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JCI Insight Jun 2024Autosomal dominant optic atrophy plus (ADOA+) is characterized by primary optic nerve atrophy accompanied by a spectrum of degenerative neurological symptoms. Despite...
Autosomal dominant optic atrophy plus (ADOA+) is characterized by primary optic nerve atrophy accompanied by a spectrum of degenerative neurological symptoms. Despite ongoing research, no effective treatments are currently available for this condition. Our study provided evidence for the pathogenicity of an unreported c.1780T>C variant in the OPA1 gene through patient-derived skin fibroblasts and an engineered HEK293T cell line with OPA1 downregulation. We demonstrated that OPA1 insufficiency promoted mitochondrial fragmentation and increased DRP1 expression, disrupting mitochondrial dynamics. Consequently, this disruption enhanced mitophagy and caused mitochondrial dysfunction, contributing to the ADOA+ phenotype. Notably, the Drp1 inhibitor, mitochondrial division inhibitor-1 (Mdivi-1), effectively mitigated the adverse effects of OPA1 impairment. These effects included reduced Drp1 phosphorylation, decreased mitochondrial fragmentation, and balanced mitophagy. Thus, we propose that intervening in DRP1 with Mdivi-1 could correct mitochondrial abnormalities, offering a promising therapeutic approach for managing ADOA+.
PubMed: 38916953
DOI: 10.1172/jci.insight.180582 -
Aging Jun 2024Mitophagy serves as a critical mechanism for tumor cell death, significantly impacting the progression of tumors and their treatment approaches. There are significant...
Mitophagy serves as a critical mechanism for tumor cell death, significantly impacting the progression of tumors and their treatment approaches. There are significant challenges in treating patients with head and neck squamous cell carcinoma, underscoring the importance of identifying new targets for therapy. The function of mitophagy in head and neck squamous carcinoma remains uncertain, thus investigating its impact on patient outcomes and immunotherapeutic responses is especially crucial. We initially analyzed the differential expression, prognostic value, intergene correlations, copy number variations, and mutation frequencies of mitophagy-related genes at the pan-cancer level. Through unsupervised clustering, we divided head and neck squamous carcinoma into three subtypes with distinct prognoses, identified the signaling pathway features of each subtype using ssGSEA, and characterized subtype B as having features of an immune desert using various immune infiltration calculation methods. Using multi-omics data, we identified the genomic variation characteristics, mutated gene pathway features, and drug sensitivity features of the mitophagy subtypes. Utilizing a combination of 10 machine learning algorithms, we have developed a prognostic scoring model called Mitophagy Subgroup Risk Score (MSRS), which is used to predict patient survival and the response to immune checkpoint blockade therapy. Simultaneously, we applied MSRS to single-cell analysis to explore intercellular communication. Through laboratory experiments, we validated the biological function of SLC26A9, one of the genes in the risk model. In summary, we have explored the significant role of mitophagy in head and neck tumors through multi-omics data, providing new directions for clinical treatment.
PubMed: 38913914
DOI: 10.18632/aging.205964 -
PeerJ 2024(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic...
BACKGROUND
(Thunb.) Makino, a well-known edible and medicinal plant, has anti-aging properties and is used to treataging-associated conditions such as diabetes, metabolic syndrome, and cardiovascular diseases. Gypenosides (GYPs) are the primary constituents of . Increasing evidence indicates that GYPs are effective at preserving mitochondrial homeostasis and preventing heart failure (HF). This study aimed to uncover the cardioprotective mechanisms of GYPs related to mitochondrial regulation.
METHODS
The bioactive components in GYPs and the potential targets in treating HF were obtained and screened using the network pharmacology approach, followed by drug-disease target prediction and enrichment analyses. The pharmacological effects of GYPs in cardioprotection, mitochondrial function, mitochondrial quality control, and underlying mechanisms were further investigated in Doxorubicin (Dox)-stimulated H9c2 cardiomyocytes.
RESULTS
A total of 88 bioactive compounds of GYPs and their respective 71 drug-disease targets were identified. The hub targets covered MAPK, EGFR, PI3KCA, and Mcl-1. Enrichment analysis revealed that the pathways primarily contained PI3K/Akt, MAPK, and FoxO signalings, as well as calcium regulation, protein phosphorylation, apoptosis, and mitophagy process. In Dox-stimulated H9c2 rat cardiomyocytes, pretreatment with GYPs increased cell viability, enhanced cellular ATP content, restored basal oxygen consumption rate (OCR), and improved mitochondrial membrane potential (MMP). Furthermore, GYPs improved PINK1/parkin-mediated mitophagy without influencing mitochondrial fission/fusion proteins and the autophagic LC3 levels. Mechanistically, the phosphorylation of PI3K, Akt, GSK-3β, and the protein level of Mcl-1 was upregulated by GYP treatment.
