Asian Journal of Pharmaceutical Research and Development Vol. 5 (3) May–June. 2017:1-10

Asian Journal of Pharmaceutical Research and Development (An International Peer-Reviewed Journal of Pharmaceutical Research and Development) www.ajprd.com ISSN 2320-4850 Review Article

A BRIEF REVIEW ON ANKIT*, RANU SHARMA, SURYA PRATAP SINGH, M. P. KHINCHI Department of Pharmacology, Kota College of Pharmacy, Kota, Rajasthan, India

ABSTRACT Apoptosis is a mechanism characterized by depolymerization of cytoskeleton, cell shrinkage, chromatin condensation, nuclear fragmentation and translocation of phosphatidylserine to the cell surface. This process is therefore called . Between 50 and 70 billion cells die each day due to apoptosis in the average human adult. Apoptosis and are considered to be distinct modes of cell death; however, apoptosis can progress to secondary necrosis if apoptotic cells are not efficiently removed by phagocytic cells. During the last decade, exceptional for the basic research, the apoptosis have attracted many attentions due to its potential application in therapying the various human . . In diseases caused by deficient apoptosis, such as cancer, viral latency and autoimmunity, methods of producing selective apoptosis are being sought

Keywords: depolymerisation, cytoskeleton, chromatin condensation, necrosis, phagocytic cell.

INTRODUCTION

poptosis is a cell death mechanism The cells of a multicellular organism are characterized by depolymerization of members of a highly organized community. A cytoskeleton, cell shrinkage, The number of cells in this community is chromatin condensation, nuclear fragmentation tightly regulated—not simply by controlling and translocation of phosphatidylserine to the the rate of cell division, but also by controlling cell surface. Apoptosis arises from a number the rate of cell death. If cells are no longer of stimuli that initiate multiple signaling needed, they commit suicide by activating an pathways which lead to caspase cascade intracellular death program. This process is activation and cell death. Increases in therefore called programmed cell death.[2] apoptotic activity are hallmarks of several Unlike necrosis, apoptosis produces cell states including AIDS, fragments called apoptotic bodies neurodegenerative disorders, insulin- that phagocytic cells are able to engulf and dependent diabetes, myocardial infarction and quickly remove before the contents of the cell atherosclerosis. .[1] can spill out onto surrounding cells and cause damage to the neighbouring cells.[3] *Corresponding author Ankit Sharma Between 50 and 70 billion cells die each day Kota College of Pharmacy, due to apoptosis in the average human Kota, Rajasthan adult. For an average child between the ages of E mail: [email protected] Mobile – 7597306841 8 and 14, approximately 20 billion to 30 billion cells die a day.[4] Research on apoptosis has increased substantially since the early 1990s. In addition to its importance as a

Ankit Sharma et al www.ajprd.com 1 Asian Journal of Pharmaceutical Research and Development Vol. 5 (3) May–June. 2017:1-10 biological phenomenon, defective apoptotic processes have been implicated in a wide variety of diseases. Excessive apoptosis example, the separation of fingers and toes in a causes , whereas an insufficient developing human embryo occurs because amount results in uncontrolled cell cells between the digits undergo apoptosis.[5] proliferation, such as cancer. Some factors like Fas receptors and caspases promote PATHWAYS apoptosis, while some members of the Bcl-2 The mechanisms of apoptosis are highly family of proteins inhibit apoptosis. Because complex and sophisticated, involving an apoptosis cannot stop once it has begun, it is a energy-dependent cascade of molecular highly regulated process. Apoptosis can be events. To date, research indicates that there initiated through one of two pathways. In are two main apoptotic pathways: the extrinsic the intrinsic pathway the cell kills itself or death receptor pathway and the intrinsic or because it senses cell stress, while in mitochondrial pathway. However, there is now the extrinsic pathway the cell kills itself evidence that the two pathways are linked and because of signals from other cells. Both that molecules in one pathway can influence pathways induce cell death by the other. There is an additional pathway that activating caspases, which are proteases, or involves T-cell mediated cytotoxicity and enzymes that degrade proteins. The two perforin-granzyme-dependent killing of the pathways both activate initiator caspases, cell. The perforin/granzyme pathway can which then activate executioner caspases, induce apoptosis via either granzyme B or which then kill the cell by degrading proteins granzyme A. The extrinsic, intrinsic, and indiscriminately. granzyme B pathways converge on the same Apoptosis and necrosis are considered to be terminal, or execution pathway. This pathway distinct modes of cell death; however, is initiated by the cleavage of caspase-3 and apoptosis can progress to secondary necrosis if results in DNA fragmentation, degradation of apoptotic cells are not efficiently removed by cytoskeletal and nuclear proteins, cross-linking phagocytic cells.In contrast to necrosis, which of proteins, formation of apoptotic bodies, is a form of traumatic cell death that results expression of ligands for phagocytic cell from acute cellular injury, apoptosis is a highly receptors and finally uptake by phagocytic regulated and controlled process that confers cells. The granzyme A pathway activates a advantages during an organism's lifecycle. For parallel, caspase-independent cell death pathway via single stranded DNA damage.[6]

