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

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.

Giuseppe Moruzzi: a tribute to a "formidable" scientist and a "formidable" man.

Giuseppe Moruzzi was born one century ago; he was an outstanding Italian neurophysiologist, who was particularly famous for his contributions to the study of the mechanisms underlying the control of the sleep-waking cycle in mammals. In 1990, Rita Levi-Montalcini, Moruzzi's great friend and admirer, used the occasion of an invitation by the University of Parma, where Moruzzi graduated in medicine in 1933, to celebrate Moruzzi's scientific achievements. She wished to pay a tribute to Moruzzi's human and ethical qualities by portraying him as a "perfect model" for the young generation wishing to pursue scientific research. The transcription of "Rita's" tribute to Moruzzi links two of the greatest figures of Italian neuroscience and also provides a lively account of how the personal histories of two promising young scientists intertwined with the great and tragic events of world history in the past century.

Experimental and clinical evidence of neuroprotection by nerve growth factor eye drops: Implications for glaucoma.

Elevated intraocular pressure (IOP) in glaucoma causes loss of retinal ganglion cells (RGCs) and damage to the optic nerve. Although IOP is controlled pharmacologically, no treatment is available to restore retinal and optic nerve function. We evaluated the effects of NGF eye drops in a rat model of glaucoma. We also treated 3 patients with progressive visual field defects despite IOP control. Glaucoma was induced in rats through injection of hypertonic saline into the episcleral vein. Initially, 2 doses of NGF (100 and 200 mug/mL) were tested on 24 rats, and the higher dose was found to be more effective. Glaucoma was then induced in an additional 36 rats: half untreated and half treated with 200 mug/mL NGF QID for 7 weeks. Apoptosis/survival of RGCs was evaluated by histological, biochemical, and molecular analysis. Three patients with advanced glaucoma underwent psychofunctional and electrofunctional tests at baseline, after 3 months of NGF eye drops, and after 3 months of follow-up. Seven weeks of elevated IOP caused RGC degeneration resulting in 40% cell death. Significantly less RGC loss was observed with NGF treatment (2,530 +/- 121 vs. 1,850 +/- 156 RGCs/mm(2)) associated with inhibition of cell death by apoptosis. Patients treated with NGF demonstrated long lasting improvements in visual field, optic nerve function, contrast sensitivity, and visual acuity. NGF exerted neuroprotective effects, inhibiting apoptosis of RGCs in animals with glaucoma. In 3 patients with advanced glaucoma, treatment with topical NGF improved all parameters of visual function. These results may open therapeutic perspectives for glaucoma and other neurodegenerative diseases.

Recombinant human nerve growth factor with a marked activity in vitro and in vivo.

Recombinant human nerve growth factor (rhNGF) is regarded as the most promising therapy for neurodegeneration of the central and peripheral nervous systems as well as for several other pathological conditions involving the immune system. However, rhNGF is not commercially available as a drug. In this work, we provide data about the production on a laboratory scale of large amounts of a rhNGF that was shown to possess in vivo biochemical, morphological, and pharmacological effects that are comparable with the murine NGF (mNGF), with no apparent side effects, such as allodynia. Our rhNGF was produced by using conventional recombinant DNA technologies combined with a biotechnological approach for high-density culture of mammalian cells, which yielded a production of approximately 21.5 +/- 2.9 mg/liter recombinant protein. The rhNGF-producing cells were thoroughly characterized, and the purified rhNGF was shown to possess a specific activity comparable with that of the 2.5S mNGF by means of biochemical, immunological, and morphological in vitro studies. This work describes the production on a laboratory scale of high levels of a rhNGF with in vitro and, more important, in vivo biological activity equivalent to the native murine protein.

Thyroid hormone administration enhances remyelination in chronic demyelinating inflammatory disease.

Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degeneration, which follow remyelination failure. Due to the presence of numerous oligodendrocyte precursors inside demyelination plaques, one reason for demyelination failure could be the inability of oligodendrocyte precursor cells to turn into myelinating oligodendrocytes. In this study, we show that thyroid hormone enhances and accelerates remyelination in an experimental model of chronic demyelination, i.e., experimental allergic encephalomyelitis in congenic female Dark Agouti rats immunized with complete guinea pig spinal cord. Thyroid hormone, when administered during the acute phase of the disease, increases expression of platelet-derived growth factor alpha receptor, restores normal levels of myelin basic protein mRNA and protein, and allows an early and morphologically competent reassembly of myelin sheaths. Moreover, thyroid hormone exerts a neuroprotective effect with respect to axonal pathology.