Association of Circulating Autophagy Proteins ATG5 and Beclin 1 with Acute Myocardial Infarction in a Case-Control Study.

INTRODUCTION: Acute myocardial infarction (AMI) is a main contributor of sudden cardiac death worldwide. The discovery of new biomarkers that can improve AMI risk prediction meets a major clinical need for the identification of high-risk patients and the tailoring of medical treatment. Previously, we reported that autophagy a highly conserved catabolic mechanism for intracellular degradation of cellular components is involved in atherosclerotic plaque phenotype and cardiac pathological remodeling. The crucial role of autophagy in the normal and diseased heart has been well described, and its activation functions as a pro-survival process in response to myocardial ischemia. However, autophagy is dysregulated in ischemia/reperfusion injury, thus promoting necrotic or apoptotic cardiac cell death. Very few studies have focused on the plasma levels of autophagy markers in cardiovascular disease patients, even though they could be companion biomarkers of AMI injury. The aims of the present study were to evaluate (1) whether variations in plasma levels of two key autophagy regulators autophagy-related gene 5 (ATG5) and Beclin 1 (the mammalian yeast ortholog Atg6/Vps30) are associated with AMI and (2) their potential for predicting AMI risk. METHODS: The case-control study population included AMI patients (n = 100) and control subjects (n = 99) at high cardiovascular risk but without known coronary disease. Plasma levels of ATG5 and Beclin 1 were measured in the whole population study by enzyme-linked immunosorbent assay. RESULTS: Multivariate analyses adjusted on common cardiovascular factors and medical treatments, and receiver operating characteristic curves demonstrated that ATG5 and Beclin 1 levels were inversely associated with AMI and provided original biomarkers for AMI risk prediction. CONCLUSION: Plasma levels of autophagy regulators ATG5 and Beclin 1 represent relevant candidate biomarkers associated with AMI.

Autophagy-related 5 in acute ischemic stroke: Variation and linkage with neurofunction, and survival.

OBJECTIVE: Autophagy-related 5 (ATG5) facilitates the pathologic process of acute ischemic stroke (AIS) via multiple ways. This study aimed to identify the association of serum ATG5 with clinical outcomes in AIS patients. METHODS: Serum ATG5 from 280 AIS patients were detected at admission, Day (D)1, D3, D7, D30, and D90 after admission by enzyme-linked immunosorbent assay. The median (interquartile range) follow-up was 21.1 (5.9-43.9) months. Another 50 healthy controls (HCs) were also enrolled for serum ATG5 determination. RESULTS: ATG5 was elevated (p < 0.001) (vs. HCs), and positively correlated with hyperlipidemia (p = 0.016), and the national institutes of health stroke scale score (p = 0.001) in AIS patients. Interestingly, ATG5 was increased from admission to D1, but gradually decreased until D90 (p < 0.001). Besides, 85 (30.4%) and 195 (69.6%) AIS patients were assessed as modified Rankin Scale (mRS) >2 and mRS ≤2 at D90, respectively. ATG5 at admission, D1, D3, D30, and D90 was elevated in AIS patients with mRS >2 versus those with mRS ≤2 (all p < 0.050). ATG5 at admission, D1, D3, D7, D30, or D90 was elevated in relapsed (vs. non-relapsed) or died (vs. survived) AIS patients (all p < 0.050). Recurrence-free survival was shortened in AIS patients with high (≥52.0 ng/mL) ATG5 versus those with low (<52.0 ng/mL) ATG5 at admission, D3, D7, and D30 (all p < 0.050); overall survival was shorter in AIS patients with high (vs. low) ATG5 at D7 and D30 (both p < 0.050). INTERPRETATION: Serum ATG5 elevates at first, thereafter gradually declines, whose elevation associates with neurological dysfunction, recurrence, and death risk in AIS patients.

Clinically Applicable Serum Biomarkers Among 14 Candidates Associated With Recurrence of Stage II and III Colorectal Cancer.

