Species-specific effects of neuregulin-1β (cimaglermin alfa) on glucose handling in animal models and humans with heart failure

Serum neuregulin 1 in relation to ventricular function and subclinical atherosclerosis in type 2 diabetes patients

BACKGROUND AND AIMS

Neuregulin 1 (NRG-1) is one of the members of the epidermal growth factors proteins. The present study provides novel insights into the relationship between serum levels of NRG-1 and insulin resistance, subclinical atherosclerosis and cardiac dysfunction that occur in type 2 diabetes (T2D).

METHODS

The study included 50 patients with T2D and 40 healthy age- and gender-matched controls. Serum NRG-1 was measured using ELISA. Glycemic parameters, lipid profile and insulin resistance were assessed. Trans-thoracic echocardiography and carotid intima media thickness (CIMT) were studied for all study subjects.

RESULTS

T2D patients had significantly lower serum NRG-1 levels than controls. Serum NRG-1 was negatively correlated with age, fasting blood glucose, HbA1c, insulin resistance, blood urea, serum creatinine and LDL-C, and positively correlated with HDL-C, eGFR and CIMT. Regarding echocardiographic variables, serum NRG-1 was found to correlate positively with left ventricular global longitudinal strain and negatively with E/Ea ratio. NRG-1 was found to predict subclinical atherosclerosis in type 2 diabetes patients at a cut-off value<108.5pg/ml with 78% sensitivity and 80% specificity.

CONCLUSIONS

A robust relationship was found between serum NRG-1 levels and hyperglycemia, insulin resistance, subclinical atherosclerosis, and cardiac dysfunction in patients with type 2 diabetes. These results shed light on a possible role of NRG-1 as a potential noninvasive biomarker for detection of cardiometabolic risk in T2D.

Neuregulin (NRG-1β) Is Pro-Myogenic and Anti-Cachectic in Respiratory Muscles of Post-Myocardial Infarcted Swine

Neuregulin-1β (NRG-1β) is a growth and differentiation factor with pleiotropic systemic effects. Because NRG-1β has therapeutic potential for heart failure and has known growth effects in skeletal muscle, we hypothesized that it might affect heart failure-associated cachexia, a severe co-morbidity characterized by a loss of muscle mass. We therefore assessed NRG-1β's effect on intercostal skeletal muscle gene expression in a swine model of heart failure using recombinant glial growth factor 2 (USAN-cimaglermin alfa), a version of NRG-1β that has been tested in humans with systolic heart failure. Animals received one of two intravenous doses (0.67 or 2 mg/kg) of NRG-1β bi-weekly for 4 weeks, beginning one week after infarct. Based on paired-end RNA sequencing, NRG-1β treatment altered the intercostal muscle gene expression of 581 transcripts, including genes required for myofiber growth, maintenance and survival, such as MYH3, MYHC, MYL6B, KY and HES1. Importantly, NRG-1β altered the directionality of at least 85 genes associated with cachexia, including myostatin, which negatively regulates myoblast differentiation by down-regulating MyoD expression. Consistent with this, MyoD was increased in NRG-1β-treated animals. In vitro experiments with myoblast cell lines confirmed that NRG-1β induces ERBB-dependent differentiation. These findings suggest a NRG-1β-mediated anti-atrophic, anti-cachexia effect that may provide additional benefits to this potential therapy in heart failure.

Mechanisms of the Multitasking Endothelial Protein NRG-1 as a Compensatory Factor During Chronic Heart Failure

Heart failure is a complex syndrome whose phenotypic presentation and disease progression depends on a complex network of adaptive and maladaptive responses. One of these responses is the endothelial release of NRG (neuregulin)-1—a paracrine growth factor activating ErbB2 (erythroblastic leukemia viral oncogene homolog B2), ErbB3, and ErbB4 receptor tyrosine kinases on various targets cells. NRG-1 features a multitasking profile tuning regenerative, inflammatory, fibrotic, and metabolic processes. Here, we review the activities of NRG-1 on different cell types and organs and their implication for heart failure progression and its comorbidities. Although, in general, effects of NRG-1 in heart failure are compensatory and beneficial, translation into therapies remains unaccomplished both because of the complexity of the underlying pathways and because of the challenges in the development of therapeutics (proteins, peptides, small molecules, and RNA-based therapies) for tyrosine kinase receptors. Here, we give an overview of the complexity to be faced and how it may be tackled.