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Induction of resistin-like molecule ß (Relm-ß) and mitofusin 2 (MFN2) mediated aberrant mitochondrial fission have been found to be involved in the pathogenesis of pulmonary arterial hypertension (PAH). However, the molecular mechanisms underlying Relm-ß regulation of MFN2 therefore mitochondrial fission remain unclear. This study aims to address these issues. Primary cultured PASMCs and monocrotaline (MCT)-induced PAH rats were applied in this study. The results showed that Relm-ß promoted cells proliferation in PASMCs, this was accompanied with the upregulation of USP18, Twist1 and miR-214, and downregulation of MFN2. We found that Relm-ß increased USP18 expression which in turn raised Twist1 by suppressing its proteasome degradation. Elevation of Twist1 increased miR-214 expression and then reduced MFN2 expression and mitochondrial fragmentation leading to PASMCs proliferation. In vivo study, we confirmed that Relm-ß was elevated in MCT-induced PAH rat model, and USP18/Twist1/miR-214/MFN2 axis was altered similar as in vitro. Targeting this cascade by Relm-ß receptor inhibitor Calhex231, proteasome inhibitor MG-132, Twist1 inhibitor Harmine or miR-214 antagomiR prevented the development of pulmonary vascular remodeling and therefore PAH in MCT-treated rats. In conclusion, we demonstrate that Relm-ß promotes PASMCs proliferation and vascular remodeling by activating USP18/Twist1/miR-214 dependent MFN2 reduction and mitochondrial fission, suggesting that this signaling pathway might be a promising target for management of PAH.
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Proliferação de Células , GTP Fosfo-Hidrolases , MicroRNAs , Mitocôndrias , Ratos Sprague-Dawley , Transdução de Sinais , Proteína 1 Relacionada a Twist , Ubiquitina Tiolesterase , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Masculino , Ratos , Ubiquitina Tiolesterase/metabolismo , Ubiquitina Tiolesterase/genética , Proteína 1 Relacionada a Twist/metabolismo , Proteína 1 Relacionada a Twist/genética , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , GTP Fosfo-Hidrolases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Hipertensão Arterial Pulmonar/metabolismo , Hipertensão Arterial Pulmonar/induzido quimicamente , Hipertensão Arterial Pulmonar/patologia , Hipertensão Arterial Pulmonar/fisiopatologia , Monocrotalina/toxicidade , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/patologia , Hipertensão Pulmonar/fisiopatologia , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/patologia , Artéria Pulmonar/metabolismo , Proteínas MitocondriaisRESUMO
Mitochondria are crucial for cellular ATP production. They are highly dynamic organelles, whose morphology and function are controlled through mitochondrial fusion and fission. The specific roles of mitochondria in podocytes, the highly specialized cells of the kidney glomerulus, remain less understood. Given the significant structural, functional, and molecular similarities between mammalian podocytes and Drosophila nephrocytes, we employed fly nephrocytes to explore the roles of mitochondria in cellular function. Our study revealed that alterations in the Pink1-Park (mammalian PINK1-PRKN) pathway can disrupt mitochondrial dynamics in Drosophila nephrocytes. This disruption led to either fragmented or enlarged mitochondria, both of which impaired mitochondrial function. The mitochondrial dysfunction subsequently triggered defective intracellular endocytosis, protein aggregation, and cellular damage. These findings underscore the critical roles of mitochondria in nephrocyte functionality.
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Proteínas de Drosophila , Drosophila melanogaster , Endocitose , Mitocôndrias , Dinâmica Mitocondrial , Podócitos , Animais , Podócitos/metabolismo , Podócitos/patologia , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Drosophila melanogaster/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ubiquitina-Proteína LigasesRESUMO
The lack of amino acids triggers the autophagic response. Some studies have shown such starvation conditions also induce mitochondrial fusion, revealing a close correlation between the two processes. Although Mitofusin-2 (MFN2) has been demonstrated to play a role in fusion regulation, its role in the autophagic response and the variables that activate MFN2 under stress remain unknown. In this investigation, we screened and confirmed that forkhead box protein O3 (FOXO3) participates in MFN2's expression during short periods of starvation. Luciferase reporter test proved that FOXO3 facilitates MFN2's transcription by binding to its promoter region, and FOXO3 downregulation directly depresses MFN2's expression. Consequently, inhibiting the FOXO3-MFN2 axis results in the loss of mitochondrial fusion, disrupting the normal morphology of mitochondria, impairing the degradation of substrates, and reducing autophagosome accumulation, ultimately leading to the blockage of the autophagy. In conclusion, our work demonstrates that the FOXO3-MFN2 pathway is essential for adaptive changes in mitochondrial morphology and cellular autophagy response under nutritional constraints.