BACKGROUND/AIM: We evaluated the predictive value of candidate serum biomarkers for recurrence in stage II and III colorectal cancer (CRC) after curative surgery. PATIENTS AND METHODS: A total of 33 and 120 patients with CRC with or without recurrence at 5 years after curative surgery were included in the training set and the validation set, respectively. Possible serum biomarkers were examined for associations with CRC recurrence using receiver operating characteristics (ROC) curve analysis. RESULTS: In the training set, the expression levels of the 14 biomarkers were compared according to recurrence. Among them, five biomarkers that had significantly different expression levels were validated in 60 patients with recurrence at 5 years after curative surgery and 60 patients without. Multivariate analysis showed that natural log-transformed values of carcinoembryonic antigen (CEA), cyclin-dependent kinase regulatory subunit 2 (CKS2), 2'-5'-oligoadenylate synthetase 2 (OAS2), and autophagy-related gene 5 (ATG5) in preoperative serum were significantly related to recurrence. ROC analysis showed that these biomarkers were able to discriminate patients with recurrence from those without (area under the curve=0.828, 95% confidence interval=0.755-0.990). CONCLUSION: Preoperative serum levels of CEA, CKS2, OAS2 and ATG5 were independent risk factors for recurrence. A combination of serum CEA, CKS2, OAS2 and ATG5 predicted tumor recurrence well in patients with stage II and III CRC.

Evaluation of the Diagnostic and Predictive Value of Serum Levels of ANT1, ATG5, and Parkin in Multiple Sclerosis.

OBJECTIVE: Multiple Sclerosis (MS) is a disease of the central nervous system, which ultimately may lead to various disabilities in patients. No definitive cure has yet been developed for the disease. MRI is the method of choice for imaging MS plaques, which would be useful in disease diagnosis as it becomes progressive. Therefore, this study aimed to investigate the serum levels of ANT1 (adenine nucleotide translocase 1), ATG5 (autophagy-related protein 5), and Parkin in patients with MS, all of which play essential roles in MS pathophysiology, as novel serum biomarkers for early diagnosis of the disease. DESIGN AND METHODS: Forty patients in the early stages of the disease, and 40 healthy individuals were selected as the case and control groups. Upon sampling, the serum levels of the biomarkers were measured. RESULTS: The results indicated that autophagy, mitophagy, and mitochondrial apoptosis were different in the case and control groups. The oxidative stress level evaluation revealed low concertation of total antioxidant status (TAS) in the MS patients, while a partial increase accompanied the malondialdehyde (MDA). No significant correlation was observed between oxidative stress and autophagy or mitophagy factors. CONCLUSION: According to the results obtained from this study, the evaluation of serum levels of ANT1, ATG5, and Parkin could be applied in the diagnosis and follow-up of MS patients.

Evaluation of autophagy-related genes in Egyptian systemic lupus erythematosus patients.

Disturbances in autophagy are known to be implicated in autoimmune disorders. Many studies have connected polymorphisms in autophagy-related gene 5 (ATG-5) to systemic lupus erythematosus (SLE). Our aim was the determination of the expression level of ATG-5, Beclin-1 and microtubule-associated protein-light chain 3 (LC-3) in Egyptian SLE patients to investigate the impact of disturbances in autophagy genes on the incidence and progression of the disease. Also, we investigated the incidence of single nucleotide polymorphism (SNP) rs573775 in ATG-5 gene among Egyptian SLE patients. Our results showed that the mean levels of Beclin-1, LC-3 and interleukin (IL)-10 transcripts were significantly higher in SLE patients compared to healthy controls. The previous transcripts were positively correlated with SLE Disease Activity Index (SLEDAI). Beclin-1 and LC-3 transcripts were negatively correlated to complement component 3 (C3) levels. Only LC-3 transcripts were negatively correlated to complement component 4 (C4). The rs573775 SNP of ATG-5 with the variant allele was significantly associated with disease susceptibility, conferring a higher risk of SLE development. This variant allele was more prevalent in patients below 30 years, patients with anemia and in patients with anti-double-stranded DNA (dsDNA), confirming the essential role of ATG-5 polymorphism in the susceptibility of Egyptian patients to SLE.

The relationship between ANT1 and NFL with autophagy and mitophagy markers in patients with multiple sclerosis.

Multiple sclerosis (MS) is the most common inflammatory neurodegenerative disease. Neurofilament light chain (NFL) is a novel adverting biomarker of axonal damage that suggested as a useful assistant in the monitoring of MS patients. It has been shown that the auto/mitophagy associated with MS pathogenesis. In this study, we aimed to study correlation between ATG5 and Parkin, as markers of autophagy and mitophagy respectively, with NFL and ANT1 in serum and cerebrospinal fluid (CSF) in MS subjects. ATG5, Parkin, NFL, and ANT1 levels were measured in a cross-sectional study of 40 MS patients compared with gender, age and BMI matching healthy volunteers. Based on our results, levels of ATG5, Parkin, and NFL significantly were elevated in both serum and CSF of MS patients comparing control individuals (p < 0.0001) but ANT1 levels significantly was decreased in both serum and CSF of MS patients comparing control individuals (p < 0.0001). The correlation indices between NFL, ANTI1, ATG5 and Parkin in both case and control groups showed a direct and moderate the correlation between ANTI1 and ATG5 in the CSF level of the control group (r = 0.554, P = 0.011). Our data support the feasibility of quantifying of NFL as a sensitive and clinically meaningful serum/CSF biomarker to follow-up nerve tissue injury in MS condition.

