Melatonin enhanced the cardioprotective effects of HTK solution on Langendorff-perfused mouse hearts subjected to ischemia/reperfusion.

Objectives: Cardiac arrest is a crucial procedure in various cardiac surgeries, during which the heart is subjected to an ischemic state. The occurrence of ischemia/reperfusion (I/R) injury is inevitable due to aortic blockage and opening. The Histidine-tryptophan-ketoglutarate (HTK) solution is commonly used as an organ protection liquid to mitigate cardiac injury during cardiac surgery. Despite its widespread use, there is significant potential for improving its protective efficacy. Materials and Methods: The cardioprotective effect of HTK solution with and without melatonin was evaluated using the isolated Langendorff-perfused mouse heart model. The isolated C57bL/6 mouse hearts were randomly divided into four groups: control, I/R, HTK solution treatment before reperfusion (HTK+I/R), and HTK solution combined with melatonin before reperfusion (HTK+M+I/R). Cardiac function and myocardial injury markers were then measured. AMP-activated protein kinase α2 (AMPKα2) KO mice were used to investigate the underlying mechanism. Results: In our study, we found that melatonin significantly improved the protective effects of HTK solution in an isolated Langendorff-perfused mouse model, mechanistically by reducing mitochondrial damage, improving energy metabolism, inhibiting cardiomyocyte apoptosis, and reducing myocardial infarction size. We also observed that the HTK solution alone was ineffective in inhibiting ER stress, but when melatonin was added, there was a significant reduction in ER stress. Furthermore, melatonin was found to alleviate carbonyl stress during cardiac I/R. Interestingly, our results showed that the cardioprotective properties of melatonin were dependent on AMPKα2. Conclusion: The findings presented in this study offer a valuable empirical foundation for the development of perioperative cardioprotective strategies.

Modified Transannular Patching Palliation versus Modified Blalock-Taussig-Thomas Shunt in Infants with Severe Tetralogy of Fallot with Diminutive Pulmonary Arteries.

OBJECTIVE: The purpose of this study was to compare pulmonary arterial (PA) growth and morbidity, mortality, reintervention and complete repair rates after modified transannular patching palliation (mTAP) versus modified Blalock-Taussig-Thomas shunt (mBTS) for palliation in infants with severe tetralogy of Fallot (TOF) with diminutive pulmonary arteries. METHODS: This was a retrospective case review study of 107 patients (64 males) with severe TOF who underwent staged repair with either mTAP (n = 55) or mBTS (n = 52) over an 8-year period. Procedure-related PA growth and morbidity, mortality, reintervention and complete repair rates were compared. RESULTS: Two deaths occurred in the mBTS group due to sudden cardiac arrest, and five patients needed reintervention after the mBTS procedure because of shunt thrombosis or stenosis. Postoperative complications of mBTS included sudden cardiac arrest, shunt thrombosis/stenosis, vocal cord palsy and diaphragmatic palsy. Unlike in the mBTS group, no death, severe complications or reintervention occurred in the mTAP group. Oxygen saturations post mTAP and mBTS were significantly higher, which improved from 67.73 ± 4.36% to 94.33 ± 2.19% in the mTAP group and from 68.24 ± 3.87% to 86.87 ± 3.38% in the mBTS group. The increase in oxygen saturation and pulmonary artery growth (from pre- to post palliation) was significantly better with mTAP than with mBTS palliation (p < 0.01). All 55 patients showed complete repair after mTAP, and the time from palliation to complete repair was significantly shorter in the mTAP group. CONCLUSIONS: In a severe form of TOF with the hypoplastic PA tree, mTAP seems to be a better strategy that is safe and better facilitates satisfactory pulmonary arterial growth until complete repair than the mBTS procedure.

Association of Metformin with the Mortality and Incidence of Cardiovascular Events in Patients with Pre-existing Cardiovascular Diseases.