Fig.1 Normal apoptosis process

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Figure 2 : Apoptotic Pathway By Different Pathways

Intrinsic Pathway Extrinsic Pathway Two theories of the direct initiation of The intrinsic signaling pathways that initiate apoptotic mechanisms in mammals have been apoptosis involve a diverse array of non-receptor- suggested: the TNF-induced (tumor necrosis mediated stimuli that produce intracellular signals factor) model and the Fas-Fas ligand- that act directly on targets within the cell and are mediated model, both involving receptors of mitochondrial-initiated events. The stimuli that the TNF receptor (TNFR) family[9] coupled to initiate the intrinsic pathway produce intracellular extrinsic signals. signals that may act in either a positive or negative fashion. Negative signals involve the absence of TNF path certain growth factors, hormones and cytokines that can lead to failure of suppression of death TNF-alpha is a cytokine produced mainly by programs, thereby triggering apoptosis. In other activated macrophages, and is the major words, there is the withdrawal of factors, loss of extrinsic mediator of apoptosis. Most cells in apoptotic suppression, and subsequent activation of the human body have two receptors for TNF- apoptosis. Other stimuli that act in a positive alpha: TNFR1 and TNFR2. The binding of fashion include, but are not limited to, radiation, TNF-alpha to TNFR1 has been shown to toxins, hypoxia, hyperthermia, viral , and initiate the pathway that leads to caspase free radicals. The mitochondria are essential to activation via the intermediate membrane multicellular life. Without them, a cell ceases proteins TNF receptor-associated death to respire aerobically and quickly dies. This fact domain (TRADD) and Fas-associated death forms the basis for some apoptotic pathways. domain protein (FADD). cIAP1/2 can inhibit Apoptotic proteins that target mitochondria affect TNF-α signaling by binding to TRAF2. FLIP [10] them in different ways. They may cause inhibits the activation of caspase-8. Binding mitochondrial swelling through the formation of of this receptor can also indirectly lead to the membrane pores, or they may increase the activation of transcription factors involved in permeability of the mitochondrial membrane and cell survival and inflammatory cause apoptotic effectors to leak out.[7][8] responses. However, signalling through TNFR1 might also induce apoptosis in a caspase-independent manner.[35]The link

Ankit Sharma et al www.ajprd.com 3 Asian Journal of Pharmaceutical Research and Development Vol. 5 (3) May–June. 2017:1-10 between TNF-alpha and apoptosis shows why bypassed and there is direct induction of the an abnormal production of TNF-alpha plays a execution phase of apoptosis. fundamental role in several human diseases, especially in autoimmune diseases. Execution Pathway

