-
The FEBS Journal Nov 2022As a type of lytic cell death driven by unrestricted lipid peroxidation and subsequent plasma membrane damage, ferroptosis occurs and develops because of sophisticated... (Review)
Review
As a type of lytic cell death driven by unrestricted lipid peroxidation and subsequent plasma membrane damage, ferroptosis occurs and develops because of sophisticated signals and regulatory mechanisms. The reactive oxygen species (ROS) used to initiate ferroptosis come from a variety of sources, including iron-mediated Fenton reactions, mitochondrial ROS, and membrane-associated ROS driven by the NOX protein family. Polyunsaturated fatty acid-containing phospholipids are the main substrates of lipid peroxidation in ferroptosis, which is positively regulated by enzymes, such as ACSL4, LPCAT3, ALOXs, or POR. Selective activation of autophagic degradation pathways promotes ferroptosis by increasing iron accumulation to cause lipid peroxidation. In contrast, system xc -glutathione-GPX4 axis plays a central role in limiting lipid peroxidation, although other antioxidants (such as coenzyme Q10 and tetrahydrobiopterin) can also inhibit ferroptosis. A main nuclear mechanism of cell defense against ferroptosis is the activation of the NFE2L2-dependent antioxidant response by transcriptionally upregulating the expression of antioxidants or cytoprotective genes. Additionally, the membrane damage caused by ferroptotic stimulus can be repaired by ESCRT-III-dependent membrane scission machinery. In this review, we summarize recent progress in understanding the signaling pathways and defense mechanisms of ferroptosis.
Topics: Ferroptosis; Reactive Oxygen Species; Antioxidants; Signal Transduction; Iron; Defense Mechanisms
PubMed: 34092035
DOI: 10.1111/febs.16059 -
PeerJ 2022The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense... (Review)
Review
The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense mechanisms used to deal with the pandemic. It then discusses different categories of defense mechanisms and their roles in managing the impacts of psychological distress. The aim of this review is to highlight the various psychological defense mechanisms individuals use to deal with the pandemic and to discuss how adjustment mechanisms can protect individuals from internal and external threats by shielding the integrity of the ego (the mind) and helping individuals maintain their self-schema.
Topics: Humans; COVID-19; Pandemics; Psychological Distress; Defense Mechanisms
PubMed: 35186458
DOI: 10.7717/peerj.12811 -
International Journal of Environmental... Dec 2021Internalisation of appearance ideals moderates the relationship between exposure to media images and body dissatisfaction. To date, the role of thin- and muscular-ideal...
Internalisation of appearance ideals moderates the relationship between exposure to media images and body dissatisfaction. To date, the role of thin- and muscular-ideal internalisation in the context of social media remains under explored, particularly for boys. As such, we aimed to explore how social media use (Instagram and Snapchat) was related to body dissatisfaction, and whether thin- and muscular-ideal internalisation would moderate this relationship in a sample of 1153 adolescent boys and girls (55.42% males; = 13.71, = 1.14). As hypothesised, social media use, and thin- and muscular ideal internalisation were positively correlated with body dissatisfaction in both genders. In moderation analyses, thin-ideal internalisation emerged as the only variable that had a significant effect on body dissatisfaction in both genders. Additionally, the influence of social media use on body dissatisfaction was moderated by muscular-ideal internalisation in boys, whereby for boys with high muscular-ideal internalisation, greater social media use was associated with greater body dissatisfaction. The two-way (muscular x thin-ideal internalisation) and three-way interaction (social media use x thin-ideal internalisation x muscular-ideal internalisation) effects on body dissatisfaction were non-significant. These findings emphasise the importance of considering the sociocultural environment (i.e., new media influences) as frameworks for understanding body dissatisfaction and suggest targeting of internalisation of appearance ideals in body dissatisfaction prevention programs.
Topics: Adolescent; Body Dissatisfaction; Body Image; Defense Mechanisms; Female; Humans; Male; Personal Satisfaction; Social Media
PubMed: 34948830
DOI: 10.3390/ijerph182413222 -
The Primary Care Companion For CNS... Mar 2020To investigate the self-esteem and defense mechanisms in patients diagnosed with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS).
OBJECTIVE
To investigate the self-esteem and defense mechanisms in patients diagnosed with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS).
METHODS
This prospective, cross-sectional study included 29 patients diagnosed with HIV/AIDS admitted to inpatient or outpatient clinics between March 2018 and January 2019 and 29 healthy subjects. Participants were assessed using a sociodemographic and clinical data form, the Rosenberg Self-Esteem Inventory (RSEI), the Defense Style Questionnaire (DSQ), and the Beck Anxiety Inventory (BAI).
