Programmed cell death (PCD) is an integral part of plant development and of responses to abiotic stress or pathogens. Although the morphology of plant PCD is, in some cases, well characterised and molecular mechanisms controlling plant PCD are beginning to emerge, there is still confusion about the classification of PCD in plants. Here we suggest a classification based on morphological criteria. According to this classification, the use of the term 'apoptosis' is not justified in plants, but at least two classes of PCD can be distinguished: vacuolar cell death and necrosis. During vacuolar cell death, the cell contents are removed by a combination of autophagy-like process and release of hydrolases from collapsed lytic vacuoles. Necrosis is characterised by early rupture of the plasma membrane, shrinkage of the protoplast and absence of vacuolar cell death features. Vacuolar cell death is common during tissue and organ formation and elimination, whereas necrosis is typically found under abiotic stress. Some examples of plant PCD cannot be ascribed to either major class and are therefore classified as separate modalities. These are PCD associated with the hypersensitive response to biotrophic pathogens, which can express features of both necrosis and vacuolar cell death, PCD in starchy cereal endosperm and during self-incompatibility. The present classification is not static, but will be subject to further revision, especially when specific biochemical pathways are better defined.

http://labs.bio.unc.edu/Dangl/pub/pdf/CellDeathDiff_vanDoorn_Nomenclature_2011.pdf

Morphological classification of plant cell deaths.

1560 Epithelial cells require attachment to extra-cellular matrix (ECM) to suppress an apoptotic cell death program termed anoikis. We describe a non-apoptotic cell death program in matrix-detached cells, termed entosis, that is initiated by a previously unrecognized and unusual process involving the invasion of one cell into another, leading to a transient state in which a live cell is contained within a neighboring host cell. These 9cell-in-cell9 structures closely resemble similar cytological features in human cancers. Although a small percentage of live internalized cells can be released, the majority of internalized cells undergo non-apoptotic cell death by lysosomal acidification. Based on these data, we present evidence for a tumor suppressive role of entosis in human breast cancer. Paradoxically, we have also found that entosis can promote the development of aneuploidy, as live internalized cells can disrupt cytokinesis of host cells leading to multinucleation in vitro and in vivo. Thus, entosis may be tumor suppressive in some contexts and paradoxically tumor promoting in others. Models to investigate the role of entosis in human tumors will be presented.

A non-apoptotic cell death process, entosis, that occurs by cell-in-cell invasion.

Lipid metabolism is regulated by multiple signaling pathways, and generates a variety of bioactive lipid molecules. These bioactive lipid molecules known as signaling molecules, such as fatty acid, eicosanoids, diacylglycerol, phosphatidic acid, lysophophatidic acid, ceramide, sphingosine, sphingosine-1-phosphate, phosphatidylinositol-3 phosphate, and cholesterol, are involved in the activation or regulation of different signaling pathways. Lipid metabolism participates in the regulation of many cellular processes such as cell growth, proliferation, differentiation, survival, apoptosis, inflammation, motility, membrane homeostasis, chemotherapy response, and drug resistance. Bioactive lipid molecules promote apoptosis via the intrinsic pathway by modulating mitochondrial membrane permeability and activating different enzymes including caspases. In this review, we discuss recent data in the fields of lipid metabolism, lipid-mediated apoptosis, and cancer therapy. In conclusion, understanding the underlying molecular mechanism of lipid metabolism and the function of different lipid molecules could provide the basis for cancer cell death rationale, discover novel and potential targets, and develop new anticancer drugs for cancer therapy.

Lipid Metabolism, Apoptosis and Cancer Therapy

The term “immunogenic cell death” (ICD) is commonly employed to indicate a peculiar instance of regulated cell death (RCD) that engages the adaptive arm of the immune system. The inoculation of cancer cells undergoing ICD into immunocompetent animals elicits a specific immune response associated with the establishment of immunological memory. Only a few agents are intrinsically endowed with the ability to trigger ICD. These include a few chemotherapeutics that are routinely employed in the clinic, like doxorubicin, mitoxantrone, oxaliplatin, and cyclophosphamide, as well as some agents that have not yet been approved for use in humans. Accumulating clinical data indicate that the activation of adaptive immune responses against dying cancer cells is associated with improved disease outcome in patients affected by various neoplasms. Thus, novel therapeutic regimens that trigger ICD are urgently awaited. Here, we discuss current combinatorial approaches to convert otherwise non-immunogenic instances of RCD into bona fide ICD.

https://biblio.ugent.be/publication/5960912/file/5960913.pdf

Combinatorial Strategies for the Induction of Immunogenic Cell Death

The process of apoptosis is essential for maintaining the physiologic balance between cell death and cell growth. This complex process is executed by two major pathways that participate in activating an executioner mechanism leading to chromatin disintegration and nuclear fragmentation. Dysregulation of these pathways often contributes to cancer development and resistance to cancer therapy. Here, we review the most recent discoveries in apoptosis regulation and possible mechanisms for resensitizing tumor cells to therapy.

https://www.mdpi.com/1422-0067/16/2/2942/pdf

A Time to Kill: Targeting Apoptosis in Cancer

In 1972 Kerr and colleagues collect the cell death under two headings. Although cell death is known as apoptosis ve necrosis, molecular studies add to morphological studies and according to this, this classification is extended. In 2009 NCCD classifies it entosis, mitotic collapse, necrosis, necropitosis and pyroptosis by using terminological words. In addition to these there are diffirent types of cell death in terms of signal pathway. These are autophagic cell death, carnification cell death, netoz cell death, partanatoz cell death, anoikis cell death. In this article these types of cell death is noticed in detail.