Fas path The extrinsic and intrinsic pathways both end at the point of the execution phase, considered the final The fas receptor (First apoptosis signal) – (also pathway of apoptosis. It is the activation of the known as Apo-1 or CD95) is a transmembrane execution caspases that begins this phase of protein of the TNF family which binds the Fas apoptosis. Execution caspases activate cytoplasmic ligand (FasL). The interaction between Fas endonuclease, which degrades nuclear material, and FasL results in the formation of the death- and proteases that degrade the nuclear and inducing signaling complex (DISC), which cytoskeletal proteins. Caspase-3, caspase-6, and contains the FADD, caspase-8 and caspase-10. caspase-7 function as effector or ―executioner‖ In some types of cells (type I), processed caspases, cleaving various substrates including caspase-8 directly activates other members of cytokeratins, PARP, the plasma membrane the caspase family, and triggers the execution cytoskeletal protein alpha fodrin, the nuclear of apoptosis of the cell. In other types of cells protein NuMA and others, that ultimately cause the (type II), the Fas-DISC starts a feedback loop morphological and biochemical changes seen in that spirals into increasing release of apoptosis. proapoptotic factors from mitochondria and the amplified activation of caspase-8.[10] Caspase-3 is considered to be the most important of the executioner caspases and is activated by any Perforin/granzyme Pathway of the initiator caspases (caspase-8, caspase-9, or caspase-10). Caspase-3 specifically activates the T-cell mediated cytotoxicity is a variant of type IV endonuclease CAD. In proliferating cells CAD is hypersensitivity where sensitized CD8+ cells kill complexed with its inhibitor, ICAD. In apoptotic antigen-bearing cells. These cytotoxic T cells, activated caspase-3 cleaves ICAD to release lymphocytes (CTLs) are able to kill target cells via CAD. CAD then degrades chromosomal DNA the extrinsic pathway and the FasL/FasR within the nuclei and causes chromatin interaction is the predominant method of CTL- condensation. Caspase-3 also induces cytoskeletal induced apoptosis. However, they are also able to reorganization and disintegration of the cell into exert their cytotoxic effects on tumor cells and apoptotic bodies. Gelsolin, an actin binding virus-infected cells via a novel pathway that protein, has been identified as one of the key involves secretion of the transmembrane pore- substrates of activated caspase-3. forming molecule perforin with a subsequent exophytic release of cytoplasmic granules through BIOCHEMICAL FEATURES the pore and into the target cell. The serine proteases granzyme A and granzyme B are the Apoptotic cells exhibit several biochemical most important component within the granules . modifications such as protein cleavage, protein cross-linking, DNA breakdown, and phagocytic Granzyme B will cleave proteins at aspartate recognition that together result in the distinctive residues and will therefore activate procaspase-10 structural described previously.[11] and can cleave factors like ICAD (Inhibitor of Caspases are widely expressed in an inactive Caspase Activated DNAse) . Reports have also proenzyme form in most cells and once activated shown that granzyme B can utilize the can often activate other procaspases, allowing mitochondrial pathway for amplification of the initiation of a protease cascade. Some procaspases death signal by specific cleavage of Bid and can also aggregate and autoactivate. This induction of cytochrome c release. However, proteolytic cascade, in which one caspase can granzyme B can also directly activate caspase-3. In activate other caspases, amplifies the apoptotic this way, the upstream signaling pathways are signaling pathway and thus leads to rapid cell death.