RESULTS
Patients with HIV/AIDS had significantly higher scores on the fantasy, psychosomatic symptoms, and parental interest subscales of the RSEI. There was no significant difference between the groups on the other subscales, including the self-esteem subscale. There was no correlation between the duration of the disease and self-esteem. The neurotic defense mechanism and immature defense mechanism subscale scores of the DSQ were significantly higher in the HIV/AIDS group compared to the control group (P < .01). Undoing and reaction formation scores in neurotic defense mechanisms and projection, devaluation, autistic fantasy, and splitting scores in immature defense mechanisms were significantly higher in the HIV/AIDS group compared to controls (P < .05). There was no significant difference between the groups based on the mature defense mechanisms subscale scores.
CONCLUSIONS
No difference was found in the self-esteem scores of the HIV/AIDS and control groups, and this finding could be associated with the stability of the self-esteem concept. It was also determined that patient group members utilized neurotic and immature defense mechanisms more often compared to the healthy group, and there was no difference between the groups based on mature defense mechanisms.
Topics: Acquired Immunodeficiency Syndrome; Adult; Cross-Sectional Studies; Defense Mechanisms; Female; HIV Infections; Humans; Male; Middle Aged; Prospective Studies; Self Concept
PubMed: 32220150
DOI: 10.4088/PCC.19m02577 -
Viruses May 2018RNAi is considered a major antiviral defense mechanism in insects, but its relative importance as compared to other antiviral pathways has not been evaluated... (Review)
Review
RNAi is considered a major antiviral defense mechanism in insects, but its relative importance as compared to other antiviral pathways has not been evaluated comprehensively. Here, it is attempted to give an overview of the antiviral defense mechanisms in that involve both RNAi and non-RNAi. While RNAi is considered important in most viral infections, many other pathways can exist that confer antiviral resistance. It is noted that very few direct recognition mechanisms of virus infections have been identified in and that the activation of immune pathways may be accomplished indirectly through cell damage incurred by viral replication. In several cases, protection against viral infection can be obtained in RNAi mutants by non-RNAi mechanisms, confirming the variability of the RNAi defense mechanism according to the type of infection and the physiological status of the host. This analysis is aimed at more systematically investigating the relative contribution of RNAi in the antiviral response and more specifically, to ask whether RNAi efficiency is affected when other defense mechanisms predominate. While can function as a useful model, this issue may be more critical for economically important insects that are either controlled (agricultural pests and vectors of diseases) or protected from parasite infection (beneficial insects as bees) by RNAi products.
Topics: Animals; Drosophila melanogaster; Immunity, Innate; RNA Interference; RNA, Double-Stranded; Virus Diseases; Virus Replication
PubMed: 29723993
DOI: 10.3390/v10050230 -
Frontiers in Psychology 2021Breast cancer (BC) is one of the highest incidence rates in Lebanon. Previous studies had focused scarcely on the unconscious protective shield of patients with BC or...
Breast cancer (BC) is one of the highest incidence rates in Lebanon. Previous studies had focused scarcely on the unconscious protective shield of patients with BC or BC survivors against cancer, while only some studies had focused on the relationship between defense mechanisms (DMs) and high adaptation with the disease process and progress. Therefore, this study aimed to investigate the reaction of inpatients with BC toward the disease by measuring DMs in the Lebanon context. Seventy inpatients with BC were recruited randomly from six hospitals. Their DMs were measured using the Defense Mechanism Rating Scale. Moreover, the Relationship Anecdotes Paradigm (RAP) was used with three recent life vignettes of initial diagnosis, family, and daily life. The data were analyzed using repeated measure ANOVA, Wilcoxon rank-sum test, and Spearman's rank. Patients with stage 2 BC used more high-adaptive defense levels than patients with stage 4 BC who used more minor image distorting defense levels. Moreover, patients with stage 2 BC used more self-observation and undoing, while patients with stage 4 BC used more devaluation. The severity of BC, the age of carriers, and the social status may lead to higher use of DMs, at the level of the individual defense and the hierarchal or the tripartite levels.
PubMed: 34456786
DOI: 10.3389/fpsyg.2021.666373 -
Frontiers in Psychology 2021The study investigated the extent to which defensive functioning and defense mechanisms predict clinically meaningful symptomatic improvement within brief psychodynamic...
