P75 neurotrophin receptor is a regulatory factor in sudden cardiac death with myocardial infarction

Implication of the neurotrophin receptor p75NTR in vascular diseases: beyond the eye

INTRODUCTION

The p75 neurotrophin receptor (p75^NTR) is a member of TNF-α receptor superfamily that bind all neurotrophins, mainly regulating their pro-apoptotic actions. Ischemia is a common pathology in different cardiovascular diseases affecting multiple organs, however the contribution of p75^NTR remains not fully addressed. The aim of this work is to review the current evidence through published literature studying the impact of p75^NTR receptor in ischemic vascular diseases.

AREAS COVERED

In the eye, several ischemic ocular diseases are associated with enhanced p75^NTR expression. Ischemic retinopathy including diabetic retinopathy, retinopathy of prematurity and retinal vein occlusion are characterized initially by ischemia followed by excessive neovascularization. Beyond the eye, cerebral ischemia, myocardial infarction and critical limb ischemia are ischemic cardiovascular diseases that are characterized by altered expression of neurotrophins and p75^NTR expression. We surveyed both clinical and experimental studies that examined the impact of p75^NTR receptor in ischemic diseases of eye, heart, brain and peripheral limbs.

EXPERT COMMENTARY

p75^NTR receptor is a major player in multiple ischemic vascular diseases affecting the eye, brain, heart and peripheral limbs with significant increases in its expression accompanying neuro-vascular injury. This has been addressed in the current review along with the beneficial vascular outcomes of p75^NTR inhibition.

Functional Ser205Leu polymorphism of the nerve growth factor receptor (NGFR) gene is associated with vagal autonomic dysregulation in humans

Evidence indicates that reduced cardiac vagal (parasympathetic) tone, a robust cardiovascular risk factor, is a trait vulnerability marker of major depressive disorder (MDD). The Ser205/Ser205 genotype of the functional polymorphism (Ser205Leu) of the nerve growth factor receptor (NGFR), also called p75 neurotrophin receptor (p75^NTR), gene is reported to increase the risk of MDD. Here, we hypothesized that the NGFR Ser205Leu polymorphism may have an effect on vagal control. A sample of 810 healthy, drug-free, unrelated Han Chinese (413 males, 397 females; mean age 35.17 ± 8.53 years) was included in the NGFR genotyping. Short-term heart rate variability (HRV) was used to assess vagus-mediated autonomic function. Potential HRV covariates, such as mood/anxiety status and serum metabolic parameters, were assessed. Homozygotes of the Ser205 allele had significantly lower high frequency power and root mean square of successive heartbeat interval differences, both HRV indices of vagal modulation, compared to Leu205 allele carriers. Even after adjusting for relevant confounders, these associations remained significant. Further stratification by sex revealed that the associations were observed only in males. Our results implicate that decreased parasympathetic activity is associated with the NGFR Ser205/Ser205 genotype in a gender-specific manner, suggesting a potential role of NGFR polymorphism in modulating cardiac autonomic function.