INTRODUCTION: Whether metformin reduces all-cause cardiovascular mortality and the incidence of cardiovascular events in patients with pre-existing cardiovascular diseases (CVD) remains inconclusive. Some randomised controlled trials (RCTs) and cohort studies have shown that metformin is associated with an increased risk of mortality and cardiovascular events. METHODS: We conducted a pooling synthesis to assess the effects of metformin in all-cause cardiovascular mortality and incidence of cardiovascular events in patients with CVD. Studies published up to October 2021 in PubMed or Embase with a registration in PROSPERO (CRD42020189905) were collected. Both RCT and cohort studies were included. Hazard ratios (HR) with 95% CI were pooled across various trials using the random-effects model. RESULTS: This study enrolled 35 published studies (in 14 publications) for qualitative synthesis and identified 33 studies (published in 26 publications) for quantitative analysis. We analysed a total of 61,704 patients, among them 58,271 patients were used to calculate all-cause mortality while 12,814 patients were used to calculate cardiovascular mortality. Compared with non-metformin control, metformin usage is associated with a reduction in all-cause mortality (HR: 0.90; 95% CI 0.83, 0.98; p = 0.01), cardiovascular mortality (HR: 0.89; 95% CI 0.85, 0.94; p < 0.0001), incidence of coronary revascularisation (HR: 0.79; 95% CI 0.64, 0.98; p = 0.03), and heart failure (HR: 0.90; 95% CI 0.87, 0.94; p < 0.0001) in patients with pre-existing cardiovascular diseases. CONCLUSION: Metformin use is associated with a reduction in all-cause mortality, cardiovascular mortality, incidence of coronary revascularisation, and heart failure in patients with CVD; however, metformin usage was not associated with reduction in the incidence of myocardial infarction, angina, or stroke.

Analysis of 85 Cases of Minimal Media Lower Hemisternotomy for Congenital Cardiac Surgery Under Cardiopulmonary Bypass in Infants.

OBJECTIVE: To investigate the feasibility and effect of minimal media lower hemisternotomy for cardiac surgery under cardiopulmonary bypass (CPB) in infant congenital heart disease. METHODS: In our hospital from May 2019 to October 2019, 170 infants with congenital heart disease underwent surgical treatment (median age 6.6 months; weight 6.0 kg). They were divided into 2 groups: those with conventional chest median incision and those with minimal sternotomy. Minimal lower hemisternotomy began from the third intercostal level and ended 0.5 cm above the xiphoid, just enough to insert a small sternal distractor. RESULTS: There was no significant difference between the 2 groups in CPB time. The operation time of small incision group was slightly longer (P < .05). There was no difference in prognosis between the 2 groups, but the wound length of the small incision group was significantly reduced (4.0 ± 0.5 versus 7.8 ± 0.8 cm, P < .05). Time of intensive care unit and hospital stay was shorter among hemisternotomy patients at a statistically significant level (P < .05). CONCLUSION: Minimal media lower hemisternotomy with the basic advantages of the sternal incision can expose the various parts of the heart, which meets most cardiac exploration and surgical operation needs, and the incision may still be extended if necessary. Lower hemisternotomy appears to be a safe, effective, and versatile alternative for many surgical interventions in infants with congenital heart disease.

Association of metformin monotherapy or combined therapy with cardiovascular risks in patients with type 2 diabetes mellitus.

BACKGROUND: Metformin is a first-line drug in type 2 diabetes mellitus (T2DM) treatment, yet whether metformin may increase all-cause or cardiovascular mortality of T2DM patients remains inconclusive. METHODS: We searched PubMed and Embase for data extracted from inception to July 14, 2020, with a registration in PROSPERO (CRD42020177283). This study included randomized controlled trials (RCT) assessing the cardiovascular effects of metformin for T2DM. This study is followed by PRISMA and Cochrane guideline. Risk ratio (RR) with 95% CI was pooled across trials by a random-effects model. Primary outcomes include all-cause mortality and cardiovascular mortality. RESULTS: We identified 29 studies that randomly assigned patients with 371 all-cause and 227 cardiovascular death events. Compared with untreated T2DM patients, metformin-treated patients was not associated with lower risk of all-cause mortality (RR: 0.98; 95%CI: 0.69-1.38; P = 0.90), cardiovascular mortality (RR: 1.13; 95% CI: 0.60, 2.15; P = 0.70), macrovascular events (RR: 0.87; 95%CI: 0.70-1.07; P = 0.19), heart failure (RR: 1.02; 95% CI:0.61-1.71; P = 0.95), and microvascular events (RR: 0.78; 95% CI:0.54-1.13; P = 0.19). Combination of metformin with another hypoglycemic drug was associated with higher risk of all-cause mortality (RR: 1.49; 95% CI: 1.02, 2.16) and cardiovascular mortality (RR: 2.21; 95% CI: 1.22, 4.00) compared with hypoglycemic drug regimens with no metformin. CONCLUSION: The combination of metformin treatment may impose higher risk in all-cause and cardiovascular mortality. This finding, at least in part, shows no evidence for benefits of metformin in combination in terms of all-cause/cardiovascular mortality and cardiovascular events for T2DM. However, the conclusion shall be explained cautiously considering the limitations from UK Prospective Diabetes Study (UKPDS).

