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Autophagy Feb 2023Mitophagy neutralizes defective mitochondria lysosomal elimination. Increased levels of mitophagy hallmark metabolic transitions and are induced by iron depletion, yet...
Mitophagy neutralizes defective mitochondria lysosomal elimination. Increased levels of mitophagy hallmark metabolic transitions and are induced by iron depletion, yet its metabolic basis has not been studied in-depth. How mitophagy integrates with different homeostatic mechanisms to support metabolic integrity is incompletely understood. We examined metabolic adaptations in cells treated with deferiprone (DFP), a therapeutic iron chelator known to induce PINK1-PRKN-independent mitophagy. We found that iron depletion profoundly rewired the cellular metabolome, remodeling lipid metabolism within minutes of treatment. DGAT1-dependent lipid droplet biosynthesis occurs upstream of mitochondrial turnover, with many LDs bordering mitochondria upon iron chelation. Surprisingly, DGAT1 inhibition restricts mitophagy by lysosomal dysfunction. Genetic depletion of mdy/DGAT1 impairs neuronal mitophagy and locomotor function in , demonstrating the physiological relevance of our findings.
Topics: Animals; Mitophagy; Protein Kinases; Lipid Droplets; Autophagy; Ubiquitin-Protein Ligases; Drosophila; Iron; Protein Serine-Threonine Kinases; Drosophila Proteins
PubMed: 35939345
DOI: 10.1080/15548627.2022.2089956 -
Cell Death and Differentiation Jan 2023Glaucoma can result in retinal ganglion cell (RGC) death and permanently damaged vision. Pathologically high intraocular pressure (ph-IOP) is the leading cause of...
Glaucoma can result in retinal ganglion cell (RGC) death and permanently damaged vision. Pathologically high intraocular pressure (ph-IOP) is the leading cause of damaged vision during glaucoma; however, controlling ph-IOP alone does not entirely prevent the loss of glaucomatous RGCs, and the underlying mechanism remains elusive. In this study, we reported an increase in ferric iron in patients with acute primary angle-closure glaucoma (the most typical glaucoma with ph-IOP damage) compared with the average population by analyzing free iron levels in peripheral serum. Thus, iron metabolism might be involved in regulating the injury of RGCs under ph-IOP. In vitro and in vivo studies confirmed that ph-IOP led to abnormal accumulation of ferrous iron in cells and retinas at 1-8 h post-injury and elevation of ferric iron in serum at 8 h post-injury. Nuclear receptor coactivator 4 (NCOA4)-mediated degradation of ferritin heavy polypeptide 1(FTH1) is essential to disrupt iron metabolism in the retina after ph-IOP injury. Furthermore, knockdown of Ncoa4 in vivo inhibited FTH1 degradation and reduced the retinal ferrous iron level. Elevated ferrous iron induced by ph-IOP led to a marked accumulation of pro-ferroptotic factors (lipid peroxidation and acyl CoA synthetase long-chain family member 4) and a depletion of anti-ferroptotic factors (glutathione, glutathione peroxidase 4, and nicotinamide adenine dinucleotide phosphate). These biochemical changes resulted in RGC ferroptosis. Deferiprone can pass through the blood-retinal barrier after oral administration and chelated abnormally elevated ferrous iron in the retina after ph-IOP injury, thus inhibiting RGC ferroptosis and protecting visual function. In conclusion, this study revealed the role of NCOA4-FTH1-mediated disturbance of iron metabolism and ferroptosis in RGCs during glaucoma. We demonstrate the protective effect of Deferiprone on RGCs via inhibition of ferroptosis, providing a research direction to understand and treat glaucoma via the iron homeostasis and ferroptosis pathways.
Topics: Humans; Animals; Retinal Ganglion Cells; Intraocular Pressure; Deferiprone; Ferroptosis; Glaucoma; Homeostasis; Iron; Disease Models, Animal
PubMed: 35933500
DOI: 10.1038/s41418-022-01046-4 -
Autophagy Nov 2021PINK1 and PRKN, which cause Parkinson disease when mutated, form a quality control mitophagy pathway that is well-characterized in cultured cells. The extent to which...