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Caspases have proteolytic activity and are able to Calreticulin is a protein that binds to an LDL- cleave proteins at aspartic acid residues, although receptor related protein on the engulfing cell and is different caspases have different specificities suggested to cooperate with phosphatidylserine as involving recognition of neighboring amino acids. a recognition signal.[12] The adhesive glycoprotein, Once caspases are initially activated, there seems thrombospondin-1, can be expressed on the outer to be an irreversible commitment towards cell surface of activated microvascular endothelial cells death. To date, ten major caspases have been and, in conjunction with CD36, caspase-3-like identified and broadly categorized into initiators proteases and other proteins, induce receptor- (caspase-2,-8,-9,-10). effectors or executioners mediated apoptosis. (caspase-3,-6,-7) and inflammatory caspases PROTEOLYTIC CASPASE CASCADE (caspase-1,-4,-5). The other caspases that have been identified include caspase-11, which is Many pathways and signals lead to apoptosis, but reported to regulate apoptosis and cytokine these converge on a single mechanism that actually maturation during septic shock, caspase-12, which causes the death of the cell. After a cell receives mediates endoplasmic-specific apoptosis and stimulus, it undergoes organized degradation of cytotoxicity by amyloid-β, caspase-13, which is cellular organelles by activated suggested to be a bovine gene, and caspase-14, proteolytic caspases. In addition to the destruction which is highly expressed in embryonic tissues but of cellular organelles, mRNA is rapidly and not in adult tissues globally degraded by a mechanism that is not yet Extensive protein cross-linking is another fully characterized[13]. mRNA decay is triggered characteristic of apoptotic cells and is achieved very early in apoptosis. A cell undergoing through the expression and activation of tissue apoptosis shows a characteristic morphology: transglutaminase . DNA breakdown by Ca2+-and Mg2+-dependent endonucleases also occurs, Cell shrinkage and rounding are shown because resulting in DNA fragments of 180 to 200 base of the breakdown of the proteinaceous pairs. A characteristic ―DNA ladder‖ can be cytoskeleton by caspases. visualized by agarose gel electrophoresis with an The cytoplasm appears dense, and the ethidium bromide stain and ultraviolet organelles appear tightly packed. illumination.

Another biochemical feature is the expression of Chromatin undergoes condensation into cell surface markers that result in the early compact patches against the nuclear phagocytic recognition of apoptotic cells by envelope (also known as the perinuclear adjacent cells, permitting quick phagocytosis with envelope) in a process known as , a minimal compromise to the surrounding tissue. hallmark of apoptosis. This is achieved by the movement of the normal The nuclear envelope becomes discontinuous inward-facing phosphatidyl serine of the cell’s and the DNA inside it is fragmented in a lipid bilayer to expression on the outer layers of the process referred to as . The nucleus plasma membrane. Although externalization of breaks into several discrete chromatin phosphatidyl serine is a well-known recognition bodies or nucleosomal units due to the ligand for phagocytes on the surface of the degradation of DNA. apoptotic cell, recent studies have shown that other proteins are also be exposed on the cell surface The cell membrane shows irregular buds known during apoptotic cell clearance. These include as blebs. Annexin I and calreticulin. The cell breaks apart into Annexin V is a recombinant phosphatidylserine- multiple vesicles called apoptotic bodies, which binding protein that interacts strongly and are then phagocytosed. specifically with phosphatidylserine residues and can be used for the detection of apoptosis.

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Apoptosis progresses quickly and its products on agar gel after electrophoresis[14] Tests are quickly removed, making it difficult to for DNA laddering differentiate apoptosis detect or visualize. During karyorrhexis, from ischemic or toxic cell death. endonuclease activation leaves short DNA fragments, regularly spaced in size. These give a characteristic "laddered" appearance

Fig 3 : Degradation of cellular organelles by activated proteolytic caspases

Methods for Distinguishing Apoptotic From biochemical markers of necrotic cell death have Necrotic Cells been identified yet, and only negative markers are available. These include absence of apoptotic In order to perform analysis of apoptotic versus markers (caspase activation, cytochrome c release, necrotic (necroptotic) cells, one can do analysis of and oligonucleosomal DNA fragmentation) and morphology by time-lapse microscopy[15], flow differential kinetics of cell death markers fluorocytometry, and transmission electron (phosphatidylserine exposure and cell membrane microscopy. There are also various biochemical permeabilization). techniques for analysis of cell surface markers (phosphatidylserine exposure versus cell Trigger Apoptosis Ligands and Cell permeability by flow fluorocytometry), cellular Environment Materials markers such as DNA fragmentation[55] (flow Apoptosis, as a major cell death procession for cytometry), caspase activation, Bid cleavage, and healthy, play an important role in homeostasis of cytochrome c release (Western blotting). It is whole life. In the period of fetation, apoptosis important to know how primary and secondary happened, as the essential affair for the finger and necrotic cells can be distinguished by analysis toe formation. due the cells between fingers of supernatant for caspases, HMGB1, and release occured apoptosis, we can form five fingers per of cytokeratin 18. However, no distinct surface or hand. Apoptosis also can enhance embryonic stem