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Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Microglial activation and neuroinflammation are key cellular events that determine the outcome of TBI, especially neuronal and cognitive function. Studies have suggested that the metabolic characteristics of microglia dictate their inflammatory response. The pyruvate kinase isoform M2 (PKM2), a key glycolytic enzyme, is involved in the regulation of various cellular metabolic processes, including mitochondrial metabolism. This suggests that PKM2 may also participate in the regulation of microglial activation during TBI. Therefore, the present study aimed to evaluate the role of PKM2 in regulating microglial activation and neuroinflammation and its effects on cognitive function following TBI. A controlled cortical impact (CCI) mouse model and inflammation-induced primary mouse microglial cells in vitro were used to investigate the potential effects of PKM2 inhibition and regulation. PKM2 was significantly increased during the acute and subacute phases of TBI and was predominantly detected in microglia rather than in neurons. Our results demonstrate that shikonin and TEPP-46 can inhibit microglial inflammation, improving mitochondria, improving mouse behavior, reducing brain defect volume, and alleviating pathological changes after TBI. There is a difference in the intervention of shikonin and TEPP-46 on PKM2. Shikonin directly inhibits General PKM2; TEPP-46 can promote the expression of PKM2 tetramer. In vitro experiments, TEPP-46 can promote the expression of PKM2 tetramer, enhance the interaction between PKM2 and MFN2, improve mitochondria, alleviate neuroinflammation. General inhibition and tetramerization activation of PKM2 attenuated cognitive function caused by TBI, whereas PKM2 tetramerization exhibited a better treatment effect. Our experiments demonstrated the non-metabolic role of PKM2 in the regulation of microglial activation following TBI. Both shikonin and TEPP-46 can inhibit pro-inflammatory factors, but only TEPP-46 can promote PKM2 tetramerization and upregulate the release of anti-inflammatory factors from microglia.
Assuntos
Lesões Encefálicas Traumáticas , Microglia , Mitocôndrias , Naftoquinonas , Piruvato Quinase , Animais , Microglia/efeitos dos fármacos , Microglia/metabolismo , Lesões Encefálicas Traumáticas/metabolismo , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/tratamento farmacológico , Camundongos , Piruvato Quinase/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Naftoquinonas/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Multimerização Proteica/efeitos dos fármacos , Células CultivadasRESUMO
Charcot-Marie-Tooth type 2A (CMT2A) is a single-gene motor sensory neuropathy caused by Mfn2 mutation. It is generally believed that CMT2A involves mitochondrial fusion disruption. However, how Mfn2 mutation mediates the mitochondrial membrane fusion loss and its further pathogenic mechanisms remain unclear. Here, in vivo and in vitro mouse models harboring the Mfn2R364W, Mfn2G176S and Mfn2H165R mutations were constructed. Mitochondrial membrane fusion and fission proteins analysis showed that Mfn2R364W, Mfn2G176S, and Mfn2H165R/+ mutations maintain the expression of Mfn2, but promote Drp1 upregulation and Opa1 hydrolytic cleavage. In Mfn2H165R/H165R mutation, Mfn2, Drp1, and Opa1 all play a role in inducing mitochondrial fragmentation, and the mitochondrial aggregation is affected by Mfn2 loss. Further research into the pathogenesis of CMT2A showed these three mutations all induce mitochondria-mediated apoptosis, and mitochondrial oxidative phosphorylation damage. Overall, loss of overall fusion activity affects mitochondrial DNA (mtDNA) stability and causes mitochondrial loss and dysfunction, ultimately leading to CMT2A disease. Interestingly, the differences in the pathogenesis of CMT2A between Mfn2R364W, Mfn2G176S, Mfn2H165R/+ and Mfn2H165R/H165R mutations, including the distribution of Mfn2 and mitochondria, the expression of mitochondrial outer membrane-associated proteins (Bax, VDAC1 and AIF), and the enzyme activity of mitochondrial complex I, are related to the expression of Mfn2.