https://www.entomoljournal.com/vol1Issue5/Issue_oct_2013/14.1.pdf

Classification of Cell Death

The objective of the present study was to describe functional morphological features of venom apparatus in the tube web spider, Segestria florentina (Rossi, 1790) (Araneae: Segestriidae) by using scanning electron microscope (SEM). The venom apparatus is situated in the anterior part of the prosoma, and is composed of a pair of venom glands and chelicerae. The chelicera of S. florentina has two parts: basal segment and a movable articulated apical segment (fang). The cheliceral fang rests in a groove on the basal segment of chelicerae. A venom hole is located on the subterminal part of each fang. A pair of venom glands is completely separate but similar to each other within the prosoma.Each venom gland is surrounded by striated muscle bundles, such as with the capsules. The venom, produced in the venom glands, is carried by venom ducts passing throughout the chelicerae. Each venom gland has its own venom duct, chelicera and fang. The venom is excreted from the venom pore on the subterminal part of the fang by means of muscular contractions covering the venom gland.

https://www.entomoljournal.com/archives/2013/vol1issue4/PartA/23.pdf

Determining with SEM, structure of the venom apparatus in the tube web spider, Segestria florentina rn(Araneae: Segestriidae)

Acomys cilicicus, a species of the genus Acomys, which is the first mammal to have regeneration ability and attracts attention with its spiny-like structure, is an endemic species in Turkey. In recent years, species in the genus Acomys have been examined histologically due to their regeneration abilities. Although there are researches with regard to taxonomy of that species in the literature, there is not enough study on the subject of histology of its tissues. The aim of this study is to evaluate the available histomorphological data and documenting the normal microscobic features of the spleen and thymus tissues in A. cilicicus. In this study, 3 adult spiny mice (2 male and one female) were examined. All tissues obtained from those samples were fixed in 10% formalin and embedded in paraffin. Periodic Acid Schiff (PAS), Masson's trichrome, Gomori's silver soaking and Haematoxylin-Eosin were used for staining paraffin embedded sections. Histological analysis was carried out by using light microscopy. Histological data of the spleen and thymus tissues of A.cilicicus were reported in detailed.

/pdf/histological-evaluation-of-spleen-and-thymus-of-acomys-22d0b7ag.pdf

Histological Evaluation of Spleen and Thymus of Acomys cilicicus

Abstract Diabetes mellitus is a serious disease worldwide and causes other associated diseases. In this study, we observed the effect of streptozotocin (STZ)-induced diabetes and benfluorex treatment on muscular capillary ultrastructure. Adult male rats were used as the test subjects and each individual was intraperitoneally injected with one dose of STZ (45 mg/kg) to induce diabetes. Doses (50 mg/kg) of benfluorex were given to the subjects with tap water by intragastric gavage application once daily for 21 days. At the end of day 21, muscle tissues were obtained from animals and examined under transmission electron microscopy. From the data obtained with the electron microscope, it was observed that the control group had typical continuous capillary vascular structures in their muscles, while STZ caused disruptive disorder of the muscle cells in the capillary wall of the STZ-diabetic group. Additionally, the thickening of the basement membrane around endothelial cells, loss of mitochondrial crista in the muscle cells, enlarged endothelial cells, and narrowed vessel lumen were observed in the muscle tissue. The findings of our study revealed that STZ-induced diabetes disrupted the vascular structure, while benfluorex partially improved it.

The Ultrastructure of Skeletal Muscle Capillaries of Streptozotocin Diabetic Rats and the Therapeutic Effect of Benfluorex

Antioxidants are known to restrains various tissue damage caused by the administration of carbon tetrachloride (CCl4). This study examined whether melatonin (MEL), a molecule known to have antioxidant properties, has a protective effect on the rat soleus muscle, where toxic damage is caused by the application of CCl4. In the study, eighteen albino-type male Wistar rats were used and divided into three groups as Control Group (group 1), CCl4 group (group 2) and CCl4 + MEL group (group 3). End of the 12 weeks, blood samples were taken as intracardiac from the rats under ketamine/rompun anesthesia, and the soleus muscles of the rats were removed. Tissue samples were subjected to routine preparation procedures for light microscopy. Sections 5 µm thick taken and stained with hematoxylin-eosin (HE) for histopathological examinations and Masson’s Trichrome stain for fibrosis formations. In conclusion, the CCl4 group displayed muscular hypertrophy, fiber orientation dysfunction and atrophy in some areas. In addition, fibrosis was spotted around the venous and nerve plexuses. In contrast to the CCl4 group, the melatonin group displayed no fibrosis and maintained tissue integrity. Therefore, when comparing CCl4+MEL and CCl4 groups, it was observed that melatonin had a stabilizing or even curative effect on the injuries.

/pdf/the-effect-of-melatonin-on-rat-soleus-muscle-treated-with-3dh2i4hg.pdf

Suna Cebesoy

Papers

Classification of Cell Death

Determining with SEM, structure of the venom apparatus in the tube web spider, Segestria florentina rn(Araneae: Segestriidae)

Histological Evaluation of Spleen and Thymus of Acomys cilicicus

The Ultrastructure of Skeletal Muscle Capillaries of Streptozotocin Diabetic Rats and the Therapeutic Effect of Benfluorex

The effect of melatonin on rat soleus muscle treated with carbon tetrachloride