A novel triarylboron based ratiometric fluorescent probe for in vivo targeting and specific imaging of cancer cells expressing abnormal concentration of GGT

Abnormal expression of γ-glutamyltranspeptidase (GGT) in living organisms is closely associated with tumorigenesis. However, few reported fluorescence probes can specifically respond to abnormal concentration of GGT. Here, by functionalizing triarylboron moiety with three GGT-specific substrate (GSH) units, a novel fluorescence probe, TAB-3-GSH, was developed for detecting GGT. The results showed that TAB-3-GSH selectively responds to abnormally high levels of GGT (100-1000 U/L) rather than to normal GGT levels (<100 U/L) with ratiometric readout, since the amide linkage can be further hydrolyzed under high GGT levels. TAB-3-GSH was also capable of differentiating GGT-overexpressing ovarian cancer cells from normal cells, because of an improvement in the probe's cell membrane permeability upon reaction with GGT. Moreover, the probe could achieve selective imaging of SKOV-3 tumor site in xenograft mice model. Thus, TAB-3-GSH is a promising probe for tumor targeting in vivo.

Association Between γ-Glutamyltransferase Level and Cardiovascular or All-Cause Mortality in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis

This meta-analysis assessed the prognostic value of serum γ-glutamyltransferase (GGT) level for cardiovascular (CV) and all-cause mortality in patients with coronary artery disease (CAD). We conducted a systematic literature search of PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang, and Weipu databases until December 2018. Observational studies investigating the prognostic role of serum GGT level for CV and all-cause mortality in patients with CAD were included. Pooled risk ratios (RR) with 95% confidence intervals (CI) for the highest versus the lowest GGT level were used to summarize the prognostic value. Twelve studies involving 12 531 patients with CAD were included. Meta-analysis showed that elevated GGT level was significantly associated with higher risk of CV mortality (RR: 2.04; 95% CI: 1.57-2.64) and all-cause mortality (RR: 1.49; 95% CI: 1.27-1.74) in patients with CAD. This meta-analysis suggests that elevated serum GGT levels are an independent predictor of CV and all-cause mortality in patients with CAD. Determination of GGT level may improve the prediction of CV and all-cause mortality in patients with CAD.

Serum gamma-glutamyl transferase is a predictor of mortality in patients with acute myocardial infarction

Gamma-glutamyl transferase (GGT) is involved in the pathogenesis of atherosclerosis and has been associated with adverse cardiovascular outcomes in patients with ischemic heart disease. However, the association between GGT and long-term mortality has not been studied in patients with acute myocardial infarction (AMI).A total of 2239 AMI patients for whom serum GGT values were available and who underwent percutaneous coronary intervention (PCI) were enrolled in the COREA-AMI (CardiOvascular Risk and idEntificAtion of potential high-risk population in Korean patients with AMI) registry. Patients with acute liver injury were excluded. Patients were classified into 2 groups according to normal (n = 1983) or elevated (n = 256) levels of serum GGT. The primary clinical outcome was all-cause mortality. The secondary outcome was cardiac death and recurrent non-fatal myocardial infarction (MI).The median follow-up period was 3.7 years, and both groups had similar characteristics. Patients with elevated GGT had significantly higher all-cause mortality compared to patients with normal GGT (21.9% vs. 14.4%, P = .001). The multivariate Cox proportional hazards model showed that elevated serum GGT level was independently correlated with mortality (hazard ratio 2.12[1.44-3.11]; P < .001). Although elevated serum GGT was independently associated with long-term mortality after 30 days after PCI, there was no association within 30 days after PCI. Elevated GGT was also associated with death of cardiac causes with statistical significance. In the subgroup analysis, stronger associations were observed in the young and female patients and in patients who had ST-segment elevation MI and preserved left ventricular ejection fraction at the first echocardiography after the indexed PCI.Elevated serum GGT is an independent predictor of long-term mortality in AMI patients.