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Economic decision-making plays a paramount role in both individual and national interests. Individuals have fairness preferences in economic decision-making, but a proposer's moral-related information may affect fairness considerations. In prior ERP studies, researchers have suggested moral identity influences fairness preferences in the Ultimatum Game (UG), but there are discrepancies in the results. Furthermore, whether role models (individuals whom someone else looks to help decide suitable behaviors), who can modulate people's moral standards, can affect fairness concerns in UG is still understudied. To address the questions, we selected the moral-related statements by eliminating those with illegal information and employed the ERP technique to explore whether the interplay of the proposer's role model and moral-related behavior influenced fairness processing in the modified UG and the corresponding neural mechanisms. We mainly found that the aforementioned interaction effect on proposal considerations in UG could be mirrored in both rejection rates and P300 variations. The results demonstrate that the interaction between the proposer's role model and moral behavior can modulate fairness concerns in UG. Our current work provides new avenues for elucidating the time course of the influencing mechanism of fair distributions in complicated social environments.
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Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the JC1 staining images in Fig. 2C were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published elsewhere prior to the submission of this paper to Molecular Medicine Reports, or were under consideration for publication at around the same time (a small number of which have been retracted). In addition, the Snail western blot data in Fig. 3E bore a close similarity to certain of the Mfn2 data shown in Fig. 4A. In view of the fact that certain of the contentious data had already apparently been published previously, and owing to a lack of confidence in the presentation of certain of the data in this paper, the Editor of Molecular Medicine Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 22: 398404, 2020; DOI: 10.3892/mmr.2020.11098].
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It has been demonstrated that circular RNAs (circRNAs) are associated with the development of diabetic retinopathy (DR). Nevertheless, the function of circSLC16A10 in the development of DR remains unclear. In order to investigate the role of circSLC16A10, we employed cell and animal models of DR. An analysis of a public database revealed that hsa_circSLC16A10 was expressed at lower levels in DR patients than in diabetic patients without DR or healthy controls. Additionally, the level of hsa_circSLC16A10 was lower in high glucose (HG)-exposed ARPE-19 cells and diabetic mice. hsa_circSLC16A10 was observed to be mainly distributed in the cytoplasm. Moreover, overexpression of hsa_circSLC16A10 alleviated HG-induced endoplasmic reticulum stress and cell apoptosis in vitro. Furthermore, overexpression of hsa_circSLC16A10 ameliorated HG-induced mitochondrial dysfunction, as evidenced by improvements in mitochondrial structure and function. hsa_circSLC16A10 acted as a hsa-miR-761-5p sponge to increase MFN2 expression. MFN2 knockdown or hsa-miR-761-5p overexpression partially reversed the protective effect of hsa_circSLC16A10 in vitro. The protective effect of mmu_circSLC16A10 against DR was confirmed in an animal model of DR. These findings indicate that circSLC16A10 may regulate DR progression by improving mitochondrial function via the miR-761-5p/MFN2 axis.
Assuntos
Retinopatia Diabética , GTP Fosfo-Hidrolases , MicroRNAs , Mitocôndrias , RNA Circular , Retinopatia Diabética/genética , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , RNA Circular/genética , RNA Circular/metabolismo , Animais , MicroRNAs/metabolismo , MicroRNAs/genética , Humanos , Camundongos , Mitocôndrias/metabolismo , GTP Fosfo-Hidrolases/metabolismo , GTP Fosfo-Hidrolases/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética , Masculino , Apoptose , Camundongos Endogâmicos C57BL , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Estresse do Retículo Endoplasmático , Linhagem CelularRESUMO
Following the publication of the above article, a concerned reader drew to the Editor's attention that certain of the immunofluorescence data featured in Fig. 1H, TUNEL assay data in Fig. 2A, cytochome c leakage assay data in Fig. 2H, staining of cardiolipin images in Fig. 2H, lamellipodiastained data in Fig. 3A, and immunofluorescence assay data in Figs. 3F and 5D were strikingly similar to data appearing in different form in other articles written by different authors at different research institutes that had either already been published elsewhere prior to the submission of this paper to Oncology Reports, or were under consideration for publication at around the same time (several of which have now been retracted). In addition, overlapping sections of data were noted within the data panels in Fig. 3D and F, such that data which were intended to represent the results from differently performed experiments had apparently been derived from the same original source(s). In view of the fact that certain of these data had already apparently been published prior to the submission of this article for publication, and in view of an overall lack of confidence in the presented data, the Editor of Oncology Reports has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 39: 16711681, 2018; DOI: 10.3892/or.2018.6252].
