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The Omega-3 Fatty Acid Docosahexaenoic Acid Modulates Inflammatory Mediator Release in Human Alveolar Cells Exposed to Bronchoalveolar Lavage Fluid of ARDS Patients.

Cotogni P, Trombetta A, Muzio G, Maggiora M, Canuto RA - Biomed Res Int (2015)

Bottom Line: The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001) but was increased by the 1 : 7 ratio (P < 0.01).The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001) as well as NF-κB translocation into the nucleus (P < 0.01), while it increased activation of PPARγ and IL-10 release (P < 0.001).Conclusion.

View Article: PubMed Central - PubMed

Affiliation: Anesthesiology and Intensive Care, Department of Medicine, S. Giovanni Battista Hospital, University of Turin, Via A.M. Dogliotti 14, 10126 Turin, Italy.

ABSTRACT

Background: This study investigated whether the 1 : 2 ω-3/ω-6 ratio may reduce proinflammatory response in human alveolar cells (A549) exposed to an ex vivo inflammatory stimulus (bronchoalveolar lavage fluid (BALF) of acute respiratory distress syndrome (ARDS) patients). Methods. We exposed A549 cells to the BALF collected from 12 ARDS patients. After 18 hours, fatty acids (FA) were added as docosahexaenoic acid (DHA, ω-3) and arachidonic acid (AA, ω-6) in two ratios (1 : 2 or 1 : 7). 24 hours later, in culture supernatants were evaluated cytokines (TNF-α, IL-6, IL-8, and IL-10) and prostaglandins (PGE2 and PGE3) release. The FA percentage content in A549 membrane phospholipids, content of COX-2, level of PPARγ, and NF-κB binding activity were determined.

Results: The 1 : 2 DHA/AA ratio reversed the baseline predominance of ω-6 over ω-3 in the cell membranes (P < 0.001). The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001) but was increased by the 1 : 7 ratio (P < 0.01). The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001) as well as NF-κB translocation into the nucleus (P < 0.01), while it increased activation of PPARγ and IL-10 release (P < 0.001). Conclusion. This study demonstrated that shifting the FA supply from ω-6 to ω-3 decreased proinflammatory mediator release in human alveolar cells exposed to BALF of ARDS patients.

No MeSH data available.


Related in: MedlinePlus

Effects of ω-3/ω-6 PUFA ratios on PPARγ expression. PPARγ relative protein content in A549 cells stimulated with BALF and treated with 50 μM 1 : 2 or 1 : 7 DHA/AA ratios. Data are expressed as “a.u.” (arbitrary units) of the densitometric values, normalized on the corresponding β-actin. The value of unstimulated cells was arbitrarily set as 100. Data are presented as mean ± standard deviation of 6 independent determinations (n = 6). The image is representative of all the WB experiments. PUFA, polyunsaturated fatty acid; PPAR, peroxisome proliferator-activated receptor; BALF, bronchoalveolar lavage fluid; DHA, docosahexaenoic acid; AA, arachidonic acid; WB, western blot. *P < 0.05 BALF versus unstimulated cells. **P < 0.01 1 : 7 DHA/AA versus BALF and unstimulated cells. ***P < 0.001 1 : 2 DHA/AA versus BALF and unstimulated cells. #P < 0.05 1 : 2 DHA/AA versus 1 : 7 DHA/AA.
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fig7: Effects of ω-3/ω-6 PUFA ratios on PPARγ expression. PPARγ relative protein content in A549 cells stimulated with BALF and treated with 50 μM 1 : 2 or 1 : 7 DHA/AA ratios. Data are expressed as “a.u.” (arbitrary units) of the densitometric values, normalized on the corresponding β-actin. The value of unstimulated cells was arbitrarily set as 100. Data are presented as mean ± standard deviation of 6 independent determinations (n = 6). The image is representative of all the WB experiments. PUFA, polyunsaturated fatty acid; PPAR, peroxisome proliferator-activated receptor; BALF, bronchoalveolar lavage fluid; DHA, docosahexaenoic acid; AA, arachidonic acid; WB, western blot. *P < 0.05 BALF versus unstimulated cells. **P < 0.01 1 : 7 DHA/AA versus BALF and unstimulated cells. ***P < 0.001 1 : 2 DHA/AA versus BALF and unstimulated cells. #P < 0.05 1 : 2 DHA/AA versus 1 : 7 DHA/AA.

Mentions: Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear transcription factors encoded by different genes. PPARs include 3 subtypes (α, β, and γ), which are characterized by unique functions such as ligand specificities and tissue distribution [51]. PPAR ligands encompass endogenous metabolites such as prostanoids and PUFAs, as well as synthetic drugs such as fibrates and thiazolidinediones. In macrophages, activation of PPARγ negatively influences the production of inflammatory cytokines like TNF-α, IL-6, and IL-1β [52]. It has been demonstrated that most of the effects of PPARs on cytokine expression result from crosstalk with other transcriptional factors and in particular with NF-κB [53]. To verify if also in our experimental model the anti-inflammatory effects of ω-3 were correlated with PPAR activation, we determined the PPARγ content (Figure 7). The results indicated that the proinflammatory stimulus was associated with the inhibition of PPARγ expression. Moreover, as we previously demonstrated [35], in the present study we found both PUFA ratios were associated with an increased PPARγ content but to a greater extent with the 1 : 2 DHA/AA treatment.