The study investigated the extent to which defensive functioning and defense mechanisms predict clinically meaningful symptomatic improvement within brief psychodynamic psychotherapy for recurrent and chronic depression in an inpatient setting. Treatment response was defined as a reduction in symptom severity of 46% or higher from the baseline score on the Montgomery-Asberg Depression Rating Scale (MADRS). A subsample of 41 patients (19 responders and 22 non-responders) from an RCT was included. For each case, two sessions (the second and the penultimate) of brief inpatient psychodynamic psychotherapy (a manualized 12-session therapy program developed in Lausanne) were transcribed and then coded using the Defense Mechanism Rating Scales (DMRS) and the Psychotic Defense Mechanism Rating Scales (P-DMRS), an additional scale developed to study psychotic defenses. Results showed that defensive functioning and mature and immature defense changed during psychotherapy and predicted treatment response. Patient's defenses observed throughout therapy also predicted treatment response at 12-month follow-up. The addition of psychotic defenses allows a better prediction of the treatment response. Overall, these results are in line with previous research and provide further validation of defensive functioning as a predictor of outcomes and a mechanism of change in psychotherapy.
PubMed: 33815219
DOI: 10.3389/fpsyg.2021.633939 -
Frontiers in Plant Science 2021Plants are subjected to a plethora of environmental cues that cause extreme losses to crop productivity. Due to fluctuating environmental conditions, plants encounter... (Review)
Review
Plants are subjected to a plethora of environmental cues that cause extreme losses to crop productivity. Due to fluctuating environmental conditions, plants encounter difficulties in attaining full genetic potential for growth and reproduction. One such environmental condition is the recurrent attack on plants by herbivores and microbial pathogens. To surmount such attacks, plants have developed a complex array of defense mechanisms. The defense mechanism can be either preformed, where toxic secondary metabolites are stored; or can be inducible, where defense is activated upon detection of an attack. Plants sense biotic stress conditions, activate the regulatory or transcriptional machinery, and eventually generate an appropriate response. Plant defense against pathogen attack is well understood, but the interplay and impact of different signals to generate defense responses against biotic stress still remain elusive. The impact of light and dark signals on biotic stress response is one such area to comprehend. Light and dark alterations not only regulate defense mechanisms impacting plant development and biochemistry but also bestow resistance against invading pathogens. The interaction between plant defense and dark/light environment activates a signaling cascade. This signaling cascade acts as a connecting link between perception of biotic stress, dark/light environment, and generation of an appropriate physiological or biochemical response. The present review highlights molecular responses arising from dark/light fluctuations elicitation of defense mechanisms in plants.
PubMed: 33763093
DOI: 10.3389/fpls.2021.631810 -
Current Opinion in Microbiology Feb 2015Epithelial cells line the surfaces of the body, and are on the front lines of defense against microbial infection. Like many other metazoans, the nematode Caenorhabditis... (Review)
Review
Epithelial cells line the surfaces of the body, and are on the front lines of defense against microbial infection. Like many other metazoans, the nematode Caenorhabditis elegans lacks known professional immune cells and relies heavily on defense mediated by epithelial cells. New results indicate that epithelial defense in C. elegans can be triggered through detection of pathogen-induced perturbation of core physiology within host cells and through autophagic defense against intracellular and extracellular pathogens. Recent studies have also illuminated a diverse array of pathogenic attack strategies used against C. elegans. These findings are providing insight into the underpinnings of host/pathogen interactions in a simple animal host that can inform studies of infectious diseases in humans.
Topics: Animals; Autophagy; Caenorhabditis elegans; Defense Mechanisms; Epithelial Cells; Host-Pathogen Interactions
PubMed: 25461579
DOI: 10.1016/j.mib.2014.11.009 -
Frontiers in Microbiology 2018As one of the predominant pollinator, honeybees provide important ecosystem service to crops and wild plants, and generate great economic benefit for humans.... (Review)
Review
As one of the predominant pollinator, honeybees provide important ecosystem service to crops and wild plants, and generate great economic benefit for humans. Unfortunately, there is clear evidence of recent catastrophic honeybee colony failure in some areas, resulting in markedly negative environmental and economic effects. It has been demonstrated that various environmental stresses, including both abiotic and biotic stresses, functioning singly or synergistically, are the potential drivers of colony collapse. Honeybees can use many defense mechanisms to decrease the damage from environmental stress to some extent. Here, we synthesize and summarize recent advances regarding the effects of environmental stress on honeybees and the wisdom of honeybees to respond to external environmental stress. Furthermore, we provide possible future research directions about the response of honeybees to various form of stressors.
PubMed: 29765357
DOI: 10.3389/fmicb.2018.00722