Gamma-glutamyl transferase and cardiovascular disease

Gamma-glutamyl transferase (GGT) is an enzyme located on the external surface of cellular membranes. GGT contributes in maintaining the physiological concentrations of cytoplasmic glutathione and cellular defense against oxidative stress via cleavage of extracellular glutathione and increased availability of amino acids for its intracellular synthesis. Increased GGT activity is a marker of antioxidant inadequacy and increased oxidative stress. Ample evidence suggests that elevated GGT activity is associated with increased risk of cardiovascular disease (CVD) such as coronary heart disease (CHD), stroke, arterial hypertension, heart failure, cardiac arrhythmias and all-cause and CVD-related mortality. The evidence is weaker for an association between elevated GGT activity and acute ischemic events and myocardial infarction. The risk for CVD or CVD-related mortality mediated by GGT may be explained by the close correlation of GGT with conventional CVD risk factors and various comorbidities, particularly non-alcoholic fatty liver disease, alcohol consumption, oxidative stress, metabolic syndrome, insulin resistance and systemic inflammation. The finding of GGT activity in atherosclerotic plaques and correlation of intra-plaque GGT activity with histological indexes of plaque instability may suggest a participation of GGT in the pathophysiology of CVD, particularly atherosclerosis. However, whether GGT has a direct role in the pathophysiology of CVD or it is an epiphenomenon of coexisting CVD risk factors or comorbidities remains unknown and Hill's criteria of causality relationship between GGT and CVD are not fulfilled. The exploration whether GGT provides prognostic information on top of the information provided by known cardiovascular risk factors regarding the CVD or CVD-related outcome and exploration of molecular mechanisms of GGT involvement in the pathophysiology of CVD and eventual use of interventions to reduce circulating GGT activity remain a duty of future studies.

Mitochondria-targeting ratiometric fluorescent probe for γ-glutamyltranspeptidase and its application to colon cancer

An indocyanine-based probe for γ-glutamyltranspeptidase exhibited ratiometric fluorescence in mitochondria through an enzyme-mediated amide-to-amine transformation reaction applicable for colon cancer detection.

Comparison of the effects of metoprolol or carvedilol on serum gamma-glutamyltransferase and uric acid levels among patients with acute coronary syndrome without ST segment elevation

Objective:

Serum gamma-glutamyltransferase (GGT) and uric acid levels measured in patients with acute coronary syndrome without ST segment elevation (NSTEMI) are important in diagnosis and in predicting the prognosis of the disease. There is a limited number of clinical studies investigating the effects of beta-blockers on GGT and uric acid levels in these patients. In our study, we aimed to investigate the effects of beta-blocker therapy on GGT and uric acid levels.

Methods:

We conducted a randomized, prospective clinical study. Hundred patients with NSTEMI were included in this study, and they were divided into two groups. Fifty patients were administered metoprolol succinate treatment (1 × 50 mg), whereas the remaining 50 patients were administered carvedilol treatment (2 × 12.5 mg). Thereafter, all of the patients underwent coronary angiography. Blood samples were taken at the time of admission, at the 1^st month, and 3^rd month to detect GGT and uric acid levels.

Results:

There was no statistically significant difference among the metoprolol or carvedilol groups in terms of the GGT levels measured at the baseline, 1^st month, and 3^rd month (p=0.904 and p=0.573, respectively). In addition, there was no statistically significant difference among the metoprolol or carvedilol groups in terms of uric acid levels measured at the baseline, 1^st month, and 3^rd month (p=0.601 and p=0.601, respectively).

Conclusion:

We found that GGT and uric acid levels did not show any change compared to the baseline values, with metoprolol and carvedilol treatment initiated in the early period in patients with NSTEMI.

What does serum γ-glutamyltransferase tell us as a cardiometabolic risk marker?

γ-glutamyltransferase plays a key role in the synthesis and metabolism of extracellular glutathione, a major antioxidant in several defence mechanisms in the body. γ-glutamyltransferase is affected by environmental and genetic factors, and is raised when there is depletion of glutathione. Hence, it is a marker of oxidative stress. There is robust evidence that γ-glutamyltransferase even when values are within the reference interval is associated with increased cardiovascular and all-cause mortality in both sexes, in normal subjects and subjects with coronary artery disease, in the middle-aged and the elderly after adjusting for confounding factors. γ-glutamyltransferase even within the reference interval is associated with future presentation of type 2 diabetes, and the longitudinal increase in γ-glutamyltransferase activity is associated with increased risk of type 2 diabetes and cardiovascular mortality. γ-glutamyltransferase is associated with cardiovascular risk factors and metabolic syndrome. It has a prognostic value after a previous acute myocardial infarction and may be an indicator of adverse outcome in acute coronary syndromes and other chronic cardiac disorders. There is limited data about γ-glutamyltransferase and any association with peripheral arterial disease and also whether knowing γ-glutamyltransferase activity improves cardiovascular risk prediction beyond conventional risk factors. γ-glutamyltransferase is present in atherosclerotic lesions in the coronary and carotid arteries, and has a prooxidant role leading to the production of reactive oxygen species and atherosclerosis. Current reference intervals for γ-glutamyltransferase are inappropriate and need to be addressed. Some laboratories still use non- International Federation of Clinical Chemistry methods for estimation of γ-glutamyltransferase which are associated with lower results. Such laboratories should review their method and consider changing to the International Federation of Clinical Chemistry method.

