Биолюминесценция Визуализация активности NADPH оксидазы на различных животных моделях
Summary
NADPH оксидазы является основным источником активных форм кислорода (АФК) в фагоцитов. Из-за эфемерность ROS, это трудно для измерения и мониторинга уровня АФК в живых животных. Минимально инвазивных методов для последовательного количественного АФК в живых мышей описано.
Abstract
NADPH oxidase is a critical enzyme that mediates antibacterial and antifungal host defense. In addition to its role in antimicrobial host defense, NADPH oxidase has critical signaling functions that modulate the inflammatory response 1. Thus, the development of a method to measure in “real-time” the kinetics of NADPH oxidase-derived ROS generation is expected to be a valuable research tool to understand mechanisms relevant to host defense, inflammation, and injury.
Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase characterized by severe infections and excessive inflammation. Activation of the phagocyte NADPH oxidase requires translocation of its cytosolic subunits (p47phox, p67phox, and p40phox) and Rac to a membrane-bound flavocytochrome (composed of a gp91phox and p22phox heterodimer). Loss of function mutations in any of these NADPH oxidase components result in CGD. Similar to patients with CGD, gp91phox -deficient mice and p47phox-deficient mice have defective phagocyte NADPH oxidase activity and impaired host defense 2, 13. In addition to phagocytes, which contain the NADPH oxidase components described above, a variety of other cell types express different isoforms of NADPH oxidase.
Here, we describe a method to quantify ROS production in living mice and to delineate the contribution of NADPH oxidase to ROS generation in models of inflammation and injury. This method is based on ROS reacting with L-012 (an analogue of luminol) to emit luminescence that is recorded by a charge-coupled device (CCD). In the original description of the L-012 probe, L-012-dependent chemiluminescence was completely abolished by superoxide dismutase, indicating that the main ROS detected in this reaction was superoxide anion 14. Subsequent studies have shown that L-012 can detect other free radicals, including reactive nitrogen species 15, 16. Kielland et al. 16 showed that topical application of phorbol myristate acetate, a potent activator of NADPH oxidase, led to NADPH oxidase-dependent ROS generation that could be detected in mice using the luminescent probe L-012. In this model, they showed that L-012-dependent luminescence was abolished in p47phox-deficient mice.
We compared ROS generation in wildtype mice and NADPH oxidase-deficient p47phox-/- mice 2 in the following three models: 1) intratracheal administration of zymosan, a pro-inflammatory fungal cell wall-derived product that can activate NADPH oxidase; 2) cecal ligation and puncture (CLP), a model of intra-abdominal sepsis with secondary acute lung inflammation and injury; and 3) oral carbon tetrachloride (CCl4), a model of ROS-dependent hepatic injury. These models were specifically selected to evaluate NADPH oxidase-dependent ROS generation in the context of non-infectious inflammation, polymicrobial sepsis, and toxin-induced organ injury, respectively. Comparing bioluminescence in wildtype mice to p47phox-/- mice enables us to delineate the specific contribution of ROS generated by p47phox-containing NADPH oxidase to the bioluminescent signal in these models.
Bioluminescence imaging results that demonstrated increased ROS levels in wildtype mice compared to p47phox-/- mice indicated that NADPH oxidase is the major source of ROS generation in response to inflammatory stimuli. This method provides a minimally invasive approach for “real-time” monitoring of ROS generation during inflammation in vivo.
Protocol
Discussion
"Реального времени" измерения активных форм кислорода (АФК) в живых животных может быть достигнуто с помощью флуоресцентных зондов и хемилюминесцентных. В то время как флуоресцентные зонды страдают от того, слабая сигнал-шум 12, изображениями методике, описанной более чувств…
Divulgations
The authors have nothing to disclose.
Acknowledgements
Эта работа финансировалась NIH RO1 AI079253 и Департамент по делам ветеранов.
Materials
| Name of the reagent | Company | Catalog number | Comments |
| L-012 | Wako Chemicals USA, Inc. | 120-04891 | |
| Zymosan | Sigma, St. Louis, MO | Z4250 | |
| carbon tetrachloride | Sigma, St. Louis, MO | 289116 |
References
- Segal, B., Han, W., Bushey, J. NADPH oxidase limits innate immune response in the lungs in mice. PLoS ONE. 5, e9631 (2010).
- Jackson, S., Gallin, J., Holland, S. M. The p47phox mouse knock-out model of chronic granulomatous disease. J. Exp. Med. 182, 751-758 (1995).
- Gantner, B. N., Simmons, R. M., Underhill, D. M. Collaborative induction of inflammatory responses by dectin-1 and Toll-like receptor 2. J. Exp. Med. 197, 1107-1117 (2003).
- Dejager, L., Pinheiro, I., Libert, C. Cecal ligation and puncture: the gold standard model for polymicrobial sepsis. Trends Microbiol. 19, 198-208 (2011).
- Tsiotou, A. G., Sakorafas, G. H., Bramis, J. Septic shock; current pathogenetic concepts from a clinical perspective. Med. Sci. Monit. 11, 76-85 (2005).
- Fujii, T., Fuchs, B. C., Tanabe, K. K. Mouse model of carbon tetrachloride induced liver fibrosis: Histopathological changes and expression of CD133 and epidermal growth factor. BMC Gastroenterology. 10, 79-90 (2010).
- Kubo, H., Morgensterm, D., Doerschuk, C. M. Preservation of complement-induced lung injury in mice with deficiency of NADPH oxidase. J. Clin. Invest. 97, 2680-2684 (1996).
- Segal, B., Sakamoto, N., Bulkley, G. B. Xanthine oxidase contributes to host defense against Burkholderia cepacia in the p47(phox-/-) mouse model of chronic granulomatous disease. Infect Immun. 68, 2374-2378 (2000).
- Droge, W. Free radicals in the physiological control of cell function. Physiological reviews. 82, 47-95 (2002).
- Jones, D. Radical-free biology of oxidative stress. American journal of physiology. Cell physiology. 295, C849-C868 (2008).
- Hubbard, W. J., Choudhry, M., Chaudry, I. H. Cecal ligation and puncture. Shock. 24, 52-57 .
- Wardman, P. Fluorescent and luminescent probes for measurement of oxidative and nitrosative species in cells and tissues: progress, pitfalls, and prospects. Free Radic. Biol. Med. 43, 995-1022 (2007).
- Pollock, J. D., Williams, D. A., Gifford, M. A. Mouse model of X-linked chronic granulomatous disease, an inherited defect in phagocyte superoxide production. Nat. Genet. 9, 202-209 (1995).
- Aramaki, Y., Y, ., Yoshida, H. A new sensitive chemiluminescence probe, L-012, for measuring the production of superoxide anion by cells. Biochem. Biophys. Res. Commun. 193, 554-559 (1993).
- Daiber, A., Oelze, M., August, M. Detection of superoxide and peroxynitrite in model systems and mitochondria by the luminol analogue L-012. Free Radic. Res. 38, 259-269 (2004).
- Kielland, A., Blom, T., Nandakumar, K. S. In vivo imaging of reactive oxygen and nitrogen species in inflammation using the luminescent probe L-012. Free Radic. Biol. Med. 47, 760-766 (2009).
