scholarly journals Necrosis-induced apoptosis promotes regeneration in Drosophila wing imaginal discs

Genetics ◽  
2021 ◽  
Author(s):  
Jacob Klemm ◽  
Michael J Stinchfield ◽  
Robin E Harris

Abstract Regeneration is a complex process that requires a coordinated genetic response to tissue loss. Signals from dying cells are crucial to this process and are best understood in the context of regeneration following programmed cell death, like apoptosis. Conversely, regeneration following unregulated forms of death such as necrosis have yet to be fully explored. Here we have developed a method to investigate regeneration following necrosis using the Drosophila wing imaginal disc. We show that necrosis stimulates regeneration at an equivalent level to that of apoptosis-mediated cell death and activates a similar response at the wound edge involving localized JNK signaling. Unexpectedly however, necrosis also results in significant apoptosis far from the site of ablation, which we have termed necrosis-induced apoptosis (NiA). This apoptosis occurs independent of changes at the wound edge and importantly does not rely on JNK signaling. Furthermore, we find that blocking NiA limits proliferation and subsequently inhibits regeneration, suggesting that tissues damaged by necrosis can activate programmed cell death at a distance from the injury to promote regeneration.

2021 ◽  
Author(s):  
Jacob Klemm ◽  
Michael J. Stinchfield ◽  
Robin Eastwood Harris

Regeneration is a complex process that requires a coordinated genetic response to tissue loss. Signals from dying cells are crucial to this process and are best understood in the context of regeneration following programmed cell death, like apoptosis. Conversely, regeneration following unregulated forms of death such as necrosis have yet to be fully explored. Here we have developed a novel method to investigate regeneration following necrosis using the Drosophila wing imaginal disc. We show that necrosis stimulates regeneration at levels comparable to that of apoptosis-mediated cell death, and activates a similar response at the wound edge involving local JNK signaling. Unexpectedly however, necrosis also results in significant apoptosis far from the site of ablation, which we have termed necrosis-induced apoptosis (NiA). This apoptosis occurs independent of changes at the wound edge and importantly does not rely on JNK signaling. Furthermore, we find that blocking NiA inhibits blastema formation and subsequently limits regeneration, suggesting that tissues damaged by necrosis activate programmed cell death at a distance from the injury to promote regeneration.


1994 ◽  
Vol 345 (1313) ◽  
pp. 247-250 ◽  

During Drosophila development, large numbers of cells undergo natural cell death. Even though the onset of these deaths is controlled by many different signals, most of the dying cells undergo common morphological and biochemical changes that are characteristic of apoptosis in vertebrates. We have surveyed a large fraction of the Drosophila genome for genes that are required for programmed cell death by examining the pattern of apoptosis in embryos homozygous for previously identified chromosomal deletions. A single region on the third chromosome (in position 75C1,2) was found to be essential for all cell deaths that normally occur during Drosophila embryogenesis. We have cloned the corresponding genomic DNA and isolated a gene, reaper , which is capable of restoring apoptosis when reintroduced into cell death defective deletions. The reaper gene is specifically expressed in cells that are doomed to die, and its expression precedes the first morphological signs of apoptosis by 1-2 h. This gene is also rapidly induced upon X-ray irradiation, and reaper deletions offer significant protection against radiation-induced apoptosis. Our results suggest that reaper represents a key regulatory switch for the activation of apoptosis in response to a variety of distinct signals.


2008 ◽  
Vol 6 (9) ◽  
pp. 6
Author(s):  
A. Strasser ◽  
A. Villunger ◽  
P. Bouillet ◽  
E.M. Michalak ◽  
L.A. O'Reilly ◽  
...  

Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 29-43 ◽  
Author(s):  
J.M. Abrams ◽  
K. White ◽  
L.I. Fessler ◽  
H. Steller

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.


1993 ◽  
Vol 106 (1) ◽  
pp. 201-208 ◽  
Author(s):  
V. Garcia-Martinez ◽  
D. Macias ◽  
Y. Ganan ◽  
J.M. Garcia-Lobo ◽  
M.V. Francia ◽  
...  

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.


Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1165-1174 ◽  
Author(s):  
A.J. Blaschke ◽  
K. Staley ◽  
J. Chun

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.


2018 ◽  
Vol 27 (1) ◽  
pp. 9-16
Author(s):  
Piret Hussar ◽  
Tõnu Järveots ◽  
Lazo Pendovski ◽  
Katerina Blagoevska ◽  
Trpe Ristoski ◽  
...  

