Abstract 333: Cardiomyocyte Death and Fibrotic Scarring in the Infarcted Neonatal Mouse Heart

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Mary Mohr ◽  
Ge Tao ◽  
Shuang Li ◽  
Patrick Roddy

As one the leading causes of death in the United States, myocardial infarction (MI) occurs every 40 seconds, causing severe public health burden. Following MI, the loss of healthy cardiomyocytes leads to decreased contractility and eventually heart failure. Mature mammalian cardiomyocytes have a low turnover rate at only 0.5-2% per year, insufficient for repopulating damaged myocardium after MI. However, a contradictory discovery was made showing that the neonatal mammalian heart is regenerative, although this reparative ability is lost within days after birth. A great amount of effort is needed to understand the mechanisms underlying neonatal cardiomyocyte regeneration. In the current project, we attempt to profile different types of cell death in regenerating and non-regenerating mouse models following MI, in order to gain insights into a favorable type of cardiomyocyte death during regeneration. We induced MI in postnatal day 1 (P1, regenerative), and postnatal day 7 (P7, non-regenerative) mouse hearts by left anterior descending artery occlusion (LAD-O). The progressive scar formation was assessed using Masson’s Trichrome staining at multiple timepoints up to 14 days after MI. At each time point, we profile three major types of regulated cell death, apoptosis, necroptosis, and ferroptosis, using immunofluorescence staining. We also used AC16, a human cardiomyocyte cell line, to investigate the role of cell density in the regulation of ferroptosis. We found that the scar formation was most dynamic between 2 and 3 days after MI and that the course of scar formation varied greatly between P1 and P7 hearts. Immunofluorescence of different cell death markers reveal differentially progressed cell death between P1 and P7 hearts after MI. Our results indicate a different pattern of cardiomyocyte death in the regenerative P1 heart compared to the non-regenerative P7 heart, that could be more favorable for myocardial regeneration.

Author(s):  
Anne Nassauer

This book provides an account of how and why routine interactions break down and how such situational breakdowns lead to protest violence and other types of surprising social outcomes. It takes a close-up look at the dynamic processes of how situations unfold and compares their role to that of motivations, strategies, and other contextual factors. The book discusses factors that can draw us into violent situations and describes how and why we make uncommon individual and collective decisions. Covering different types of surprise outcomes from protest marches and uprisings turning violent to robbers failing to rob a store at gunpoint, it shows how unfolding situations can override our motivations and strategies and how emotions and culture, as well as rational thinking, still play a part in these events. The first chapters study protest violence in Germany and the United States from 1960 until 2010, taking a detailed look at what happens between the start of a protest and the eruption of violence or its peaceful conclusion. They compare the impact of such dynamics to the role of police strategies and culture, protesters’ claims and violent motivations, the black bloc and agents provocateurs. The analysis shows how violence is triggered, what determines its intensity, and which measures can avoid its outbreak. The book explores whether we find similar situational patterns leading to surprising outcomes in other types of small- and large-scale events: uprisings turning violent, such as Ferguson in 2014 and Baltimore in 2015, and failed armed store robberies.


2021 ◽  
pp. 089443932110115
Author(s):  
Benoît Dupont ◽  
Thomas Holt

This volume highlights the central role of the human factor in cybercrime and the need to develop a more interdisciplinary research agenda to understand better the constant evolution of online harms and craft more effective responses. The term “human factor” is understood very broadly and encompasses individual, institutional, and societal dimensions. It covers individual human behaviors and the social structures that enable collective action by groups and communities of various sizes, as well as the different types of institutional assemblages that shape societal responses. This volume is organized around three general themes whose complementary perspectives allow us to map the complex interplay between offenders, machines, and victims, moving beyond static typologies to offer a more dynamic analysis of the cybercrime ecology and its underlying behaviors. The contributions use quantitative and qualitative methodologies and bring together researchers from the United States, the United Kingdom, the Netherlands, Denmark, Australia, and Canada.


Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4576
Author(s):  
Hung-Yu Lin ◽  
Hui-Wen Ho ◽  
Yen-Hsiang Chang ◽  
Chun-Jui Wei ◽  
Pei-Yi Chu

Breast cancer (BC) is the most common malignancy among women worldwide. The discovery of regulated cell death processes has enabled advances in the treatment of BC. In the past decade, ferroptosis, a new form of iron-dependent regulated cell death caused by excessive lipid peroxidation has been implicated in the development and therapeutic responses of BC. Intriguingly, the induction of ferroptosis acts to suppress conventional therapy-resistant cells, and to potentiate the effects of immunotherapy. As such, pharmacological or genetic modulation targeting ferroptosis holds great potential for the treatment of drug-resistant cancers. In this review, we present a critical analysis of the current understanding of the molecular mechanisms and regulatory networks involved in ferroptosis, the potential physiological functions of ferroptosis in tumor suppression, its potential in therapeutic targeting, and explore recent advances in the development of therapeutic strategies for BC.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Sipeng Zuo ◽  
Jie Yu ◽  
Hui Pan ◽  
Linna Lu

Abstract Ferroptosis belongs to a novel form of regulated cell death. It is characterized by iron dependence, destruction of intracellular redox balance and non-apoptosis. And cellular structure and molecules level changes also occur abnormally during ferroptosis. It has been proved that ferroptosis exist widespreadly in many diseases, such as heart disease, brain damage or alzheimer disease. At the same time, the role of ferroptosis in cancer cannot be underestimated. More and more indications have told that ferroptosis is becoming a powerful weapon against cancer. In addition, therapies rely on ferroptosis have been applied to the clinic. Therefore, it is necessary to understand this newly discovered form of cell death and its connection with cancer. This review summarizes the mechanism of ferroptosis, ferroptosis inducers based on different targets and inspection methods. At last, we analyzed the relationship between ferroptosis and malignancies, in order to provide a novel theory basis for cancer treatment.


2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Lihong Mao ◽  
Tianming Zhao ◽  
Yan Song ◽  
Lin Lin ◽  
Xiaofei Fan ◽  
...  

Abstract Ferroptosis is an iron- and lipotoxicity-dependent form of regulated cell death (RCD). It is morphologically and biochemically distinct from characteristics of other cell death. This modality has been intensively investigated in recent years due to its involvement in a wide array of pathologies, including cancer, neurodegenerative diseases, and acute kidney injury. Dysregulation of ferroptosis has also been linked to various liver diseases and its modification may provide a hopeful and attractive therapeutic concept. Indeed, targeting ferroptosis may prevent the pathophysiological progression of several liver diseases, such as hemochromatosis, nonalcoholic steatohepatitis, and ethanol-induced liver injury. On the contrary, enhancing ferroptosis may promote sorafenib-induced ferroptosis and pave the way for combination therapy in hepatocellular carcinoma. Glutathione peroxidase 4 (GPx4) and system xc− have been identified as key players to mediate ferroptosis pathway. More recently diverse signaling pathways have also been observed. The connection between ferroptosis and other forms of RCD is intricate and compelling, where discoveries in this field advance our understanding of cell survival and fate. In this review, we summarize the central molecular machinery of ferroptosis, describe the role of ferroptosis in non-cancer hepatic disease conditions and discuss the potential to manipulate ferroptosis as a therapeutic strategy.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Bartosz Wiernicki ◽  
Hanne Dubois ◽  
Yulia Y. Tyurina ◽  
Behrouz Hassannia ◽  
Hülya Bayir ◽  
...  

Abstract Lipid peroxidation (LPO) drives ferroptosis execution. However, LPO has been shown to contribute also to other modes of regulated cell death (RCD). To clarify the role of LPO in different modes of RCD, we studied in a comprehensive approach the differential involvement of reactive oxygen species (ROS), phospholipid peroxidation products, and lipid ROS flux in the major prototype modes of RCD viz. apoptosis, necroptosis, ferroptosis, and pyroptosis. LC-MS oxidative lipidomics revealed robust peroxidation of three classes of phospholipids during ferroptosis with quantitative predominance of phosphatidylethanolamine species. Incomparably lower amounts of phospholipid peroxidation products were found in any of the other modes of RCD. Nonetheless, a strong increase in lipid ROS levels was detected in non-canonical pyroptosis, but only during cell membrane rupture. In contrast to ferroptosis, lipid ROS apparently was not involved in non-canonical pyroptosis execution nor in the release of IL-1β and IL-18, while clear dependency on CASP11 and GSDMD was observed. Our data demonstrate that ferroptosis is the only mode of RCD that depends on excessive phospholipid peroxidation for its cytotoxicity. In addition, our results also highlight the importance of performing kinetics and using different methods to monitor the occurrence of LPO. This should open the discussion on the implication of particular LPO events in relation to different modes of RCD.


