Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s easYmer HLA-A*03:01 MHC Tetramers Kit was utilized in a recent publication that explored T cells specific for α-myosin drive immunotherapy-related myocarditis. Check out the full text and abstract below.


Abstract

Immune-related adverse events, particularly severe toxicities such as myocarditis, are major challenges to the utility of immune checkpoint inhibitors (ICIs) in anticancer therapy1. The pathogenesis of ICI-associated myocarditis (ICI-MC) is poorly understood. Pdcd1–/–Ctla4+/– mice recapitulate clinicopathological features of ICI-MC, including myocardial T cell infiltration2. Here, using single-cell RNA and T cell receptor (TCR) sequencing of cardiac immune infiltrates from Pdcd1–/–Ctla4+/– mice, we identify clonal effector CD8+ T cells as the dominant cell population. Treatment with anti-CD8-depleting, but not anti-CD4-depleting, antibodies improved the survival of Pdcd1–/–Ctla4+/– mice. Adoptive transfer of immune cells from mice with myocarditis induced fatal myocarditis in recipients, which required CD8+ T cells. The cardiac-specific protein α-myosin, which is absent from the thymus3,4, was identified as the cognate antigen source for three major histocompatibility complex class I-restricted TCRs derived from mice with fulminant myocarditis. Peripheral blood T cells from three patients with ICI-MC were expanded by α-myosin peptides. Moreover, these α-myosin-expanded T cells shared TCR clonotypes with diseased heart and skeletal muscle, which indicates that α-myosin may be a clinically important autoantigen in ICI-MC. These studies underscore the crucial role for cytotoxic CD8+ T cells, identify a candidate autoantigen in ICI-MC and yield new insights into the pathogenesis of ICI toxicity.

Axelrod, M.L., Meijers, W.C., Screever, E.M. et al. T cells specific for α-myosin drive immunotherapy-related myocarditis. Nature 611, 818–826 (2022).


If you have any questions about the easYmer HLA-A*03:01 MHC Tetramers Kit or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Serotonin ELISA Assay was utilized in a recent publication that explored how gut enterochromaffin cells drive visceral pain and anxiety. Check out the full text and abstract below.


Abstract

Gastrointestinal (GI) discomfort is a hallmark of most gut disorders and represents an important component of chronic visceral pain. For the growing population afflicted by irritable bowel syndrome, GI hypersensitivity and pain persist long after tissue injury has resolved2. Irritable bowel syndrome also exhibits a strong sex bias, afflicting women three times more than men. Here, we focus on enterochromaffin (EC) cells, which are rare excitable, serotonergic neuroendocrine cells in the gut epithelium. EC cells detect and transduce noxious stimuli to nearby mucosal nerve endings but involvement of this signaling pathway in visceral pain and attendant sex differences has not been assessed. By enhancing or suppressing EC cell function in vivo, we show that these cells are sufficient to elicit hypersensitivity to gut distension and necessary for the sensitizing actions of isovalerate, a bacterial short-chain fatty acid associated with GI inflammation. Remarkably, prolonged EC cell activation produced persistent visceral hypersensitivity, even in the absence of an instigating inflammatory episode. Furthermore, perturbing EC cell activity promoted anxiety-like behaviors which normalized after blockade of serotonergic signaling. Sex differences were noted across a range of paradigms, indicating that the EC cell–mucosal afferent circuit is tonically engaged in females. Our findings validate a critical role for EC cell–mucosal afferent signaling in acute and persistent GI pain, in addition to highlighting genetic models for studying visceral hypersensitivity and the sex bias of gut pain.

Bayrer, James R., et al. “Gut Enterochromaffin Cells Drive Visceral Pain and Anxiety.” Nature, vol. 616, no. 7955, 2023, pp. 137–142., https://doi.org/10.1038/s41586-023-05829-8.


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Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Pepsinogen I ELISA Kit was highlighted in a recent publication that focused on the discrimination between precancerous gastric lesions and gastritis. Check out the full text and abstract below.


Abstract

Background: Seropositivity to certain Helicobacter pylori proteins may affect development of gastric lesions that could become cancerous. Previously, we developed a model of gastric cancer risk including gender, age, HP0305 sero- positivity, HP1564 sero-positivity, UreA antibody titer and serologically defined chronic atrophic gastritis (termed: “Lasso model”).

