Recombinant Elabela-Fc fusion protein has extended plasma half-life and mitigates post-infarct heart dysfunction in rats

Advances in the study of ELABELA in renal physiological functions and related diseases

ELABELA (ELA), also known as Toddler or Apela, is a novel endogenous ligand of the angiotensin receptor AT1-related receptor protein (APJ). ELA is highly expressed in human embryonic, cardiac, and renal tissues and involves various biological functions, such as embryonic development, blood circulation regulation, and maintaining body fluid homeostasis. ELA is also closely related to the occurrence and development of acute kidney injury, hypertensive kidney damage, diabetic nephropathy, renal tumors, and other diseases. Understanding the physiological role of ELA and its mechanism of action in kidney-related diseases would provide new targets and directions for the clinical treatment of kidney diseases.

Development of HEK293T-produced recombinant receptor-Fc proteins as potential candidates against canine distemper virus

Canine distemper (CD) is a highly contagious viral disease worldwide. Although live attenuated vaccine is available as a preventive measure against the disease, cases of vaccination failure highlight the importance of potential alternative agent against canine distemper virus (CDV). CDV infects cells mainly by binding signaling lymphocyte activation molecule (SLAM) and Nectin-4 receptor. Here, to develop a new and safe antiviral biological agent for CD, we constructed and expressed CDV receptor proteins fused with Fc region of canine IgG-B, namely, SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc in HEK293T cells, and antiviral activity of these receptor-Fc proteins was subsequently evaluated. The results showed that the receptor-Fc proteins efficiently bound to receptor binding domain (RBD) of CDV-H, meanwhile, these receptor-Fc proteins competitively inhibited the binding of His-tagged receptor proteins (SLAM-His or Nectin-His) to CDV-H-RBD-Flag protein. Importantly, receptor-Fc proteins exhibited potent anti-CDV activity in vitro. Treatment with receptor-Fc proteins at the pre-entry stage dramatically suppressed CDV infectivity in Vero cells stably expressing canine SLAM. The minimum effective concentration (MEC) of SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc was 0.2 μg/mL, 0.2 μg/mL, 0.02 μg/mL. The 50% inhibition concentration (IC₅₀) of three proteins was 0.58 μg/mL, 0.32 μg/mL and 0.18 μg/mL, respectively. Moreover, treatment with receptor-Fc proteins post viral infection can also inhibit CDV reproduction, the MEC of SLAM-Fc, Nectin-Fc and SLAM-Nectin-Fc was same as pre-treatment, and the IC₅₀ of receptor-Fc proteins was 1.10 μg/mL, 0.99 μg/mL and 0.32 μg/mL, respectively. The results suggested that the receptor-Fc proteins were more effective for pre-entry treatment than post-infection treatment, furthermore, SLAM-Nectin-Fc was more effective than SLAM-Fc and Nectin-Fc. These findings revealed the receptor-Fc proteins were promising candidates as inhibitor against CDV.

Plasma Levels of Apelinergic System Components in Patients with Chronic and Acute Coronary Syndromes-A Pilot Study

The effects of the apelinergic system components apelin (AP) and elabela (ELA) in the regulation of human cardiovascular homeostasis, and data concerning the relationship between ELA and AP and coronary artery disease (CAD) are yet unknown. The aim of the study was the evaluation of AP, ELA and APJ-receptor levels in the plasma of patients with chronic coronary syndromes (CCS) and acute coronary syndromes (ACS). The study group consisted of 114 patients with CAD and 33 healthy controls. Patients were divided into two groups: with CCS (n = 30) and ACS (n = 84). Routine laboratory tests and plasma ELA, AP-17, AP-13 and APJ receptor levels were measured. Echocardiographic data were analyzed in all patients. Levels of AP-17 and ELA were significantly lower in CCS than in healthy controls and ACS patients. We demonstrated significant increase of levels of plasma apelinergic system peptides, especially ELA and AP-17 in ACS patients compared with healthy controls and CCS, suggestive of compensating up-regulation mechanisms. There is a relationship between circulating ELA and AP-17 levels and classical, biochemical markers of ischemia and left ventricular ejection faction as well.