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Autophagy Feb 2021Influenza A virus (IAV) infection induces mitophagy, which is essential for the clearance of damaged mitochondria. Dysfunctional mitochondria can be selectively targeted...
Influenza A virus (IAV) infection induces mitophagy, which is essential for the clearance of damaged mitochondria. Dysfunctional mitochondria can be selectively targeted by PINK1, which recruits PRKN/PARK2 and leads to subsequent mitochondrial sequestration within autophagosomes. The IAV PB1-F2 protein translocates to mitochondria, accelerates the mitochondrial fragmentation and impairs the innate immunity. However, whether PB1-F2 mediates IAV-induced mitophagy and the relation between mitophagy and PB1-F2-attenuated innate immunity remain obscure. Here, we showed that PB1-F2 translocated to mitochondria by interacting and colocalizing with TUFM (Tu translation elongation factor, mitochondrial). Further studies revealed that PB1-F2 induced complete mitophagy, which required the interactions of PB1-F2 with both TUFM and MAP1LC3B/LC3B that mediated the autophagosome formation. PB1-F2-induced mitophagy was critical for the MAVS (mitochondrial antiviral signaling protein) degradation and led to its suppression of the type I IFN production. Importantly, the C-terminal LIR motif of PB1-F2 protein was demonstrated to be essential for its mitophagy induction and attenuated innate immunity. In conclusion, PB1-F2-induced mitophagy strongly correlates with impaired cellular innate immunity, revealing it is a potential therapeutic target. BCL2L13: BCL2 like 13; BECN1: beclin 1; BNIP3L/Nix: BCL2 interacting protein 3 like; CQ: chloroquine; DDX58: DExD/H-box helicase 58; eGFP: enhanced green fluorescent protein; hpi: hours post infection; IAV: influenza A virus; IFN: interferon; IP: immunoprecipitation; LIR: LC3-interacting region; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAVS: mitochondrial antiviral signaling protein; MMP: mitochondrial membrane potential; MOI, multiplicity of infection; mRFP: monomeric red fluorescent protein; NBR1: NBR1 autophagy cargo receptor; NC: negative control; NLRP3: NLR family pyrin domain containing 3; PINK1: PTEN induced kinase 1; PRKN/PARK2: parkin RBR E3 ubiquitin protein ligase; RLR: RIG-I-like-receptor; ROS: reactive oxygen species; SEV: sendai virus; SQSTM1/p62: sequestosome 1; TAX1BP1: Tax1 binding protein 1; TM: transmembrane; TOMM20/40: translocase of outer mitochondrial membrane 20/40; TUFM: Tu translation elongation factor, mitochondrial.
Topics: Autophagy; Humans; Immunity, Innate; Influenza A virus; Mitochondria; Mitochondrial Membranes; Mitophagy; Viral Proteins
PubMed: 32013669
DOI: 10.1080/15548627.2020.1725375 -
Cell Reports. Medicine May 2022Targeting mitophagy to activate the recycling of faulty mitochondria during aging is a strategy to mitigate muscle decline. We present results from a randomized,... (Randomized Controlled Trial)
Randomized Controlled Trial
Targeting mitophagy to activate the recycling of faulty mitochondria during aging is a strategy to mitigate muscle decline. We present results from a randomized, placebo-controlled trial in middle-aged adults where we administer a postbiotic compound Urolithin A (Mitopure), a known mitophagy activator, at two doses for 4 months (NCT03464500). The data show significant improvements in muscle strength (∼12%) with intake of Urolithin A. We observe clinically meaningful improvements with Urolithin A on aerobic endurance (peak oxygen oxygen consumption [VO]) and physical performance (6 min walk test) but do not notice a significant improvement on peak power output (primary endpoint). Levels of plasma acylcarnitines and C-reactive proteins are significantly lower with Urolithin A, indicating higher mitochondrial efficiency and reduced inflammation. We also examine expression of proteins linked to mitophagy and mitochondrial metabolism in skeletal muscle and find a significant increase with Urolithin A administration. This study highlights the benefit of Urolithin A to improve muscle performance.
Topics: Biomarkers; Coumarins; Mitochondria; Mitophagy; Muscle Strength
PubMed: 35584623
DOI: 10.1016/j.xcrm.2022.100633 -
Brain : a Journal of Neurology Dec 2022Loss-of-function mutations in the PRKN, PINK1 and PARK7 genes (encoding parkin, PINK1 and DJ-1, respectively) cause autosomal recessive forms of Parkinson's disease....