Gamma-glutamyltransferase predicts increased risk of mortality: a systematic review and meta-analysis of prospective observational studies

The aim of this study was to evaluate the association between gamma-glutamyltransferase (GGT) and mortality through a comprehensive analysis of existing evidence. PubMed, Embase, Chinese Biomedical Literature, and Science Citation Index databases were electronically searched. Studies were included if the study design was prospective and included reference and at-risk levels of GGT at baseline and mortality as a separate outcome. The quality of the studies included was assessed on the basis of Newcastle-Ottawa scale. Data from selected qualified studies were systematically reviewed, pooled, and analyzed according to the MOOSE guidelines and PRISMA statement. The results included the following: 1. 35 studies including 571,511 participants and 72,196 cases of mortality; 2. GGT, even at physiologic levels, was associated with increased all-cause mortality and cardiovascular mortality, and might also be associated with cancer-related mortality in the general population; and 3. GGT was very likely to be associated with all-cause mortality and cardiovascular mortality in patients with coronary artery disease and type 2 diabetes mellitus. Many of the studies included did not specifically exclude subjects with hepatic diseases or alcohol abuse, which may have obscured the results. Moderate heterogeneity was observed in the meta-analysis of GGT and all-cause mortality. Different compositions of cause-specific mortality might be the reason. However, subgroup analysis could only be performed on cardiovascular death because of insufficient information. GGT, even at physiologic high levels, predicted mortality, especially cardiovascular mortality and cancer mortality. The underlining mechanism and potential effects of GGT-targeted intervention on health warrant further investigation.

γ-Glutamyl transferase activity and the burden of coronary atherosclerosis in patients with ST-segment elevation myocardial infarction

The relationship between extent, severity, and complexity of coronary artery disease (CAD) in patients with ST-segment elevation myocardial infarction (STEMI) and serum γ-glutamyl transferase (GGT) activity has not been adequately studied. We evaluated the relationship between GGT activity and the burden of CAD as assessed by SYNTAX score (SXscore) in patients with STEMI. A total of 243 patients (age 67.1 ± 8.6, 77.4% male) with STEMI were divided into 2 groups. Low- and high-SXscore groups were defined as SXscore <22 and ≥22, respectively. Admission GGT activities were similar between low- and high-SXscore groups (32 ± 17 vs 33 ± 18; P = .625), and there was no significant correlation between GGT activity and SXscore. Although there was an association between high SXscore and major adverse cardiovascular events, as expected, our results did not demonstrate any relationship between admission GGT activities and complexity and extent of the coronary lesions in patients with STEMI.

The neutrophil to lymphocyte ratio was associated with impaired myocardial perfusion and long term adverse outcome in patients with ST-elevated myocardial infarction undergoing primary coronary intervention

OBJECTIVES

In the present study we aimed to reveal any probable correlation between neutrophil-to-lymphocyte ratio (N/L ratio) and the occurrence of no-reflow, along with assessment of the prognostic value of N/L ratio in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The N/L ratio stands practically for the balance between neutrophil and lymphocyte counts in the body, which can also be utilized as an index for systemic inflammatory status.

METHODS

In our study, we included 204 consecutive patients suffering from STEMI who underwent primary percutaneous coronary intervention (PCI). Patients with STEMI were assigned into distinct tertiles based on their N/L ratios on admission. No-reflow encountered following PCI was evaluated through both angiography [Thrombolysis in Myocardial Infarction (TIMI) flow and myocardial blush grade (MBG)] and electrocardiography (as ST-segment resolution).

RESULTS

Patients featured with no ST-resolution were documented to have displayed significantly higher N/L ratio on admission compared to those with intermediate or complete ST-segment resolution. The number of the patients characterized with no-reflow, evident both angiographically (TIMI flow ≤ 2 or TIMI flow 3 with final myocardial bush grade ≤ 2 after PCI) and electrocardiographically (ST-resolution <30%), was encountered to depict increments throughout successive N/L ratio tertiles. Moreover, the same also held true for three-year mortality rates across the tertile groups (9% vs. 15% vs. 35%, p < 0.01). Multivariable logistic regression analysis disclosed that N/L ratio on admission stood for a significant indicator for long-term mortality in patients with no-reflow phenomenon detected with MBG. Elevated N/L ratio on admission was also found to be a significant indicator for three-year mortality and major adverse cardiac events.

CONCLUSIONS

In patients with STEMI who underwent primary PCI, elevated N/L ratios on admission were revealed to be correlated with both no-reflow phenomenon and long-term prognosis.