Author: Eagle Biosciences

Categories

RANKL and RANK Biomarker Spotlight

by Eagle Biosciences

RANKL and RANK Biomarker Spotlight

Receptor activator of nuclear factor kappa B ligand, RANKL, and its specific receptor RANK, are members of the tumor necrosis factor (TNF) family and are the main stimulatory factor for the formation of mature osteoclasts and are essential for their survival. The major source of RANKL are osteocytes, former osteoblasts that become embedded within the mineralized bone matrix. RANKL and its specific receptor RANK are not only key regulators of bone remodeling but also play an essential role in immunobiology, e.g. lymph node formation, establishment of the thymic microenvironment, mammary gland development during pregnancy, bone metastasis in cancer and sex-hormone, progestin-driven breast cancer, thermoregulation, and finally in the development of type 2 diabetes mellitus.

A recent study has uncovered a new role for RANKL and RANK in bone remodeling. Researchers have found that extracellular vesicles containing RANKL and RANK may have an important role in the long range signaling for bone remodeling. These signaling molecules have the potential to be targeted for therapeutics and also used diagnostically.

Click here to learn more.

Holliday LS, Patel SS, Rody WJ. RANKL and RANK in Extracellular Vesicles: Surprising New Players in Bone Remodeling. Extracell Vesicles Circ Nucleic Acids. 2021; 2:18-28.

Related Products
Free Soluble RANKL ELISA Assay Kit
iLite® RANKL Assay Ready Cells
Osteoprotegerin ELISA Assay Kit
Sclerostin ELISA Assay Kit

Categories

COVID-19 ELISA Highlighted in Recent Study

by Eagle Biosciences

COVID-19 ELISA

Eagle Biosciences’ COVID-19 IgM and IgG ELISA Assay Kits were recently highlighted in a study. This study evaluated the different tools that have become available for COVID testing and research.

Abstract

Recent severe acute respiratory syndrome 2 (SARS-CoV-2) known as COVID-19, presents a deadly challenge to the global healthcare system of developing and developed countries, exposing the limitations of health facilities preparedness for emerging infectious disease pandemic. Opportune detection, confinement, and early treatment of infected cases present the first step in combating COVID-19. In this review, we elaborate on various COVID-19 diagnostic tools that are available or under investigation. Consequently, cell culture, followed by an indirect fluorescent antibody, is one of the most accurate methods for detecting SARS-CoV-2 infection. However, restrictions imposed by the regulatory authorities prevented its general use and implementation. Diagnosis via radiologic imaging and reverse transcriptase PCR assay is frequently employed, considered as standard procedures, whereas isothermal amplification methods are currently on the verge of clinical introduction. Notably, techniques such as CRISPR-Cas and microfluidics have added new dimensions to the SARS-CoV-2 diagnosis. Furthermore, commonly used immunoassays such as enzyme-linked immunosorbent assay (ELISA), lateral flow immunoassay (LFIA), neutralization assay, and the chemiluminescent assay can also be used for early detection and surveillance of SARS-CoV-2 infection. Finally, advancement in the next generation sequencing (NGS) and metagenomic analysis are smoothing the viral detection further in this global challenge.

To read more click here.

Oishee MJ, Ali T, Jahan N, et al. COVID-19 Pandemic: Review of Contemporary and Forthcoming Detection Tools. Infect Drug Resist. 2021;14:1049-1082. Published 2021 Mar 17. doi:10.2147/IDR.S289629

Related Products
Coronavirus COVID-19 IgM ELISA Assay Kit
Coronavirus COVID-19 IgG ELISA Assay Kit
COVID-19 Nucleocapsid IgG Quantitative ELISA Assay Kit
COVID-19 S-Protein Specific IgG Quantitative ELISA Assay Kit
COVID-19 Neutralizing Antibody Quantitative ELISA Assay Kit

