Metabolic events during programmed cell death in insect labial glands

The labial gland of Manduca sexta is a valuable system to study the mechanisms of programmed cell death since the death of the gland is nearly synchronous and, except for the anterior duct, involves all of the tissue. The gland degenerates in 5 days during pupation. Our previous work documents a drop in total protein synthesis as the gland degenerates. To evaluate potential causes of this altered protein synthesis, we monitored several parameters of metabolism in dying cells: levels of adenosine triphosphate to estimate the energy resources of the gland; reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide to assess mitochondrial respiration; levels of acid phosphatase to assay lysosomal enzyme activity; and concentrations of cyclic nucleotides and inositol triphosphate to monitor signaling. While protein synthesis fell precipitously on day 0, total adenosine triphosphate and mitochondrial respiration were unchanged until the cells underwent massive collapse on day 3. Lysosomal acid phosphatase increased during early metamorphosis, and ultimately the bulk of the cytoplasm was destroyed in autophagic vacuoles. Changes in the concentrations of second messengers were modest and late. The relationships between the metabolism and the collapse of the labial gland are under investigation.Key words: programmed cell death, Manduca sexta, energetics, lysosomes, second messengers, protein synthesis.

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Programmed cell death in the tobacco hornworm,Manduca sexta: Alteration in protein synthesis

Microscopy Research and Technique ◽

10.1002/(sici)1097-0029(19960615)34:3<192::aid-jemt2>3.0.co;2-s ◽

1996 ◽

Vol 34 (3) ◽

pp. 192-201 ◽

Cited By ~ 14

Author(s):

Zahra Zakeri ◽

Daniela Quaglino ◽

Theresa Latham ◽

Kim Woo ◽

Richard A. Lockshin

Keyword(s):

Cell Death ◽

Protein Synthesis ◽

Programmed Cell Death ◽

Manduca Sexta ◽

Tobacco Hornworm

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Programmed cell death: early changes in metamorphosing cells

Biochemistry and Cell Biology ◽

10.1139/o94-078 ◽

1994 ◽

Vol 72 (11-12) ◽

pp. 589-596 ◽

Cited By ~ 21

Author(s):

Richard A. Lockshin ◽

Zahra Zakeri

Keyword(s):

Cell Death ◽

Protein Synthesis ◽

Programmed Cell Death ◽

Manduca Sexta ◽

Energy Resources ◽

Type Ii ◽

Heavy Load ◽

Lysosomal Compartment ◽

Active Cell Death ◽

Labial Glands

Programmed cell death in intersegmental muscles and labial glands of Manduca sexta is a type II form of active cell death, in which lysosomal destruction of cytoplasm is a prominent and early feature, and the collapse of the nucleus is late and relatively modest until the bulk of the cytoplasm has been eroded. The prominent features of this collapse include an early expansion of the lysosomal compartment and a decrease in overall protein synthesis, while a small number of mRNAs persist or are upregulated. Energy resources appear to be adequate during the early stages of degeneration, and changes in levels of second messages likewise do not seem to be sufficiently dramatic to explain the failure of the tissue. There is some suggestion that DNA may not be completely intact long before the labial gland finally collapses, suggesting that it may fail under heavy load. Otherwise, we do not yet have an explanation for the precipitous drop in overall protein synthesis.Key words: programmed cell death, apoptosis, lysosomes, endonuclease, protein synthesis, Manduca sexta.

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Nerve growth factor withdrawal-induced cell death in neuronal PC12 cells resembles that in sympathetic neurons.

The Journal of Cell Biology ◽

10.1083/jcb.119.6.1669 ◽

1992 ◽

Vol 119 (6) ◽

pp. 1669-1680 ◽

Cited By ~ 156

Author(s):

P W Mesner ◽

T R Winters ◽

S H Green

Keyword(s):

Cell Death ◽

Protein Synthesis ◽

Nerve Growth Factor ◽

Growth Factor ◽

Programmed Cell Death ◽

Pc12 Cells ◽

Sympathetic Neurons ◽

Nerve Growth ◽

Neuronal Pc12 Cells ◽

New Protein

Previous studies have shown that in neuronal cells the developmental phenomenon of programmed cell death is an active process, requiring synthesis of both RNA and protein. This presumably reflects a requirement for novel gene products to effect cell death. It is shown here that the death of nerve growth factor-deprived neuronal PC12 cells occurs at the same rate as that of rat sympathetic neurons and, like rat sympathetic neurons, involves new transcription and translation. In nerve growth factor-deprived neuronal PC12 cells, a decline in metabolic activity, assessed by uptake of [3H]2-deoxyglucose, precedes the decline in cell number, assessed by counts of trypan blue-excluding cells. Both declines are prevented by actinomycin D and anisomycin. In contrast, the death of nonneuronal (chromaffin-like) PC12 cells is not inhibited by transcription or translation inhibitors and thus does not require new protein synthesis. DNA fragmentation by internucleosomal cleavage does not appear to be a consistent or significant aspect of cell death in sympathetic neurons, neuronal PC12 cells, or nonneuronal PC12 cells, notwithstanding that the putative nuclease inhibitor aurintricarboxylic acid protects sympathetic neurons, as well as neuronal and nonneuronal PC12 cells, from death induced by trophic factor removal. Both phenotypic classes of PC12 cells respond to aurintricarboxylic acid with similar dose-response characteristics. Our results indicate that programmed cell death in neuronal PC12 cells, but not in nonneuronal PC12 cells, resembles programmed cell death in sympathetic neurons in significant mechanistic aspects: time course, role of new protein synthesis, and lack of a significant degree of DNA fragmentation.

