Nerve growth factor regulates axial rotation during early stages of chick embryo development

Abstract

Nerve growth factor (NGF) was discovered because of its neurotrophic actions on sympathetic and sensory neurons in the developing chicken embryo. NGF was subsequently found to influence and regulate the function of many neuronal and non neuronal cells in adult organisms. Little is known, however, about the possible actions of NGF during early embryonic stages. However, mRNAs encoding for NGF and its receptors TrkA and p75 NTR are expressed at very early stages of avian embryo development, before the nervous system is formed. The question, therefore, arises as to what might be the functions of NGF in early chicken embryo development, before its well-established actions on the developing sympathetic and sensory neurons. To investigate possible roles of NGF in the earliest stages of development, stage HH 11-12 chicken embryos were injected with an anti-NGF antibody (mAb αD11) that binds mature NGF with high affinity. Treatment with anti-NGF, but not with a control antibody, led to a dose-dependent inversion of the direction of axial rotation. This effect of altered rotation after anti NGF injection was associated with an increased cell death in somites. Concurrently, a microarray mRNA expression analysis revealed that NGF neutralization affects the expression of genes linked to the regulation of development or cell proliferation. These results reveal a role for NGF in early chicken embryo development and, in particular, in the regulation of somite survival and axial rotation, a crucial developmental process linked to left-right asymmetry specification.neurotrophins | rotatin | csk | furin | proNGF

Evidence for the involvement of NGF in human sperm motility

“…The low-affinity receptor p75, serves as a panneurotrophin receptor mediating pro-apoptotic or prosurvival cell programs [4]. NGF and its receptors had been reported to exist in the testis and NGF was expressed in Leydig cells, primary spermatocytes and pachytene spermatocytes [5].…”

Rita Levi-Montalcini: Neuroscientist par excellence

“…With her colleague Antonino Cattaneo, anti-NGF antibodies were injected into early chicken embryos. They observed a surprising result and the findings were published in January 2012 in PNAS (20). This was a fitting end to an illustrious career.…”

Rita Levi-Montalcini: NGF, the prototypical growth factor

“…Her most recent experiments were published in January 2012 (2), which made her the oldest member of the National Academy of Sciences to publish in PNAS. Levi-Montalcini is no longer alive, but she has transferred her knowledge and enthusiasm to a cadre of talented young scientists, who undoubtedly will continue to carry on her search for the biological functions of NGF.…”

“…To her surprise, Capsoni observed localized cell death at the level of somites, but also noticed a more significant effect: the embryos injected with anti-NGF antibodies displayed an abnormal 3D shape within 48 hours of injection, which the team determined was caused by a defect in a crucial rotation process that the embryo undergoes during development ( Fig. 2) (2). This rotation is the result of a coordinated wave of proliferation that seems to be regulated by NGF.…”