CONCLUSION
Our findings reveal that GYPs exert cardioprotective effects by rescuing the defective mitophagy, and PI3K/Akt/GSK-3/Mcl-1 signaling is potentially involved in this process.
Topics: Gynostemma; Mitophagy; Glycogen Synthase Kinase 3 beta; Signal Transduction; Myeloid Cell Leukemia Sequence 1 Protein; Proto-Oncogene Proteins c-akt; Cardiotonic Agents; Plant Extracts; Phosphatidylinositol 3-Kinases; Animals; Rats; Myocytes, Cardiac; Cell Line
PubMed: 38912051
DOI: 10.7717/peerj.17538 -
European Journal of Pharmacology Jun 2024Fenofibrate, a PPAR-α agonist clinically used to lower serum lipid levels, reduces cardiac remodeling and improves cardiac function. However, its mechanism of action is...
Fenofibrate, a PPAR-α agonist clinically used to lower serum lipid levels, reduces cardiac remodeling and improves cardiac function. However, its mechanism of action is not completely elucidated. In this study we examined the effect of fenofibrate on mitochondria in a rat model of renovascular hypertension, focusing on mediators controlling mitochondrial dynamics and autophagy. Rats with two-kidney one-clip (2K1C) hypertension were treated with fenofibrate 150 mg/kg/day (2K1C-FFB) or vehicle (2K1C-VEH) for 8 weeks. Systolic blood pressure and cardiac functional were in-vivo assessed, while cardiomyocyte size and protein expression of mediators of cardiac hypertrophy and mitochondrial dynamics were ex-vivo examined by histological and Western blot analyses. Fenofibrate treatment counteracted the development of hypertension and the increase of left ventricular mass, relative wall thickness and cross-sectional area of cardiomyocytes. Furthermore, fenofibrate re-balanced the expression Mfn2, Drp1 and Parkin, regulators of fusion, fission, mitophagy respectively. Regarding autophagy, the LC3-II/LC3-I ratio was increased in 2K1C-VEH and 2K1C-FFB, whereas the autophagy was increased only in 2K1C-FFB. In cultured H9C2 cardiomyoblasts, fenofibrate reversed the Ang II-induced mRNA up-regulation of hypertrophy markers Nppa and Myh7, accumulation of reactive oxygen species and depolarization of the mitochondrial membrane exerting protection mediated by up-regulation of the Uncoupling protein 2. Our results indicate that fenofibrate acts directly on cardiomyocytes and counteracts the pressure overload-induced cardiac maladaptive remodeling. This study reveals a so far hidden mechanism involving mitochondrial dynamics in the beneficial effects of fenofibrate, support its repurposing for the treatment of cardiac hypertrophy and provide new potential targets for its pharmacological function.
PubMed: 38909934
DOI: 10.1016/j.ejphar.2024.176767 -
Pharmacological Research Jun 2024Several cardiovascular illnesses are associated with aberrant activation of cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis, and macrophage... (Review)
Review
Several cardiovascular illnesses are associated with aberrant activation of cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis, and macrophage polarisation as hallmarks contributing to vascular damage and abnormal cardiac function. Meanwhile, these three novel forms of cellular dysfunction are closely related to mitochondrial homeostasis. Mitochondria are the main organelles that supply energy and maintain cellular homeostasis. Mitochondrial stability is maintained through a series of regulatory pathways, such as mitochondrial fission, mitochondrial fusion and mitophagy. Studies have shown that mitochondrial dysfunction (e.g., impaired mitochondrial dynamics and mitophagy) promotes ROS production, leading to oxidative stress, which induces cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis and macrophage M1 phenotypic polarisation. Therefore, an in-depth knowledge of the dynamic regulation of mitochondria during cellular pyroptosis, ferroptosis, necroptosis, cuproptosis, disulfidptosis and macrophage polarisation is necessary to understand cardiovascular disease development. This paper systematically summarises the impact of changes in mitochondrial dynamics and mitophagy on regulating novel cellular dysfunctions and macrophage polarisation to promote an in-depth understanding of the pathogenesis of cardiovascular diseases and provide corresponding theoretical references for treating cardiovascular diseases.
