BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways
Background. Heart failure is a critical health problem worldwide, and cardiac hypertrophy is an important characteristic of heart failure. Bromodomain-containing protein 4 (BRD4) is involved in various cellular processes, including cardiac hypertrophy. This study aimed to investigate the mechanism u...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Hindawi Limited
2022-01-01
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| Series: | Cardiology Research and Practice |
| Online Access: | http://dx.doi.org/10.1155/2022/8372707 |
| _version_ | 1811181665840529408 |
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| author | Ming Fang Jun Luo Xi Zhu Yingbiao Wu Xinming Li |
| author_facet | Ming Fang Jun Luo Xi Zhu Yingbiao Wu Xinming Li |
| author_sort | Ming Fang |
| collection | DOAJ |
| description | Background. Heart failure is a critical health problem worldwide, and cardiac hypertrophy is an important characteristic of heart failure. Bromodomain-containing protein 4 (BRD4) is involved in various cellular processes, including cardiac hypertrophy. This study aimed to investigate the mechanism underlying the effects of BRD4 on cardiac hypertrophy. Methods. Rat myoblast H9c2 cells were treated with angiotensin II (Ang II) to increase the mRNA and protein expressions of BRD4. BRD4 was silenced by small interfering RNA (siRNA) in H9c2 cells. Proteins involved in Nrf2-HO-1 pathway were determined by Western blot. Results. Our data suggest that BRD4 silencing attenuated Ang II, increased the percentage of TUNEL + cells and caspase-3 activity, increased oxidative stress, and increased the expression and content of pro-inflammatory cytokines. Mechanistically, we found that BRD4 silencing enhanced the protein expressions of Nrf2 and HO-1 and inhibited the TLR4 and phosphorylation of NF-kappa B in Ang II-stimulated H9c2 cells. TLR4 overexpression attenuated cardioprotection against Ang II by BRD4 silencing, including cardiac hypertrophy, oxidative stress, and inflammatory cytokine production. Additionally, TLR4 overexpression attenuated an increase in Nrf2 and HO-1 proteins and decreased phosphorylated NF-kappa B in H9c2 cells. Conclusion. Our results speculate that the BRD4/TLR4 axis might be a promising strategy for treating cardiovascular diseases with cardiac hypertrophy, including HF. |
| first_indexed | 2024-04-11T09:21:28Z |
| format | Article |
| id | doaj.art-613255f2275848ea97cf19f0640890a1 |
| institution | Directory Open Access Journal |
| issn | 2090-0597 |
| language | English |
| last_indexed | 2024-04-11T09:21:28Z |
| publishDate | 2022-01-01 |
| publisher | Hindawi Limited |
| record_format | Article |
| series | Cardiology Research and Practice |
| spelling | doaj.art-613255f2275848ea97cf19f0640890a12022-12-22T04:32:10ZengHindawi LimitedCardiology Research and Practice2090-05972022-01-01202210.1155/2022/8372707BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 PathwaysMing Fang0Jun Luo1Xi Zhu2Yingbiao Wu3Xinming Li4Department of CardiologyDepartment of CardiologyDepartment of CardiologyDepartment of CardiologyDepartment of CardiologyBackground. Heart failure is a critical health problem worldwide, and cardiac hypertrophy is an important characteristic of heart failure. Bromodomain-containing protein 4 (BRD4) is involved in various cellular processes, including cardiac hypertrophy. This study aimed to investigate the mechanism underlying the effects of BRD4 on cardiac hypertrophy. Methods. Rat myoblast H9c2 cells were treated with angiotensin II (Ang II) to increase the mRNA and protein expressions of BRD4. BRD4 was silenced by small interfering RNA (siRNA) in H9c2 cells. Proteins involved in Nrf2-HO-1 pathway were determined by Western blot. Results. Our data suggest that BRD4 silencing attenuated Ang II, increased the percentage of TUNEL + cells and caspase-3 activity, increased oxidative stress, and increased the expression and content of pro-inflammatory cytokines. Mechanistically, we found that BRD4 silencing enhanced the protein expressions of Nrf2 and HO-1 and inhibited the TLR4 and phosphorylation of NF-kappa B in Ang II-stimulated H9c2 cells. TLR4 overexpression attenuated cardioprotection against Ang II by BRD4 silencing, including cardiac hypertrophy, oxidative stress, and inflammatory cytokine production. Additionally, TLR4 overexpression attenuated an increase in Nrf2 and HO-1 proteins and decreased phosphorylated NF-kappa B in H9c2 cells. Conclusion. Our results speculate that the BRD4/TLR4 axis might be a promising strategy for treating cardiovascular diseases with cardiac hypertrophy, including HF.http://dx.doi.org/10.1155/2022/8372707 |
| spellingShingle | Ming Fang Jun Luo Xi Zhu Yingbiao Wu Xinming Li BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways Cardiology Research and Practice |
| title | BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways |
| title_full | BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways |
| title_fullStr | BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways |
| title_full_unstemmed | BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways |
| title_short | BRD4 Silencing Protects Angiotensin II-Induced Cardiac Hypertrophy by Inhibiting TLR4/NF-κB and Activating Nrf2-HO-1 Pathways |
| title_sort | brd4 silencing protects angiotensin ii induced cardiac hypertrophy by inhibiting tlr4 nf κb and activating nrf2 ho 1 pathways |
| url | http://dx.doi.org/10.1155/2022/8372707 |
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