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Cancer Letters Feb 2024Cancer is considered as the second leading cause of mortality, and cancer incidence is still growing rapidly worldwide, which poses an increasing global health burden.... (Review)
Review
Cancer is considered as the second leading cause of mortality, and cancer incidence is still growing rapidly worldwide, which poses an increasing global health burden. Although chemotherapy is the most widely used treatment for cancer, its effectiveness is limited by drug resistance and severe side effects. Mitophagy is the principal mechanism that degrades damaged mitochondria via the autophagy/lysosome pathway to maintain mitochondrial homeostasis. Emerging evidence indicates that mitophagy plays crucial roles in tumorigenesis, particularly in cancer therapy. Mitophagy can exhibit dual effects in cancer, with both cancer-inhibiting or cancer-promoting function in a context-dependent manner. A variety of natural compounds have been found to affect cancer cell death and display anticancer properties by modulating mitophagy. In this review, we provide a systematic overview of mitophagy signaling pathways, and examine recent advances in the utilization of natural compounds for cancer therapy through the modulation of mitophagy. Furthermore, we address the inquiries and challenges associated with ongoing investigations concerning the application of natural compounds in cancer therapy based on mitophagy. Overcoming these limitations will provide opportunities to develop novel interventional strategies for cancer treatment.
Topics: Humans; Autophagy; Cell Death; Mitochondria; Mitophagy; Neoplasms
PubMed: 38097131
DOI: 10.1016/j.canlet.2023.216590 -
Journal of Neuroinflammation Nov 2020Intermittent hypoxia (IH) caused by obstructive sleep apnea (OSA) leads to neuroinflammation. Pinocembrin has been shown to have neuroprotective effects, while the...
BACKGROUND
Intermittent hypoxia (IH) caused by obstructive sleep apnea (OSA) leads to neuroinflammation. Pinocembrin has been shown to have neuroprotective effects, while the therapeutic functions under IH condition are still unknown.
METHODS
An OSA model was established by CIH exposure inside custom-made chambers. C57BL/6 mice were intraperitoneally injected with pinocembrin (40 mg/kg, i.p.) or vehicle (PBS containing 5% povidone; i.p.), and the changes of behavior on mice were detected by the Morris water maze test. Immunohistochemical staining, western blotting, immunofluorescence assays, and immunoprecipitation were used to investigate the association between NLRP3 inflammasome and BNIP3-dependent mitophagy. The mitochondrial morphology and mitophagosomes were detected under a transmission electron microscope. The detrimental effects of IH were tested by annexin V-FITC/PI staining, Mito SOX Red staining, and JC-1 mitochondrial membrane potential assay.
RESULTS
In this study, our observations in vivo indicated that the administration of pinocembrin can restore spatial learning and memory ability and reduce neuronal apoptosis and hippocampal inflammation. Pinocembrin treatment significantly inhibited the formation of NLRP3 inflammasome and infiltration of microglia and enhanced BNIP3-mediated mitophagy in the hippocampus of IH mice. Additionally, our in vitro results show that pinocembrin protects microglial cells against IH-induced cytotoxicity by activating BNIP3-dependent mitophagy through the JNK-ERK signaling pathway.
CONCLUSIONS
In summary, our findings demonstrated that pinocembrin can act as a potential therapeutic strategy for IH-induced neuroinflammation.
Topics: Animals; Flavanones; Hypoxia; Inflammation; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Proteins; Mitophagy; Sleep Apnea Syndromes
PubMed: 33176803
DOI: 10.1186/s12974-020-02014-w -
Brain : a Journal of Neurology Dec 2022This scientific commentary refers to ‘Regulation of mitophagy by the NSL complex underlies genetic risk for Parkinson's disease at 16q11.2 and MAPT H1 loci’ by...
This scientific commentary refers to ‘Regulation of mitophagy by the NSL complex underlies genetic risk for Parkinson's disease at 16q11.2 and MAPT H1 loci’ by Soutar . (https://doi.org/10.1093/brain/awac325); and ‘DJ-1 is an essential downstream mediator in PINK1/parkin-dependent mitophagy’ by Imberechts (https://doi.org/10.1093/brain/awac313).
Topics: Humans; Mitophagy; Parkinson Disease; Ubiquitin-Protein Ligases; Protein Kinases
PubMed: 36319596
DOI: 10.1093/brain/awac405 -
Autophagy Jun 2024Mitophagy is a cellular process that enables the selective degradation of damaged, dysfunctional, or superfluous mitochondria. During mitophagy, specific proteins...