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MicroRNAs (miRNAs) are implicated in the development of cancers and may serve as potential targets for therapy. However, the functions and underlying mechanisms of miRNAs in cancers are not well understood. This work aims to study the role of miR-373-3p in colon cancer cells. We find that the expression of miR-373-3p mimics promotes and the miR-373-3p inhibitor suppresses aerobic glycolysis and proliferation of colon cancer cells. Mechanistically, miR-373-3p inhibits the expression of MFN2, a gene that is known to suppress glycolysis, which leads to the activation of glycolysis and eventually the proliferation of cells. In a nude mouse tumor model, the expression of miR-373-3p in colon cancer cells promotes tumor growth by enhancing lactate formation, which is inhibited by the co-expression of MFN2 in the cells. Administration of the miR-373-3p antagomir blunts in vivo tumor growth by decreasing lactate production. In addition, in human colon cancers, the expression levels of miR-373-3p are increased, while those of MFN2 mRNA are decreased, and the increase of miR-373-3p is associated with the decrease of MFN2 mRNA. Our results reveal a previously unknown function and underlying mechanism of miR-373-3p in the regulation of glycolysis and proliferation in cancer cells and underscore the potential of targeting miR-373-3p for colon cancer treatment.
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The use of stem cells capable of multilineage differentiation in treating Pelvic Floor Dysfunction (PFD) holds great promise since they are susceptible to entering connective tissue of various cell types and repairing damaged tissues. This research investigated the effect of microRNA-181a-5p (miR-181a-5p) on Bone Marrow Mesenchymal Stem Cells (BMSCs) in rats with PFD. BMSCs were transfected and analyzed for their fibroblast differentiation ability. miR-181a-5p, MFN1, and fibroblast-related genes were quantitatively analyzed. Whether MFN1 is a target gene of miR-181a-5p was predicted and confirmed. The efficacy of BMSCs in vivo rats with PFD was evaluated by measuring Leak Point Pressure (LPP), Conscious Cystometry (CMG), hematoxylin and eosin staining, and Masson staining. The present results discovered that miR-181a-5p was up-regulated and MFN1 was down-regulated during the differentiation of BMSCs into fibroblasts. Fibroblast differentiation of BMSCs was promoted after miR-181a-5p was induced or MFN1 was suppressed, but it was suppressed after miR-181a-5p was silenced. miR-181a-5p improved LPP and conscious CMG outcomes in PDF rats by targeting MFN1 expression, thereby accelerating fibroblast differentiation of BMSCs. In brief, miR-181a-5p induces fibroblast differentiation of BMSCs in PDF rats by MFN1, potentially targeting PDF therapeutics.
