Click the blue word " international circulation" at the top to follow us,
and click the "…" menu in the upper right corner, select ""
Beijing Friendship Hospital Affiliated to Capital Medical University Huang Rongchong blockquoteblockquoteblockquoteblockquote
_Editor's note: The Annual Meeting of the European Society of Cardiology (ESC) is one of the world-class important meetings in the cardiovascular field, held online from August 27th to 30th, Huang Rongchong, Beijing Friendship Hospital, Capital Medical University The professor team has a total of 2 studies to be exchanged at the conference, and this journal specially invites the research team to interpret them in detail.
Myocardial infarction is a continuous process from atherosclerosis to heart failure, and the inflammatory immune response participates in the entire process from the initial stage to the terminal stage. Our previous studies confirmed that the up-regulation of serum tenascin C (TN-C) after infarction has a good predictive value for the occurrence of major adverse cardiovascular events (MACE). Inflammation, pyrolysis and myocardial injury after infarction is a key factor affecting myocardial repair and prognosis, and the NLRP3/caspase-1 axis is very important in the mechanism of pyrolysis. We searched the GEPIA database and found that TN-C in heart tissue was positively correlated with NLRP3 (r=0.52, p<0.05),> TN The relationship and mechanism of -C, NLRP3 and scorch.
In this study, parallel experiments in vitro and in vivo were conducted. In vivo study constructed 24 TN-C gene knockout and 74 C57BL/6J wild-type (WT) mouse models, which were divided into WT sham operation group (WT sham, n=32) and WT myocardial infarction group (WT MI, n =42), TNKO sham (n=12), TNKO MI (n=12); in vitro studies used small interference RNA to knock down the TN-C gene in cardiomyocytes and hydrogen peroxide intervention to simulate the in vivo microenvironment.Relevant experimental studies were carried out by Elisa, immunostaining, qPCR, CCK8, flow cytometry, western blot, echocardiography, TUNEL staining and other techniques.
This study found that TN-C expression increased after myocardial infarction, and reached a peak on the 5th day after infarction (Figure 1) . Loss of TN-C can improve the deterioration of heart function (EF, FS, LVIDd, LVIDs) and reduce the death of cardiomyocytes (Figure 2). Both in vivo and in vitro experiments confirmed that pyrolysis-related cytokines caspase-1, cleaved caspase-1, NLRP3, ASC, IL-18, and IL-1β levels were up-regulated after modelling, but knocking out TN-C can inhibit these factors Activate and reduce myocardial pyrolysis, improve cardiac function, and inhibit the expression of downstream inflammatory factors IL-6, TNF-α, MCP-1 (Figure 3, 4, 5, 6) .
Figure 1. TN-C is highly expressed after MI, reaching a peak on the 5th day
(A) (B) TN-C levels in myocardial tissue of mice in WT sham group and WT MI group. (C) TN-C protein expression and quantification in the heart of WT mice on days 1, 5, 10, 14, and 29 after myocardial infarction. (D) Plasma TN-C levels in sham and MI groups of C57BL/6J mice on days 1, 3, 5, 7, 10, 14, 29 after myocardial infarction.
Figure 2. TN-C deficiency reduces pyrolysis after infarction and improves cardiac function
(A) Four groups of mice with echocardiography measured WT Sham, TNKO Sham, WT MI, and TNKO MI on the 5th day after myocardial infarction ejection fraction (EF), short axis shortening rate (FS), left ventricular end diastolic diameter (LVIDd), left ventricular end systolic diameter (LVIDs). (B) TUNEL staining of myocardial necrosis cells in WTMI and TNKO MI mice. (C) (D) The expression of caspase-1 and cleaved caspase-1 in the myocardial tissue of the four groups of mice.
Figure 3. Loss of TN-C reduces the expression of pyrolysis-related inflammatory bodies after myocardial infarction
(A) The correlation between TN-C and cardiac NLRP3 in the GEPIA database. (B) (C) Expression of NLRP3, IL-18 and IL-1β in myocardial tissues of WT sham, TNKO sham, WT MI and TNKO MI groups. (D) The expression of NLRP3, ASC, IL-18 and IL-1β in the myocardial tissues of the four groups of mice.
