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Consistent inhibition of cyclooxygenase drives macrophages towards the inflammatory phenotype.

Na YR, Yoon YN, Son D, Jung D, Gu GJ, Seok SH - PLoS ONE (2015)

Bottom Line: Thus alterations of macrophage function can have unexpected pathological results.Cyclooxygenase (COX) inhibitors are widely used to relieve pain, but the effects of long-term usage on macrophage function remain to be elucidated.YmI and IRF4 expression was reduced significantly, indicative of a more inflammatory phenotype.

View Article: PubMed Central - PubMed

Affiliation: Macrophage Lab, Department of Microbiology and Immunology, and Institute of Endemic Disease, Seoul National University College of Medicine, 103 Daehak-ro, Chongno-gu, Seoul 110-799, South Korea.

ABSTRACT
Macrophages play important roles in defense against infection, as well as in homeostasis maintenance. Thus alterations of macrophage function can have unexpected pathological results. Cyclooxygenase (COX) inhibitors are widely used to relieve pain, but the effects of long-term usage on macrophage function remain to be elucidated. Using bone marrow-derived macrophage culture and long-term COX inhibitor treatments in BALB/c mice and zebrafish, we showed that chronic COX inhibition drives macrophages into an inflammatory state. Macrophages differentiated in the presence of SC-560 (COX-1 inhibitor), NS-398 (COX-2 inhibitor) or indomethacin (COX-1/2 inhibitor) for 7 days produced more TNFα or IL-12p70 with enhanced p65/IκB phosphoylation. YmI and IRF4 expression was reduced significantly, indicative of a more inflammatory phenotype. We further observed that indomethacin or NS-398 delivery accelerated zebrafish death rates during LPS induced sepsis. When COX inhibitors were released over 30 days from an osmotic pump implant in mice, macrophages from peritoneal cavities and adipose tissue produced more TNFα in both the basal state and under LPS stimulation. Consequently, indomethacin-exposed mice showed accelerated systemic inflammation after LPS injection. Our findings suggest that macrophages exhibit a more inflammatory phenotype when COX activities are chronically inhibited.

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Survival curve of indomethacin-treated zebrafish larvae after LPS immersion.Panel A: A scheme of zebrafish sepsis model. Zebrafish larvae were maintained in Ringer’s solution containing 2.5 μM indomethacin or 0.01% DMSO from 3 to 8 days after fertilization (dpf). Solution and dead larvae were washed and fresh medium was added daily. After 5 days of indomethacin treatment, solution was changed and the larvae were immersed in 75 μg/ml LPS. Panel B: Survival curve of indomethacin treated zebrafish larvae in sepsis model. Data represents two independent experiments (n = 20). Statistical analysis was performed by Log-rank (Mantel-Cox) test between LPS Vs inhibitor+LPS groups. ***P<0.0001.
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pone.0118203.g004: Survival curve of indomethacin-treated zebrafish larvae after LPS immersion.Panel A: A scheme of zebrafish sepsis model. Zebrafish larvae were maintained in Ringer’s solution containing 2.5 μM indomethacin or 0.01% DMSO from 3 to 8 days after fertilization (dpf). Solution and dead larvae were washed and fresh medium was added daily. After 5 days of indomethacin treatment, solution was changed and the larvae were immersed in 75 μg/ml LPS. Panel B: Survival curve of indomethacin treated zebrafish larvae in sepsis model. Data represents two independent experiments (n = 20). Statistical analysis was performed by Log-rank (Mantel-Cox) test between LPS Vs inhibitor+LPS groups. ***P<0.0001.

Mentions: Macrophages are the leading cause of death associated with overproduction of pro-inflammatory cytokines in response to bacterial components. To explore the effects of COX inhibition on macrophage activity in vivo, we used zebrafish larvae, which have advantages as septic shock models in that they possess only innate immune systems until 7 days after fertilization, they are small and easily visible under a microscope, zebrafish larvae macrophages can produce TNFα and IL-1β similar to rodents [15], and they adhere to the animal welfare concept. Zebrafish larvae 3 days after fertilization were exposed to 1.25 μM NS-398 or 2.5 μM indomethacin and stimulated with a lethal dose (50∼75 μg/ml) of LPS (Fig. 4A). DMSO, NS-398 or indomethacin alone did not induce toxicity. During the observation period, NS-398 treated larvae showed rapid death rates by 20 h (75% versus 45%) compared to LPS alone group (Fig. 4B). Indomethacin-exposed larvae for five days showed more rapid death rates by 5 h (40% versus 5%) after LPS-induced sepsis, and all had died by 24 h (Fig. 4C). Without indomethacin, LPS induced a 25% death rate at 12 h and 100% at 30 h. These results suggest that macrophage activation might occur after COX inhibition in vivo.


