Addition Of Nerve Growth Factor Research Articles

Increased phosphorylation of a specific nuclear protein in rat superior cervical ganglia in response to nerve growth factor

The addition of nerve growth factor to the media of cultures of sympathetic ganglia produces an increase in the phosphorylation of a specific nuclear protein. Similar data are obtained when nerve growth factor is administered in vivo . A comparable effect is produced by analogs of cyclic AMP.

Nerve growth factor increases activity of ornithine decarboxylase in superior cervical ganglia of young rats.

Nerve growth factor produces a rapid increase in the activity of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) in superior cervical ganglia of young rats in vivo and in vitro. Maximum activity occurs 6-7 hr after the addition of nerve growth factor. The nerve growth factor-mediated increase in ornithine decarboxylase activity in vitro can be prevented by the addition of cycloheximide, actinomycin D, or antibody to nerve growth factor. A number of other agents were tested for their ability to increase ornithine decarboxylase were tested for their ability to increase ornithine decarboxylase activity in the ganglia; only nerve growth factor, and, to a slight extent, insulin were able to raise the activity of the enzyme. High concentrations of dibutyryl cyclic AMP (10 mM) were able to mimic the effect of nerve growth factor.

Selective de novo synthesis of tyrosine hydroxylase in organ cultures of rat superior cervical ganglia after in vivo administration of nerve growth factor.

Tyrosine hydroxylase is synthesized de novo in rat superior cervical ganglia in organ culture. The differential rate of synthesis is not increased significantly by the addition of nerve growth factor to the culture. Prior administration of nerve growth factor in vivo, however, leads to an augmented synthesis of tyrosine hydroxylase in ganglia subsequently cultured in vitro. The differential rate of tyrosine hydroxylase synthesis was increased by a factor of between 3 and 4. Increases in the differential rate of synthesis were detected within 6 h; the rate reached a maximum 24 to 36 h after a single injection of nerve growth factor. Administration of actinomycin D or of nerve growth factor antibody in vivo prevented the nerve growth factor-induced increase in the differential rate of tyrosine hydroxylase synthesis in vitro. However, the increase in the synthetic rate of tyrosine hydroxylase was not prevented by the addition of actinomycin D to the culture.

Effect of nerve growth factor on the expression of colchicine-binding activity and 14-3-2 protein in an established line of human neuroblastoma.

Purified nerve growth factor induced the outgrowth of neurites from cultured human neuroblastoma cells (NJB line) and a concomitant increase in colchicine-binding activity in extracts from these cultures. The parallel stimulation of neurite outgrowth from the cells and colchicine-binding activity of the extracts is interpreted to represent de novo synthesis of microtubular subunit protein in response to the challenge by nerve growth factor. The regulation of the expression of 14-3-2 protein, a protein characteristic of differentiated neuronal cells, was not affected in NJB cells by the addition of nerve growth factor to the culture medium. 14-3-2 protein is present in NJB cells at a concentration equal to that present in human brain from subculture to the stationary phase of growth of the tumor cells. It was concluded that these two gene products, characteristic of differentiated neural cells, are not coordinately regulated in NJB human neuroblastoma cells.

Interaction of nerve growth factor with the mouse-brain neurotubule protein(s).

Addition of nerve growth factor to a 105,000 x g supernatant of mouse brain induces the formation of a precipitate whose main constituent is the microtubule protein(s) (tubulin). The binding of nerve growth factor to purified tubulin is not inhibited by colchicine and does not appear to depend on the presence of GTP or Mg(++). GTP, however, and divalent cations, exert a marked effect on the increased turbidity induced by interaction of nerve growth factor with tubulin. These findings are tentatively interpreted with the hypothesis that binding of the factor to tubulin and the induced aggregation is a sequential two-step process; the latter but not the former would be influenced by GTP or divalent cations.

Nerve growth factor: relationship to the cyclic AMP system of sensory ganglia.

Nerve growth factor and N(6),O(2)' dibutyryl adenosine 3',5'-monophosphate both stimulate neurite elongation by explanted ganglia. However, the addition of nerve growth factor does not lead to increased amounts of adenosine 3',5'-monophosphate in intact ganglia, nor does it stimulate adenylate cyclase activity in broken ganglia cells.

IN VITRO AGGREGATION OF MIXED EMBRYONIC KIDNEY AND NERVE CELLS

The possible role of nerve on growth of embryonic parenchymal organs such as kidney was explored by measuring macromolecular synthesis (DNA, RNA, and protein and three enzymes) in aggregates of mixed suspensions of cells from dissociated chick embryo kidney and nerve tissue. One and one-half to threefold increments in net synthesis of the three different types of macromolecules were observed in the mixed aggregates of kidney and nerve cells as compared with those of single organs or mixtures of kidney with nonneural cells. The addition of nerve-growth factor (NGF) did not significantly affect the results. Increased incorporation of label was paralleled by increases in chemically measured DNA and protein, suggesting an increase in growth in the mixed kidney-nerve aggregates compared with those of single tissues. Measurements of survival rate did not indicate increased cell stability in the mixed aggregates. The activities of three enzymes, acid phosphatase, alkaline phosphatase, and lactic dehydrogenase, were also enhanced two to four times in cultures of kidney plus nerve cells. Morphologic studies indicated a high degree of reorganization of tubular structures within the reaggregates of kidney cells alone or in those mixed with nerve. In addition, radioautographs of thymidine-(3)H-labeled cells in the aggregates showed a high level of DNA synthesis in the reformed tubular cells. Electron micrographs revealed the presence of large numbers of nerve fibers containing microtubules in the mixed cell aggregates. The data suggest a significant role for nerve in the growth processes of embryonic parenchymal organs.

Effect of a nerve growth factor on glucose metabolism by sympathetic and sensory nerve cells

The effect of a nerve factor on glucose metabolism of sympathetic, and sensory nerve cells has been investigated. The addition of nerve growth factor (0.05 μg/ml) to the incubation medium markedly increases the oxidation of glucose to CO 2. From experiments with specifically labelled glucose it would appear that this increase is mainly due to the oxidation of [ i- 14C]glucose. The ratio of the radioactivity recovered as 14CO 2 from C- i over that from C-6 was found to be approx. i.3 in control ganglia and approx. 2, or more, in the nerve growth factor-treated ganglia. These findings would suggest an activation of the hexose monophosphate pathway in the nerve cells under the influence of the nerve growth factor.