High mobility group box 1 (HMGB1) is a nonhistone nuclear protein that has multiple functions according to its subcellular location. In the nucleus, HMGB1 is a DNA chaperone that maintains the ...structure and function of chromosomes. In the cytoplasm, HMGB1 can promote autophagy by binding to BECN1 protein. After its active secretion or passive release, extracellular HMGB1 usually acts as a damage-associated molecular pattern (DAMP) molecule, regulating inflammation and immune responses through different receptors or direct uptake. The secretion and release of HMGB1 is fine-tuned by a variety of factors, including its posttranslational modification (e.g., acetylation, ADP-ribosylation, phosphorylation, and methylation) and the molecular machinery of cell death (e.g., apoptosis, pyroptosis, necroptosis, alkaliptosis, and ferroptosis). In this minireview, we introduce the basic structure and function of HMGB1 and focus on the regulatory mechanism of HMGB1 secretion and release. Understanding these topics may help us develop new HMGB1-targeted drugs for various conditions, especially inflammatory diseases and tissue damage.
Ferroptosis is a type of regulated necrosis that is triggered by a combination of iron toxicity, lipid peroxidation, and plasma membrane damage. The upstream inducers of ferroptosis can be divided ...into two categories (biological versus chemical) and activate two major pathways (the extrinsic/transporter versus the intrinsic/enzymatic pathways). Excessive or deficient ferroptotic cell death is implicated in a growing list of physiological and pathophysiological processes, coupled to a dysregulated immune response. This review focuses on new discoveries related to how ferroptotic cells and their spilled contents shape innate and adaptive immunity in health and disease. Understanding the immunological characteristics and activity of ferroptotic death not only illuminates an intersection between cell death and immunity but may also lead to the development of novel treatment approaches for immunopathological diseases.
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.
Ferroptosis is a type of oxidative stress‐mediated cell death characterized by iron accumulation, lipid peroxidation, and plasma membrane damage. Excessive autophagy can promote ferroptosis, whereas ESCRT‐III‐mediated membrane repair can limit ferroptosis. In this review, we highlight the current understanding of the main signaling pathways and defense mechanisms of ferroptosis.
Cell death can be executed through different subroutines. Since the description of ferroptosis as an iron-dependent form of non-apoptotic cell death in 2012, there has been mounting interest in the ...process and function of ferroptosis. Ferroptosis can occur through two major pathways, the extrinsic or transporter-dependent pathway and the intrinsic or enzyme-regulated pathway. Ferroptosis is caused by a redox imbalance between the production of oxidants and antioxidants, which is driven by the abnormal expression and activity of multiple redox-active enzymes that produce or detoxify free radicals and lipid oxidation products. Accordingly, ferroptosis is precisely regulated at multiple levels, including epigenetic, transcriptional, posttranscriptional and posttranslational layers. The transcription factor NFE2L2 plays a central role in upregulating anti-ferroptotic defense, whereas selective autophagy may promote ferroptotic death. Here, we review current knowledge on the integrated molecular machinery of ferroptosis and describe how dysregulated ferroptosis is involved in cancer, neurodegeneration, tissue injury, inflammation, and infection.
The hallmarks of COVID-19 disease Tang, Daolin; Comish, Paul; Kang, Rui
PLoS pathogens,
05/2020, Letnik:
16, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel coronavirus that has caused a worldwide pandemic of the human respiratory illness COVID-19, resulting in a severe threat to ...public health and safety. Analysis of the genetic tree suggests that SARS-CoV-2 belongs to the same Betacoronavirus group as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). Although the route for viral transmission remains a mystery, SARS-CoV-2 may have originated in an animal reservoir, likely that of bat. The clinical features of COVID-19, such as fever, cough, shortness of breath, and fatigue, are similar to those of many acute respiratory infections. There is currently no specific treatment for COVID-19, but antiviral therapy combined with supportive care is the main strategy. Here, we summarize recent progress in understanding the epidemiological, virological, and clinical characteristics of COVID-19 and discuss potential targets with existing drugs for the treatment of this emerging zoonotic disease.
The changeable molecular dynamics of flexible polar cations in the variable confined space between inorganic chains brings about a new type of two‐step nonlinear optical (NLO) switch with genuine ...“off–on–off” second harmonic generation (SHG) conversion between one NLO‐active state and two NLO‐inactive states.