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Programmed cell death during Drosophila embryogenesis

Development ◽

10.1242/dev.117.1.29 ◽

1993 ◽

Vol 117 (1) ◽

pp. 29-43 ◽

Cited By ~ 30

Author(s):

J.M. Abrams ◽

K. White ◽

L.I. Fessler ◽

H. Steller

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Acridine Orange ◽

Nile Blue ◽

Molecular Genetic ◽

Blue Staining ◽

Nuclear Condensation ◽

The Central Nervous System ◽

Ultrastructural Appearance ◽

Dying Cells

The deliberate and orderly removal of cells by programmed cell death is a common phenomenon during the development of metazoan animals. We have examined the distribution and ultrastructural appearance of cell deaths that occur during embryogenesis in Drosophila melanogaster. A large number of cells die during embryonic development in Drosophila. These cells display ultrastructural features that resemble apoptosis observed in vertebrate systems, including nuclear condensation, fragmentation and engulfment by macrophages. Programmed cell deaths can be rapidly and reliably visualized in living wild-type and mutant Drosophila embryos using the vital dyes acridine orange or nile blue. Acridine orange appears to selectively stain apoptotic forms of death in these preparations, since cells undergoing necrotic deaths were not significantly labelled. Likewise, toluidine blue staining of fixed tissues resulted in highly specific labelling of apoptotic cells, indicating that apoptosis leads to specific biochemical changes responsible for the selective affinity to these dyes. Cell death begins at stage 11 (approximately 7 hours) of embryogenesis and thereafter becomes widespread, affecting many different tissues and regions of the embryo. Although the distribution of dying cells changes drastically over time, the overall pattern of cell death is highly reproducible for any given developmental stage. Detailed analysis of cell death in the central nervous system of stage 16 embryos (13-16 hours) revealed asymmetries in the exact number and position of dying cells on either side of the midline, suggesting that the decision to die may not be strictly predetermined at this stage. This work provides the basis for further molecular genetic studies on the control and execution of programmed cell death in Drosophila.

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Internucleosomal DNA fragmentation and programmed cell death (apoptosis) in the interdigital tissue of the embryonic chick leg bud

Journal of Cell Science ◽

10.1242/jcs.106.1.201 ◽

1993 ◽

Vol 106 (1) ◽

pp. 201-208 ◽

Cited By ~ 10

Author(s):

V. Garcia-Martinez ◽

D. Macias ◽

Y. Ganan ◽

J.M. Garcia-Lobo ◽

M.V. Francia ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Dna Fragmentation ◽

Limb Development ◽

Light Transmission ◽

Morphological Changes ◽

Death Process ◽

Chondrogenic Potential ◽

Cell Death Process ◽

Dying Cells

In this work we have attempted to characterize the programmed cell death process in the chick embryonic interdigital tissue. Interdigital cell death is a prominent phenomenon during limb development and has the role of sculpturing the digits. Morphological changes in the regressing interdigital tissue studied by light, transmission and scanning electron microscopy were correlated with the occurrence of internucleosomal DNA fragmentation, evaluated using agarose gels. Programming of the cell death process was also analyzed by testing the chondrogenic potential of the interdigital mesenchyme, in high density cultures. Our results reveal a progressive loss of the chondrogenic potential of the interdigital mesenchyme, detectable 36 hours before the onset of the degenerative process. Internucleosomal DNA fragmentation was only detected concomitant with the appearance of cells dying with the morphology of apoptosis, but unspecific DNA fragmentation was also present at the same time. This unspecific DNA fragmentation was explained by a precocious activation of the phagocytic removal of the dying cells, confirmed in the tissue sections. From our observations it is suggested that programming of cell death involves changes before endonuclease activation. Further, cell surface changes involved in the phagocytic uptake of the dying cells appear to be as precocious as endonuclease activation.

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Widespread programmed cell death in proliferative and postmitotic regions of the fetal cerebral cortex

Development ◽

10.1242/dev.122.4.1165 ◽

1996 ◽

Vol 122 (4) ◽

pp. 1165-1174 ◽

Cited By ~ 35

Author(s):

A.J. Blaschke ◽

K. Staley ◽

J. Chun

Keyword(s):

Cell Death ◽

Cerebral Cortex ◽

Programmed Cell Death ◽

Nuclear Dna ◽

Temporal Distribution ◽

Embryonic Cell ◽

Postnatal Life ◽

Neuron Development ◽

Cortical Cells ◽

Dying Cells

A key event in the development of the mammalian cerebral cortex is the generation of neuronal populations during embryonic life. Previous studies have revealed many details of cortical neuron development including cell birthdates, migration patterns and lineage relationships. Programmed cell death is a potentially important mechanism that could alter the numbers and types of developing cortical cells during these early embryonic phases. While programmed cell death has been documented in other parts of the embryonic central nervous system, its operation has not been previously reported in the embryonic cortex because of the lack of cell death markers and the difficulty in following the entire population of cortical cells. Here, we have investigated the spatial and temporal distribution of dying cells in the embryonic cortex using an in situ endlabelling technique called ‘ISEL+’ that identifies fragmented nuclear DNA in dying cells with increased sensitivity. The period encompassing murine cerebral cortical neurogenesis was examined, from embryonic days 10 through 18. Dying cells were rare at embryonic day 10, but by embryonic day 14, 70% of cortical cells were found to be dying. This number declined to 50% by embryonic day 18, and few dying cells were observed in the adult cerebral cortex. Surprisingly, while dying cells were observed throughout the cerebral cortical wall, the majority were found within zones of cell proliferation rather than in regions of postmitotic neurons. These observations suggest that multiple mechanisms may regulate programmed cell death in the developing cortex. Moreover, embryonic cell death could be an important factor enabling the selection of appropriate cortical cells before they complete their differentiation in postnatal life.

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