Loss-of-function mutations in the PRKN, PINK1 and PARK7 genes (encoding parkin, PINK1 and DJ-1, respectively) cause autosomal recessive forms of Parkinson's disease. PINK1 and parkin jointly mediate selective autophagy of damaged mitochondria (mitophagy), but the mechanisms by which loss of DJ-1 induces Parkinson's disease are not well understood. Here, we investigated PINK1/parkin-mediated mitophagy in cultured human fibroblasts and induced pluripotent stem cell-derived neurons with homozygous PARK7 mutations. We found that DJ-1 is essential for PINK1/parkin-mediated mitophagy. Loss of DJ-1 did not interfere with PINK1 or parkin activation after mitochondrial depolarization but blocked mitophagy further downstream by inhibiting recruitment of the selective autophagy receptor optineurin to depolarized mitochondria. By contrast, starvation-induced, non-selective autophagy was not affected by loss of DJ-1. In wild-type fibroblasts and induced pluripotent stem cell-derived dopaminergic neurons, endogenous DJ-1 translocated to depolarized mitochondria in close proximity to optineurin. DJ-1 translocation to depolarized mitochondria was dependent on PINK1 and parkin and did not require oxidation of cysteine residue 106 of DJ-1. Overexpression of DJ-1 did not rescue the mitophagy defect of PINK1- or parkin-deficient cells. These findings position DJ-1 downstream of PINK1 and parkin in the same pathway and suggest that disruption of PINK1/parkin/DJ-1-mediated mitophagy is a common pathogenic mechanism in autosomal recessive Parkinson's disease.
Topics: Humans; Mitochondria; Mitophagy; Parkinson Disease; Protein Kinases; Ubiquitin-Protein Ligases
PubMed: 36039535
DOI: 10.1093/brain/awac313 -
Trends in Cell Biology Oct 2022More than 800 million people suffer from kidney disease. Genetic studies and follow-up animal models and cell biological experiments indicate the key role of proximal... (Review)
Review
More than 800 million people suffer from kidney disease. Genetic studies and follow-up animal models and cell biological experiments indicate the key role of proximal tubule metabolism. Kidneys have one of the highest mitochondrial densities. Mitochondrial biogenesis, mitochondrial fusion and fission, and mitochondrial recycling, such as mitophagy are critical for proper mitochondrial function. Mitochondrial dysfunction can lead to an energetic crisis, orchestrate different types of cell death (apoptosis, necroptosis, pyroptosis, and ferroptosis), and influence cellular calcium levels and redox status. Collectively, mitochondrial defects in renal tubules contribute to epithelial atrophy, inflammation, or cell death, orchestrating kidney disease development.
Topics: Animals; Humans; Kidney Diseases; Kidney Tubules; Mitochondria; Mitochondrial Dynamics; Mitophagy
PubMed: 35473814
DOI: 10.1016/j.tcb.2022.03.012 -
Frontiers in Immunology 2023Vitiligo is an acquired, autoimmune, depigmented skin disease with unclear pathogenesis. Mitochondrial dysfunction contributes significantly to vitiligo, and mitophagy...
BACKGROUND
Vitiligo is an acquired, autoimmune, depigmented skin disease with unclear pathogenesis. Mitochondrial dysfunction contributes significantly to vitiligo, and mitophagy is vital for removing damaged mitochondria. Herein, using bioinformatic analysis, we sought to determine the possible role of mitophagy-associated genes in vitiligo and immune infiltration.
METHODS
Microarrays GSE53146 and GSE75819 were used to identify differentially expressed genes (DEGs) in vitiligo. By crossing vitiligo DEGs with mitophagy-related genes, the mitophagy-related DEGs were identified. Functional enrichment and protein-protein intersection (PPI) analyses were conducted. Then, the hub genes were identified using two machine algorithms, and receiver operating characteristic (ROC) curves were generated. Next, the immune infiltration and its connection with hub genes in vitiligo were investigated. Finally, the Regnetwork database and NetworkAnalyst were used to predict the upstream transcriptional factors (TFs), microRNAs (miRNAs), and the protein-compound network.