Damage-associated molecular pattern molecules (DAMPs) are endogenous danger signals that alert the innate immune system and shape the inflammation response to cell death. However, the release and ...activity of DAMPs in ferroptosis, a recently identified form of regulated necrosis characterized by iron overload and lipid peroxidation, still remain poorly understood. Here, we demonstrate that HMGB1 is a DAMP released by ferroptotic cells in an autophagy-dependent manner. Both type I and II ferroptosis activators, including erastin, sorafenib, RSL3, and FIN56, induce HMGB1 release in cancer and noncancer cells. In contrast, genetic ablation (using ATG5−/− or ATG7−/− cells) or pharmacologic inhibition (the administration of bafilomycin A1 or chloroquine) of autophagy was found to block ferroptosis activator-induced HMGB1 release. Mechanically, autophagy-mediated HDAC inhibition promotes HMGB1 acetylation, resulting in HMGB1 release in ferroptosis. Moreover, AGER, but not TLR4, is required for HMGB1-mediated inflammation in macrophages in response to ferroptotic cells. These studies suggest that HMGB1 inhibition might have some potential therapeutic effects in ferroptosis-associated human disease.
•Ferroptosis activators induce HMGB1 release.•Autophagy promotes HMGB1 release in ferroptosis.•Autophagy promotes HMGB1 acetylation in ferroptosis.•HMGB1-AGER pathway mediates inflammation response in ferroptosis.
Ferroptosis, a recently identified form of non-apoptotic cell death, is involved in several physiological and pathological processes. Although lipid peroxidation plays a central role in triggering ...ferroptosis, the essential regulator of lipid metabolism in ferroptosis remains poorly defined. Here, we show that acyl-CoA synthetase long-chain family member 4 (ACSL4) is required for ferroptotic cancer cell death. Compared with ferroptosis-sensitive cells (e.g., HepG2 and HL60), the expression of ACSL4 was remarkably downregulated in ferroptosis-resistant cells (e.g., LNCaP and K562). In contrast, the expression of other ACSLs, including ACSL1, ACSL3, ACSL5, and ACSL6, did not correlate with ferroptosis sensitivity. Moreover, knockdown of ACSL4 by specific shRNA inhibited erastin-induced ferroptosis in HepG2 and HL60 cells, whereas overexpression of ACSL4 by gene transfection restored sensitivity of LNCaP and K562 cells to erastin. Mechanically, ACSL4-mediated production of 5-hydroxyeicosatetraenoic acid (5-HETE) contributed to ferroptosis. Pharmacological inhibition of 5-HETE production by zileuton limited ACSL4 overexpression-induced ferroptosis. Collectively, these results indicate that ACSL4 is not only a sensitive monitor of ferroptosis, but also an important contributor of ferroptosis.
Iron Metabolism in Ferroptosis Chen, Xin; Yu, Chunhua; Kang, Rui ...
Frontiers in cell and developmental biology,
10/2020, Letnik:
8
Journal Article
Recenzirano
Odprti dostop
Ferroptosis is a form of regulated cell death that is characterized by iron-dependent oxidative damage and subsequent plasma membrane ruptures and the release of damage-associated molecular patterns. ...Due to the role of iron in mediating the production of reactive oxygen species and enzyme activity in lipid peroxidation, ferroptosis is strictly controlled by regulators involved in many aspects of iron metabolism, such as iron uptake, storage, utilization, and efflux. Translational and transcriptional regulation of iron homeostasis provide an integrated network to determine the sensitivity of ferroptosis. Impaired ferroptosis is implicated in various iron-related pathological conditions or diseases, such as cancer, neurodegenerative diseases, and ischemia-reperfusion injury. Understanding the molecular mechanisms underlying the regulation of iron metabolism during ferroptosis may provide effective strategies for the treatment of ferroptosis-associated diseases. Indeed, iron chelators effectively prevent the occurrence of ferroptosis, which may provide new approaches for the treatment of iron-related disorders. In this review, we summarize recent advances in the theoretical modeling of iron-dependent ferroptosis, and highlight the therapeutic implications of iron chelators in diseases.
Two‐dimensional (2D) materials and ultrathin nanosheets are advantageous for elevating the catalysis performance and elucidating the catalysis mechanism of heterogeneous catalysts, but they are ...mostly restricted to inorganic or organic materials based on covalent bonds. We report an electrochemical/chemical exfoliation strategy for synthesizing metal–organic 2D materials based on coordination bonds. A catechol functionalized ligand is used as the redox active pillar to construct a pillared‐layer framework. When the 3D pillared‐layer MOF serves as an electrocatalyst for water oxidation (pH 13), the pillar ligands can be oxidized in situ and removed. The remaining ultrathin (2 nm) nanosheets of the metal–organic layers are an efficient catalyst with overpotentials as low as 211 mV at 10 mA cm−2 and a turnover frequency as high as 30 s−1 at an overpotential of 300 mV.
MOF slicing: A pillared‐layer metal–organic framework (MOF), in which the catechol functionalized pillars can be oxidized and removed in an electrochemical process, gives ultrathin nanosheets (2 nm). These are efficient electrocatalysts for water oxidation at pH 13 with a low overpotential and high turnover frequency (TOF).
PDF