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Diferenciação Celular , Fibroblastos , Células-Tronco Mesenquimais , MicroRNAs , Animais , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Feminino , Ratos Sprague-Dawley , Distúrbios do Assoalho Pélvico/genética , Distúrbios do Assoalho Pélvico/terapia , Ratos , Regulação para Cima , Modelos Animais de Doenças , Regulação para Baixo , Células CultivadasRESUMO
MicroRNA and mitofusin-2 (Mfn2) play an important role in the myocardial apoptosis induced by acute myocardial infarction (AMI). However, the target relationship and underlying mechanism associated with interorganelle interaction between endoplasmic reticulum (ER) and mitochondria under ischemic condition is not completely clear. MI-induced injury, Mfn2 expression, Mfn2-mediated mitochondrial function and ER stress, and target regulation by miRNA-15b (miR-15b) were evaluated by animal MI and cellular hypoxic models with advanced molecular techniques. The results confirmed that Mfn2 was down-regulated and miR-15b was up-regulated upon the target binding profile under ischemic/hypoxic condition. Our data showed that miR-15b caused cardiac apoptotic injury that was reversed by rAAV9-anti-miR-15b or AMO-15b. The damage effect of miR-15b on Mfn2 expression and mitochondrial function was observed and rescued by rAAV9-anti-miR-15b or AMO-15b. The targeted regulation of miR-15b on Mfn2 was verified by luciferase reporter and microRNA-masking. Importantly, miR-15b-mediated Mfn2 suppression activated PERK/CHOP pathway, by which leads to ER stress and mitochondrial dysfunction, and cardiac apoptosis eventually. In conclusion, our research, for the first time, revealed the missing molecular link in Mfn2 and apoptosis and elucidated that pro-apoptotic miR-15b plays crucial roles during the pathogenesis of AMI through down-regulation of Mfn2 and activation of PERK-mediated ER stress. These findings may provide an opportunity to develop new therapies for prophylaxis and treatment of ischemic heart disease.
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GTP Fosfo-Hidrolases , MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Animais , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Masculino , eIF-2 Quinase/metabolismo , eIF-2 Quinase/genética , eIF-2 Quinase/antagonistas & inibidores , Transdução de Sinais/fisiologia , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/genética , Isquemia Miocárdica/patologia , Camundongos , Estresse do Retículo Endoplasmático/fisiologia , Estresse do Retículo Endoplasmático/genética , Apoptose , Camundongos Endogâmicos C57BLRESUMO
INTRODUCTION: Diabetic cataract (DC) is a common ocular complication of diabetes. Mitofusin 2 (MFN2), a mitochondrial fusion protein, is involved in the pathogenesis of cataract and diabetic complications. However, its role and molecular mechanisms in DC remain unclear. MATERIALS AND METHODS: DC models in rats were induced by intraperitoneal injection of streptozocin (STZ) for 12 weeks. We measured the body weight of rats, blood glucose concentrations, sorbitol dehydrogenase (SDH) activity and advanced glycation end products (AGE) content in the lenses of rats. MFN2 mRNA and protein expression levels in the lenses were detected by RT-qPCR and western blot assays. In vitro, human lens epithelial (HLE) B3 cells were treated for 48 h with 25 mM glucose (high glucose, HG) to induce cell damage. To determine the role of MFN2 in HG-induced cell damage, HLE-B3 cells were transfected with lentivirus loaded with MFN2 overexpression plasmid or short hairpin RNA (shRNA) to overexpress or knock down MFN2 expression, followed by HG exposure. Cell viability was assessed by CCK-8 assay. Flow cytometry was used to detect cell apoptosis and reactive oxygen species (ROS) level. JC-1 staining showed the changes in mitochondrial membrane potential (Δψm). The mediators related to apoptosis, mitochondrial damage, and autophagy were determined. RESULTS: STZ-administrated rats showed reduced body weight, increased blood glucose levels, elevated SDH activity and AGE content, suggesting successful establishment of the DC rat model. Interestingly, MFN2 expression was significantly downregulated in DC rat lens and HG-induced HLE-B3 cells. Further analysis showed that under HG conditions, MFN2 overexpression enhanced cell viability and inhibited apoptosis accompanied by decreased Bax, cleaved caspase-9 and increased Bcl-2 expression in HLE-B3 cells. MFN2 overexpression also suppressed the mitochondrial damage elicited by HG as manifested by reduced ROS production, recovered Δψm and increased mitochondrial cytochrome c (Cyto c) level. Moreover, MFN2 overexpression increased LC3Bâ ¡/LC3Bâ ratio and Beclin-1 expression, but decreased p62 level, and blocked the phosphorylation of mTOR in HG-treated HLE-B3 cells. In contrast, MFN2 silencing exerted opposite effects. CONCLUSIONS: Presented findings indicate that MFN2 expression may be essential for preventing lens epithelial cell apoptosis during development of diabetic cataract.
