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Saxena R, Weintraub NL, Tang Y. Optimizing cardiac ischemic preconditioning and postconditioning via epitranscriptional regulation. Med Hypotheses 2020; 135:109451. [PMID: 31731058 PMCID: PMC6983341 DOI: 10.1016/j.mehy.2019.109451] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/18/2019] [Accepted: 10/23/2019] [Indexed: 02/02/2023]
Abstract
Ischemic cardiac preconditioning protects the heart during myocardial infarction by activating critical cardioprotective genes such as eNOS, SOD, and HO-1. Clinical trials only show marginal effects of conventional preconditioning strategies, however, in part due to transient activation of cardioprotective genes. Recent studies have shown that N6-methyladenosine (m6A) mRNA methylation is the most abundant RNA modification in eukaryotes, and governs mRNA stability and, in turn, the level of protein expression. We hypothesize that regulation of m6A mRNA methylation levels of cardioprotective mRNAs will result in stable expression of the cardioprotective proteins, rendering ischemic cardiac preconditioning more robust and reducing infarct size. To test this hypothesis, we will test the effects of introducing m6A methylases/demethylases into ischemic preconditioned/post conditioned hearts and subjecting them to myocardial infarction. We will assess the half-life of key cardioprotective mRNAs (e.g., eNOS, SOD, and HO-1) and cardiac apoptosis to determine which m6A methylases/demethylases have a synergistic effect on cardiac preconditioning.
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Affiliation(s)
- Richa Saxena
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA; Ardrey Kell High School, Charlotte, NC, USA
| | - Neal L Weintraub
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yaoliang Tang
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA, USA.
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Deja MA, Piekarska M, Malinowski M, Wiaderkiewicz R, Czekaj P, Machej L, Węglarzy A, Kowalówka A, Kołodziej T, Czech E, Plewka D, Mizia M, Latusek T, Szurlej B. Can human myocardium be remotely preconditioned? The results of a randomized controlled trial. Eur J Cardiothorac Surg 2019; 55:1086-1094. [PMID: 30649238 DOI: 10.1093/ejcts/ezy441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/02/2018] [Accepted: 11/17/2018] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES No experimental study has shown that the myocardium of a remotely preconditioned patient is more resistant to a standardized ischaemic/hypoxic insult. METHODS This was a single-centre randomized (1:1), double-blinded, sham-controlled, parallel-group study. Patients referred for elective coronary bypass surgery were allocated to either remote ischaemic preconditioning (3 cycles of 5-min ischaemia/5-min reperfusion of the right arm using a blood pressure cuff inflated to 200 mmHg) or sham intervention. One hundred and thirty-four patients were recruited, of whom 10 dropped out, and 4 were excluded from the per-protocol analysis. The right atrial trabecula harvested on cannulation for cardiopulmonary bypass was subjected to 60 min of simulated ischaemia and 120 min of reoxygenation in an isolated organ experiment. Postoperative troponin T release and haemodynamics were assessed in an in vivo study. RESULTS The atrial trabeculae obtained from remotely preconditioned patients recovered 41.9% (36.3-48.3) of the initial contraction force, whereas those from non-preconditioned patients recovered 45.9% (39.1-53.7) (P = 0.399). Overall, the content of cleaved poly (ADP ribose) polymerase in the right atrial muscle increased from 9.4% (6.0-13.5) to 19.1% (13.2-23.8) (P < 0.001) after 1 h of ischaemia and 2 h of reperfusion in vitro. The amount of activated Caspase 3 and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells also significantly increased. No difference was observed between the remotely preconditioned and sham-treated myocardium. In the in vivo trial, the area under the curve for postoperative concentration of troponin T over 72 h was 16.4 ng⋅h/ml (95% confidence interval 14.2-18.9) for the remote ischaemic preconditioning and 15.5 ng⋅h/ml (13.4-17.9) for the control group in the intention-to-treat analysis. This translated into an area under the curve ratio of 1.06 (0.86-1.30; P = 0.586). CONCLUSIONS Remote ischaemic preconditioning with 3 cycles of 5-min ischaemia/reperfusion of the upper limb before cardiac surgery does not make human myocardium more resistant to ischaemia/reperfusion injury. CLINICAL TRIAL REGISTRATION NUMBER NCT01994707.
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Affiliation(s)
- Marek A Deja
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.,Department of Cardiac Surgery, Upper-Silesian Heart Center, Katowice, Poland
| | - Magda Piekarska
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.,Department of Cardiac Surgery, Upper-Silesian Heart Center, Katowice, Poland
| | - Marcin Malinowski
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.,Department of Cardiac Surgery, Upper-Silesian Heart Center, Katowice, Poland
| | - Ryszard Wiaderkiewicz
- Department of Histology and Embryology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Piotr Czekaj
- Department of Histology and Embryology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Leszek Machej
- Department of Anesthesia and Intensive Care Nursing, School of Health Sciences, Medical University of Silesia, Katowice, Poland
| | - Andrzej Węglarzy
- Department of Cardiac Anesthesia, Upper-Silesian Heart Center, Katowice, Poland
| | - Adam Kowalówka
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.,Department of Cardiac Surgery, Upper-Silesian Heart Center, Katowice, Poland
| | - Tadeusz Kołodziej
- Department of Cardiac Surgery, Upper-Silesian Heart Center, Katowice, Poland
| | - Ewa Czech
- Department of Histology and Embryology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Danuta Plewka
- Department of Histology and Embryology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Magdalena Mizia
- 1 Department of Cardiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Tomasz Latusek
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Bartosz Szurlej
- Department of Cardiac Surgery, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
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