The Pivotal Role of Mitsugumin 53 in Cardiovascular Diseases.

The MG53 (also known as TRIM72) is a conserved, muscle-specific tripartite motif family protein that is abundantly expressed in cardiac or skeletal muscle and present in circulation. Recently, the MG53 had been hypothesized to serve a dual role in the heart: involving in repairing cell membranes that protect myocardial function while acting as an E3 ligase to trigger insulin resistance and cardiovascular complications. This review discusses the roles of MG53 in cardiac physiological function with emphasis on MG53 protective function in the heart and its negative impact on the myocardium due to the continuous elevation of MG53. Besides, this work reviewed the significance of MG53 as a potential therapeutic in human cardiovascular diseases. Despite the expression of MG53 being rare in the human, thus exogenous MG53 can potentially be a new treatment for human cardiovascular diseases. Notably, the specific mechanism of MG53 in cardiovascular diseases remains elusive.

Aortic regurgitation after closure of ventricular septal defect by transcatheter device: the long-term complication.

Ventricular septal defect is the most common type of CHD, and transcatheter ventricular septal defect closure has been shown to be an alternative to surgical closure with acceptable mortality and morbidity as well as encouraging results. Short-term and mid-term follow-ups have indicated the safety and efficacy of transcatheter closure, but long-term follow-up results were rare. In this report, we first found that aortic regurgitation occurred in patients 9-12 years following transcatheter closure and regurgitation were gradually increased. The findings indicate that the long-term outcome of transcatheter closure of ventricular septal defect may not be as satisfied as expected.

Metformin mediates cardioprotection against aging-induced ischemic necroptosis.

Necroptosis is crucially involved in severe cardiac pathological conditions. However, whether necroptosis contributes to age-related intolerance to ischemia/reperfusion (I/R) injury remains elusive. In addition, metformin as a potential anti-aging related injury drug, how it interacts with myocardial necroptosis is not yet clear. Male C57BL/6 mice at 3-4- (young) and 22-24 months of age (aged) and RIPK3-deficient (Ripk3-/- ) mice were used to investigate aging-related I/R injury in vivo. Metformin (125 µg/kg, i.p.), necrostatin-1 (3.5 mg/kg), and adenovirus vector encoding p62-shRNAs (Ad-sh-p62) were used to treat aging mice. I/R-induced myocardial necroptosis was exaggerated in aged mice, which correlated with autophagy defects characterized by p62 accumulation in aged hearts or aged human myocardium. Functionally, blocking autophagic flux promoted H/R-evoked cardiomyocyte necroptosis in vitro. We further revealed that p62 forms a complex with RIP1-RIP3 (necrosome) and promotes the binding of RIP1 and RIP3. In mice, necrostatin-1 treatment (a RIP1 inhibitor), RIP3 deficiency, and cardiac p62 knockdown in vivo demonstrated that p62-RIP1-RIP3-dependent myocardial necroptosis contributes to aging-related myocardial vulnerability to I/R injury. Notably, metformin treatment disrupted p62-RIP1-RIP3 complexes and effectively repressed I/R-induced necroptosis in aged hearts, ultimately reducing mortality in this model. These findings highlight previously unknown mechanisms of aging-related myocardial ischemic vulnerability: p62-necrosome-dependent necroptosis. Metformin acts as a cardioprotective agent that inhibits this unfavorable chain mechanism of aging-related I/R susceptibility.