Categories

Osteoprotegerin Biomarker Spotlight

by Eagle Biosciences

Osteoprotegerin Biomarker Spotlight

Osteoprotegerin (ORG) is a secreted protein that affects bone turnover and is implicated in heart and kidney disease. It is a glycoprotein of the TNF receptor superfamily 11b (gene name TNFRSF11B). OPG is synthesized as a monomer of 380 amino acids and is assembled as a homodimer within the cell and then secreted mainly as a disulfide-linked homodimer into the extracellular compartment. OPG is produced by many different tissues and cell types including osteoblasts. OPG is a negative regulator of bone resorption by acting as decoy receptor for RANKL, thus neutralizing its function in osteoclastogenesis. This glycoprotein is also involved in the regulation of vascular calcification. A recent study identifies OPG as an independent risk factor for all-cause mortality in patients after kidney transplantation. 982 prevalent kidney transplant (KT) recipients were followed up for all-cause mortality for 6 years. The researchers observed that each 1 pmol/L higher-serum OPG level was associated with a 49% higher risk of mortality.

Association between serum osteoprotegerin level and mortality in kidney transplant recipients. Gupta V et al., 2021. Transpl Int 19. doi: 10.1111/tri.13847. Epub ahead of print. PMID: 33606319.

Osteoprotegerin Related Products

Osteoprotegerin ELISA Assay Kit
Sclerostin ELISA Assay Kit
Periostin ELISA Assay Kit

Categories

iLite Assay Ready Cells Technical Spotlight

by Eagle Biosciences

iLite Assay Ready Cells

iLite® Assay Ready Cells are developed by our partners at Svar Life Science. iLite technology is based upon a reporter gene assay format, modified and adapted for applications during the whole drug development cycle as well as for monitoring of biological drugs. These cell lines can be developed for any biopharmaceutical target and assays for drug potency, i.e. drug activity, and neutralizing antibodies (NAbs) can easily be set-up using the same cell line. The Assay Ready cells are genetically engineered to be used with a reporter gene assay technique for detection the the drug potency and the NAbs.

A Message from SVAR about iLite:

“Many therapeutic antibodies that are used to treat common disorders, such as cancer and autoimmune diseases work – at least in part – by activating ADCC.

Our reporter gene-based iLite® ADCC bioassays offer a convenient and powerful way of measuring the ability of an antibody to elicit ADCC.

Read our new white paper and learn about the performance of our ADCC bioassays and how they compare to a leading competitor in terms of sensitivity and dynamic range.”

Download the White Paper here.

Find all of the iLite products offered on the iLite Assay Ready Cells product page.

Categories

DHEA ELISA Used in a Recent Study

by Eagle Biosciences

DHEA ELISA Publication

Evidence for fasting induced extra-adrenal steroidogenesis in the male brown anole, Anolis sagrei

The Eagle Biosciences DHEA ELISA was used in a recent study testing if fasting could induce adrenal tissues to produce glucocorticoids (GCs) and dehydroepiandrosterone (DHEA) to coordinate different physiological processes.

Abstract

Glucocorticoids (GCs) and dehydroepiandrosterone (DHEA) are steroids secreted by the adrenal glands into circulation to effect distant target tissues and coordinate physiological processes. This classic systemic view of steroids has been challenged by evidence that other tissues can independently synthesize their own steroids. Little is known however regarding circumstances that can promote this extra-adrenal steroidogenesis. Here we tested if fasting can induce tissues to increase GC and DHEA synthesis in the brown anole lizard Anolis sagrei. Lizards fasted for eight days lost body mass and increased fatty acid oxidation. Fasting also increased plasma concentrations of DHEA and corticosterone, but not cortisol. Corticosterone concentration within the adrenals, heart, intestines, lungs and liver exceeded that in plasma, with the latter two increasing with fasting. Levels of DHEA in the adrenals and heart were higher than in plasma, but no significant effect of fasting was observed, expect for a noticeable increase in intestinal DHEA. Two steroidogenic genes, the steroidogenic acute regulatory (Star) protein and Cyp17a1, a cytochrome P450 enzyme, were expressed in several tissues including the liver, lungs and intestines, which were increased with fasting. Continued research should aim to test for expression of additional enzymes further along the steroidogenic pathway. Nonetheless these data document potential extra-adrenal steroidogenesis as a possible mechanism for coping with energy shortages, although much work remains to be done to determine the specific roles of locally synthesized steroids in each tissue.