The Effect of Chloroquine on the Development of Dry Eye in Sjögren Syndrome Animal Model.

Purpose: Sjögren syndrome (SS) is an autoimmune disease characterized by the inflammatory destruction of salivary and lacrimal glands (LG). Chloroquine (CQ) was known as an immunomodulatory drug and in the inhibition of autophagy. The purpose of the study is to investigate the effect of CQ on the development of dry eye in NOD-LtJ mice. Methods: NOD-LtJ mice were observed, during which the occurrence of dry eye was confirmed by tear secretion, corneal staining, and the infiltration of foci into the LG from 13-week-old mice. Intraperitoneal (IP) administration of CQ was performed in 13-week-old mice for 4 weeks and maintained untreated for another 4 weeks. Additionally, CQ was injected IP in 19-week-old mice for 2 weeks from when the disease was fully developed. Results: Interestingly, the expression of autophagy marker ATG5 and LC3B-II was observed in the LG from week 5. When CQ had been administered for 4 weeks from week 13 and then maintained untreated for 4 weeks, tear secretion, corneal staining score, foci formation in the LG, conjunctival goblet cells and proinflammatory cytokine expressions were significantly better than untreated mice. The infiltration of immune cells and the expression of autophagy markers in LG were decreased in the CQ group. These indices improved significantly as well when the 19-week-old mice with severe clinical phenotypes had been treated with CQ for 2 weeks. Conclusions: This study demonstrated that autophagy was induced in the early stages of the SS model and that CQ treatment in the early stages could inhibit disease progression.

Plasma ATG5 is increased in Alzheimer's disease.

Alzheimer's disease (AD) is a major cause of dementia. Growing evidence suggests that dysregulation of autophagy, a cellular mechanism essential for self-digestion of damaged proteins and organelles, is involved in neurological degenerative diseases including AD. Previously, we reported that autophagosomes are increased in the brains of AD mouse model. However, the plasma levels of autophagic markers have not yet been investigated in patients with AD. In this study, we investigated the expression of autophagy-related genes 5 and 12 (ATG5 and ATG12, respectively) in cells in vitro upon amyloid-beta (Aß) treatment and in the plasma of AD patients. ATG5-ATG12 complex levels were increased in primary rat cortical neurons and human umbilical vein endothelial cells after Aß treatment. Furthermore, we compared plasma from 69 patients with dementia, 82 patients with mild cognitive impairment (MCI), and 127 cognitively normal control participants. Plasma levels of ATG5 were significantly elevated in patients with dementia (149.3 ± 7.5 ng/mL) or MCI (152.9 ± 6.9 ng/mL) compared with the control subjects (129.0 ± 4.1 ng/mL) (p = 0.034, p = 0.016, respectively). Our results indicate that alterations in the plasma ATG5 levels might be a potential biomarker in patients at risk for AD.

Role of autophagy in the progress of coronary total occlusion.

OBJECTIVE: In this study, we measured the level of autophagy enzyme in patients with coronary artery disease (CAD) and investigated whether the role of autophagy existed in the progress of coronary collateral and coronary total occlusion (TO). METHODS: Overall, 115 participants were included in this study. They were divided into the three groups: group 1: patients had chronic TO (n=49); group 2: patients had acute TO such as myocardial infarction (n=36); and group 3: participants were normal controls (n=30). The enzyme-linked immunosorbent assay (ELISA) kit for autophagy-related protein 5 (ATG5) in the plasma was studied for these three groups. RESULTS: Autophagy levels were significantly different between the groups (13.7±5.3, 11.7±3.4, and 7.5±3 ng/mL, respectively; p<0.001). In the subgroup analysis, we found significant positive correlations between the level of autophagy and Rentrop score in the Group 1 (r=0.463, p<0.001). CONCLUSION: In the present study, autophagy levels were higher in the patients with CAD than in healthy controls. In addition, serum autophagy levels showed a significant positive correlation with the Rentrop score. An increased autophagy level may be considered an important activator and marker of the atherosclerotic inflammatory process in CAD (Tab. 1, Fig. 2, Ref. 20).