Endotoxin induction of nitric oxide synthase and cyclooxygenase-2 in equine alveolar macrophages.
Abstract: To determine the amount of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzymes induced in vitro in equine alveolar macrophages in response to lipopolysaccharide (LPS). Sample Population-Alveolar macrophages obtained from 12 horses. Methods: Alveolar macrophages were collected by bronchoalveolar lavage from 12 horses and incubated for 6 hours with LPS (0.001 to 10 microg/ml) or vehicle. Total RNA was extracted and purified. After first-strand cDNA synthesis, mRNA induction was measured, using a polymerase chain reaction (PCR) technique for COX-2, iNOS, and glyceraldehyde 3-phosphate dehydrogenase. In a second study, cells were incubated with LPS or vehicle for 24 hours. Culture medium was assayed for COX-2 and iNOS activity by determining prostaglandin E2 (PGE2) and total nitrite concentrations, respectively. Results: Lipopolysaccharide induces COX-2 and iNOS mRNA in equine alveolar macrophages. Sequencing revealed that PCR products for COX-2 and iNOS had a high degree of nucleotide homology with the human sequences (91% COX-2, 93% iNOS). Production of mRNA for COX-2 and iNOS was accompanied by induction of enzyme activity. Comparing PCR fragment production, expression of mRNA for iNOS appeared to be less than that for COX-2. Induction of COX-2, but not iNOS, was LPS-concentration dependent. Conclusion-Lipopolysaccharide induces COX-2 and iNOS in equine macrophages. Conclusions: The induction of iNOS and COX-2 by LPS in equine macrophages suggests these enzymes may be important in the pathophysiology of sepsis. Pharmacologic modulation of iNOS and COX-2 activity may represent a novel therapeutic target in the management of endotoxemia in horses.
Publication Date: 1999-04-22 PubMed ID: 10211684
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
This study explores the levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzymes produced in horse alveolar macrophages in reaction to lipopolysaccharide (LPS), which could have implications for the treatment of sepsis and endotoxemia in horses.
Research methods
- The study used alveolar macrophages, a kind of immune cell, taken from 12 horses via a procedure called bronchoalveolar lavage.
- These cells were then exposed to various concentrations of a substance called lipopolysaccharide (LPS) for 6 hours. LPS is a molecule that provokes strong immune responses in animals.
- Then, the researchers extracted total RNA from the cells, which was processed into cDNA. The development of mRNA, which carries the genetic information that instructs the formation of proteins, was measured through PCR (polymerase chain reaction) for COX-2, iNOS, and glyceraldehyde 3-phosphate dehydrogenase.
- In a second part of the study, the cells were exposed to LPS for 24 hours before assessing levels of COX-2 and iNOS activity by noting their impact on levels of prostaglandin E2 (PGE2) and total nitrite concentrations, respectively.
Findings
- The research indicated that the exposure to LPS induced the production of both COX-2 and iNOS mRNA in equine alveolar macrophages.
- These molecules were found to have a high degree of similarity with human mRNA sequences (91% for COX-2 and 93% for iNOS).
- Formation of COX-2 and iNOS mRNA was also followed by an increase in enzyme activity.
- However, the results showed less iNOS mRNA production compared to COX-2 mRNA. Furthermore, only the induction of COX-2 was found to be dependent on the concentration of LPS introduced to the cells.
Implications
- The study concludes that these findings suggest a significant role for iNOS and COX-2 in the pathophysiology of sepsis, implying these enzymes could be crucial in the body’s response to severe infection.
- Regulating the activity of iNOS and COX-2 could potentially provide a new therapeutic approach for managing endotoxemia (the presence of endotoxins in the blood) in horses.
Cite This Article
APA
Hammond RA, Hannon R, Frean SP, Armstrong SJ, Flower RJ, Bryant CE.
(1999).
Endotoxin induction of nitric oxide synthase and cyclooxygenase-2 in equine alveolar macrophages.
Am J Vet Res, 60(4), 426-431.
Publication
Researcher Affiliations
- Department of Biochemical Pharmacology, St Bartholomew's and the Royal London School of Medicine and Dentistry, United Kingdom.
MeSH Terms
- Animals
- Base Sequence
- Cyclooxygenase 2
- Dinoprostone / metabolism
- Female
- Horses / metabolism
- Humans
- Isoenzymes / biosynthesis
- Lipopolysaccharides / pharmacology
- Macrophages, Alveolar / drug effects
- Macrophages, Alveolar / enzymology
- Male
- Membrane Proteins
- Molecular Sequence Data
- Nitric Oxide Synthase / biosynthesis
- Nitric Oxide Synthase Type II
- Polymerase Chain Reaction / veterinary
- Prostaglandin-Endoperoxide Synthases / biosynthesis
- Radioimmunoassay / veterinary
- Sequence Alignment
- Tumor Necrosis Factor-alpha / biosynthesis
Citations
This article has been cited 9 times.- Estrada McDermott J, Pezzanite L, Goodrich L, Santangelo K, Chow L, Dow S, Wheat W. Role of Innate Immunity in Initiation and Progression of Osteoarthritis, with Emphasis on Horses. Animals (Basel) 2021 Nov 13;11(11).
- Son E, Yoon JM, An BJ, Lee YM, Cha J, Chi GY, Kim DS. Comparison among Activities and Isoflavonoids from Pueraria thunbergiana Aerial Parts and Root. Molecules 2019 Mar 5;24(5).
- Sun Z, Li G, Tong T, Chen J. Micheliolide suppresses LPS-induced neuroinflammatory responses. PLoS One 2017;12(10):e0186592.
- Tuan Anh HL, Kim DC, Ko W, Ha TM, Nhiem NX, Yen PH, Tai BH, Truong LH, Long VN, Gioi T, Hong Quang T, Minh CV, Oh H, Kim YC, Kiem PV. Anti-inflammatory coumarins from Paramignya trimera. Pharm Biol 2017 Dec;55(1):1195-1201.
- Kim M, Lee HJ, Randy A, Yun JH, Oh SR, Nho CW. Stellera chamaejasme and its constituents induce cutaneous wound healing and anti-inflammatory activities. Sci Rep 2017 Feb 21;7:42490.
- Bak MJ, Truong VL, Kang HS, Jun M, Jeong WS. Anti-inflammatory effect of procyanidins from wild grape (Vitis amurensis) seeds in LPS-induced RAW 264.7 cells. Oxid Med Cell Longev 2013;2013:409321.
- Karagianni AE, Kapetanovic R, McGorum BC, Hume DA, Pirie SR. The equine alveolar macrophage: functional and phenotypic comparisons with peritoneal macrophages. Vet Immunol Immunopathol 2013 Oct 1;155(4):219-28.
- Hsieh IN, Chang AS, Teng CM, Chen CC, Yang CR. Aciculatin inhibits lipopolysaccharide-mediated inducible nitric oxide synthase and cyclooxygenase-2 expression via suppressing NF-κB and JNK/p38 MAPK activation pathways. J Biomed Sci 2011 May 6;18(1):28.
- Gysemans C, Stoffels K, Giulietti A, Overbergh L, Waer M, Lannoo M, Feige U, Mathieu C. Prevention of primary non-function of islet xenografts in autoimmune diabetic NOD mice by anti-inflammatory agents. Diabetologia 2003 Aug;46(8):1115-23.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