Mitophagy is a cellular process that enables the selective degradation of damaged, dysfunctional, or superfluous mitochondria. During mitophagy, specific proteins recognize and tag mitochondria for degradation. These tagged mitochondria are engulfed by specialized structures called phagophores that then mature into autophagosomes/mitophagosomes. Mitophagosomes subsequently transport their mitochondrial cargo to lysosomes, where the mitochondria are broken down and recycled. While the PINK1-PRKN-dependent mitophagy pathway is well understood, mitophagy can also occur independently of this pathway. BNIP3 and BNIP3L/NIX, paralogous membrane proteins on the outer mitochondrial membrane (OMM), serve as ubiquitin-independent mitophagy receptors. Historically, BNIP3 regulation was thought to be primarily transcriptional through HIF1A (hypoxia inducible factor 1 subunit alpha). However, recent work has revealed a significant post-translational dimension, highlighting the strong role of the ubiquitin-proteasome system (UPS) in BNIP3 regulation. With these emerging concepts in mind, we aimed to develop a unified understanding of how steady-state levels of BNIP3 are established and maintained and how this regulation governs underlying cell physiology.
Topics: Animals; Humans; Autophagy; Lysosomes; Membrane Proteins; Mitochondria; Mitochondrial Proteins; Mitophagy; Proteasome Endopeptidase Complex; Proto-Oncogene Proteins
PubMed: 38449384
DOI: 10.1080/15548627.2024.2312038 -
Drug Discovery Today May 2023Mitochondrial function is essential for maintaining neuronal integrity, because neurons have a high energy demand. Neurodegenerative diseases, such as Alzheimer's... (Review)
Review
Mitochondrial function is essential for maintaining neuronal integrity, because neurons have a high energy demand. Neurodegenerative diseases, such as Alzheimer's disease (AD), are exacerbated by mitochondrial dysfunction. Mitochondrial autophagy (mitophagy) attenuates neurodegenerative diseases by eradicating dysfunctional mitochondria. In neurodegenerative disorders, there is disruption of the mitophagy process. High levels of iron also interfere with the mitophagy process and the mtDNA released after mitophagy is proinflammatory and triggers the cGAS-STING pathway that aids AD pathology. In this review, we critically discuss the factors that affect mitochondrial impairment and different mitophagy processes in AD. Furthermore, we discuss the molecules used in mouse studies as well as clinical trials that could result in potential therapeutics in the future.
Topics: Mice; Animals; Alzheimer Disease; Mitochondria; Autophagy; Mitophagy; Neurodegenerative Diseases
PubMed: 36871845
DOI: 10.1016/j.drudis.2023.103547 -
Cells Nov 2023Autophagy is an essential lysosome-mediated degradation pathway that maintains cellular homeostasis and viability in response to various intra- and extracellular... (Review)
Review
Autophagy is an essential lysosome-mediated degradation pathway that maintains cellular homeostasis and viability in response to various intra- and extracellular stresses. Mitophagy is a type of autophagy that is involved in the intricate removal of dysfunctional mitochondria during conditions of metabolic stress. In this review, we describe the multifaceted roles of autophagy and mitophagy in normal physiology and the field of cancer biology. Autophagy and mitophagy exhibit dual context-dependent roles in cancer development, acting as tumor suppressors and promoters. We also discuss the important role of autophagy and mitophagy within the cancer microenvironment and how autophagy and mitophagy influence tumor host-cell interactions to overcome metabolic deficiencies and sustain the activity of cancer-associated fibroblasts (CAFs) in a stromal environment. Finally, we explore the dynamic interplay between autophagy and the immune response in tumors, indicating their potential as immunomodulatory targets in cancer therapy. As the field of autophagy and mitophagy continues to evolve, this comprehensive review provides insights into their important roles in cancer and cancer microenvironment.
Topics: Humans; Mitophagy; Autophagy; Neoplasms; Biology; Tumor Microenvironment
PubMed: 38067169
DOI: 10.3390/cells12232742 -
Methods in Molecular Biology (Clifton,... 2022Mitophagy, a process of selective elimination of mitochondria by autophagy, is a mechanism of mitochondrial quality control that maintains mitochondrial network...
Mitophagy, a process of selective elimination of mitochondria by autophagy, is a mechanism of mitochondrial quality control that maintains mitochondrial network functionality. The elimination of damaged mitochondria through autophagy requires two steps: induction of general autophagy and priming of damaged mitochondria for selective autophagic recognition. Mitophagy impairment is linked to various pathologies; thus, removal of malfunctioning or even harmful mitochondria is vital to cellular physiology. Here, we describe methods that can be applied to the investigation of mitophagy.
Topics: Autophagy; Macroautophagy; Mitochondria; Mitophagy
PubMed: 34972995
DOI: 10.1007/978-1-0716-2071-7_14 -
Autophagy Oct 2023Mitochondria are susceptible to damage resulting from their activity as energy providers. Damaged mitochondria can cause harm to the cell and thus mitochondria are...