Novel role of the SRY-related high-mobility-group box D gene in cancer.

The SRY-related high-mobility-group box (Sox) gene family encodes a set of transcription factors and is defined by the presence of highly conserved domains. The Sox gene can be divided into 10 groups (A-J). The SoxD subpopulation consists of Sox5, Sox6, Sox13 and Sox23, which are involved in the transcriptional regulation of developmental processes, including embryonic development, nerve growth and cartilage formation. Recently, the SoxD gene family was recognized as important transcriptional regulators associated with many types of cancer. In addition, Sox5 and Sox6 are representatives of the D subfamily, and there are many related studies; however, there are few reports on Sox13 and Sox23. In this review, we first introduce the structures of the SoxD genes. Next, we summarize the latest research progress on SoxD in various types of cancer. Finally, we discuss the potential direction of future SoxD research. In general, the information reviewed here may contribute to future experimental design and increase the potential of SoxD as a cancer treatment target.

Akt is a critical node of acute myocardial insulin resistance and cardiac dysfunction after cardiopulmonary bypass.

AIMS: Acute myocardial insulin resistance is an independent risk factor for patients who undergo cardiac surgery with cardiopulmonary bypass (CPB). However, the underlying mechanism of insulin resistance during CPB has not been fully investigated. MATERIALS AND METHODS: To explore the role of myocardial insulin resistance on the cardiac function and its underlying mechanism, CPB operation and pharmacological intervention were applied in mini pigs, and myocardial insulin signaling, glucose uptake, ATP production and cardiac function were examined. KEY FINDINGS: Our data showed that CPB elicited not only hyperglycemia and hyperinsulinemia, but also inactivated Akt, and impaired the transposition of membrane glucose transporter-4 (GLUT-4), reduced glucose uptake and ATP production in the myocardium as well, which in turn was accompanied with cardiac dysfunction. Meanwhile, linear correlations were established among reduced myocardial glucose uptake, ATP production, and depressed cardiac systolic or diastolic function. Reactivation of Akt by SC79, an Akt agonist, partially alleviated myocardial insulin resistance and restored post CPB cardiac function via augmenting myocardial glucose uptake and ATP production. SIGNIFICANCE: These findings revealed that acute myocardial insulin resistance due to inactivation of Akt played a key role in cardiac dysfunction post CPB via suppressing glucose metabolism related energy supply.

Targeting NLRP3 (Nucleotide-Binding Domain, Leucine-Rich-Containing Family, Pyrin Domain-Containing-3) Inflammasome in Cardiovascular Disorders.

Inflammation is an important innate immune response to infection or tissue damage. Inflammasomes are involved in the onset and development of inflammation. The NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome is the best-characterized inflammasome. Recent evidence has indicated the importance of the NLRP3 inflammasome in the pathophysiology of cardiovascular disorders. To further understand the roles of the NLRP3 inflammasome in the cardiovascular system, we provide a comprehensive overview and discuss the remaining questions. First, a summary of NLRP3 inflammasome in the cardiovascular system is introduced. Then, the associations between NLRP3 inflammasome and cardiovascular disorders are presented. Finally, we discuss existing problems and potential directions with this issue. The information compiled here summarizes recent progress, thus potentially aiding in the understanding of the NLRP3 inflammasome in cardiovascular disorders, designing experimental and clinical research about the NLRP3 inflammasome, and promoting therapeutics for cardiovascular disorders.

Three-dimensional printed degradable splint in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis.

Pulmonary artery sling is a congenital cardiovascular disease and is usually accompanied by tracheobronchial stenosis. Generally, infants diagnosed with pulmonary artery sling should have surgery. However, the treatment of tracheobronchial stenosis is still controversial. Our team developed a customised, degradable, three-dimensional printed splint and successfully applied it in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis. We suggested that three-dimensional printing may be a novel and effective way to treat tracheobronchial stenosis and other diseases in children.

AMPK: Potential Therapeutic Target for Ischemic Stroke.