Ankit Sharma et al www.ajprd.com 6 Asian Journal of Pharmaceutical Research and Development Vol. 5 (3) May–June. 2017:1-10 cell survival during stress by increased expression decreased, the apoptosis will happen[19], this is one Bcl-2 protein which significantly weaken the mechanism by which the hormone act as inhibitor apoptosis and help colony formation ,Apoptosis of apoptosis, the other mechanism is that hormone also take part in some tissues regeneration and act as an inducer of apoptosis homeostasis.[16] Pathogen Effectors EXTRINSIC CELL MATERIALS During the fight between host and pathogen, there Cytokines are many roads that benefit the cell survival. There is the proverb ―Survival of the fittest‖. If failing to TNF-alpha plus z-VAD can trigger cell apoptosis, defense the pathogen, host will be ill, and give the and this method is well-known in creating cell phenomenon of or cell apoptosis model. TNF-alpha can bind to death（apoptosis, necrosis, auto-phage, pyropt extracellular domain of TNF-alpha receptor, and the cytoplasm domain can aggregate FADD and osis）. In this part, we will give the conclusion FLICE which can initiated the apoptosis; Another about host cell apoptosis which can be triggered by famous cytokine, IFN—γ ,which can induce the some pathogens, If cell occured apoptosis, the macrophage apoptosis, plays a key role in pathogen can not survival either, so through this clearance of the mycobacterium tuberculosis by way, host cells can clear the pathogen with little inducing host cell apoptosis depended by the nitric bad effects. [17] oxide(NO). Native Activities Compounds Drugs Although apoptosis is the programmed cell Some cytotoxic drugs (Cisplatin, Gemcitabin death and can be recognized as the normal cell Tooitecan, and paclitaxel）can trigger death by the immune system; and apoptosis have many important functions in the tissue apoptosis; Didymin induce apoptosis by development. While everything have two preventing N-Myc protein expression and sides, in some cases, apoptosis also have the make the cell G2/M arrest, which may be a damage and negative effect to the life healthy. novel mechanism to anti-neuroblastoma.[18] Recently, food scientists and biologist found apart from this anti-neuroblastoma properties, that some native compounds from the daily didymin have an anti-no small cell lung cancer life dietary can block or hamper apoptosis, and ability by induced the Fas-mediated apoptosis, through this way, these native compounds can it may be a novel new chemotherapeutic agent help to keep the body healthy. to treat the lung cancer.

Hormone Intrinsic Cell Apoptosis Signal Materials

Apoptosis occurs in the embryonic development Oxidative Stress (Ros; No; Gsh) and during the formation of organs, Hormones is usually a peptide or steroid, produced by one tissue Keratin is a cytoskeleton protein which have and conveyed by the bloodstream to another place some abilities to maintain the cell shape, Guo- to affect physiological activity, such as growth, Zhong Tao group found that keratin can proliferation, metabolism. Some researchers also modulate the shape of mitochondria and found that hormones can regulate the apoptosis, contribute to hepatocyte predisposition to [20] and through this way hormone can control the apoptosis and oxidative injury . Depletion metabolism of tissues or organs. For example, the the mitochondria GSH in the human B leptin is one hormone produced by adipocytes, and lymphoma cell line by treatment with L- it has been found as a inhibitor of apoptosis, leptin buthionine sulfoximine can induce caspase-3 can down-regulate cleaved caspase-3 and Bcl-2 activation and apoptosis, and indicating that associated X protein and up-regulate Bcl-2 protein, GSH may be the potential early activator of if this hormone level is normal, there will be no apoptotic signal. ROS is a type of toxic apoptosis, however, if the hormone level compound and usually detoxified by cells

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GSH, when the oxidative stress occur, the overload stress, the cells which have lots of ROS detoxify will be failed, and ROS will unfolded proteins will apoptosis, Differing from participate in apoptosis through redox- the ER stress, chaperons will protect this cell death. sensitive death pathway. Implication of Apoptosis Cytochrome C

