Nerve Growth Factor-β (Beta-NGF)

Nerve Growth Factor-β (Beta-NGF; NGF) is a basic protein of 118 amino acids which acts are a trophic factor for sensory and sympathetic neurons of the peripheral nervous system, and on cholinergic neurons of the anterior basal cerebrum^[1]. NGF involves in the regulation of neuronal survival and differentiation. Elevated levels of NGF are associated with the risk of post-traumatic stress disorder (PTSD). The trauma response leads to methylation of DNA nucleotides responsible for NGF expression. NGF levels have shown increased sympathetic fiber density proportional to NGF messenger RNA (mRNA) levels. NGF is also a seminal plasma protein commonly found in mammals. For example, NGF acts as an ovulation stimulating factor in camels and has been shown to have luteinizing effects in bulls. NGF has a potential function in the female reproductive system. For example, NGF plays an important role in ovulation induction, LH release, ovulation, luteal development, progesterone (P4) production, vascularization of luteal body, and gonadotropin response. Application of NGF to cattle enhances steroid production, luteal formation and function by increasing LH release, and leads to increased mRNA expression of markers of pregnancy and development downstream. In addition, the potential luteinizing effect of NGF could help overcome the current problem of early embryo loss^[2][3]. The similarity between human and bovine NGF protein sequence was 90.87%. Meanwhile, the similarity rate of human NGF with rat and mouse was 85.89% and 85.06%, respectively.