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Interleukin-17A contributes to the development of post-operative atrial fibrillation by regulating inflammation and fibrosis in rats with sterile pericarditis.

Fu XX, Zhao N, Dong Q, Du LL, Chen XJ, Wu QF, Cheng X, Du YM, Liao YH - Int. J. Mol. Med. (2015)

Bottom Line: Western blot analysis was applied to quantify the expression of IL-17A.Quantitative PCR was used to detect the mRNA expression of IL-17A, IL-6, IL-1β, transforming growth factor-β1 (TGF-β1), collagen type 1 (Col-1), collagen type 3 (Col-3) and α-smooth muscle actin (α-SMA).Gelatin zymography and reverse gelatin zymography were used to quantify the levels of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs).

View Article: PubMed Central - PubMed

Affiliation: Research Center of Ion Channelopathy, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.

ABSTRACT
Post-operative atrial fibrillation (AF) remains a common cause of morbidity. Increasing evidence indicates that inflammation and atrial fibrosis contribute to the pathogenesis of this condition. Interleukin (IL)-17A, a potent pro-inflammatory cytokine, has been implicated in the development of a number of cardiovascular diseases. However, its role in post-operative AF remains unknown. In the present study, sterile pericarditis (SP) was induced in rats by the epicardial application of sterile talc. AF was induced by transesophageal burst pacing. Western blot analysis was applied to quantify the expression of IL-17A. Quantitative PCR was used to detect the mRNA expression of IL-17A, IL-6, IL-1β, transforming growth factor-β1 (TGF-β1), collagen type 1 (Col-1), collagen type 3 (Col-3) and α-smooth muscle actin (α-SMA). Gelatin zymography and reverse gelatin zymography were used to quantify the levels of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs). Histological analyses were performed to determine the extent of tissue inflammation and fibrosis. The rats with SP presented with a shorter refractoriness, a higher incidence and duration of AF, an enhanced susceptibility to developing AF, increased mRNA levels of AF-related pro-inflammatory cytokines (IL-6, IL-1β and TGF-β1), as well as marked atrial inflammation and fibrosis. The atrial IL-17A levels were elevated and correlated with the probability of developing AF. Treatment with anti-IL-17A monoclonal antibody decreased the levels of atrial IL-17A, prolonged refraction and markedly suppressed the development of AF. Simultaneously, inflammation and fibrosis were alleviated, which was further demonstrated by a decreased expression of AF-related pro-inflammatory cytokines, a downregulation in fibrosis-related mRNA expression (Col-1, Col-3 and α-SMA) and by the decreased activity of MMP-2/9 and TIMPs. Thus, the findings of our study indicate that IL-17A may play a pathogenic role in post-operative AF by inducing inflammation and fibrosis in rats with SP.

No MeSH data available.


Related in: MedlinePlus

Changes in the activity of matrix metalloproteinase (MMP)-2 and MMP-3 in the atrial samples at 4 days after surgery. (A) A representative gelatin zymogram is shown. Gelatinolytic bands of 220, 95, 72 and 68 kDa corresponded to pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2, respectively. Molecular mass markers (M) are indicated on right side. (B) Quantification of gelatinase activity was achieved by computer-assisted image analysis of the zymographic gels. The data are presented as the fold change vs. Sham. *P<0.05 and **P<0.01 vs. Sham; #P<0.05 and ##P<0.01 vs. IgG2a control. Sham, sham-operated rats; SP, rats with sterile pericarditis.
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f8-ijmm-36-01-0083: Changes in the activity of matrix metalloproteinase (MMP)-2 and MMP-3 in the atrial samples at 4 days after surgery. (A) A representative gelatin zymogram is shown. Gelatinolytic bands of 220, 95, 72 and 68 kDa corresponded to pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2, respectively. Molecular mass markers (M) are indicated on right side. (B) Quantification of gelatinase activity was achieved by computer-assisted image analysis of the zymographic gels. The data are presented as the fold change vs. Sham. *P<0.05 and **P<0.01 vs. Sham; #P<0.05 and ##P<0.01 vs. IgG2a control. Sham, sham-operated rats; SP, rats with sterile pericarditis.

Mentions: Imbalances in the levels of MMPs and TIMPs have been linked with AF (23,28). In this study, we used gelatinzymography to determine the activity of MMP-2 and MMP-9 in the atrial tissues.A representative gelatin zymogram is shown in Fig. 8A. Gelatinases of 220 and 95 kDa corresponded to pro-MMP-9 and an active form of MMP-9, respectively. Gelatinases of 72 and 68 kDa were considered to be pro-MMP-2 and its active form, respectively. Data analysis revealed significantly higher mean levels of pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2 in the rats with SP compared with the sham-operated rats. However, their activities were significantly decreased following treatment with anti-IL-17A mAb (Fig. 8B). The activity of TIMPs was also determined by reverse gelatin zymography. Densitometric analysis of these TIMP activities revealed a significantly decreased TIMP-2 (19 kDa) and glycosylated TIMP-3 (22 kDa) activity in the rats with SP compared with the sham-operated rats. However, the activities of TIMPs returned to almost normal levels following treatment with anti-IL-17A mAb (Fig. 9).