RESULTS
A total of 24 mitophagy-related genes were screened. Then, five mitophagy hub genes (, , , , and ) were identified using two machine learning algorithms, and these genes showed high diagnostic specificity for vitiligo. The PPI network showed that hub genes interacted with each other. The mRNA expression levels of five hub genes were validated in vitiligo lesions by qRT-PCR and were compatible with the bioinformatic results. Compared with controls, the abundance of activated CD4 T cells, CD8 T cells, immature dendritic cells and B cells, myeloid-derived suppressor cells (MDSCs), gamma delta T cells, mast cells, regulatory T cells (Tregs), and T helper 2 (Th2) cells was higher. However, the abundance of CD56 bright natural killer (NK) cells, monocytes, and NK cells was lower. Correlation analysis revealed a link between hub genes and immune infiltration. Meanwhile, we predicted the upstream TFs and miRNAs and the target compounds of hub genes.
CONCLUSION
Five hub mitophagy-related genes were identified and correlated with immune infiltration in vitiligo. These findings suggested that mitophagy may promote the development of vitiligo by activating immune infiltration. Our study might enhance our comprehension of the pathogenic mechanism of vitiligo and offer a treatment option for vitiligo.
Topics: Humans; Vitiligo; CD8-Positive T-Lymphocytes; Mitophagy; Algorithms; Computational Biology; GTPase-Activating Proteins
PubMed: 37287971
DOI: 10.3389/fimmu.2023.1164124 -
Nature Biomedical Engineering Jan 2022A reduced removal of dysfunctional mitochondria is common to aging and age-related neurodegenerative pathologies such as Alzheimer's disease (AD). Strategies for...
A reduced removal of dysfunctional mitochondria is common to aging and age-related neurodegenerative pathologies such as Alzheimer's disease (AD). Strategies for treating such impaired mitophagy would benefit from the identification of mitophagy modulators. Here we report the combined use of unsupervised machine learning (involving vector representations of molecular structures, pharmacophore fingerprinting and conformer fingerprinting) and a cross-species approach for the screening and experimental validation of new mitophagy-inducing compounds. From a library of naturally occurring compounds, the workflow allowed us to identify 18 small molecules, and among them two potent mitophagy inducers (Kaempferol and Rhapontigenin). In nematode and rodent models of AD, we show that both mitophagy inducers increased the survival and functionality of glutamatergic and cholinergic neurons, abrogated amyloid-β and tau pathologies, and improved the animals' memory. Our findings suggest the existence of a conserved mechanism of memory loss across the AD models, this mechanism being mediated by defective mitophagy. The computational-experimental screening and validation workflow might help uncover potent mitophagy modulators that stimulate neuronal health and brain homeostasis.
Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Machine Learning; Mitophagy; Workflow
PubMed: 34992270
DOI: 10.1038/s41551-021-00819-5 -
Nature Aging Jun 2022The effects of aging on the brain are widespread and can have dramatic implications on the overall health of an organism. Mitochondrial dysfunction is a hallmark of...
The effects of aging on the brain are widespread and can have dramatic implications on the overall health of an organism. Mitochondrial dysfunction is a hallmark of brain aging, but, the interplay between mitochondrial quality control, neuronal aging, and organismal health is not well understood. Here, we show that aging leads to a decline in mitochondrial autophagy (mitophagy) in the brain with a concomitant increase in mitochondrial content. We find that induction of BCL2-interacting protein 3 (BNIP3), a mitochondrial outer membrane protein, in the adult nervous system induces mitophagy and prevents the accumulation of dysfunctional mitochondria in the aged brain. Importantly, neuronal induction of BNIP3-mediated mitophagy increases organismal longevity and healthspan. Furthermore, BNIP3-mediated mitophagy in the nervous system improves muscle and intestinal homeostasis in aged flies, indicating cell non-autonomous effects. Our findings identify BNIP3 as a therapeutic target to counteract brain aging and prolong overall organismal health with age.
Topics: Animals; Mitophagy; Drosophila; Aging; Autophagy; Mitochondria
PubMed: 36213625
DOI: 10.1038/s43587-022-00214-y -
Molecular Cell Dec 2019Protein silencing represents an essential tool in biomedical research. Targeted protein degradation (TPD) strategies exemplified by PROTACs are rapidly emerging as...