PubMed: 38909638
DOI: 10.1016/j.phrs.2024.107258 -
Environment International Jun 2024Triclosan is a potent antibacterial compound widely used in everyday products. Whether triclosan affects Leydig cell function in adult male rats remains unknown. In this...
Triclosan is a potent antibacterial compound widely used in everyday products. Whether triclosan affects Leydig cell function in adult male rats remains unknown. In this study, 0, 50, 100, or 200 mg/kg/day triclosan was gavaged to Sprague-Dawley male rats from 56 to 63 days postpartum. Triclosan significantly reduced serum testosterone levels at ≥ 50 mg/kg/day via downregulating the expression of Leydig cell gene Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and regulatory transcription factor Nr3c2 at 100-200 mg/kg. Further analysis showed that triclosan markedly increased autophagy as shown by increasing LC3II and BECN1 and decreasing SQSTM1. The mRNA m6A modification analysis revealed that triclosan significantly downregulated Fto expression at 200 mg/kg while upregulating Ythdf1 expression at 100 and 200 mg/kg, leading to methylation of Becn1 mRNA as shown by MeRIP assay. Triclosan significantly inhibited testosterone output in rat R2C Leydig cells at ≥ 5 μM via downregulating Fto and upregulating Ythdf1. SiRNA Ythdf1 knockdown can reverse triclosan-mediated mitophagy in R2C cells, thereby reversing the reduction of testosterone output. In summary, triclosan caused Becn1 m6A methylation by downregulating Fto and upregulating Ythdf1, which accelerated Becn1 translation, thus leading to the occurrence of autophagy and the decrease of testosterone biosynthesis.
PubMed: 38908274
DOI: 10.1016/j.envint.2024.108827 -
Biomedicine & Pharmacotherapy =... Jun 2024Neuropathic pain is a pathological state induced by the aberrant generation of pain signals within the nervous system. Ginkgolide B(GB), an active component found of...
Neuropathic pain is a pathological state induced by the aberrant generation of pain signals within the nervous system. Ginkgolide B(GB), an active component found of Ginkgo. biloba leaves, has neuroprotective properties. This study aimed to explore the effects of GB on neuropathic pain and its underlying mechanisms. In the in vivo study, we adopted the rat chronic constriction injury model, and the results showed that GB(4 mg/kg) treatment effectively reduced pain sensation in rats and decreased the expressions of Iba-1 (a microglia marker), NLRP3 inflammasome, and inflammatory factors, such as interleukin (IL)-1β, in the spinal cord 7 days post-surgery. In the in vitro study, we induced microglial inflammation using lipopolysaccharide (500 ng/mL) / adenosine triphosphate (5 mM) and treated it with GB (10, 20, and 40 μM). GB upregulated the expression of mitophagy proteins, such as PINK1, Parkin, LC3 II/I, Tom20, and Beclin1, and decreased the cellular production of reactive oxygen species. Moreover, it lowered the expression of inflammation-related proteins, such as Caspase-1, IL-1β, and NLRP3 in microglia. However, this effect was reversed by Parkin shRNA/siRNA or the autophagy inhibitor 3-methyladenine (5 mM). These findings reveal that GB alleviates neuropathic pain by mitigating neuroinflammation through the activation of PINK1-Parkin-mediated mitophagy.
PubMed: 38908197
DOI: 10.1016/j.biopha.2024.117006 -
Life Science Alliance Sep 2024Mitochondrial dysfunction is a common feature of amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD); however, it remains unclear whether this is a cause or...
Mitochondrial dysfunction is a common feature of amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD); however, it remains unclear whether this is a cause or consequence of the pathogenic process. Analysing multiple aspects of mitochondrial biology across several models of -ALS/FTD, we found morphology, oxidative stress, and mitophagy are commonly affected, which correlated with progressive loss of locomotor performance. Notably, only genetic manipulations that reversed the oxidative stress levels were also able to rescue locomotor deficits, supporting a causative link between mitochondrial dysfunction, oxidative stress, and behavioural phenotypes. Targeting the key antioxidant Keap1/Nrf2 pathway, we found that genetic reduction of or pharmacological inhibition by dimethyl fumarate significantly rescued the -related oxidative stress and motor deficits. Finally, mitochondrial ROS levels were also elevated in patient-derived iNeurons and were effectively suppressed by dimethyl fumarate treatment. These results indicate that mitochondrial oxidative stress is an important mechanistic contributor to pathogenesis, affecting multiple aspects of mitochondrial function and turnover. Targeting the Keap1/Nrf2 signalling pathway to combat oxidative stress represents a therapeutic strategy for -related ALS/FTD.
