Sarawut Kumphune

Combinatorial Determination of Ischemia Modified Albumin and Protein Carbonyl in the Diagnosis of NonST-Elevation Myocardial Infarction

Ischemia modified albumin (IMA) and Protein Carbonyl (PC) have known as proteins that are modified on the similar basis of oxidative stress induced protein modification and may have diagnostic potential in acute myocardial infarction. This study aims to evaluate the ability of using IMA and PC content to diagnose Non-ST elevation myocardial infarction (NSTEMI) and efficiency of combining these two markers. Serum from NSTEMI and healthy control were determined for serum IMA and PC content. The results showed that both of serum IMA level and PC content in NSTEMI was significantly higher than that of healthy controls. However, the PC content showed greater diagnostic performance than IMA. Combinatorial determination of serum IMA level with PC content level was enhanced test efficiency. In conclusion, our finding demonstrated that IMA and PC content can be used as a diagnostic marker for NSTEMI.

The serum protein carbonyl content level in relation to exercise stress test

Background: Protein carbonyl (P) is oxidatively-modified protein with diagnostic potential for acute myocardial infarction. However, many findings indicated the elevation of serum PC content level related to exercise, which could cause false positive results and limiting the specificity for acute coronary syndrome diagnosis. This study aims to evaluate the level of serum protein carbonyl content in healthy volunteers subjected to exercise stress test (EST). Materials and Methods: Serum from healthy volunteers was collected 5-10 min before performing EST and 1 hour after the EST was achieved. The serum was collected, and the serum PC content level was determined by spectrophotometric DNPH assay. Results: The serum PC content level after exercise stress test was significantly higher than that of before performing EST (0.373 ± 0.05 nM/mg vs. 0.275 ± 0.02 nM/mg, P < 0.0001). The results demonstrated that in both male and female, serum PC content level after EST was significantly higher than that of before performing EST (0.29 ± 0.03 nM/mg vs. 0.36 ± 0.05 nM/mg P < 0.0001 in male, 0.27 ± 0.02 nM/mg vs. 0.38 ± 0.06 nM/mg P < 0.0001 in female, respectively). Conclusions: This study demonstrated that exercise stress test could result in non-specificity and false positive increasing in serum PC content level in healthy subjects, which may cause misinterpretation when using PC as cardiac marker, especially in patients, who underwent exercise stress test or patients who performing heavy physical activities.

An in vitro endothelial cell protective effect of secretory leukocyte protease inhibitor against simulated ischaemia/reperfusion injury

Endothelial dysfunction is an essential deleterious modulator of ischaemia/reperfusion (I/R) injury. Secretory leukocyte protease inhibitor (SLPI) has demonstrated myocardial protection in cardiac transplantation; however, the effect of SLPI in endothelial I/R injury remains unexplored. In the present study, the effect of recombinant human SLPI (rhSLPI) treatment against endothelial cells (ECs) subjected to simulated I/R injury and the effect of treatment at different time points were determined. Human umbilical vein ECs (HUVECs) were subjected to normoxic or simulated I/R (sI/R) conditions, and rhSLPI at concentrations of 1, 10, 100 and 1,000 ng/ml was added to the cells prior to ischaemia, during ischaemia or at the onset of reperfusion. Endothelial injury and cytoskeleton disruption were assessed, and western blot analysis was conducted. The results revealed that rhSLPI treatment at 1,000 ng/ml significantly increased the HUVEC viability under sI/R injury (P<0.05). In addition, treatment with rhSLPI prior to or during ischaemia markedly attenuated the activity of lactase dehydrogenase compared with that in the sI/R group. In addition, the H2O2-induced reactive oxygen species production was reduced by ~17% upon rhSLPI pretreatment. Endothelial cytoskeleton disruption was also preserved by rhSLPI added prior to the reperfusion period. Furthermore, pretreatment with rhSLPI promoted protein kinase B activation, as well as reduced p38 mitogen-activated protein kinase phosphorylation and B-cell lymphoma 2-associated X protein expression in response to I/R injury. These findings indicated that rhSLPI possesses antioxidant and antiapoptotic properties against endothelial responses to I/R injury. Therefore, the cytoprotective effect of rhSLPI may provide a potential pharmaceutical target to limit endothelial-mediated I/R injury.

Correlation between cardio-ankle vascular index and biomarkers of oxidative stress.

Abstract Arterial stiffness is a pathological event related to arteriosclerosis that is also closely related to oxidative stress. The cardio-ankle vascular index (CAVI) is a novel arteriosclerotic index that has been used to detect arterial stiffness. However, the association between CAVI and oxidative stress has not yet been elucidated, especially in patients with risk of metabolic disorders. The aim of this study was to investigate the correlation between arterial stiffness by CAVI and biomarkers of oxidative stress. A total of 83 participants were enrolled in this study. Venous blood samples were collected for measurement of plasma oxidative biomarkers. All participants were examined for CAVI score. The univariate analysis showed that age (p < 0.001), systolic blood pressure (SBP) (p = < 0.001), plasma triglyceride (p = 0.02), plasma glucose (p = 0.003) are related to CAVI value. However, the multivariate analysis showed that age was the only significant independent factor related to the CAVI value. In addition, the CAVI and plasma malondialdehyde (MDA) levels showed a positive correlation (r = 0.29, p < 0.01) while, the CAVI was negatively correlated with catalase (CAT) (r = −0.4, p < 0.001) and GPx (r = −0.60, p < 0.001). In conclusion, this study demonstrated that age is the most influential factor for assessing arterial stiffness by the CAVI method, which is possibly due to the increase in oxidative stress.

Overexpression and pre-treatment of recombinant human Secretory Leukocyte Protease Inhibitor (rhSLPI) reduces an in vitro ischemia/reperfusion injury in rat cardiac myoblast (H9c2) cell

Abstract One of the major causes of cardiac cell death during myocardial ischemia is the oversecretion of protease enzymes surrounding the ischemic tissue. Therefore, inhibition of the protease activity could be an alternative strategy for preventing the expansion of the injured area. In the present study, we investigated the effects of Secretory Leukocyte Protease Inhibitor (SLPI), by means of overexpression and treatment of recombinant human SLPI (rhSLPI) in an in vitro model. Rat cardiac myoblast (H9c2) cells overexpressing rhSLPI were generated by gene delivery using pCMV2-SLPI-HA plasmid. The rhSLPI-H9c2 cells, mock transfected cells, and wild-type (WT) control were subjected to simulated ischemia/reperfusion (sI/R). Moreover, the treatment of rhSLPI in H9c2 cells was also performed under sI/R conditions. The results showed that overexpression of rhSLPI in H9c2 cells significantly reduced sI/R-induced cell death and injury, intracellular ROS level, and increased Akt phosphorylation, when compared to WT and mock transfection (p <0.05). Treatment of rhSLPI prior to sI/R reduced cardiac cell death and injury, and intra-cellular ROS level. In addition, 400 ng/ml rhSLPI treatment, prior to sI, significantly inhibited p38 MAPK phosphorylation and rhSLPI at 400–1000 ng/ml could increase Akt phosphorylation.