PINK1 and PRKN, which cause Parkinson disease when mutated, form a quality control mitophagy pathway that is well-characterized in cultured cells. The extent to which the PINK1-PRKN pathway contributes to mitophagy , however, is controversial. This is due in large part to conflicting results from studies using one of two mitophagy reporters: mt-Keima or mito-QC. Studies using mt-Keima have generally detected PINK1-PRKN mitophagy , whereas those using mito-QC generally have not. Here, we directly compared the performance of mito-QC and mt-Keima in cell culture and in mice subjected to a PINK1-PRKN activating stress. We found that mito-QC was less sensitive than mt-Keima for mitophagy, and that this difference was more pronounced for PINK1-PRKN mitophagy. These findings suggest that mito-QC's poor sensitivity may account for conflicting reports of PINK1-PRKN mitophagy and caution against using mito-QC as a reporter for PINK1-PRKN mitophagy. DFP: deferiprone; EE: exhaustive exercise; FBS: fetal bovine serum; OAQ: oligomycin, antimycin, and Q-VD-OPH; OMM: outer mitochondrial membrane; PBS: phosphate-buffered saline; PD: Parkinson disease; UPS: ubiquitin-proteasome system.
Topics: Animals; Autophagy; Cells, Cultured; Fibroblasts; Flow Cytometry; Fluorescent Antibody Technique; Fluorescent Dyes; Mice; Mice, Transgenic; Mitophagy; Protein Kinases; Ubiquitin-Protein Ligases
PubMed: 33685343
DOI: 10.1080/15548627.2021.1896924 -
The FEBS Journal Jul 2023Ferroptosis, featuring an iron-dependent peroxidation of lipids, is a novel form of programmed cell death that may hold great potential in cancer therapy. Our study...
Ferroptosis, featuring an iron-dependent peroxidation of lipids, is a novel form of programmed cell death that may hold great potential in cancer therapy. Our study found that palmitic acid (PA) inhibited colon cancer cell viability in vitro and in vivo, in conjunction with an accumulation of reactive oxygen species and lipid peroxidation. The ferroptosis inhibitor Ferrostatin-1 but not Z-VAD-FMK (a pan-caspase inhibitor), Necrostatin-1 (a potent necroptosis inhibitor), or CQ (a potent inhibitor of autophagy), rescued the cell death phenotype induced by PA. Subsequently, we verified that PA induces ferroptotic cell death through excess iron as cell death was inhibited by iron chelator deferiprone (DFP), while it was exacerbated by a supplement of ferric ammonium citrate. Mechanistically, PA affects intracellular iron content by inducing endoplasmic reticulum (ER) stress leading to ER calcium release and regulating transferrin (TF) transport through increasing cytosolic calcium levels. Furthermore, we observed that cells with high expression of CD36 were more vulnerable to PA-induced ferroptosis. Altogether, our findings reveal that PA engages in anti-cancer properties by activating ER stress/ER calcium release/TF-dependent ferroptosis, and PA might serve as a compound to activate ferroptosis in colon cancer cells with high CD36 expression.
Topics: Humans; Ferroptosis; Iron; Calcium; Palmitic Acid; Reactive Oxygen Species; Colonic Neoplasms
PubMed: 36906928
DOI: 10.1111/febs.16772 -
Autophagy Jan 2023Aminoglycosides exhibit ototoxicity by damaging mitochondria, which in turn generate reactive oxygen species that induce hair cell death and subsequent hearing loss. It...