5'-AMP-activated protein kinase (AMPK), a member of the serine/threonine (Ser/Thr) kinase group, is universally distributed in various cells and organs. It is a significant endogenous defensive molecule that responds to harmful stimuli, such as cerebral ischemia, cerebral hemorrhage, and, neurodegenerative diseases (NDD). Cerebral ischemia, which results from insufficient blood flow or the blockage of blood vessels, is a major cause of ischemic stroke. Ischemic stroke has received increased attention due to its '3H' effects, namely high mortality, high morbidity, and high disability. Numerous studies have revealed that activation of AMPK plays a protective role in the brain, whereas its action in ischemic stroke remains elusive and poorly understood. Based on existing evidence, we introduce the basic structure, upstream regulators, and biological roles of AMPK. Second, we analyze the relationship between AMPK and the neurovascular unit (NVU). Third, the actions of AMPK in different phases of ischemia and current therapeutic methods are discussed. Finally, we evaluate existing controversy and provide a detailed analysis, followed by ethical issues, potential directions, and further prospects of AMPK. The information complied here may aid in clinical and basic research of AMPK, which may be a potent drug candidate for ischemic stroke treatment in the future.

AMP-activated protein kinase sparks the fire of cardioprotection against myocardial ischemia and cardiac ageing.

AMP-activated protein kinase (AMPK) is a pivotal regulator of some endogenous defensive molecules in various pathological processes, particularly myocardial ischemia (MI), a high risk of myocardial infarction. Thereby it is of great significance to explore the inherent mechanism between AMPK and myocardial infarction. In this review, we first introduce the structure and role of AMPK in the heart. Next, we introduce the mechanisms of AMPK in the heart; followed by the energy regulation of AMPK in MI. Lastly, the attention will be expanded to some potential directions and further perspectives. The information compiled here will be helpful for further research and drug design in the future before AMPK might be considered as a therapeutic target of MI.

Targeting ALDH2 for Therapeutic Interventions in Chronic Pain-Related Myocardial Ischemic Susceptibility.

Clinical observations have demonstrated a link between chronic pain and increased ischemic heart disease mortality, but the mechanisms remain elusive. Reactive aldehydes have recently been confirmed as a new player in pain pathologies, while our previous study demonstrated that reactive aldehydes (4-HNE) induced carbonyl stress contributing to myocardial ischemic intolerance. The aim of this study was to explore whether chronic pain increases susceptibility to myocardial ischemia/reperfusion (MI/R) injury and to investigate the underlying mechanisms focusing on toxic aldehyde and carbonyl stress. Methods: Chronic pain was induced by chronic compression of the dorsal root ganglion (CCD). After 2 weeks CCD, aldehyde dehydrogenase (ALDH2) KO or wild-type (WT) littermate mice were then subjected to in vivo MI/R. Results: In CCD-WT mice, heightened nociception paralleled circulating aldehyde (4-HNE) accumulation and cardiac protein carbonylation. Mechanistically, CCD-induced 4-HNE overload provoked cardiac Sirtuin 1 (SIRT1) carbonylative inactivation and inhibited Liver kinase B1 (LKB1) - AMP-activated protein kinase (LKB1-AMPK) interaction, which resulted in exacerbated MI/R injury and higher mortality compared with non-CCD WT mice. ALDH2 deficiency further aggravated CCD-induced susceptibility to MI/R injury. Exogenous 4-HNE exposure in peripheral tissue mimicked chronic pain-induced aldehyde overload, elicited sustained allodynia and increased MI/R injury. However, cardiac-specific ALDH2 upregulation by AAV9-cTNT-mediated gene delivery significantly ameliorated chronic pain-induced SIRT1 carbonylative inactivation and decreased MI/R injury (minor infarct size, less apoptosis, and improved cardiac function). Conclusion: Collectively, chronic pain-enhanced carbonyl stress promotes myocardial ischemic intolerance by SIRT1 carbonylative inactivation and impairment of LKB1-AMPK interaction. ALDH2 activation and prevention of protein carbonylation may be a potential therapeutic target for myocardial ischemic vulnerability in chronic pain patients. Our results newly provided overlapping cellular mechanisms of chronic pain and myocardial dysfunction interplay.

Activation of AMPK alleviates cardiopulmonary bypass-induced cardiac injury via ameliorating acute cardiac glucose metabolic disorder.

