Thioredoxin-1 maintains mechanistic target of rapamycin (mTOR) function during oxidative stress in cardiomyocytes

Thioredoxin 1 (Trx1) is a 12-kDa oxidoreductase that catalyzes thiol-disulfide exchange reactions to reduce proteins with disulfide bonds. As such, Trx1 helps protect the heart against stresses, such as ischemia and pressure overload. Mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that regulates cell growth, metabolism, and survival. We have shown previously that mTOR activity is increased in response to myocardial ischemia-reperfusion injury. However, whether Trx1 interacts with mTOR to preserve heart function remains unknown. Using a substrate-trapping mutant of Trx1 (Trx1C35S), we show here that mTOR is a direct interacting partner of Trx1 in the heart. In response to H2O2 treatment in cardiomyocytes, mTOR exhibited a high molecular weight shift in non-reducing SDS-PAGE in a 2-mercaptoethanol-sensitive manner, suggesting that mTOR is oxidized and forms disulfide bonds with itself or other proteins. The mTOR oxidation was accompanied by reduced phosphorylation of endogenous substrates, such as S6 kinase (S6K) and 4E-binding protein 1 (4E-BP1) in cardiomyocytes. Immune complex kinase assays disclosed that H2O2 treatment diminished mTOR kinase activity, indicating that mTOR is inhibited by oxidation. Of note, Trx1 overexpression attenuated both H2O2-mediated mTOR oxidation and inhibition, whereas Trx1 knockdown increased mTOR oxidation and inhibition. Moreover, Trx1 normalized H2O2-induced down-regulation of metabolic genes and stimulation of cell death, and an mTOR inhibitor abolished Trx1-mediated rescue of gene expression. H2O2-induced oxidation and inhibition of mTOR were attenuated when Cys-1483 of mTOR was mutated to phenylalanine. These results suggest that Trx1 protects cardiomyocytes against stress by reducing mTOR at Cys-1483, thereby preserving the activity of mTOR and inhibiting cell death

Clinical characteristics and outcomes of patients with chronic systemic inflammatory disease in acute myocardial infarction.

BackgroundChronic systemic inflammatory diseases (CSIDs) such as rheumatoid arthritis (RA) are reportedly associated with an increased risk of ischemic cardiovascular events including acute myocardial infarction (MI). However, data are limited on clinical characteristics and ischemic and bleeding outcomes after acute MI in patients with CSIDs.MethodsThis bi-center registry included a total of 1001 patients with acute MI undergoing percutaneous coronary intervention. CSIDs included inflammatory rheumatological conditions (RA, systemic lupus erythematosus, vasculitis, etc.) and organ-specific diseases (chronic hepatitis, psoriasis, inflammatory bowel disease, etc.). The primary endpoint was net adverse clinical events (NACE), a composite of ischemic (all-cause death, MI, and ischemic stroke) and major bleeding (Bleeding Academic Research Consortium type 3 or 5) events, during hospitalization and after discharge.ResultsOf the 1001 patients, 58 (5.8%) had CSIDs. The proportion of women was higher in patients with CSIDs than those without (37.9% vs. 22.1%, p = 0.009). During the hospitalization, no significant differences in the primary endpoint of NACE were observed between patients with and without CSIDs (10.3% vs. 12.7%, p = 0.84). During the median follow-up of 42.6 months after discharge, patients with CSIDs had a higher risk of NACE (22.5% vs. 10.1%, p = 0.01) than those without, mainly driven by an increased risk of ischemic events (18.4% vs. 8.4%, p = 0.03).ConclusionsA small but significant proportion of patients with acute MI (5.8%) had CSIDs. While the incidence of in-hospital events was similar, patients with CSIDs had worse outcomes after discharge, suggesting that further clinical investigations and therapeutic approaches are needed in this patient subset

Clinical characteristics and outcomes of patients with chronic systemic inflammatory disease in acute myocardial infarction

Background Chronic systemic inflammatory diseases (CSIDs) such as rheumatoid arthritis (RA) are reportedly associated with an increased risk of ischemic cardiovascular events including acute myocardial infarction (MI). However, data are limited on clinical characteristics and ischemic and bleeding outcomes after acute MI in patients with CSIDs. Methods This bi-center registry included a total of 1001 patients with acute MI undergoing percutaneous coronary intervention. CSIDs included inflammatory rheumatological conditions (RA, systemic lupus erythematosus, vasculitis, etc.) and organ-specific diseases (chronic hepatitis, psoriasis, inflammatory bowel disease, etc.). The primary endpoint was net adverse clinical events (NACE), a composite of ischemic (all-cause death, MI, and ischemic stroke) and major bleeding (Bleeding Academic Research Consortium type 3 or 5) events, during hospitalization and after discharge. Results Of the 1001 patients, 58 (5.8%) had CSIDs. The proportion of women was higher in patients with CSIDs than those without (37.9% vs. 22.1%, p = 0.009). During the hospitalization, no significant differences in the primary endpoint of NACE were observed between patients with and without CSIDs (10.3% vs. 12.7%, p = 0.84). During the median follow-up of 42.6 months after discharge, patients with CSIDs had a higher risk of NACE (22.5% vs. 10.1%, p = 0.01) than those without, mainly driven by an increased risk of ischemic events (18.4% vs. 8.4%, p = 0.03). Conclusions A small but significant proportion of patients with acute MI (5.8%) had CSIDs. While the incidence of in-hospital events was similar, patients with CSIDs had worse outcomes after discharge, suggesting that further clinical investigations and therapeutic approaches are needed in this patient subset

Prognostic Impact of Renal Function on 5‐Year Outcomes After Fractional Flow Reserve‐Guided Deferral of Revascularization

Background Chronic kidney disease (CKD) might influence fractional flow reserve (FFR) value, potentially attenuating its prognostic utility. However, few large‐scale data are available regarding clinical outcomes after FFR‐guided deferral of revascularization in patients with CKD. Methods and Results From the J‐CONFIRM registry (Long‐Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry), 1218 patients were divided into 3 groups according to renal function: (1) non‐CKD (estimated glomerular filtration rate ≥60 mL/min per 1.73 m2), n=385; (2) CKD (estimated glomerular filtration rate 15–59 mL/min per 1.73 m2, n=763); and (3) end‐stage renal disease (ESRD) (eGFR <15 mL/min per 1.73 m2, n=70). The primary study end point was the cumulative 5‐year incidence of target vessel failure (TVF), defined as a composite of cardiac death, target vessel myocardial infarction, and clinical driven target vessel revascularization. Cumulative 5‐year incidence of TVF was significantly higher in the ESRD group than in the CKD and non‐CKD group, whereas it did not differ between the CKD and non‐CKD groups (26.3% versus 11.9% versus 9.5%, P<0.001). Although the 5‐year TVF risk increased as the FFR value decreased regardless of renal function, patients with ESRD had a remarkably higher risk of TVF at every FFR value than those with CKD and non‐CKD. Conclusions At 5 years, patients with ESRD showed a higher incidence of TVF than patients with CKD and non‐CKD, although with similar outcomes between patients with CKD and non‐CKD. Patients with ESRD had an excess risk of 5‐year TVF at every FFR value compared with those with CKD and non‐CKD. Registration URL: https://www.umin.ac.jp; Unique identifier: UMIN000014473