Plasminogen Activator Inhibitor-1 and Pericardial Fat in Individuals with Type 2 Diabetes Mellitus

Epicardial Adipose Tissue: A Novel Potential Imaging Marker of Comorbidities Caused by Chronic Inflammation

The observation of correlations between obesity and chronic metabolic and cardiovascular diseases has led to the emergence of strong interests in “adipocyte biology”, in particular in relation to a specific visceral adipose tissue that is the epicardial adipose tissue (EAT) and its pro-inflammatory role. In recent years, different imaging techniques frequently used in daily clinical practice have tried to obtain an EAT quantification. We provide a useful update on comorbidities related to chronic inflammation typical of cardiac adiposity, analyzing how the EAT assessment could impact and provide data on the patient prognosis. We assessed for eligibility 50 papers, with a total of 10,458 patients focusing the review on the evaluation of EAT in two main contexts: cardiovascular and metabolic diseases. Given its peculiar properties and rapid responsiveness, EAT could act as a marker to investigate the basal risk factor and follow-up conditions. In the future, EAT could represent a therapeutic target for new medications. The assessment of EAT should become part of clinical practice to help clinicians to identify patients at greater risk of developing cardiovascular and/or metabolic diseases and to provide information on their clinical and therapeutic outcomes.

A Vicious Cycle: In Severe and Critically Ill COVID-19 Patients

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is one of the fastest-evolving viral diseases that has instigated a worldwide pandemic. Severe inflammatory syndrome and venous thrombosis are commonly noted in COVID-19 patients with severe and critical illness, contributing to the poor prognosis. Interleukin (IL)-6, a major complex inflammatory cytokine, is an independent factor in predicting the severity of COVID-19 disease in patients. IL-6 and tumor necrosis factor (TNF)-α participate in COVID-19-induced cytokine storm, causing endothelial cell damage and upregulation of plasminogen activator inhibitor-1 (PAI-1) levels. In addition, IL-6 and PAI-1 form a vicious cycle of inflammation and thrombosis, which may contribute to the poor prognosis of patients with severe COVID-19. Targeted inhibition of IL-6 and PAI-1 signal transduction appears to improve treatment outcomes in severely and critically ill COVID-19 patients suffering from cytokine storms and venous thrombosis. Motivated by studies highlighting the relationship between inflammatory cytokines and thrombosis in viral immunology, we provide an overview of the immunothrombosis and immunoinflammation vicious loop between IL-6 and PAI-1. Our goal is that understanding this ferocious circle will benefit critically ill patients with COVID-19 worldwide.

Pericardial fat versus BMI in the assessment of coronary atherosclerotic burden in patients with diabetes mellitus

AIMS

To investigate the association of obesity measured by body mass index (BMI) versus pericardial fat volume (PFV) measured by multi-detector computed tomography (MDCT) with coronary atherosclerotic markers (coronary artery calcium score (CAC), coronary stenosis severity and coronary plaque presence) in patients with type 2 diabetes mellitus (DM).

METHODS

Among 496 patients with suspected coronary artery disease who underwent 64-slice MDCT angiography to exclude occlusive coronary artery disease, 102 patients with DM were enrolled in the present study.

RESULTS

PFV showed a significant association with CAC (r = 0.2, P = 0.01) and significant coronary artery stenosis [PFV median (IQR) = 75 (51-136) in patients with coronary stenosis < 50% versus PFV median (IQR) = 113 (68-140) in patients with coronary stenosis ≥ 50%, P = 0.01] while there was no significant association of PFV with coronary plaque presence (PFV median (IQR) = 84 (56-140) in patients without plaque versus PFV median (IQR) = 109 (70-136) in patients with plaque presence, P = 0.4). The association between PFV with CAC persisted after adjustment for conventional cardiac risk factors. BMI showed no significant association with CAC, coronary stenosis severity and coronary plaque presence (P > 0.05).

CONCLUSIONS

PFV was independently associated with CAC in diabetic patients. PFV, rather than obesity measured by BMI, could be used as an imaging biomarker for assessing coronary atherosclerotic burden in patients with DM.

miR-34a targets PAI-1 to regulate urinary microalbumin and renal function in hypertensive mice

Background

The aim of the study is to investigate the effects of miR-34a targeted at PAI-1 on urinary microalbumin and renal function in hypertensive mice.