Recent years, studies have demonstrated that hyperglycemia is one of the main manifestations after cardiac surgeries, which contributes to myocardial injuries and increases the chance of subsequent complications and mortality in such patients. However, strategies targeting at glucose metabolic disorder after cardiac surgeries to attenuate myocardial injuries are inadequately studied. In this study, a rat model of cardiopulmonary bypass (CPB) was applied to investigate the role of Adenosine 5'-monophosphate-activated protein kinase (AMPK) in modulating myocardial glucose metabolic-induced cardiac injuries after cardiac surgery. The results revealed that CPB elicited significant cardiac dysfunction, and pronouncedly elevated the markers of myocardial injuries including serum creatine kinase MB and cardiac troponin I. Additionally, blunted myocardial glucose uptake after CPB was associated with decreased membrane glucose transporter 4 (GLUT4) content. However, pretreatment of AMPK agonist 5-aminoimidazole-4-carboxamide1-ß-D-ribofuranoside (AICAR) at the beginning of CPB activated AMPK, enhanced phosphorylation of Akt substrate 160 (AS160), and increased myocardial membrane content of GLUT4. Meanwhile, improved myocardial glucose uptake and more importantly alleviated cardiac injury were also observed after CPB pretreated with AICAR. Moreover, the application of a mutant form of AS160 (AS160-4P) abolished the beneficial effect of AICAR, as evidenced by impaired cardiac glucose uptake, reduced myocardial membrane GLUT-4 translocation, increased cardiac injury markers, and deterioration of cardiac function after CPB. In conclusion, it was suggested in this study that preactivation of AMPK by AICAR improved myocardial glucose uptake by promoting AS160 dependent myocardial membrane GLUT-4 translocation, which ultimately provided a potent cardioprotective effect.

Pigment epithelium-derived factor promotes Fas-induced cardiomyocyte apoptosis via its receptor phospholipase A2.

AIMS: Cardiovascular diseases cause significant morbidity and mortality worldwide. Recently, our research team demonstrated that a multifunctional cytokine, pigment epithelium-derived factor (PEDF), plays a critical role in regulating myocardial infarction. However, few researchers have studied the molecular mechanisms by which PEDF and its receptors influence the pathophysiology of cardiovascular disease. We tested the hypothesis that PEDF affects cardiomyocyte apoptosis under hypoxic conditions and determined the role that its receptors phospholipase A2 (PLA2) and laminin receptor play in this process. MAIN METHODS: Cardiomyocytes were isolated from neonatal mice and treated with PEDF under normoxic and hypoxic conditions; then, apoptosis was assessed using Annexin V/PI staining and flow cytometry. Western blotting and immunofluorescence staining were used to detect PEDF receptor expression, and siRNA knockdown of PEDF receptors was performed to determine which receptor was involved in mediating cardiomyocyte apoptosis. KEY FINDINGS: Our results demonstrated that PEDF increased cardiomyocyte apoptosis during hypoxia via Fas and that PEDF receptors were expressed on cardiomyocyte cell membranes. Furthermore, siRNA experiments indicated that the PEDF receptor PLA2 was responsible for inducing cardiomyocyte apoptosis via the Fas pathway. SIGNIFICANCE: PEDF promoted Fas-induced cardiomyocyte apoptosis via its receptor PLA2.

Impaired cardiac SIRT1 activity by carbonyl stress contributes to aging-related ischemic intolerance.