Cytochrome C, as a proapoptotic protein, plays During the last decade, exceptional for the basic an important role in triggering programmed research, the apoptosis have attracted many cell death, The activation of cytochrome C is attentions due to its potential application in related with the changes of Bak/Bax ratio. The therapying the various human diseases. In order to latest researches shown that the interactions of maintain the function of whole organism, millions heterotypic mitochondrial membrane will of cells will die and proliferate every day, cell change the lipid milieu, in the end, death like apoptosis is the essential for the mitochondrial membrane will be permeatable regulation of organism growth and maintenance the and cytochrome c will release.; Apart the tissue homeostasis. If the cell death and changes of lipid milieu, arachidonic acid, proliferation go to imbalance, many diseases will triiodothyronine (T3), or 6-hydroxdopamine happen. Such as: some acute (stroke, can also effect the permeability of 2+ heart attack, liver failure) ; cancer; mitochondrial membrane and release Ca and neurodegenerative syndromes; diabetes and so on. cytochrome c. Cytochrome c can thrigger Due to its no lethal effect to the body, Apoptosis caspase activation via oligomerization of play a fundamental role in organism development APAF1 protein. Caspase activation can and tissue homeostasis, while if apoptosis was not catalyze the PARP-1, Finally, the apoptosis under controlled, a variety of diseases will occur. will happen. In short, cytochrome C is the one of major intrinsic cell apoptosis signal molecules. Therapeutic Possibilities and Future Directions Calcium Iron

The concentration of calcium in vivo is the key The widespread involvement of apoptosis in the role in maintain the permeatability of pathophysiology of disease lends itself to mitochondrial membrane. The increased intra- therapeutic intervention. In diseases caused by mitochondrial calcium can result in enhanced ROS, increased cell loss, such as viral hepatitis and Furthermore, cytochrome c will be stimulated to neurodegenerative disease, the aim will release.[21] And calcium also trigger the ER stress, Anaesthesia, be to minimise apoptosis by and then activate JNK pathway, afterwards, JNK modifying the signals which trigger the response activation can stimulate Bax (e.g. Ca21, ROS) or interfering with the effectors activation;Moreover,calcuim can regulate the (e.g. caspases and endonucleases). However, cysteine protease calpain, It’s well known that inhibition of apoptosis may be deleterious because calpain participate in the cell proliferation, cell new tumours may arise when damaged cells are cycle, and apoptosis prevented from committing suicide. In diseases caused by deficient apoptosis, such as cancer, viral Endoplasmic Reticulum (Er) Stress latency and autoimmunity, methods of producing As the apoptogenic factor, the permeabilization of selective apoptosis are being sought. Agents lysosomal membrane can induce apoptosis by both targeting receptors or regulatory molecules and caspase-dependent and caspase-independent agents targeting the final common pathway are pathway;[22] Tackled with the unfolded proteins is attractive possibilities. the one of the important ER functions, cell can Agents targeting receptors or regulatory molecules regulate the unfolded proteins in ER according to and agents targeting the final common pathway are metabolically needed, while if numerous unfolded attractive possibilities. The soluble form of Fas proteins stimulate the ER and make the ER could prove useful for increasing apoptosis (e.g. in