Aminoglycosides exhibit ototoxicity by damaging mitochondria, which in turn generate reactive oxygen species that induce hair cell death and subsequent hearing loss. It is well known that damaged mitochondria are degraded by mitophagy, an important mitochondrial quality control system that maintains mitochondrial homeostasis and ensures cell survival. However, it is unclear whether dysregulation of mitophagy contributes to aminoglycoside-induced hair cell injury. In the current study, we found that PINK1-PRKN-mediated mitophagy was impaired in neomycin-treated hair cells. Our data suggested that mitochondrial recruitment of PRKN and phagophore recognition of damaged mitochondria during mitophagy were blocked following neomycin treatment. In addition, the degradation of damaged mitochondria by lysosomes was significantly decreased as indicated by the mitophagic flux reporter mt-mKeima. Moreover, we demonstrated that neomycin disrupted mitophagy through transcriptional inhibition of expression, the key initiator of mitophagy. Moreover, we found that neomycin impaired mitophagy by inducing ATF3 expression. Importantly, treatment with a mitophagy activator could rescue neomycin-treated hair cells by increasing mitophagy, indicating that genetic modulation or drug intervention in mitophagy may have therapeutic potential for aminoglycoside-induced hearing loss. AAV: adeno-associated virus; ABR: auditory brainstem response; ATF3: activating transcription factor 3; ATOH1/MATH1: atonal bHLH transcription factor 1; BafA1: bafilomycin A; CCCP: carbonyl cyanide m-chlorophenyl hydrazone; COX4I1/COXIV: cytochrome c oxidase subunit 4I1; CTBP2/RIBEYE: C-terminal binding protein 2; DFP: deferiprone; EGFP: enhanced green fluorescent protein; FOXO3: forkhead box O3; GRIA2/GLUR2: glutamate receptor, ionotropic, AMPA2 (alpha 2); HC: hair cell; HSPD1/HSP60: heat shock protein 1 (chaperonin); IHC: inner hair cell; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MYO7A: myosin VIIA; OPTN: optineurin; OMM: outer mitochondrial membrane; PRKN: parkin RBR E3 ubiquitin protein ligase; PINK1: PTEN induced putative kinase 1; RT-qPCR: real-time quantitative polymerase chain reaction; TOMM20/TOM20: translocase of outer mitochondrial membrane 20; TUNEL: Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling; USP30: ubiquitin specific peptidase 30; XBP1: X-box binding protein 1.
Topics: Mitophagy; Autophagy; Aminoglycosides; Protein Kinases; Ubiquitin-Protein Ligases; Anti-Bacterial Agents; Neomycin; Hair Cells, Auditory
PubMed: 35471096
DOI: 10.1080/15548627.2022.2062872 -
International Journal of Biological... 2023Lipocalin-2 (LCN2) is an acute-phase protein that regulates inflammatory responses to bacteria or lipopolysaccharide (LPS). Although the bacteriostatic role of LCN2 is...
Lipocalin-2 (LCN2) is an acute-phase protein that regulates inflammatory responses to bacteria or lipopolysaccharide (LPS). Although the bacteriostatic role of LCN2 is well studied, the function of LCN2 in acute lung damage remains unclear. Here, LCN2 knockout (KO) mice were used to investigate the role of LCN2 in LPS-treated mice with or without recombinant LCN2 (rLCN2). In addition, we employed patients with pneumonia. RAW264.7 cells were given LCN2 inhibition or rLCN2 with or without iron chelator deferiprone. LCN2 KO mice had a higher survival rate than wild-type (WT) mice after LPS treatment. In addition to elevated LCN2 levels in serum and bronchoalveolar lavage fluid (BALF), LPS treatment also increased LCN2 protein in alveolar macrophage lysates of BALF. LCN2 deletion attenuated neutrophil and macrophage infiltration in the lungs of LPS-treated mice as well as serum and BALF interleukin-6 (IL-6). Circulating proinflammatory cytokines and LCN2-positive macrophages were prominently increased in the BALF of pneumonia patients. In addition to increase of iron-stained macrophages in pneumonia patients, increased iron-stained macrophages and oxidative stress in LPS-treated mice were inhibited by LCN2 deletion. In contrast, rLCN2 pretreatment aggravated lung inflammation and oxidative stress in LPS-treated WT mice and then resulted in higher mortality. In RAW264.7 cells, exogenous LCN2 treatment also increased inflammation and oxidative stress, whereas LCN2 knockdown markedly diminished these effects. Furthermore, deferiprone inhibited inflammation, oxidative stress, and phagocytosis in RAW264.7 cells with high LCN2 levels, as well as LPS-induced acute lung injury in WT and LCN2 KO mice. Thus, these findings suggest that LCN2 plays a key role in inflammation and oxidative stress following acute lung injury and that LCN2 is a potential therapeutic target for pneumonia or acute lung injury.