Mitochondria are susceptible to damage resulting from their activity as energy providers. Damaged mitochondria can cause harm to the cell and thus mitochondria are subjected to elaborate quality-control mechanisms including elimination via lysosomal degradation in a process termed mitophagy. Basal mitophagy is a house-keeping mechanism fine-tuning the number of mitochondria according to the metabolic state of the cell. However, the molecular mechanisms underlying basal mitophagy remain largely elusive. In this study, we visualized and assessed the level of mitophagy in H9c2 cardiomyoblasts at basal conditions and after OXPHOS induction by galactose adaptation. We used cells with a stable expression of a pH-sensitive fluorescent mitochondrial reporter and applied state-of-the-art imaging techniques and image analysis. Our data showed a significant increase in acidic mitochondria after galactose adaptation. Using a machine-learning approach we also demonstrated increased mitochondrial fragmentation by OXPHOS induction. Furthermore, super-resolution microscopy of live cells enabled capturing of mitochondrial fragments within lysosomes as well as dynamic transfer of mitochondrial contents to lysosomes. Applying correlative light and electron microscopy we revealed the ultrastructure of the acidic mitochondria confirming their proximity to the mitochondrial network, ER and lysosomes. Finally, exploiting siRNA knockdown strategy combined with flux perturbation with lysosomal inhibitors, we demonstrated the importance of both canonical as well as non-canonical autophagy mediators in lysosomal degradation of mitochondria after OXPHOS induction. Taken together, our high-resolution imaging approaches applied on H9c2 cells provide novel insights on mitophagy during physiologically relevant conditions. The implication of redundant underlying mechanisms highlights the fundamental importance of mitophagy. ATG: autophagy related; ATG7: autophagy related 7; ATP: adenosine triphosphate; BafA1: bafilomycin A; CLEM: correlative light and electron microscopy; EGFP: enhanced green fluorescent protein; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; OXPHOS: oxidative phosphorylation; PepA: pepstatin A; PLA: proximity ligation assay; PRKN: parkin RBR E3 ubiquitin protein ligase; RAB5A: RAB5A, member RAS oncogene family; RAB7A: RAB7A, member RAS oncogene family; RAB9A: RAB9A, member RAS oncogene family; ROS: reactive oxygen species; SIM: structured illumination microscopy; siRNA: short interfering RNA; SYNJ2BP: synaptojanin 2 binding protein; TEM: transmission electron microscopy; TOMM20: translocase of outer mitochondrial membrane 20; ULK1: unc-51 like kinase 1.
Topics: Mitophagy; Autophagy; Galactose; Mitochondria; Mitochondrial Membranes; Ubiquitin-Protein Ligases
PubMed: 37405374
DOI: 10.1080/15548627.2023.2230837 -
Circulation Research Jun 2023
Topics: Humans; Mitophagy; Cardiomyopathies; Heart; Dynamins; Mitochondrial Dynamics
PubMed: 37347834
DOI: 10.1161/CIRCRESAHA.123.323013 -
Autophagy May 2024Mitophagy is the process of selective autophagy that removes superfluous and dysfunctional mitochondria. Mitophagy was first characterized in mammalian cells and is now... (Review)
Review
Mitophagy is the process of selective autophagy that removes superfluous and dysfunctional mitochondria. Mitophagy was first characterized in mammalian cells and is now recognized to follow several pathways including basal forms in specific organs. Mitophagy pathways are regulated by multiple, often interconnected factors. The present review aims to streamline this complexity and evaluate common elements that may define the evolutionary origin of mitophagy. Key issues surrounding mitophagy signaling at the mitochondrial surface may fundamentally derive from mitochondrial membrane dynamics. Elements of such membrane dynamics likely originated during the endosymbiosis of the alphaproteobacterial ancestor of our mitochondria but underwent an evolutionary leap forward in basal metazoa that determined the currently known variations in mitophagy signaling.: AGPAT, 1-acylglycerol-3-phosphate O-acyltransferase; ATG, autophagy related; BCL2L13, BCL2 like 13; BNIP3, BCL2 interacting protein 3; BNIP3L, BCL2 interacting protein 3 like; CALCOCO, calcium binding and coiled-coil domain; CL, cardiolipin; ER, endoplasmic reticulum; ERMES, ER-mitochondria encounter structure; FBXL4, F-box and leucine rich repeat protein 4; FUNDC1, FUN14 domain containing 1; GABARAPL1, GABA type A receptor associated protein like 1; HIF, hypoxia inducible factor; IMM, inner mitochondrial membrane; LBPA/BMP, lysobisphosphatidic acid; LIR, LC3-interacting region; LPA, lysophosphatidic acid; MAM, mitochondria-associated membranes; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MCL, monolysocardiolipin; ML, maximum likelihood; NBR1, NBR1 autophagy cargo receptor; OMM, outer mitochondrial membrane; PA, phosphatidic acid; PACS2, phosphofurin acidic cluster sorting protein 2; PC/PLC, phosphatidylcholine; PE, phosphatidylethanolamine; PHB2, prohibitin 2; PINK1, PTEN induced kinase 1; PtdIns, phosphatidylinositol; SAR, Stramenopiles, Apicomplexa and Rhizaria; TAX1BP1, Tax1 binding protein 1; ULK1, unc-51 like autophagy activating kinase 1; VDAC/porin, voltage dependent anion channel.
Topics: Mitophagy; Mitochondria; Humans; Animals; Prohibitins; Mitochondrial Membranes; Signal Transduction
PubMed: 38361280
DOI: 10.1080/15548627.2024.2307215