The Omega-3 Fatty Acid Docosahexaenoic Acid Modulates Inflammatory Mediator Release in Human Alveolar Cells Exposed to Bronchoalveolar Lavage Fluid of ARDS Patients.

Cotogni P, Trombetta A, Muzio G, Maggiora M, Canuto RA - Biomed Res Int (2015)

Effects of ω-3/ω-6 PUFA ratios on PPARγ expression. PPARγ relative protein content in A549 cells stimulated with BALF and treated with 50 μM 1 : 2 or 1 : 7 DHA/AA ratios. Data are expressed as “a.u.” (arbitrary units) of the densitometric values, normalized on the corresponding β-actin. The value of unstimulated cells was arbitrarily set as 100. Data are presented as mean ± standard deviation of 6 independent determinations (n = 6). The image is representative of all the WB experiments. PUFA, polyunsaturated fatty acid; PPAR, peroxisome proliferator-activated receptor; BALF, bronchoalveolar lavage fluid; DHA, docosahexaenoic acid; AA, arachidonic acid; WB, western blot. *P < 0.05 BALF versus unstimulated cells. **P < 0.01 1 : 7 DHA/AA versus BALF and unstimulated cells. ***P < 0.001 1 : 2 DHA/AA versus BALF and unstimulated cells. #P < 0.05 1 : 2 DHA/AA versus 1 : 7 DHA/AA.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig7: Effects of ω-3/ω-6 PUFA ratios on PPARγ expression. PPARγ relative protein content in A549 cells stimulated with BALF and treated with 50 μM 1 : 2 or 1 : 7 DHA/AA ratios. Data are expressed as “a.u.” (arbitrary units) of the densitometric values, normalized on the corresponding β-actin. The value of unstimulated cells was arbitrarily set as 100. Data are presented as mean ± standard deviation of 6 independent determinations (n = 6). The image is representative of all the WB experiments. PUFA, polyunsaturated fatty acid; PPAR, peroxisome proliferator-activated receptor; BALF, bronchoalveolar lavage fluid; DHA, docosahexaenoic acid; AA, arachidonic acid; WB, western blot. *P < 0.05 BALF versus unstimulated cells. **P < 0.01 1 : 7 DHA/AA versus BALF and unstimulated cells. ***P < 0.001 1 : 2 DHA/AA versus BALF and unstimulated cells. #P < 0.05 1 : 2 DHA/AA versus 1 : 7 DHA/AA.
Mentions: Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear transcription factors encoded by different genes. PPARs include 3 subtypes (α, β, and γ), which are characterized by unique functions such as ligand specificities and tissue distribution [51]. PPAR ligands encompass endogenous metabolites such as prostanoids and PUFAs, as well as synthetic drugs such as fibrates and thiazolidinediones. In macrophages, activation of PPARγ negatively influences the production of inflammatory cytokines like TNF-α, IL-6, and IL-1β [52]. It has been demonstrated that most of the effects of PPARs on cytokine expression result from crosstalk with other transcriptional factors and in particular with NF-κB [53]. To verify if also in our experimental model the anti-inflammatory effects of ω-3 were correlated with PPAR activation, we determined the PPARγ content (Figure 7). The results indicated that the proinflammatory stimulus was associated with the inhibition of PPARγ expression. Moreover, as we previously demonstrated [35], in the present study we found both PUFA ratios were associated with an increased PPARγ content but to a greater extent with the 1 : 2 DHA/AA treatment.

Bottom Line: The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001) but was increased by the 1 : 7 ratio (P < 0.01).The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001) as well as NF-κB translocation into the nucleus (P < 0.01), while it increased activation of PPARγ and IL-10 release (P < 0.001).Conclusion.

View Article: PubMed Central - PubMed

Affiliation: Anesthesiology and Intensive Care, Department of Medicine, S. Giovanni Battista Hospital, University of Turin, Via A.M. Dogliotti 14, 10126 Turin, Italy.

ABSTRACT

Background: This study investigated whether the 1 : 2 ω-3/ω-6 ratio may reduce proinflammatory response in human alveolar cells (A549) exposed to an ex vivo inflammatory stimulus (bronchoalveolar lavage fluid (BALF) of acute respiratory distress syndrome (ARDS) patients). Methods. We exposed A549 cells to the BALF collected from 12 ARDS patients. After 18 hours, fatty acids (FA) were added as docosahexaenoic acid (DHA, ω-3) and arachidonic acid (AA, ω-6) in two ratios (1 : 2 or 1 : 7). 24 hours later, in culture supernatants were evaluated cytokines (TNF-α, IL-6, IL-8, and IL-10) and prostaglandins (PGE2 and PGE3) release. The FA percentage content in A549 membrane phospholipids, content of COX-2, level of PPARγ, and NF-κB binding activity were determined.

Results: The 1 : 2 DHA/AA ratio reversed the baseline predominance of ω-6 over ω-3 in the cell membranes (P < 0.001). The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001) but was increased by the 1 : 7 ratio (P < 0.01). The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001) as well as NF-κB translocation into the nucleus (P < 0.01), while it increased activation of PPARγ and IL-10 release (P < 0.001). Conclusion. This study demonstrated that shifting the FA supply from ω-6 to ω-3 decreased proinflammatory mediator release in human alveolar cells exposed to BALF of ARDS patients.

No MeSH data available.


Related in: MedlinePlus