Methods: We evaluated the Lasso model’s ability to discriminate individuals with precancerous gastric lesions (n=320) from individuals with superficial or mild atrophic gastritis (n=226) in Linqu County, China, apopulation at high risk for gastric cancer. We also compared its performance to the ABC Method, a gastric cancer risk stratification tool currently used in East Asia.

Results: For distinguishing precancerous lesions from those with gastritis, the receiver operating characteristic curve had an area under the curve (AUC) of 73.41% (95% CI: 69.10%, 77.71%) and, at Youden’s Index, a sensitivity of 78.44% (59.38%, 82.50%) and specificity of 64.72% (95% CI: 58.85%, 81.42%). Positive predictive value (PPV) was 75.38% (72.78%, 82.51%). Specificity, AUC and PPV were significantly greater (p < 0.05) than those of the ABC Method. When specificity was held constant, the Lasso model had greater sensitivity, PPV and negative predictive value (NPV) than the ABC Method. However, adjusting the ABC Method for age and gender negated the Lasso model’s significant improvement in AUC.

Conclusions: The Lasso model for gastric cancer risk prediction can classify precancerous lesions with significantly greater AUC than the ABC Method and, at constant specificity, with greater sensitivity, PPV and NPV. However, adding age and gender to the ABC Method, as included in the Lasso model, substantially improved its performance and negated the Lasso model’s advantage.

Murphy, John, et al. “Discrimination between Precancerous Gastric Lesions and Gastritis Using a Gastric Cancer Risk Stratification Model.” Asian Pacific Journal of Cancer Prevention, vol. 24, no. 3, 2023, pp. 935–943., https://doi.org/10.31557/apjcp.2023.24.3.935.


If you have any questions about our Pepsinogen I ELISA Kit or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Calprotectin ELISA Assay was utilized in a recent publication that focused on the gut microbiota of people with asthma. Check out the full text and abstract below.


Abstract

The gut microbiota in early childhood is linked to asthma risk, but may continue to affect older patients with asthma. Here, we profile the gut microbiota of 38 children (19 asthma, median age 8) and 57 adults (17 asthma, median age 28) by 16S rRNA sequencing and find individuals with asthma harbored compositional differences from healthy controls in both adults and children. We develop a model to aid the design of mechanistic experiments in gnotobiotic mice and show enterotoxigenic Bacteroides fragilis (ETBF) is more prevalent in the gut microbiota of patients with asthma compared to healthy controls. In mice, ETBF, modulated by community context, can increase oxidative stress in the lungs during allergic airway inflammation (AAI). Our results provide evidence that ETBF affects the phenotype of airway inflammation in a subset of patients with asthma which suggests that therapies targeting the gut microbiota may be helpful tools for asthma control.

Wilson, Naomi G., et al. “The Gut Microbiota of People with Asthma Influences Lung Inflammation in Gnotobiotic Mice.” IScience, vol. 26, no. 2, 2023, p. 105991.


If you have any questions about our Calprotectin ELISA Assay or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Noradrenaline (Norepinephrine) Sensitive ELISA was utilized in a recent publication that focused on epinephrine versus vasopressin in an ovine model of perinatal cardiac arrest. Check out the full text and abstract below.


Abstract

Background: Current neonatal resuscitation guidelines recommend the use of epinephrine for bradycardia/arrest not responding to ventilation and chest compressions. Vasopressin is a systemic vasoconstrictor and is more effective than epinephrine in postnatal piglets with cardiac arrest. There are no studies comparing vasopressin with epinephrine in newly born animal models with cardiac arrest induced by umbilical cord occlusion.

Objective: To compare the effect of epinephrine and vasopressin on the incidence and time to return of spontaneous circulation (ROSC), hemodynamics, plasma drug levels, and vasoreactivity in perinatal cardiac arrest.

Design/Methods: Twenty-seven term fetal lambs in cardiac arrest induced by cord occlusion were instrumented and resuscitated following randomization to epinephrine or vasopressin through a low umbilical venous catheter.