Ankit Sharma et al www.ajprd.com 8 Asian Journal of Pharmaceutical Research and Development Vol. 5 (3) May–June. 2017:1-10 tumours). Antibodies to Fas or Fas ligand may be 6. Susan Elmore(2007)Apoptosis: A Review of Programmed Cell Death,sage journals useful in preventing apoptosis (e.g. in 7. Cotran, Ramzi, S.; Kumar, Collins neurodegenerative disease). Preliminary successes (1998). Robbins Pathologic Basis of Disease. in treating chronic inflammatory diseases, such as Philadelphia: W.B Saunders Company. 8. D. González, I. Bejarano, C. Barriga, A.B. rheumatoid arthritis and ulcerative colitis, with Rodríguez, J.A. Pariente (2010). "Oxidative TNF-α inhibitors have been reported, but these Stress-Induced Caspases are Regulated in [23] Human Myeloid HL-60 Cells by Calcium therapies have proved disappointing in sepsis Signal". Current Signal Transduction Therapy. 9. Wajant H (2002). "The Fas signaling pathway: CONCLUSION more than a paradigm". Science 10. Wajant, H. "Connection Map for Fas Signaling Apoptosis is regarded as a carefully regulated Pathway". Science 11. Hengartner et al.(2000) The biochemistry of energy-dependent process, characterized by apoptosis.Nature. specific morphological and biochemical features in 12. Michalak M, Henson PM( 2005) Cell-surface calreticulin initiates clearance of viable or which caspase activation plays a central role. apoptotic cells through trans-activation of LRP Although many of the key apoptotic proteins that on the phagocyte. are activated or inactivated in the apoptotic 13. Thomas, M. P.; Liu, X; Whangbo, J; McCrossan, G; Sanborn, K. B.; Basar, E; pathways have been identified, the molecular Walch, M; Lieberman, J (2015). "Apoptosis mechanisms of action or activation of these Triggers Specific, Rapid, and Global mRNA Decay with 3' Uridylated Intermediates proteins are not fully understood and are the focus Degraded by DIS3L2". Cell Reports. of continued research. The importance of 14. Gong JP, Traganos F, Darzynkiewicz Z. (1994) understanding the mechanistic machinery of A selective procedure for DNA extraction from apoptotic cells applicable for gel apoptosis is vital because programmed cell death is electrophoresis and flow cytome a component of both health and disease, being 15. http://www.ecdo.eu/research.html 16. Z. Zhang, et al.2012 The protection of MSCs initiated by various physiologic and pathologic from apoptosis in nerve regeneration by stimuli. Moreover, the widespread involvement of TGFβ1 through reducing inflammation and apoptosis in the pathophysiology of disease lends promoting VEGF-dependent angiogenesis. 17. Bianca E.Schneider.Interferon Gamma itself to therapeutic intervention at many different Activated Macrophage by Nitric Oxide Induced checkpoints. Understanding the mechanisms of Apoptosis. 18. R. Vitsyayan, et al. 2012 Didymin Induced apoptosis, and other variants of programmed cell Apoptosis by Inhibiting N-Myc and Up- death, at the molecular level provides deeper regulating RKIP in Neuroblastoma. insight into various disease processes and may thus 19. C. Peyronel,2011 Effects of leptin on lipopolysaccharide-induced myometrial influence therapeutic strategy. apoptosis in an in vitro human model of chorioamnionitis. REFERENCES 20. M. Looi, etal. Toivola,2011 Keratins modulate the shape and function of hepatocyte mitochondria: a mechanism for protection 1. https://www.novusbio.com/apoptosis- from apoptosis. pathway.html 21. S. L. Sitasawad,2012 glucose-induced. High, 2. https://www.ncbi.nlm.nih.gov/books/NBK2687 Ca (2, overload, stress. oxidative, to. 3/ contribute, of. apoptosis, cells. cardiac, 3. Alberts, Bruce; Johnson, Alexander; Lewis, mitochondrial. through, dependent, pathways. Julian; Raff, Martin; Roberts, Keith; Walter, independent, Biochim Biophys Acta. Peter (2008). "Chapter 18 Apoptosis: 22. Pupyshev AB2011.Lysosomal membrane Programmed Cell Death Eliminates Unwanted permeabilization as apoptogenic factor. Cells". Molecular Biology of the Cell 23. Natanson C, Hoffman WD, Suffredini (textbook) (5th ed.). Garland Science. p. 1115. AF, Eichacker PQ & Danner RL. Selected 4. Karam, Jose A. (2009). Apoptosis in treatment strategies for septic shock based on Carcinogenesis and Chemotherapy. proposed mechanisms of . Netherlands: Springer. 5. Paulina Strzyz (2017) Nature Reviews Molecular Cell Biology

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