To learn more and read the full publication, click here.

Related Products:

DHEA ELISA Assay Kit
DHEA-S ELISA Assay  Kit

Categories

Big Endothelin-1 Biomarker Spotlight

by Eagle Biosciences

Big Endothelin-1 Biomarker Spotlight

Big Endothelin-1 (Big ET-1) is a protein that is mainly produced by vascular endothelial and smooth muscle cells and cardiomyocytes. Big ET-1 is a precursor to Endothelin (ET), the most potent vasoconstrictor known today. The half life of ET is less than one minute, whereas Big ET-1 is cleared more slowly. Big ET-1 can therefore be determined more easily, and has since been identified as a risk factor for a poor prognosis in patients with atrial fibrillation or coronary artery disease. A current study has shown that plasma concentrations of Big ET-1 is a valuable tool for risk stratification in patients with left ventricular non-compaction cardiomyopathy (LVNC). Other studies have also recognized the effectiveness of Big ET-1 as a predictor for numerous cardiovascular diseases.

Prognostic value of plasma big endothelin-1 in left ventricular non-compaction cardiomyopathy. Fan P, et al. Heart 2020;0:1–6. doi:10.1136/heartjnl-2020-317059

Plasma big endothelin-1 is an effective predictor for ventricular arrythmias and end-stage events in primary prevention implantable cardioverter- defibrillator indication patients. Li XY et al., 2020. J Geriatr Cardiol 28;17(7):427-433.

Plasma big endothelin-1 predicts new-onset atrial fibrillation after surgical septal myectomy in patients with hypertrophic cardiomyopathy. Song C et al., 2019. BMC Cardiovasc Disord 22;19(1):122.

Plasma level of big endothelin-1 predicts the prognosis in patients with hypertrophic cardiomyopathy. Wang Y et al., 2017. Int J Cardiol 15;243:283-289.

Related Products:

Big Endothelin-1 ELISA Assay Kit.
NT-proANP ELISA Assay Kit
NT-proCNP ELISA Assay Kit
NT-proBNP ELISA
BNP Fragment ELISA Assay Kit

If you have any questions regarding our Big Endothelin-1 ELISA Assay Kit or any other kits in the Cardiovascular Assay line, contact us here.

Categories

EagleBio Highlights ELISpot Kits

by Eagle Biosciences

ELISpot Kits

Eagle Biosciences proudly offers a broad range of products in our extensive catalog. In addition to the well known ELISA format, we offer several assay kits in a enzyme-linked immunospot (ELISpot) assay format.

ELISA vs. ELISpot

ELISAs use antibodies to detect the presence and concentration of a protein in a liquid sample. In the most common form, antigens are applied to a stable surface (usually a microtiter plate). Then the corresponding antibody, linked with an enzyme, is added to form a complex. Finally, the enzyme’s substrate is added, which produces a measurable reaction, usually in the form of a color change.

ELISpots also utilize antibody-enzyme reactions. However, instead of measuring the concentration of protein in a sample, they measure the number of cells secreting the cytokine of interest in a sample. Antigens are applied to the plate surface, and when samples are added, cells settle on the bottom of the wells. The cytokines secreted by the cells are captured by the surrounding antigens. After the appropriate incubation time, the cells are removed and the secreted cytokine is detected using a detection antibody linked with an enzyme. The enzyme’s substrate is added, producing a reaction. The end result is visible spots on the on the surface of the plate. Each spot corresponds to an individual cell that was secreting the target protein.

The information provided by ELISpot kits is applicable to various fields of study including: transplantation, vaccine development, T-cell regulation analysis, autoimmune disease, cancer, allergy, and viral infections. These kits are highly sensitive and easy to use.