Consistent inhibition of cyclooxygenase drives macrophages towards the inflammatory phenotype.

Na YR, Yoon YN, Son D, Jung D, Gu GJ, Seok SH - PLoS ONE (2015)

Survival curve of indomethacin-treated zebrafish larvae after LPS immersion.Panel A: A scheme of zebrafish sepsis model. Zebrafish larvae were maintained in Ringer’s solution containing 2.5 μM indomethacin or 0.01% DMSO from 3 to 8 days after fertilization (dpf). Solution and dead larvae were washed and fresh medium was added daily. After 5 days of indomethacin treatment, solution was changed and the larvae were immersed in 75 μg/ml LPS. Panel B: Survival curve of indomethacin treated zebrafish larvae in sepsis model. Data represents two independent experiments (n = 20). Statistical analysis was performed by Log-rank (Mantel-Cox) test between LPS Vs inhibitor+LPS groups. ***P<0.0001.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4334507&req=5

pone.0118203.g004: Survival curve of indomethacin-treated zebrafish larvae after LPS immersion.Panel A: A scheme of zebrafish sepsis model. Zebrafish larvae were maintained in Ringer’s solution containing 2.5 μM indomethacin or 0.01% DMSO from 3 to 8 days after fertilization (dpf). Solution and dead larvae were washed and fresh medium was added daily. After 5 days of indomethacin treatment, solution was changed and the larvae were immersed in 75 μg/ml LPS. Panel B: Survival curve of indomethacin treated zebrafish larvae in sepsis model. Data represents two independent experiments (n = 20). Statistical analysis was performed by Log-rank (Mantel-Cox) test between LPS Vs inhibitor+LPS groups. ***P<0.0001.
Mentions: Macrophages are the leading cause of death associated with overproduction of pro-inflammatory cytokines in response to bacterial components. To explore the effects of COX inhibition on macrophage activity in vivo, we used zebrafish larvae, which have advantages as septic shock models in that they possess only innate immune systems until 7 days after fertilization, they are small and easily visible under a microscope, zebrafish larvae macrophages can produce TNFα and IL-1β similar to rodents [15], and they adhere to the animal welfare concept. Zebrafish larvae 3 days after fertilization were exposed to 1.25 μM NS-398 or 2.5 μM indomethacin and stimulated with a lethal dose (50∼75 μg/ml) of LPS (Fig. 4A). DMSO, NS-398 or indomethacin alone did not induce toxicity. During the observation period, NS-398 treated larvae showed rapid death rates by 20 h (75% versus 45%) compared to LPS alone group (Fig. 4B). Indomethacin-exposed larvae for five days showed more rapid death rates by 5 h (40% versus 5%) after LPS-induced sepsis, and all had died by 24 h (Fig. 4C). Without indomethacin, LPS induced a 25% death rate at 12 h and 100% at 30 h. These results suggest that macrophage activation might occur after COX inhibition in vivo.

Bottom Line: Thus alterations of macrophage function can have unexpected pathological results.Cyclooxygenase (COX) inhibitors are widely used to relieve pain, but the effects of long-term usage on macrophage function remain to be elucidated.YmI and IRF4 expression was reduced significantly, indicative of a more inflammatory phenotype.

View Article: PubMed Central - PubMed

Affiliation: Macrophage Lab, Department of Microbiology and Immunology, and Institute of Endemic Disease, Seoul National University College of Medicine, 103 Daehak-ro, Chongno-gu, Seoul 110-799, South Korea.

ABSTRACT
Macrophages play important roles in defense against infection, as well as in homeostasis maintenance. Thus alterations of macrophage function can have unexpected pathological results. Cyclooxygenase (COX) inhibitors are widely used to relieve pain, but the effects of long-term usage on macrophage function remain to be elucidated. Using bone marrow-derived macrophage culture and long-term COX inhibitor treatments in BALB/c mice and zebrafish, we showed that chronic COX inhibition drives macrophages into an inflammatory state. Macrophages differentiated in the presence of SC-560 (COX-1 inhibitor), NS-398 (COX-2 inhibitor) or indomethacin (COX-1/2 inhibitor) for 7 days produced more TNFα or IL-12p70 with enhanced p65/IκB phosphoylation. YmI and IRF4 expression was reduced significantly, indicative of a more inflammatory phenotype. We further observed that indomethacin or NS-398 delivery accelerated zebrafish death rates during LPS induced sepsis. When COX inhibitors were released over 30 days from an osmotic pump implant in mice, macrophages from peritoneal cavities and adipose tissue produced more TNFα in both the basal state and under LPS stimulation. Consequently, indomethacin-exposed mice showed accelerated systemic inflammation after LPS injection. Our findings suggest that macrophages exhibit a more inflammatory phenotype when COX activities are chronically inhibited.

Show MeSH
Related in: MedlinePlus