Protein silencing represents an essential tool in biomedical research. Targeted protein degradation (TPD) strategies exemplified by PROTACs are rapidly emerging as modalities in drug discovery. However, the scope of current TPD techniques is limited because many intracellular materials are not substrates of proteasomal clearance. Here, we described a novel targeted-clearance strategy (autophagy-targeting chimera [AUTAC]) that contains a degradation tag (guanine derivatives) and a warhead to provide target specificity. As expected from the substrate scope of autophagy, AUTAC degraded fragmented mitochondria as well as proteins. Mitochondria-targeted AUTAC accelerated both the removal of dysfunctional fragmented mitochondria and the biogenesis of functionally normal mitochondria in patient-derived fibroblast cells. Cytoprotective effects against acute mitochondrial injuries were also seen. Canonical autophagy is viewed as a nonselective bulk decomposition system, and none of the available autophagy-inducing agents exhibit useful cargo selectivity. With its target specificity, AUTAC provides a new modality for research on autophagy-based drugs.
Topics: Autophagy; Autophagy-Related Proteins; Cell Line; Guanine; Humans; Mitochondria; Mitophagy; Protein Engineering; Protein Kinases; Protein Stability; Proteolysis
PubMed: 31606272
DOI: 10.1016/j.molcel.2019.09.009 -
European Journal of Cell Biology Jan 2021In response to mitochondrial damage, mitochondria activate mitochondrial dynamics to maintain normal functions, and an imbalance in mitochondrial dynamics triggers... (Review)
Review
In response to mitochondrial damage, mitochondria activate mitochondrial dynamics to maintain normal functions, and an imbalance in mitochondrial dynamics triggers multiple programmed cell death processes. Recent studies have shown that phosphoglycerate mutase 5 (PGAM5) is associated with mitochondrial damage. PGAM5 activates mitochondrial biogenesis and mitophagy to promote a cellular compensatory response when mitochondria are mildly damaged, whereas severe damage to mitochondria leads to PGAM5 inducing excessive mitochondria fission, disruption to mitochondrial movement, and amplification of apoptosis, necroptosis and mitophagic death signals, which eventually evoke cell death. PGAM5 functions mainly through protein-protein interactions and specific Ser/Thr/His protein phosphatase activity. PGAM5 is also regulated by mitochondrial proteases. Detection of PGAM5 and its interacting protein partners should enable a more accurate evaluation of mitochondrial damage and a more precise method for the diagnosis and treatment of diseases.
Topics: Apoptosis; Humans; Mitochondrial Dynamics; Mitochondrial Proteins; Mitophagy; Necroptosis; Phosphoprotein Phosphatases
PubMed: 33370650
DOI: 10.1016/j.ejcb.2020.151144 -
ELife Aug 2021Parkinson's disease (PD) is a major and progressive neurodegenerative disorder, yet the biological mechanisms involved in its aetiology are poorly understood. Evidence...
Parkinson's disease (PD) is a major and progressive neurodegenerative disorder, yet the biological mechanisms involved in its aetiology are poorly understood. Evidence links this disorder with mitochondrial dysfunction and/or impaired lysosomal degradation - key features of the autophagy of mitochondria, known as mitophagy. Here, we investigated the role of LRRK2, a protein kinase frequently mutated in PD, in this process in vivo. Using mitophagy and autophagy reporter mice, bearing either knockout of LRRK2 or expressing the pathogenic kinase-activating G2019S LRRK2 mutation, we found that basal mitophagy was specifically altered in clinically relevant cells and tissues. Our data show that basal mitophagy inversely correlates with LRRK2 kinase activity in vivo. In support of this, use of distinct LRRK2 kinase inhibitors in cells increased basal mitophagy, and a CNS penetrant LRRK2 kinase inhibitor, GSK3357679A, rescued the mitophagy defects observed in LRRK2 G2019S mice. This study provides the first in vivo evidence that pathogenic LRRK2 directly impairs basal mitophagy, a process with strong links to idiopathic Parkinson's disease, and demonstrates that pharmacological inhibition of LRRK2 is a rational mitophagy-rescue approach and potential PD therapy.
Topics: Animals; Female; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2; Male; Mice; Mice, Knockout; Mice, Transgenic; Mitophagy; Mutation; Parkinson Disease
PubMed: 34340748
DOI: 10.7554/eLife.67604