Topics: Amyotrophic Lateral Sclerosis; Oxidative Stress; NF-E2-Related Factor 2; C9orf72 Protein; Mitochondria; Animals; Disease Models, Animal; Kelch-Like ECH-Associated Protein 1; Humans; Signal Transduction; Frontotemporal Dementia; Phenotype; Drosophila Proteins; Reactive Oxygen Species; Mitophagy; Dimethyl Fumarate; Male
PubMed: 38906677
DOI: 10.26508/lsa.202402853 -
Science Advances Jun 2024The central nervous system coordinates peripheral cellular stress responses, including the unfolded protein response of the mitochondria (UPR); however, the contexts for...
The central nervous system coordinates peripheral cellular stress responses, including the unfolded protein response of the mitochondria (UPR); however, the contexts for which this regulatory capability evolved are unknown. UPR is up-regulated upon pathogenic infection and in metabolic flux, and the olfactory nervous system has been shown to regulate pathogen resistance and peripheral metabolic activity. Therefore, we asked whether the olfactory nervous system in controls the UPR cell nonautonomously. We found that silencing a single inhibitory olfactory neuron pair, AWC, led to robust induction of UPR and reduction of oxidative phosphorylation dependent on serotonin signaling and -mediated mitophagy. Further, AWC ablation confers resistance to the pathogenic bacteria partially dependent on the UPR transcription factor and fully dependent on mitophagy machinery. These data illustrate a role for the olfactory nervous system in regulating whole-organism mitochondrial dynamics, perhaps in preparation for postprandial metabolic stress or pathogenic infection.
Topics: Animals; Caenorhabditis elegans; Mitophagy; Mitochondria; Caenorhabditis elegans Proteins; Smell; Unfolded Protein Response; Pseudomonas aeruginosa; Ubiquitin-Protein Ligases; Oxidative Phosphorylation; Signal Transduction; Serotonin; Transcription Factors
PubMed: 38905346
DOI: 10.1126/sciadv.adn0014 -
Stem Cell Research & Therapy Jun 2024Telomeres consist of repetitive DNA sequences at the chromosome ends to protect chromosomal stability, and primarily maintained by telomerase or occasionally by...
BACKGROUND
Telomeres consist of repetitive DNA sequences at the chromosome ends to protect chromosomal stability, and primarily maintained by telomerase or occasionally by alternative telomere lengthening of telomeres (ALT) through recombination-based mechanisms. Additional mechanisms that may regulate telomere maintenance remain to be explored. Simultaneous measurement of telomere length and transcriptome in the same human embryonic stem cell (hESC) revealed that mRNA expression levels of UBQLN1 exhibit linear relationship with telomere length.
METHODS
In this study, we first generated UBQLN1-deficient hESCs and compared with the wild-type (WT) hESCs the telomere length and molecular change at RNA and protein level by RNA-seq and proteomics. Then we identified the potential interacting proteins with UBQLN1 using immunoprecipitation-mass spectrometry (IP-MS). Furthermore, the potential mechanisms underlying the shortened telomeres in UBQLN1-deficient hESCs were analyzed.
RESULTS
We show that Ubiquilin1 (UBQLN1) is critical for telomere maintenance in human embryonic stem cells (hESCs) via promoting mitochondrial function. UBQLN1 deficiency leads to oxidative stress, loss of proteostasis, mitochondria dysfunction, DNA damage, and telomere attrition. Reducing oxidative damage and promoting mitochondria function by culture under hypoxia condition or supplementation with N-acetylcysteine partly attenuate the telomere attrition induced by UBQLN1 deficiency. Moreover, UBQLN1 deficiency/telomere shortening downregulates genes for neuro-ectoderm lineage differentiation.
CONCLUSIONS
Altogether, UBQLN1 functions to scavenge ubiquitinated proteins, preventing their overloading mitochondria and elevated mitophagy. UBQLN1 maintains mitochondria and telomeres by regulating proteostasis and plays critical role in neuro-ectoderm differentiation.
Topics: Humans; Human Embryonic Stem Cells; Autophagy-Related Proteins; Mitochondria; Proteostasis; Telomere; Telomere Homeostasis; Adaptor Proteins, Signal Transducing; Cell Cycle Proteins; Oxidative Stress; DNA Damage
PubMed: 38902824
DOI: 10.1186/s13287-024-03789-y