Reactive aldehydes can initiate protein oxidative damage which may contribute to heart senescence. Sirtuin 1 (SIRT1) is considered to be a potential interventional target for I/R injury management in the elderly. We hypothesized that aldehyde mediated carbonyl stress increases susceptibility of aged hearts to ischemia/reperfusion (I/R) injury, and elucidate the underlying mechanisms with a focus on SIRT1. Male C57BL/6 young (4-6 mo) and aged (22-24 mo) mice were subjected to myocardial I/R. Cardiac aldehyde dehydrogenase (ALDH2), SIRT1 activity and protein carbonyls were assessed. Our data revealed that aged heart exhibited increased endogenous aldehyde/carbonyl stress due to impaired ALDH2 activity concomitant with blunted SIRT1 activity (P<0.05). Exogenous toxic aldehydes (4-HNE) exposure in isolated cardiomyocyte verified that aldehyde-induced carbonyl modification on SIRT1 impaired SIRT1 activity leading to worse hypoxia/reoxygenation (H/R) injury, which could all be rescued by Alda-1 (ALDH2 activator) (all P<0.05). However, SIRT1 inhibitor blocked the protective effect of Alda-1 on H/R cardiomyocyte. Interestingly, myocardial I/R leads to higher carbonylation but lower activity of SIRT1 in aged hearts than that seen in young hearts (P<0.05). The application of Alda-1 significantly reduced the carbonylation on SIRT1 and markedly improved the tolerance to in vivo I/R injury in aged hearts, but failed to protect Sirt1(+/-) knockout mice against myocardial I/R injury. This was verified by Alda-1 treatment improved postischemic contractile function recovery in ex vivo perfused aged but not in Sirt1(+/-) hearts. Thus, aldehyde/carbonyl stress is accelerated in aging heart. These results provide a new insight that impaired cardiac SIRT1 activity by carbonyl stress plays a critical role in the increased susceptibility of aged heart to I/R injury. ALDH2 activation can restore this aging-related myocardial ischemic intolerance.

Relationships of adiponectin with markers of systemic inflammation and insulin resistance in infants undergoing open cardiac surgery.

BACKGROUND: Insulin resistance and systemic inflammation frequently occur in infants undergoing cardiac surgery with cardiopulmonary bypass, while adiponectin has been demonstrated to have insulin-sensitizing and anti-inflammatory properties in obesity and type 2 diabetes mellitus. In this prospective study, we aimed to investigate the association of adiponectin with insulin resistance and inflammatory mediators in infants undergoing cardiac surgery with cardiopulmonary bypass. METHODS AND RESULTS: From sixty infants undergoing open cardiac surgery, blood samples were taken before anesthesia, at the initiation of cardiopulmonary bypass and at 0, 6, 12, 24, and 48 hours after the termination of cardiopulmonary bypass. Plasma interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF- α ), and adiponectin levels were assessed in blood samples. Insulin resistance was measured by assessment of the insulin requirement to maintain euglycaemia and repeated measurements of an insulin glycaemic index. Insulin glycaemic index, IL-6, and TNF- α increased up to 3-8-fold 6 h after the operation. Adiponectin is negatively correlated with markers of systemic inflammation 6 h after CPB. CONCLUSIONS: Although the level of serum adiponectin decreased significantly, there was a significant inverse association of adiponectin with markers of systemic inflammation and insulin resistance in infants undergoing open cardiac surgery.

Cardioprotective effect of ghrelin in cardiopulmonary bypass involves a reduction in inflammatory response.

BACKGROUND: Ghrelin has been reported to protect the cardiovascular system; however, the cardioprotective effect of ghrelin against cardiopulmonary bypass (CPB) induced myocardial injury are unclear. In this study, the protective effect of ghrelin on CPB induced myocardial injury and the underlying mechanisms were investigated. METHODS AND RESULTS: Adult male rats were subjected to CPB and randomly to receive vehicle (n = 8), ghrelin (n = 8), ghrelin plus [D-Lys3]-GHRP-6, a GHSR-1a inhibitor (n = 8), or ghrelin plus wortmannin, a phosphoinositide 3'-kinase (PI3K) inhibitor (n = 8). In vitro study was performed on cultured cardiomyocytes subjected to simulated cardiopulmonary bypass (SCPB). Ghrelin attenuated the inflammatory response, as evidenced by reduced induction of TNF-α, IL-6 and myocardial myeloperoxidase activity and concurrent reduction in apoptosis, oxidative stress, and levels of myocardial injury markers following CPB. Moreover, ghrelin significantly increased cardiac function after CPB. In cultured cardiomyocytes subjected to simulated CPB, ghrelin increased cell viability and decreased the percentage of apoptotic myocytes. Inhibition of ghrelin downstream signaling blocked the cardioprotective effects both in vivo and vitro. CONCLUSIONS: Ghrelin could provide an effective approach to the attenuation of CPB induced myocardial injury. The cardioprotective effects elicited by ghrelin may contribute to the inhibition of inflammatory response through the Akt-activated pathway.