ELISpot Kit Procedure

Our available kits:

IFN gamma ELISpot Assay Kit

Mouse IFN gamma ELISpot Assay Kit

Rat IFN gamma ELISpot Assay Kit

TNF alpha ELISpot Assay Kit

Rat TNF alpha ELISpot Assay Kit

Contact us if you are looking for a specific ELISpot or if you have questions about any of our products.

Categories

Calprotectin ELISA Highlighted in a Recent Study

by Eagle Biosciences

Calprotectin ELISA

Does Human Milk Fortifier Affect Intestinal Inflammation in Preterm Infants?

Eagle Biosciences’ Calprotectin ELISA Assay Kit was used in a recent study dealing with inflammation of preterm infants in response to human milk fortifier. The Calprotectin ELISA Assay is part of our line of Gastrointestinal Assays which is a line of highly sensitive and specific kits used to detect the concentration of a variety of samples in serum, plasma, tissue, urine, and saliva.

Abstract

Background: Fecal calprotectin, a recognized marker of intestinal inflammation, is derived from neutrophil migration to a site of inflammation. Introduction of bovine-based human milk fortifier containing intact protein in preterm infants is associated with an increase in fecal calprotectin suggestive of intestinal inflammation. Newer fortifiers contain protein hydrolysates in place of intact protein.

Objective: To measure fecal calprotectin in human milk-fed preterm infants before and after human milk fortification using a fortifier containing hydrolyzed protein.

Methods: Serial stool samples were collected from 24 infants beginning at the first week to 60 days postnatal age. To compare the effect of human milk fortification, samples collected before and after fortification were compared. Infant demographics, diet, postnatal morbidities, and maternal characteristics were recorded.

Results: A total of 401 stool samples were collected from 24 study infants who had a birth weight of 993 ± 277 g (mean ± standard deviation), gestational age 27.5 ± 2.8 weeks, and fortifier initiation at 14 days. Median fecal calprotectin before and after fortification were similar. Calprotectin levels were not correlated with birth weight or gestational age but were inversely correlated with postnatal age (p = 0.005), use of fortifier (p < 0.001), receipt of antibiotics antenatally (p = 0.007) and postnatally (p = 0.008). After adjusting for postnatal age, calprotectin levels were significantly lower following receipt of fortifier (p < 0.001) and postnatal antibiotics (p < 0.001).

Conclusions: The feeding of protein hydrolysate-containing human milk fortifiers does not appear to be associated with increases in a marker of intestinal inflammation.

Click here for the full text.

Related Products

NGAL (Stool) ELISA Assay Kit
S100A8/A9 (MRP8/14, Calprotectin, Mouse/Rat) ELISA Kit
Stool Sample Collection Kit

Categories

SARS-CoV-2 ELISA Used in Recent Study

by Eagle Biosciences

COVID-19 IgG and IgA ELISA Feature in Recent Study Analyzing Antibody Response to SARS-CoV-2 Exposure and Symptom Onset

A study has been published in Viruses titled Persisting Neutralizing Activity to SARS-CoV-2 over Months in Sera of COVID-19 Patients by B, Flehming et al. This study takes a look at the long term presences of SARS-CoV-2 RNA and IgG and IgA antibodies in three patients diagnosed with COVID-19 over a six month period. This research utilized the COVID-19 Nucleocapsid IgG Quantitative ELISA Assay Kit and the Anti-SARS-CoV-2 IgA (S1 RBD) ELISA Assay offered by Eagle Biosciences. The results of this study indicate that immunity to the virus may persist for a couple of months after onset of symptoms. These findings are consistent with some other studies done with larger cohorts of COVID-19 patients, however similar longitudinal studies should be done in the future to corroborate these findings.

Abstract

The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.

Click here for the full text.

To view Eagle Biosciences’ extensive collection of SARS-CoV-2 Assays and other products click here. 

Categories

Angiopoietin-2 is Predictive for ICU Admission of COVID Patients

by Eagle Biosciences

Studies show that Angiopoietin-2 is a strong predictor in COVID-19 patients

Two research teams find that increased levels of the proinflammatory cytokine Angiopoietin-2 predicts transfer to the ICU and is responsible for hypercoagulation observed in critically ill COVID-patients.