Interleukin-17A contributes to the development of post-operative atrial fibrillation by regulating inflammation and fibrosis in rats with sterile pericarditis.

Fu XX, Zhao N, Dong Q, Du LL, Chen XJ, Wu QF, Cheng X, Du YM, Liao YH - Int. J. Mol. Med. (2015)

Changes in the activity of matrix metalloproteinase (MMP)-2 and MMP-3 in the atrial samples at 4 days after surgery. (A) A representative gelatin zymogram is shown. Gelatinolytic bands of 220, 95, 72 and 68 kDa corresponded to pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2, respectively. Molecular mass markers (M) are indicated on right side. (B) Quantification of gelatinase activity was achieved by computer-assisted image analysis of the zymographic gels. The data are presented as the fold change vs. Sham. *P<0.05 and **P<0.01 vs. Sham; #P<0.05 and ##P<0.01 vs. IgG2a control. Sham, sham-operated rats; SP, rats with sterile pericarditis.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494571&req=5

f8-ijmm-36-01-0083: Changes in the activity of matrix metalloproteinase (MMP)-2 and MMP-3 in the atrial samples at 4 days after surgery. (A) A representative gelatin zymogram is shown. Gelatinolytic bands of 220, 95, 72 and 68 kDa corresponded to pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2, respectively. Molecular mass markers (M) are indicated on right side. (B) Quantification of gelatinase activity was achieved by computer-assisted image analysis of the zymographic gels. The data are presented as the fold change vs. Sham. *P<0.05 and **P<0.01 vs. Sham; #P<0.05 and ##P<0.01 vs. IgG2a control. Sham, sham-operated rats; SP, rats with sterile pericarditis.
Mentions: Imbalances in the levels of MMPs and TIMPs have been linked with AF (23,28). In this study, we used gelatinzymography to determine the activity of MMP-2 and MMP-9 in the atrial tissues.A representative gelatin zymogram is shown in Fig. 8A. Gelatinases of 220 and 95 kDa corresponded to pro-MMP-9 and an active form of MMP-9, respectively. Gelatinases of 72 and 68 kDa were considered to be pro-MMP-2 and its active form, respectively. Data analysis revealed significantly higher mean levels of pro-MMP-9, active MMP-9, pro-MMP-2 and active MMP-2 in the rats with SP compared with the sham-operated rats. However, their activities were significantly decreased following treatment with anti-IL-17A mAb (Fig. 8B). The activity of TIMPs was also determined by reverse gelatin zymography. Densitometric analysis of these TIMP activities revealed a significantly decreased TIMP-2 (19 kDa) and glycosylated TIMP-3 (22 kDa) activity in the rats with SP compared with the sham-operated rats. However, the activities of TIMPs returned to almost normal levels following treatment with anti-IL-17A mAb (Fig. 9).

Bottom Line: Western blot analysis was applied to quantify the expression of IL-17A.Quantitative PCR was used to detect the mRNA expression of IL-17A, IL-6, IL-1β, transforming growth factor-β1 (TGF-β1), collagen type 1 (Col-1), collagen type 3 (Col-3) and α-smooth muscle actin (α-SMA).Gelatin zymography and reverse gelatin zymography were used to quantify the levels of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs).

View Article: PubMed Central - PubMed

Affiliation: Research Center of Ion Channelopathy, Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.

ABSTRACT
Post-operative atrial fibrillation (AF) remains a common cause of morbidity. Increasing evidence indicates that inflammation and atrial fibrosis contribute to the pathogenesis of this condition. Interleukin (IL)-17A, a potent pro-inflammatory cytokine, has been implicated in the development of a number of cardiovascular diseases. However, its role in post-operative AF remains unknown. In the present study, sterile pericarditis (SP) was induced in rats by the epicardial application of sterile talc. AF was induced by transesophageal burst pacing. Western blot analysis was applied to quantify the expression of IL-17A. Quantitative PCR was used to detect the mRNA expression of IL-17A, IL-6, IL-1β, transforming growth factor-β1 (TGF-β1), collagen type 1 (Col-1), collagen type 3 (Col-3) and α-smooth muscle actin (α-SMA). Gelatin zymography and reverse gelatin zymography were used to quantify the levels of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs). Histological analyses were performed to determine the extent of tissue inflammation and fibrosis. The rats with SP presented with a shorter refractoriness, a higher incidence and duration of AF, an enhanced susceptibility to developing AF, increased mRNA levels of AF-related pro-inflammatory cytokines (IL-6, IL-1β and TGF-β1), as well as marked atrial inflammation and fibrosis. The atrial IL-17A levels were elevated and correlated with the probability of developing AF. Treatment with anti-IL-17A monoclonal antibody decreased the levels of atrial IL-17A, prolonged refraction and markedly suppressed the development of AF. Simultaneously, inflammation and fibrosis were alleviated, which was further demonstrated by a decreased expression of AF-related pro-inflammatory cytokines, a downregulation in fibrosis-related mRNA expression (Col-1, Col-3 and α-SMA) and by the decreased activity of MMP-2/9 and TIMPs. Thus, the findings of our study indicate that IL-17A may play a pathogenic role in post-operative AF by inducing inflammation and fibrosis in rats with SP.

No MeSH data available.


Related in: MedlinePlus