Author(s):  
Ayelén Mariana Distéfano ◽  
Gabriel Alejandro López ◽  
Nicolás Setzes ◽  
Fernanda Marchetti ◽  
Maximiliano Cainzos ◽  
...  

Abstract Regulated cell death plays key roles during essential processes throughout the plant life cycle. It takes part in specific developmental programs and maintains homeostasis of the organism in response to unfavorable environments. Ferroptosis is a recently discovered iron-dependent cell death pathway characterized by the accumulation of lipid reactive oxygen species. In plants, ferroptosis shares all the main hallmarks described in other systems. Those specific features include biochemical and morphological signatures that seem to be conserved among species. However, plant cells have specific metabolic pathways and a high degree of metabolic compartmentalization. Together with their particular morphology, these features add more complexity to the plant ferroptosis pathway. In this review, we summarize the most recent advances in elucidating the roles of ferroptosis in plants, focusing on specific triggers, the main players, and underlying pathways.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Seahyoung Lee ◽  
Eunhyun Choi ◽  
Min-Ji Cha ◽  
Ki-Chul Hwang

Pyroptosis is the most recently identified type of regulated cell death with inflammatory response and has characteristics distinct from those of apoptosis or necrosis. Recently, independent studies have reported that small noncoding RNAs termed microRNAs (miRNAs) are involved in the regulation of pyroptosis. Nevertheless, only a handful of empirical data regarding miRNA-dependent regulation of pyroptosis is currently available. This review is aimed to provide a current update on the role of miRNAs in pyroptosis and to offer suggestions for future studies probing miRNAs as a linker connecting pyroptosis to various cardiovascular diseases (CVDs) and their potential as a therapeutic target for preventing excessive cell death of myocardium during CVDs.


Author(s):  
Qian Li ◽  
Nengxian Shi ◽  
Chen Cai ◽  
Mingming Zhang ◽  
Jing He ◽  
...  

Pyroptosis is a recently discovered aspartic aspart-specific cysteine protease (Caspase-1/4/5/11) dependent mode of gene-regulated cell death cell death, which is represented by the rupture of cell membrane perforations and the production of proinflammatory mediaters like interleukin-18(IL-18) and interleukin-1β (IL-1β). Mitochondria also play an important role in apoptotic cell death. When it comes to apoptosis of mitochondrion, mitochondrial outer membrane permeabilization (MOMP) is commonly known to cause cell death. As a downstream pathological process of apoptotic signaling, MOMP participates in the leakage of cytochrome-c from mitochondrion to the cytosol and subsequently activate caspase proteases. Hence, targeting MOMP for the sake of manipulating cell death presents potential therapeutic effects among various types of diseases, such as autoimmune disorders, neurodegenerative diseases, and cancer. In this review, we highlights the roles and significance of mitochondria in pyroptosis to provide unexplored strategies that target the mitochondria to regulate cell death for clinical benefits.


Author(s):  
Liah Greenfeld ◽  
Nicolas Prevelakis

Nationalism is the worldview of the modern world. It is based on three fundamental principles: it is secular; it sees the members of the community defined as a nation as fundamentally equal; and it presupposes popular sovereignty. Modern ethnicity, that is, ethnic identity, is the result of ethnic nationalism. One can classify nationalisms into three major types: the individualistic-civic type, as seen in England, the United States, and a few other countries, though it remains a minority in the world; the collectivistic-civic type—also a minority; and finally, the collectivistic-ethnic type, which is found in most of the nations in the world. This third and last type is what is usually referred to as “ethnic identity” in the modern world. These types of nationalism seldom exist in their ideal form. Typically, one will find a combination of elements from different types. Their relative importance may vary from one period to another, or within the same period and among different social strata. The case of Greek nationalism illustrates this point. It also represents a clear example of the causal role of nationalism in shaping ethnic identity. The seeds of ethnicity emerged in the first decades of the Greek state, though it was only in the middle of the nineteenth century that Greek nationalism took its definite ethnic form. This evolution can be seen in two areas: the emergence of Greek irredentism, and the construction of Greek historiography.


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