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Apoptose , Autofagia , Células Epiteliais , GTP Fosfo-Hidrolases , Glucose , Cristalino , Mitocôndrias , Apoptose/efeitos dos fármacos , Animais , Humanos , Autofagia/efeitos dos fármacos , GTP Fosfo-Hidrolases/metabolismo , GTP Fosfo-Hidrolases/genética , Células Epiteliais/metabolismo , Células Epiteliais/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Ratos , Cristalino/metabolismo , Cristalino/efeitos dos fármacos , Ratos Sprague-Dawley , Masculino , Diabetes Mellitus Experimental/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular , Catarata/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Potencial da Membrana Mitocondrial/efeitos dos fármacosRESUMO
Although the attractiveness of voices plays an important role in social interactions, it is unclear how voice attractiveness and social interest influence social decision-making. Here, we combined the ultimatum game with recording event-related brain potentials (ERPs) and examined the effect of attractive versus unattractive voices of the proposers, expressing positive versus negative social interest ("I like you" vs. "I don't like you"), on the acceptance of the proposal. Overall, fair offers were accepted at significantly higher rates than unfair offers, and high voice attractiveness increased acceptance rates for all proposals. In ERPs in response to the voices, their attractiveness and expressed social interests yielded early additive effects in the N1 component, followed by interactions in the subsequent P2, P3 and N400 components. More importantly, unfair offers elicited a larger Medial Frontal Negativity (MFN) than fair offers but only when the proposer's voice was unattractive or when the voice carried positive social interest. These results suggest that both voice attractiveness and social interest moderate social decision-making and there is a similar "beauty premium" for voices as for faces.
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Tomada de Decisões , Potenciais Evocados , Voz , Humanos , Masculino , Feminino , Potenciais Evocados/fisiologia , Voz/fisiologia , Tomada de Decisões/fisiologia , Adulto Jovem , Adulto , Eletroencefalografia/métodos , Encéfalo/fisiologia , AdolescenteRESUMO
Glioblastoma is one of the most challenging malignancies with high aggressiveness and invasiveness and its development and progression of glioblastoma highly depends on branched-chain amino acid (BCAA) metabolism. The study aimed to investigate effects of inhibition of BCAA metabolism with cytosolic branched-chain amino acid transaminase (BCATc) Inhibitor 2 on glioblastoma, elucidate its underlying mechanisms, and explore therapeutic potential of targeting BCAA metabolism. The expression of BCATc was upregulated in glioblastoma and BCATc Inhibitor 2 precipitated apoptosis both in vivo and in vitro with the activation of Bax/Bcl2/Caspase-3/Caspase-9 axis. In addition, BCATc Inhibitor 2 promoted K63-linkage ubiquitination of mitofusin 2 (Mfn2), which subsequently caused lysosomal degradation of Mfn2, and then oxidative stress, mitochondrial fission and loss of mitochondrial membrane potential. Furthermore, BCATc Inhibitor 2 treatment resulted in metabolic reprogramming, and significant inhibition of expression of ATP5A, UQCRC2, SDHB and COX II, indicative of suppressed oxidative phosphorylation. Moreover, Mfn2 overexpression or scavenging mitochondria-originated reactive oxygen species (ROS) with mito-TEMPO ameliorated BCATc Inhibitor 2-induced oxidative stress, mitochondrial membrane potential disruption and mitochondrial fission, and abrogated the inhibitory effect of BCATc Inhibitor 2 on glioblastoma cells through PI3K/AKT/mTOR signaling. All of these findings indicate suppression of BCAA metabolism promotes glioblastoma cell apoptosis via disruption of Mfn2-mediated mitochondrial dynamics and inhibition of PI3K/AKT/mTOR pathway, and suggest that BCAA metabolism can be targeted for developing therapeutic agents to treat glioblastoma.
