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P C Marchisio

Publications and source records attributed to P C Marchisio.

At least 127 records · Page 7Linked to original sources
PubMed1980

Intracellular distribution of nerve growth factor in rat pheochromocytoma PC12 cells: evidence for a perinuclear and intranuclear location.

The distribution of nerve growth factor (NGF) in rat pheochromocytoma cells (clone PC12) has been studied with two different techniques: immunofluorescence and autoradiography. It was found that NGF is progressively internalized in the cytoplasmic compartment and eventually accumulates in the form of discrete dots around the nucleus. A fraction of the internalized NGF appears within the nucleoplasm, often contiguous with the nucleolus. It is suggested that cytoplasmic and perinuclear NGF may be be in contact with a pool of tubulin or actin-like proteins in their soluble or organized form and play a key role in the process of arrest of division and neurite growth.

Actins↗
PubMed1979

Identification of multiple microtubule initiating sites in mouse neuroblastoma cells.

Mouse neuroblastoma N-18 cells can be induced by serum deprivation to sprout multiple neurite-like processes which contain many microtubules. Mitotic drugs such as colcemid and colchicine depolymerize these microtubules and the cells lose their processes. Reappearance of microtubules after removal of the drugs was followed by immunofluorescence microscopy using tubulin specific antibodies. At early recovery times multiple star-like structures which contained tubulin were detected in the perinuclear are and in the cytoplasm of individual cells. The mean number seen per cell as approximately 5. Their formation preceeded the organization of the complex microtubular networks typical of N-18 cells. The probable action of these structures as microtubular organization centers (MTOCs) is discussed. Multiple structures were detected during recovery from the influence of mitotic drugs both in previously induced and non-induced N-18 cells, suggesting that N-18 cells harbour the potential of formation of multiple organization centers even without previous induction. We discuss the possibility that differentiation of neuroblastoma N-18 cells may require microtubular organization centers.

Animals↗
PubMed1978

Changes in intracellular organization of tubulin and actin in N-18 neuroblastoma cells during the process of axon extension induced by serum deprivation.

Specific antibodies against actin and tubulin have been used to follow the distribution and organization of actin and tubulin containing structures in N-18 neuroblastoma cells induced to sprout axons. Immunofluorescence microscopy shows that during the time of axonal sprouting microtubules converge into growing processes forming dense bundles in which individual microtubules cannot be resolved. In the growth cone where individual fluorescent fibers can again be distinguished microtubules seem to be excluded from the very margin. Actin is predominantly located at the cell periphery both in cell bodies and in cell processes. It appears to be present in areas of high surface motility and is especially abundant at the tip of the growth cone.

Actins↗
PubMed1978

The intracellular organization of actin and tubulin in cultured C-1300 mouse neuroblastoma cells (clone NB41A3).

Cells of clone NB41A3 of the C-1300 mouse neuroblastoma were grown to a critical density at which many of the cells flatten, assume a variety of shapes and sizes and some sprout processes resembling neurites. We have studied the distribution of actin and tubulin in these cells using fluorescence microscopy and antibodies against actin or tubulin under these conditions. Actin-containing structures are variably arranged and predominantly associated with motile areas of the cell periphery including the growth cone. Microtubules appear to run radially from the perinuclear area towards the cell periphery. When neurites are present, microtubules converge into them and run to the growth cone but rarely contact its edge.

Actins↗
PubMed1975

Dynamic properties of axonal transport of proteins and glycoproteins: a study based on the effects of metaphase blocking drugs in the developing optic pathway of chick embryos.

Some properties of the axonal transport of proteins and glycoproteins along the optic pathway of chick embryos and newly hatched chicks were studied by labelling retinal ganglion cells with 3H-proline or 3H-fucose. A study of the effects of colchicine (COL) and vinblastine (VLB) on embryonic axonal transport was also carried out. Marked changes in the efficiency of axonal transport were found throughout development. In particular, the fraction of retinal ganglion cell proteins which is rapidly exported toward tectal terminals increases during embryonic life but steadily decreases after hatching. Glycoprotein transport behaves similarly except that its efficiency is relatively higher at stages when critical events of synaptic maturation in the tectum are reported to occur. Embryonic axonal transport is blocked by COL and VLB at very low intravitreal concentrations. Retinal protein synthesis and the morphology of ganglion cells are profoundly altered by the drugs: in general, COL and VLB effects were much more marked in embryonic than in mature neurons. An analysis of the time course of rapid transport along embryonic optic axons was carried out by reducing the efflux of labelled proteins from the eye by giving VLB intravitreally 2 h after the pulse. It revealed some peculiar features in the retino-tectal migration of glycoproteins and confirmed their progressive accumulation within terminals as previously described by radioautography. These results suggest that axonal transport of proteins during embryonic life undergoes changes in parallel with synaptic maturation. It may thus be considered as one of the factors controlling the genesis of neuronal networks.

Animals↗