Studies:

Angiopoietin-2 as a marker of endothelial activation is a good predictor factor for intensive care unit admission of COVID-19 patients. Smadja DM et al., Angiogenesis, 2020;1-10. Full text

Elevated Angiopoietin-2 inhibits thrombomodulin-mediated anticoagulation in critically ill COVID-19 patients. Hultstrom M et al., MedRxiv preprint server, 2021. Full text

Click here for a summary of the findings.

Background

SARS-CoV-2 is the causative agent of the coronavirus respiratory disease COVID-19. It has a diverse range of symptoms and may cause severe illness, in particular in patients with cardiovascular risk factors (1).

Endothelial damage and inflammation in SARS-CoV-2 infection

The inflammatory cytokine storm occurring in COVID-19 patients, leads to the recruitment of leukocytes which damage the capillary endothelium. The endothelial damage and inflammation in several organs in SARS-CoV-2 infection is a direct consequence of viral involvement and of the host inflammatory response (2).
Despite the routine thrombosis prophylaxis as standard of care treatment, the major COVID-19 complication is the hyperactivation of the coagulation system indicating a poor prognosis among COVID-19 patients in intensive care (3).

Angiopoietin-2 (ANG2) is a soluble marker of endothelial activation

Angiopoietin-2 is an angiogenesis regulator that can be rapidly released by the activated endothelium upon thrombin or inflammatory cytokines. ANG2 induces inflammation and vascular hyperpermeability and correlates with adverse outcomes in several critical care syndromes (4, 5).

Angiopoietin-2 is a crucial factor to predict transfer to the ICU

In COVID-19 patients, ANG2 was recently reported by Smadja and colleagues to be a relevant factor to predict transfer to the ICU as it was associated with poor lung compliance (6). Thus, showing that endothelial activation reinforces the hypothesis of a COVID-19-associated microvascular dysfunction.

Angiopoietin-2 inhibits anticoagulation in critically ill COVID-19 patients

Hulstrom and colleagues recently demonstrated that ANG2 levels in critically ill COVID-19 patients correlate with disease severity, hypercoagulation, and mortality. In addition, the researchers provided novel in vivo evidence for a direct role for ANG2 in coagulation through binding to and inhibition of thrombomodulin-mediated anticoagulation. The scientists suggest that inhibition of ANG2 might be beneficial for treating critically ill COVID-19 patients, as well as other patients with hypercoagulation (7).

About the Angiopoietin ELISA

  • Low sample volume – only 10µl needed
  • Assay range optimized for clinical samples
  • Ready to use standards and 2 controls included
  • Highly specific epitope mapped capture and detection antibodies

The human Angiopoietin-2 ELISA kit was developed and manufactured by Biomedica

Literature

  1. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Zhou F et al., Lancet, 2020; 395(10229):1054-1062.
  2. Endotheliitis in COVID-19. Varga S. Der Pathologe, 2020; 41(Suppl 2):99-102.
  3. COVID-19 and coagulation: bleeding and thrombotic manifestations of SARS-CoV-2 infection. Al-Samkari H et al., Blood, 2020:136, 489-500.
    Role of Angiopoietin-2 in Vascular Physiology and Pathophysiology. Akwii RG et al., Cells, 2019; 8(5): 471.
  4. Circulating angiopoietin-2 and the risk of mortality in patients with acute respiratory distress syndrome: a systematic review and meta-analysis of 10 prospective cohort studies. Li F et al., Therapeutic advances in respiratory disease, 2020; 14, 1753466620905274.
  5. Angiopoietin-2 as a marker of endothelial activation is a good predictor factor for intensive care unit admission of COVID-19 patients. Smadja DM et al., Angiogenesis, 2020;1-10.
  6. Elevated Angiopoietin-2 inhibits thrombomodulin-mediated anticoagulation in critically ill COVID-19 patients. Hultstrom M et al., MedRxiv preprint server, 2021.