Results: Eight lambs achieved ROSC prior to medication. Epinephrine achieved ROSC in 7/10 lambs by 8 ± 2 min. Vasopressin achieved ROSC in 3/9 lambs by 13 ± 6 min. Plasma vasopressin levels in nonresponders were much lower than responders after the first dose. Vasopressin caused in vivo increased pulmonary blood flow and in vitro coronary vasoconstriction.

Conclusions: Vasopressin resulted in lower incidence and longer time to ROSC compared to epinephrine in a perinatal model of cardiac arrest supporting the current recommendations for exclusive use of epinephrine in neonatal resuscitation.

Rawat, Munmun, et al. “Masked Randomized Trial of Epinephrine versus Vasopressin in an Ovine Model of Perinatal Cardiac Arrest.” Children, vol. 10, no. 2, 2023, p. 349.


If you have any questions about the Noradrenaline (Norepinephrine) Sensitive ELISA or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Dopamine ELISA Assay was utilized in a recent publication that focused on the diverging Parkinson’s Disease Pathology. Check out the full text and abstract below.


Abstract

Multiple neurodegenerative disorders, including Parkinson’s disease (PD) and Alzheimer’s disease-associated dementia (ADAD), are linked with dopaminergic (DA) neuron death and a resulting reduction in dopamine levels in the brain. DA neuron degeneration and the risk of developing PD is connected to genetic mutations affiliated with lysosomal function and protein degradation. Accessible human cellular models for PD-relevant genetic mutations are needed to investigate mechanisms of DA cell death and define points of therapeutic intervention. Human induced pluripotent stem cell (iPSC)-derived midbrain DA neurons offer a developmentally and physiologically relevant in vitro model for investigating PD pathogenic mechanisms across genetic backgrounds. In this study, we generated DA neurons using iPSCs from two clinically diagnosed PD patients, one harboring an inherited GBAN370Smutation and the other a mutation in LRRK2G2019S and compared pathophysiology against DA neurons from genetically engineered SNCAA53T iPSCs and its isogenic apparently healthy normal (AHN) iPSCs. Our results present a novel phenotype for GBAN370S and LRRK2G2019Sderived DA neurons, showing that they produced and released significantly more dopamine compared to the AHN and SNCAA53T mutant DA neurons. All mutant DA neurons developed deficient glucocerebrosidase (GCase) activity, increased mitochondrial stress, aberrant neuronal activity patterns, and increased α-synuclein accumulation. Together these data suggest potentially divergent origins of PD pathogenesis in GBAN370S and LRRK2G2019S DA neurons. In addition, compound screening confirmed that GCase modulators can rescue enzyme activity and impact neural activity across all DA mutant neurons, to varying degrees. These data demonstrate unique in vitro phenotypes associated with PD and suggest a diversity of underlying mechanisms across different genetic backgrounds. Together, the cell lines used in this study present a valuable tool for new therapeutic discovery.

Fathi, Ali, et al. Diverging Parkinson’s Disease Pathology between Patient-DerivedGBAn370s, LRRK2g2019sand EngineeredSNCAa53tIpsc-Derived Dopaminergic Neurons, 2023, https://doi.org/10.1101/2023.01.06.521264.


If you have any questions about the Dopamine ELISA Assay or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Proteinase 3 ELISA was highlighted in a recent publication that explored how the PRTN3 variant correlates with increased autoantigen levels. Check out the full text and abstract below.


Abstract

A genome-wide association   study (GWAS) of patients with anti-neutrophil cytoplasmic antibodies (ANCAs) found an association between proteinase-3 ANCA (PR3-ANCA) and a single nucleotide polymorphism (rs62132293) upstream of PRTN3, encoding PR3. The variant (G allele) was shown to be an expression quantitative trait locus in healthy controls, but the clinical impact remains unknown. Longitudinally followed patients with ANCA and healthy controls were genotyped. Gene expression was quantified by real-time quantitative PCR from leukocyte RNA. Plasma PR3 was quantified by ELISA. Among patients, variant carriers had elevated leukocyte PRTN3 expression compared with noncarriers (C/G vs. C/C and G/G vs. C/C). Healthy controls had low PRTN3 regardless of genotype. Myeloperoxidase (MPO) expression did not differ by genotype. PRTN3 expression correlated with circulating PR3, and variant carriers had higher plasma PR3 compared with noncarriers. Among variant carriers, there was an increased risk of relapse in patients with PR3-ANCA versus MPO-ANCA. The risk allele marked by rs62132293 is clinically significant as it is associated with increased autoantigen and may, in part, explain increased relapse in PR3-ANCA. Our results underscore the role of autoantigen availability in ANCA vasculitis.