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Aminoácidos de Cadeia Ramificada , Apoptose , GTP Fosfo-Hidrolases , Glioblastoma , Estresse Oxidativo , Humanos , Estresse Oxidativo/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Glioblastoma/metabolismo , Glioblastoma/patologia , GTP Fosfo-Hidrolases/metabolismo , Animais , Aminoácidos de Cadeia Ramificada/metabolismo , Linhagem Celular Tumoral , Camundongos , Proteínas Mitocondriais/metabolismo , Ubiquitina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Masculino , Ubiquitinação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
lncRNA ZNF593 antisense (ZNF593-AS) transcripts have been implicated in heart failure through the regulation of myocardial contractility. The decreased transcriptional activity of ZNF593-AS has also been detected in cardiac hypertrophy. However, the function of ZNF593-AS in cardiac hypertrophy remains unclear. Herein, we report that the expression of ZNF593-AS reduced in a mouse model of left ventricular hypertrophy and cardiomyocytes in response to treatment with the hypertrophic agonist phenylephrine (PE). In vivo, ZNF593-AS aggravated pressure overload-induced cardiac hypertrophy in knockout mice. By contrast, cardiomyocyte-specific transgenic mice (ZNF593-AS MHC-Tg) exhibited attenuated TAC-induced cardiac hypertrophy. In vitro, vector-based overexpression using murine or human ZNF593-AS alleviated PE-induced myocyte hypertrophy, whereas GapmeR-induced inhibition aggravated hypertrophic phenotypes. By using RNA-seq and gene set enrichment analyses, we identified a link between ZNF593-AS and oxidative phosphorylation and found that mitofusin 2 (Mfn2) is a direct target of ZNF593-AS. ZNF593-AS exerts an antihypertrophic effect by upregulating Mfn2 expression and improving mitochondrial function. Therefore, it represents a promising therapeutic target for combating pathological cardiac remodeling.
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Cardiomegalia , GTP Fosfo-Hidrolases , Miócitos Cardíacos , RNA Longo não Codificante , Regulação para Cima , Animais , Humanos , Masculino , Camundongos , Cardiomegalia/genética , Cardiomegalia/metabolismo , Modelos Animais de Doenças , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Remodelação Ventricular/genéticaRESUMO
Ferroptosis, a novel form of iron-dependent non-apoptotic cell death, plays an active role in the pathogenesis of diverse diseases, including cancer. However, the mechanism through which ferroptosis is regulated in pancreatic ductal adenocarcinoma (PDAC) remains unclear. Here, our study, via combining bioinformatic analysis with experimental validation, showed that ferroptosis is inhibited in PDAC. Genome-wide sequencing further revealed that the ferroptosis activator imidazole ketone erastin (IKE) induced upregulation of the E3 ubiquitin ligase RBCK1 in PDAC cells at the transcriptional or translational level. RBCK1 depletion or knockdown rendered PDAC cells more vulnerable to IKE-induced ferroptotic death in vitro. In a mouse xenograft model, genetic depletion of RBCK1 increased the killing effects of ferroptosis inducer on PDAC cells. Mechanistically, RBCK1 interacts with and polyubiquitylates mitofusin 2 (MFN2), a key regulator of mitochondrial dynamics, to facilitate its proteasomal degradation under ferroptotic stress, leading to decreased mitochondrial reactive oxygen species (ROS) production and lipid peroxidation. These findings not only provide new insights into the defense mechanisms of PDAC cells against ferroptotic death but also indicate that targeting the RBCK1-MFN2 axis may be a promising option for treating patients with PDAC.
Assuntos
Carcinoma Ductal Pancreático , Ferroptose , GTP Fosfo-Hidrolases , Neoplasias Pancreáticas , Espécies Reativas de Oxigênio , Ubiquitina-Proteína Ligases , Ferroptose/genética , Humanos , Animais , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Camundongos , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Ensaios Antitumorais Modelo de Xenoenxerto , Proteólise , Ubiquitinação , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Mitocôndrias/metabolismo , Mitocôndrias/genética , Mitocôndrias/patologia , Piperazinas , Fatores de TranscriçãoRESUMO
Economic decision-making is pivotal to both human private interests and the national economy. People pursue fairness in economic decision-making, but a proposer's moral identity can influence fairness processing. Previous ERP studies have revealed that moral identity has an effect on fairness considerations in the Ultimatum Game (UG), but the findings are inconsistent. To address the issue, we revised the moral-related sentences and used the ERP technique to measure the corresponding neural mechanism. We have observed that the fairness effect in UG can be mirrored in both MFN and P300 changes, whereas the moral identity effect on fairness in UG can be reflected by MFN but not P300 changes. These findings indicate that the moral identity of the proposer can modulate fairness processing in UG. The current study opens new avenues for clarifying the temporal course of the relationship between the proposer's moral identity and fairness in economic decision-making, which is beneficial for understanding the influencing mechanism of fairness processing and fair allocations in complex social contexts.
