Serum Progranulin As a Risk Predictor in Patients with Acute Myocardial Infarction

Increased circulating progranulin is not sufficient to induce cardiac dysfunction or supraventricular arrhythmia

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, and the incidence of new-onset AF has been increasing over the past two decades. Several factors contribute to the risk of developing AF including age, preexisting cardiovascular disease, chronic kidney disease, and obesity. Concurrent with the rise in AF, obesity has followed the same two-decade trend. The contribution of circulating proteins to obesity-related AF is of particular interest in the field. In this study, we investigated the effects of increased circulating levels of the glycoprotein progranulin on the development of supraventricular arrhythmias and changes to cardiac function. AAV8-mediated overexpression of full-length mouse progranulin was used to increase plasma protein levels and determine susceptibility to supraventricular arrhythmias and changes in cardiac structure and function. C57Bl/6N mice were subjected to increased circulating levels of progranulin for 20 weeks. Cardiac conduction was evaluated by surface ECG with and without isoproterenol challenge, and cardiac structure and function were measured by echocardiography after 20 weeks of circulating progranulin overexpression. Increased circulating levels of progranulin were maintained throughout the 20-week study. The cardiac structure and function remained unchanged in mice with increased circulating progranulin. ECG indices (P wave duration, P amplitude, QRS interval) were unaffected by increased progranulin levels and no arrhythmogenic events were observed following the isoproterenol challenge. In our model, increased levels of circulating progranulin were not sufficient to induce changes in cardiac structure and function or elicit ECG abnormalities suggestive of susceptibility to supraventricular arrhythmias.

Determination of Serum Progranulin in Patients with Untreated Familial Hypercholesterolemia

Background: Familial hypercholesterolemia (FH) is an autosomal dominant trait characterized by elevated LDL-C concentrations and is associated with an increased risk of premature atherosclerosis. Progranulin (PGRN) is a multifunctional protein that is known to have various anti-atherogenic effects. To date, the use of serum PGRN in patients with FH has not been studied. Methods: In total, 81 untreated patients with heterozygous FH (HeFH) and 32 healthy control subjects were included in this study. Serum PGRN, sICAM-1, sVCAM-1, oxLDL and TNFα concentrations were determined by ELISA. Lipoprotein subfractions were detected by Lipoprint. We diagnosed FH using the Dutch Lipid Clinic Network criteria. Results: We could not find a significant difference between the PGRN concentrations of the HeFH patients and controls (37.66 ± 9.75 vs. 38.43 ± 7.74 ng/mL, ns.). We found significant positive correlations between triglyceride, TNFα, sVCAM-1, the ratio of small HDL subfraction and PGRN, while significant negative correlations were found between the ratio of large HDL subfraction and PGRN both in the whole study population and in FH patients. PGRN was predicted by sVCAM-1, logTNFα and the ratio of small HDL subfraction. Conclusions: The strong correlations between HDL subfractions, inflammatory markers and PGRN suggest that PGRN may exert its anti-atherogenic effect in HeFH through the alteration of HDL composition and the amelioration of inflammation rather than through decreasing oxidative stress.