Chen, Dhruti P., et al. “PRTN3 Variant Correlates with Increased Autoantigen Levels and Relapse Risk in PR3-Anca versus MPO-Anca Disease.” JCI Insight, vol. 8, no. 4, 2023, https://doi.org/10.1172/jci.insight.166107.


If you have any questions about the Proteinase 3 ELISA or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Noradrenaline (Norepinephrine) Sensitive ELISA was utilized in two recent publications! On study explored how norepinephrine transporter defects lead to sympathetic hyperactivity in familial dysautonomia models and the other focused on the effects of a caffeine containing pre-workout supplement on β2-adrenergic and MAPK signaling during resistance exercise. Check out the full text and abstracts below.


Norepinephrine transporter defects lead to sympathetic hyperactivity in Familial Dysautonomia models

Abstract

Familial dysautonomia (FD), a rare neurodevelopmental and neurodegenerative disorder affects the sympathetic and sensory nervous system. Although almost all patients harbor a mutation in ELP1, it remains unresolved exactly how function of sympathetic neurons (symNs) is affected; knowledge critical for understanding debilitating disease hallmarks, including cardiovascular instability or dysautonomic crises, that result from dysregulated sympathetic activity. Here, we employ the human pluripotent stem cell (hPSC) system to understand symN disease mechanisms and test candidate drugs. FD symNs are intrinsically hyperactive in vitro, in cardiomyocyte co-cultures, and in animal models. We report reduced norepinephrine transporter expression, decreased intracellular norepinephrine (NE), decreased NE re-uptake, and excessive extracellular NE in FD symNs. SymN hyperactivity is not a direct ELP1 mutation result, but may connect to NET via RAB proteins. We found that candidate drugs lowered hyperactivity independent of ELP1 modulation. Our findings may have implications for other symN disorders and may allow future drug testing and discovery.

Wu, HF., Yu, W., Saito-Diaz, K. et al. Norepinephrine transporter defects lead to sympathetic hyperactivity in Familial Dysautonomia models. Nat Commun 13, 7032 (2022). https://doi.org/10.1038/s41467-022-34811-7


The effects of a caffeine containing pre-workout supplement on β2-adrenergic and MAPK signaling during resistance exercise

Abstract

Aim: The acute myocellular responses of caffeine supplementation during resistance exercise (RE) have not been investigated. β2-Adrenergic receptors (β2AR) may be a target of the stimulatory effects of caffeine and stimulate bioenergetic pathways including protein kinase A (PKA), and mitogen-activated protein kinases (MAPK).
Purpose: Elucidate the effects of pre-workout supplementation on signaling responses to an acute RE bout.
Methods: In a randomized, counter-balanced, double-blind, placebo-controlled, within-subject crossover study, ten resistance-trained males (mean ± SD; age = 22 ± 2.4 years, height = 175 ± 7 cm, body mass = 84.1 ± 11.8 kg) consumed a caffeine containing multi-ingredient pre-workout supplement (SUPP) or color and flavor matched placebo (PL) 60 min prior to an acute RE bout of barbell back squats. Pre- and post-exercise muscle biopsies were analyzed for the phosphorylation (p-) of β2AR, PKA, and MAPK (ERK, JNK, p38). Epinephrine was determined prior to supplementation (baseline; BL), after supplementation but prior to RE (PRE), and immediately after RE (POST).
Results: Epinephrine increased at PRE in SUPP (mean ± SE: 323 ± 34 vs 457 ± 68 pmol/l; p = 0.028), and was greatest at POST in the SUPP condition compared to PL (5140 ± 852 vs 2862 ± 498 pmol/l; p = 0.006). p-β2AR and p-MAPK increased post-exercise (p < 0.05) with no differences between conditions (p > 0.05). Pearson correlations indicated there was a relationship between epinephrine and p-β2AR in PL (r = − 0.810; p = 0.008), and p-β2AR and ERK in SUPP (r = 0.941; p < 0.001).
Conclusion: Consumption of a caffeine containing pre-workout supplement improves performance, possibly through increases in pre-exercise catecholamines. However, the acute myocellular signaling responses were largely similar post-exercise.