Assuntos
Tomada de Decisões , Potenciais Evocados , Jogos Experimentais , Princípios Morais , Humanos , Masculino , Adulto Jovem , Feminino , Tomada de Decisões/fisiologia , Adulto , Potenciais Evocados/fisiologia , Eletroencefalografia , Encéfalo/fisiologiaRESUMO
Repeated sevoflurane exposure in neonatal mice can leads to neuronal apoptosis and mitochondrial dysfunction. The mitochondria are responsible for energy production to maintain homeostasis in the central nervous system. The mitochondria-associated endoplasmic reticulum membrane (MAM) is located between the mitochondria and endoplasmic reticulum (ER), and it is critical for mitochondrial function and cell survival. MAM malfunction contributes to neurodegeneration, however, whether it is involved in sevoflurane-induced neurotoxicity remains unknown. Our study demonstrated that repeated sevoflurane exposure induced mitochondrial dysfunction and dampened the MAM structure. The upregulated ER-mitochondria tethering enhanced Ca2+ transition from the cytosol to the mitochondria. Overload of mitochondrial Ca2+ contributed to opening of the mitochondrial permeability transition pore (mPTP), which caused neuronal apoptosis. Mitofusin 2(Mfn2), a key regulator of ER-mitochondria contacts, was found to be suppressed after repeated sevoflurane exposure, while restoration of Mfn2 expression alleviated cognitive dysfunction due to repeated sevoflurane exposure in the adult mice. These evidences suggest that sevoflurane-induced MAM malfunction is vulnerable to Mfn2 suppression, and the enhanced ER-mitochondria contacts promotes mitochondrial Ca2+ overload, contributing to mPTP opening and neuronal apoptosis. This paper sheds light on a novel mechanism of sevoflurane-induced neurotoxicity. Furthermore, targeting Mfn2-mediated regulation of the MAM structure and mitochondrial function may provide a therapeutic advantage in sevoflurane-induced neurodegeneration.
Assuntos
Retículo Endoplasmático , GTP Fosfo-Hidrolases , Mitocôndrias , Sevoflurano , Animais , Sevoflurano/toxicidade , Sevoflurano/farmacologia , GTP Fosfo-Hidrolases/metabolismo , Camundongos , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Camundongos Endogâmicos C57BL , Apoptose/efeitos dos fármacos , Anestésicos Inalatórios/toxicidade , Anestésicos Inalatórios/farmacologia , Masculino , Cálcio/metabolismo , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/efeitos dos fármacosRESUMO
Our study aimed to explore the potential positive effects of cold water exercise on mitochondrial biogenesis and muscle energy metabolism in aging rats. The study involved 32 male and 32 female rats aged 15 months, randomly assigned to control sedentary animals, animals training in cold water at 5 ± 2 °C, or animals training in water at thermal comfort temperature (36 ± 2 °C). The rats underwent swimming training for nine weeks, gradually increasing the duration of the sessions from 2 min to 4 min per day, five days a week. The results demonstrated that swimming in thermally comfortable water improved the energy metabolism of aging rat muscles (increased metabolic rates expressed as increased ATP, ADP concentration, TAN (total adenine nucleotide) and AEC (adenylate energy charge value)) and increased mRNA and protein expression of fusion regulatory proteins. Similarly, cold-water swimming improved muscle energy metabolism in aging rats, as shown by an increase in muscle energy metabolites and enhanced mitochondrial biogenesis and dynamics. It can be concluded that the additive effect of daily activity in cold water influenced both an increase in the rate of energy metabolism in the muscles of the studied animals and an intensification of mitochondrial biogenesis and dynamics (related to fusion and fragmentation processes). Daily activity in warm water also resulted in an increase in the rate of energy metabolism in muscles, but at the same time did not cause significant changes in mitochondrial dynamics.