease. Here, the authors associate common genetic variants with protein levels, finding overlap of genetic associations with circulating proteins and complex disease.
Journal Article