Nicoll, J.X., Fry, A.C. & Mosier, E.M. The effects of a caffeine containing pre-workout supplement on β2-adrenergic and MAPK signaling during resistance exercise. Eur J Appl Physiol 123, 585–599 (2023). https://doi.org/10.1007/s00421-022-05085-0


If you have any questions about our Noradrenaline (Norepinephrine) Sensitive ELISA or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s High Sensitive CRP ELISA was utilized in a recent publication exploring risk factors for cardiometabolic disease in professional firefighters. Check out the full text and abstract below.


Abstract

Objective: Firefighters are plagued with cardiometabolic disease (CMD). Obesity, poor cardiorespiratory and muscular fitness, and blood lipids (LDL-C, triglycerides, low HDL-C) are risk factors for CMD. However, markers of oxidative stress, inflammation and insulin resistance can provide further insight regarding CMD risk.

Methods: This study investigated the relationships between fitness metrics (cardiorespiratory and muscular fitness, percent body fat, waist circumference), blood lipids, blood pressure, and years of experience as a firefighter to blood markers of insulin resistance: (homeostatic model assessment for insulin resistance, HOMA-IR), oxidative stress: advanced oxidation protein products (AOPP) and inflammation: C-reactive protein (CRP).

Results: Waist circumference and blood concentrations of triglycerides were significantly related to AOPP and HOMA-IR. Cardiorespiratory fitness was inversely related to AOPP, HOMA-IR and CRP.

Conclusion: These findings demonstrate the importance of high cardiorespiratory fitness and low waist circumference to reduce markers of CMD.

McAllister, Matthew J., et al. “Risk Factors for Cardiometabolic Disease in Professional Firefighters.” Journal of Occupational & Environmental Medicine, Publish Ahead of Print, 2022, https://doi.org/10.1097/jom.0000000000002743.


If you have any questions about the High Sensitive CRP ELISA or our other offerings, please contact us here.

Dopamine Sensitive ELISA Assay Utilized in Recent Publication

The Eagle Bioscience’s Ultra-Sensitive Streptavidin Coated Clear 96 Well Microplate was utilized in a recent publication that explored non-viral precision T cell receptor replacement for personalized cell therapy. Check out the full text and abstract below.


Abstract

T cell receptors (TCRs) enable T cells to specifically recognize mutations in cancer cells. Here we developed a clinical-grade approach based on CRISPR–Cas9 non-viral precision genome-editing to simultaneously knockout the two endogenous TCR genes TRAC (which encodes TCRα) and TRBC (which encodes TCRβ). We also inserted into the TRAC locus two chains of a neoantigen-specific TCR (neoTCR) isolated from circulating T cells of patients. The neoTCRs were isolated using a personalized library of soluble predicted neoantigen–HLA capture reagents. Sixteen patients with different refractory solid cancers received up to three distinct neoTCR transgenic cell products. Each product expressed a patient-specific neoTCR and was administered in a cell-dose-escalation, first-in-human phase I clinical trial (NCT03970382). One patient had grade 1 cytokine release syndrome and one patient had grade 3 encephalitis. All participants had the expected side effects from the lymphodepleting chemotherapy. Five patients had stable disease and the other eleven had disease progression as the best response on the therapy. neoTCR transgenic T cells were detected in tumor biopsy samples after infusion at frequencies higher than the native TCRs before infusion. This study demonstrates the feasibility of isolating and cloning multiple TCRs that recognize mutational neoantigens. Moreover, simultaneous knockout of the endogenous TCR and knock-in of neoTCRs using single-step, non-viral precision genome-editing are achieved. The manufacture of neoTCR engineered T cells at clinical grade, the safety of infusing up to three gene-edited neoTCR T cell products and the ability of the transgenic T cells to traffic to the tumors of patients are also demonstrated

Foy, Susan P., et al. “Non-Viral Precision T Cell Receptor Replacement for Personalized Cell Therapy.” Nature, 2022, https://doi.org/10.1038/s41586-022-05531-1.


If you have any questions about the Ultra-Sensitive Streptavidin Coated Clear 96 Well Microplate or our other offerings, please contact us here.