Topics: Animals; Mice; Acute Lung Injury; Deferiprone; Inflammation; Iron; Lipocalin-2; Lipopolysaccharides; Lung; Macrophages; Mice, Inbred C57BL; Oxidative Stress; Pneumonia
PubMed: 36923935
DOI: 10.7150/ijbs.79915 -
Hemoglobin Jan 2022The population of Cambodia (in 2019) was approximately 16 million with an annual growth rate of 1.4% in which the prevalence of hemoglobinopathies was estimated at about... (Review)
Review
The population of Cambodia (in 2019) was approximately 16 million with an annual growth rate of 1.4% in which the prevalence of hemoglobinopathies was estimated at about 40.0% (range 30.0-50.0%) to be carriers, and 2240 annual births for β-thalassemia major (β-TM). The overall prevalence of β-thalassemia (β-thal) and α-thalassemia (α-thal) were 40.9 and 39.6%, respectively. Currently, the specific epidemiological data regarding the abnormal gene frequency/mutations among different ethnic groups is unknown. In 2011, national guidelines for the Clinical Management of Patients with Thalassemia in Cambodia were developed and published by the Ministry of Health (MoH). Packed red cells (PRCs) are available at most referral hospitals (provincial hospitals). Oral iron chelators [deferiprone (DFP) and deferasirox (DFX)] are only available from a private pharmaceutical company. The future needs for Cambodia are to develop a national policy on the prevention or control of β-thal and α-thal, and a national registry of patients with thalassemia, to determine the gene frequency of α- and β-thal in different regions of the country, and to place the iron chelators on the list of essential medicines.
Topics: Cambodia; Hemoglobinopathies; Humans; Iron Chelating Agents; alpha-Thalassemia; beta-Thalassemia
PubMed: 35950584
DOI: 10.1080/03630269.2021.2008956 -
Naunyn-Schmiedeberg's Archives of... Nov 2022Renal I/R injury is a severe medical condition contributing to acute kidney injury (AKI), leading to rapid kidney dysfunction and high mortality rates. It is generally... (Review)
Review
Renal I/R injury is a severe medical condition contributing to acute kidney injury (AKI), leading to rapid kidney dysfunction and high mortality rates. It is generally observed during renal transplantation, shock, trauma, and urologic and cardiovascular surgery, for which there is no effective treatment. Cell death and damage are commonly linked to I/R. Cell death triggered by iron-dependent lipid peroxidation, such as ferroptosis, has been demonstrated to have a significant detrimental effect in renal IRI models, making it a new type of cell death currently being researched. Ferroptosis is a nonapoptotic type of cell death that occurs when free iron enters the cell and is a critical component of many biological processes. In ferroptosis-induced renal I/R injury, iron chelators such as Deferasirox, Deferiprone, and lipophilic antioxidants are currently suppressed lipid peroxidation Liproxstatin-1 (Lip-1), Ferrostatin-1 along with antioxidants like vitamin and quercetin. Ferroptosis has been considered a potential target for pharmaceutical intervention to alleviate renal IRI-associated cell damage. Thus, this review emphasized the role of ferroptosis and its inhibition in renal IRI. Also, Pharmacological modulation of ferroptosis mechanism in renal I/R injury has been conferred. Graphical abstract.
Topics: Deferasirox; Deferiprone; Ferroptosis; Humans; Iron; Iron Chelating Agents; Ischemia; Kidney; Pharmaceutical Preparations; Quercetin; Reperfusion; Reperfusion Injury; Vitamins
PubMed: 35920897
DOI: 10.1007/s00210-022-02277-5