Methods

Twenty specific-pathogen-free (SPF) BPN/3J mice were selected in normal group, and 120 SPF BPH/2J mice were evenly divided into model group, negative control group, miR-34a mimic group, miR-34a inhibitor group, Si-PAI-1 group, and miR-34a inhibitor + Si-PAI-1 group. qRT-PCR was used to detect the expression of miR-34a and PAI-1 mRNA. The protein expressions of PAI-1, angiotensin-converting enzyme (ACE) and ACE2 were detected by Western blot. Serum levels of AngII and Ang1-7 were detected by ELISA.

Results

miR-34a negatively regulated the expression of PAI-1. Compared with the normal group, mice in the other groups had significantly lower body weight, increased systolic blood pressure and 24-h urinary microalbumin content, decreased miR-34a expression, superoxide dismutase (SOD) and nitric oxide (NO) content, and ACE2 protein expression, and increased PAI-1 expression, serum creatinine (Scr), blood urea nitrogen (BUN) malondialdehyde (MDA), AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the model group, mice in the miR-34a mimic group and Si-PAI-1 group had no significant changes in body weight (all P > 0.05), while they had significantly lower systolic blood pressure and 24-h urinary microalbumin content, increased SOD and NO levels and ACE2 protein expression, and decreased PAI-1 expression, Scr, BUN, MDA, AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the miR-34a inhibitor group, symptoms in miR-34a inhibitor + Si-PAI-1 group were significantly improved (all P < 0.05).

Conclusions

miR-34a can inhibit the expression of PAI-1, thereby reducing urinary microalbumin content in hypertensive mice and protecting their renal function.

Association of SERPINE1 rs6092 with type 2 diabetes and related metabolic traits in a Chinese population

BACKGROUND

Plasminogen activator inhibitor-1 (PAI-I), encoded by SERPINE1 gene, is a member of the serine protease inhibitor superfamily, and polymorphisms in SERPINE1 have been reported to be associated with type 2 diabetes (T2D). This study investigated whether the polymorphism in PAI-I contribute to the risk for T2D.

METHODS

A 1:1 case-control study was conducted to investigate the association of rs6092 in SERPINE1 with T2D and diabetes-related metabolic traits, including body mass index, waist circumference (WC), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol, low density lipoprotein cholesterol, fasting plasma glucose and glycosylated hemoglobin (HbA1c) in a Chinese population, with a total of 1572 subjects (786 T2D patients and 786 healthy controls). The polymorphism was genotyped based on MassARRAY genotyping system.

RESULTS

The AA genotype and A allele of rs6092 exerted a protective effect on T2D risk (odds ratio (OR) = 0.431 and 0.630, respectively). In a recessive model, we also observed the protective association of rs6092 with T2D (OR = 0.195). The above associations were only observed in men. In female patients, there was a significant difference in HbA1c level between the AA homozygotes and GG homozygotes, as well as between the AA homozygotes and combined GG and GA genotypes. In male patients, the WC level in the subjects carrying AA genotype was lower than those in the subjects with GG genotype (P = 0.000), and the association was also significant in a recessive model (P = 0.000). Additionally, there was a significant difference in TG level between the AA homozygotes and GG homozygotes (P = 0.017), as well as the AA homozygotes and combined GG and GA genotypes (P = 0.032).

CONCLUSIONS

Our study suggests that the A allele and AA genotype of rs6092 may protect against T2D, and have a protective effect on WC, but a negative effect on TG in men, while may contribute to a lower HbA1c level in women.

Re: "Plasminogen Activator Inhibitor-1 and Pericardial Fat in Individuals with Type 2 Diabetes Mellitus" by Bayomi et al. (Metab Syndr Relat Disord 2017;15:269-275)

Plasminogen activator inhibitor-1 (PAI-1) is a member of the serine protease inhibitor (serpin) superfamily, which inactivates tissue plasminogen activator (tPA); therefore, increased level of PAI-1 antigen counteracts the anticoagulant effect of tPA and facilitates the fibrin clot formation. Plasma PAI-1 antigen and activity levels are associated with increased body mass index and with features of the insulin resistance syndrome like obesity and diabetes. Visceral adipose tissue produces more PAI-1 than subcutaneous adipose tissue: This increased production of PAI-1 from the visceral adipose tissue is one important link between visceral obesity and cardiovascular disease. Besides visceral adipose tissue, there is mounting evidence that epicardial adipose tissue may be an important source of PAI-1, especially in patients with type 2 diabetes.