Figure 4. Endogenous TN-C knockdown reduces h2o2-induced cell death through NLRP3/caspase-1
(A) TN-C protein expression in cardiomyocytes transfected with si-NC or si-TNC Condition. (B) The expression of superoxide dismutase 2 (SOD2) after treatment with different concentrations of H2O2 (0, 25, 100, 150, 300, 500 μM) for 24 h. (C) Cellular reactive oxygen species (ROS) expression after exposure to 150 μM H2O2 for 24 hours. (D) Flow cytometry analysis of cell apoptosis after si-NC or si-TNC transfected cardiomyocytes treated with 150 μM H2O2 for 24 hours. (E) The expression of NLRP3, cleaved caspase-1, ASC, IL-18, and IL-1β in the above-mentioned treated cells.
Figure 5. TN-C deficiency inhibits cell pyrolysis through TLR4/p-NF-κB
(A) intervenes in Si-TNC, H2O2 (150 μm, 24h) transfection and NLRP3 activator (nigericin), respectively , Determination of the viability of cardiomyocytes. (B) After the intervention of Si-TNC and nigericin, the protein levels of Caspase-1, cleaved Caspase-1, IL-18 and IL-1β in cells. (C) The expression of TLR4 and p-NF-κB p65 in cells after intervention of Si-TNC and H2O2.
Figure 6. TN-C deficiency inhibits the expression of inflammatory factors in vivo and in vitro
(A) (B) WT sham group, TNKO Sham group, WT MI group and TNKO MI group mice on the 5th day after myocardial infarction Changes of IL-6, TNF-α and MCP-1 in myocardial tissue.(C) immunohistochemistry and quantitative expression of IL-6, TNF-α and MCP-1 in myocardial tissue on the 5th day after myocardial infarction. (D) (E) After H2O2 (150 μM 24h) and si-TNC interfered with cardiomyocytes, IL-6, TNF-α and MCP-1 were expressed at gene and protein levels.
This study demonstrated for the first time the direct connection between the up-regulation of TN-C caused by myocardial infarction and caspase-1-dependent pyrolysis, and this process is partly controlled by TLR4/NF-kB/NLRP3 and IL-18, IL -1β signaling pathway mediated. These findings provide new insights into the role of TN-C in myocardial pyrolysis and inflammation after myocardial infarction, and the results of this research will be accepted by the ESC meeting in 2021 for poster presentation.
Expert profile
Professor Huang Rongchong
Chief physician, doctoral tutor, mainly engaged in coronary heart disease basic and clinical research, and clinical research on cardiovascular disease in doctor-patient joint decision-making.Deputy Director of Cardiovascular Center and Deputy Director of Department of Cardiology, Beijing Friendship Hospital, Capital Medical University.
Fellow of the American College of Cardiology (FACC), Fellow of the European Society of Cardiology (FESC), Member of the International Doctor-Patient Joint Decision Committee, Member of the Chronic Disease Prevention and Control Branch of the Chinese Preventive Medicine Association, Interventional Heart Disease of the Chinese Society of Chinese Medicine Member of the Standing Committee of the Society, Member of the Interventional Cardiology Group of the Cardiovascular Branch of the Chinese Medical Association, Member of the Cardiac Regeneration Branch of the Society of Tissue Repair and Regeneration of the Cardiovascular Branch of the Chinese Medical Association, Member of the Guidance Group of the Cardiovascular Branch of the Chinese Medical Doctor Association, etc.( Source: Editorial Department of "International Circulation")
version
right
sound
Ming
The copyright of the original article belongs to "International Circulation".Personal forwarding and sharing are welcome. Any other media or website that needs to reprint or quote the copyrighted content of this website must be marked "Reprinted from "International Circulation"" in the location of awake strong2strong
.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-