Apoptosis is a process of programmed cell death that occurs in multicellular organisms. As T-2 toxin is known to induce apoptosis in mammalian cells, the aim of the present experiment was to study the toxic effect of T-2 on chicken liver tissue using apoptosis-related antibodies p21 and p53 which are involved in the p53/p21-mediated apoptotic signalling pathway. The experiment was conducted on fourteen 40-day-old broilers (Gallus gallus domesticus) who were divided into control and T-2 toxin groups. For the T-2 toxin group, T-2 toxin (Sigma, Germany) was dissolved in water and given per os for three consecutive days. The material of the liver was taken 24 hours after the last application. The specimens were fixed with 10% formalin and embedded into paraffin; slices 5 μm in thickness were cut followed by immunohistochemical staining with polyclonal primary antibodies p21 and p53 (Abcam, UK) according to the manufacturer’s guidelines (IHC kit, Abcam, UK). Strong expression of p21 and p53 found in hepatocytes, endotheliocytes and around blood vessels together with large tissue destructions in T-2 toxin group birds’ liver indicates apoptosis and histopathological changes in liver tissue during T-2 mycotoxicosis.


1999 ◽  
Vol 13 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Melissa P. Allen ◽  
Chan Zeng ◽  
Kristina Schneider ◽  
Xiaoyan Xiong ◽  
Mary Kay Meintzer ◽  
...  

Abstract We identified Ark, the mouse homolog of the receptor tyrosine kinase Axl (Ufo, Tyro7), in a screen for novel factors involved in GnRH neuronal migration by using differential-display PCR on cell lines derived at two windows during GnRH neuronal development. Ark is expressed in Gn10 GnRH cells, developed from a tumor in the olfactory area when GnRH neurons are migrating, but not in GT1–7 cells, derived from a tumor in the forebrain when GnRH neurons are postmigratory. Since Ark (Axl) signaling protects from programmed cell death in fibroblasts, we hypothesized that it may play an antiapoptotic role in GnRH neurons. Gn10 (Ark positive) GnRH cells were more resistant to serum withdrawal-induced apoptosis than GT1–7 (Ark negative) cells, and this effect was augmented with the addition of Gas6, the Ark (Axl) ligand. Gas6/Ark stimulated the extracellular signal-regulated kinase, ERK, and the serine-threonine kinase, Akt, a downstream component of the phosphoinositide 3-kinase (PI3-K) pathway. To determine whether ERK or Akt activation is required for the antiapoptotic effects of Gas6/Ark in GnRH neurons, cells were serum starved in the absence or presence of Gas6, with or without inhibitors of ERK and PI3-K signaling cascades. Gas6 rescued Gn10 cells from apoptosis, and this effect was blocked by coincubation of the cells with the mitogen-activated protein/ERK kinase (MEK) inhibitor, PD98059, or wortmannin (but not rapamycin). These data support an important role for Gas6/Ark signaling via the ERK and PI3-K (via Akt) pathways in the protection of GnRH neurons from programmed cell death across neuronal migration.


1994 ◽  
Vol 72 (11-12) ◽  
pp. 597-601 ◽  
Author(s):  
Reginald Halaby ◽  
Zahra Zakeri ◽  
Richard A. Lockshin

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.


Blood ◽  
1995 ◽  
Vol 86 (11) ◽  
pp. 4184-4193 ◽  
Author(s):  
G Eissner ◽  
F Kohlhuber ◽  
M Grell ◽  
M Ueffing ◽  
P Scheurich ◽  
...  

In this report, we show that ionizing radiation (IR) at a clinically relevant dose (4 Gy) causes apoptosis in macrovascular and microvascular human endothelial cells. Treatment of irradiated cells with a low dose of bacterial endotoxin (LPS), similar to the levels observed in serum during endotoxemia, enhanced the rate of apoptosis, although LPS alone was unable to induce programmed cell death. The cytokine and endotoxin antagonist interleukin-10 (IL-10) reduced the rate of LPS + IR-induced apoptosis to levels obtained with irradiation alone. Using neutralizing antibodies against tumor necrosis factor- alpha (TNF), we could show crucial involvement of TNF in the LPS- mediated enhancement of IR-induced apoptosis, but not in the IR-induced apoptosis per se. However, further analysis strongly suggested the transmembrane form of TNF (mTNF), but not soluble TNF, to be accountable for the LPS-mediated cytotoxic effects. Studies with anatagonistic receptor specific antibodies clearly showed that TNF receptor type I (TR60) is essential and sufficient to elicit this effect. These findings are of potential clinical importance because they may disclose a relevant mechanism that leads to endothelial damage after radiotherapy or total body irradiation used for conditioning in bone marrow transplantation and that may thus contribute to transplant related complications, especially in association with endotoxemia or related inflammatory states.


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