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Obese subjects exhibit lower adipose tissue oxygen consumption in accordance with the lower adipose tissue blood flow. Thereby, compared to lean subjects, obese individuals have almost half lower capillary density and more than half lower vascular endothelial growth factor (VEGF). The VEGF expression together with hypoxia-inducible transcription factor-1 alpha (HIF-1α) activity also requires phosphatidylinositol 3-kinase (PI3K) and mammalian target of rapamycin (mTOR)-mediated signaling. Especially HIF-1α is an important signaling molecule for hypoxia to induce the inflammatory responses. Hypoxia contributes to several biological functions, such as angiogenesis, cell proliferation, apoptosis, inflammation, and insulin resistance (IR). Pathogenesis of obesity-related comorbidities is attributed to intermittent hypoxia (IH), which is mostly observed in visceral obesity. Proinflammatory phenotype of the adipose tissue is a crucial link between IH and the development of IR. Inhibition of adaptive unfolded protein response (UPR) in hypoxia increases ß cell death. Moreover, deletion of HIF-1α worsens ß cell function. Oxidative stress, as well as the release of proinflammatory cytokines/adipokines in obesity, is proportional to the severity of IH. Reactive oxygen species (ROS) generation at mitochondria is responsible for propagation of the hypoxic signal; however, mitochondrial ROS production is required for hypoxic HIF-1α protein stabilization. Alterations in oxygen availability of adipose tissue directly affect the macrophage polarization and are responsible for the dysregulated adipocytokines production in obesity. Hypoxia both inhibits adipocyte differentiation from preadipocytes and macrophage migration from the hypoxic adipose tissue. Upon reaching a hypertrophic threshold beyond the adipocyte fat loading capacity, excess extracellular matrix (ECM) components are deposited, causing fibrosis. HIF-1α initiates the whole pathological process of fibrosis and inflammation in the obese adipose tissue. In addition to stressed adipocytes, hypoxia contributes to immune cell migration and activation which further aggravates adipose tissue fibrosis. Therefore, targeting HIF-1α might be an efficient way to suppress hypoxia-induced pathological changes in the ECM. The fibrosis score of adipose tissue correlates negatively with the body mass index and metabolic parameters. Inducers of browning/beiging adipocytes and adipokines, as well as modulations of matrix remodeling enzyme inhibitors, and associated gene regulators, are potential pharmacological targets for treating obesity.
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Tejido Adiposo , Obesidad , Humanos , Obesidad/metabolismo , Obesidad/patología , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Animales , Hipoxia/metabolismo , Transducción de Señal , Resistencia a la InsulinaRESUMEN
Myocardial ischemia-reperfusion (I/R) injury exacerbates cellular damage upon restoring blood flow to ischemic cardiac tissue, causing oxidative stress, inflammation, and apoptosis. This study investigates Nicotinamide Riboside (NR), a precursor of nicotinamide adenine dinucleotide (NAD+), for its cardioprotective effects. Administering NR to mice before I/R injury and evaluating heart function via echocardiography showed that NR significantly improved heart function, increased left ventricular ejection fraction (LVEF) and fractional shortening (FS), and reduced left ventricular end-diastolic (LVDd) and end-systolic diameters (LVSd). NR also restored E/A and E/e' ratios. It reduced cardiomyocyte apoptosis both in vivo and in vitro, inhibiting elevated caspase-3 activity and returning Bax protein levels to normal. In vitro, NR reduced the apoptotic rate in hydrogen peroxide (H2O2)-treated HL-1 cells from 30% to 10%. Mechanistically, NR modulated the SIRT3/mtROS/JNK pathway, reversing H2O2-induced SIRT3 downregulation, reducing mitochondrial reactive oxygen species (mtROS), and inhibiting JNK activation. Using SIRT3-knockout (SIRT3-KO) mice, we confirmed that NR's cardioprotective effects depend on SIRT3. Echocardiography showed that NR's benefits were abrogated in SIRT3-KO mice. In conclusion, NR provides significant cardioprotection against myocardial I/R injury by enhancing NAD+ levels and modulating the SIRT3/mtROS/JNK pathway, suggesting its potential as a novel therapeutic agent for ischemic heart diseases, meriting further clinical research.
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Apoptosis , Ratones Noqueados , Daño por Reperfusión Miocárdica , Niacinamida , Compuestos de Piridinio , Especies Reactivas de Oxígeno , Sirtuina 3 , Animales , Sirtuina 3/metabolismo , Sirtuina 3/genética , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Niacinamida/análogos & derivados , Niacinamida/farmacología , Niacinamida/uso terapéutico , Ratones , Compuestos de Piridinio/farmacología , Compuestos de Piridinio/administración & dosificación , Especies Reactivas de Oxígeno/metabolismo , Apoptosis/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Estrés Oxidativo/efectos de los fármacos , Humanos , Cardiotónicos/farmacología , Cardiotónicos/uso terapéutico , Modelos Animales de Enfermedad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Ratones Endogámicos C57BL , Transducción de Señal/efectos de los fármacosRESUMEN
AIMS: Study of the role of mitochondria-generated reactive oxygen species (mtROS) and mitochondrial polarization in mitochondrial fragmentation at the initial stages of myogenesis. MAIN METHODS: Mitochondrial morphology, Drp1 protein phosphorylation, mitochondrial electron transport chain components content, mtROS and mitochondrial lipid peroxidation levels, and mitochondrial polarization were evaluated on days 1 and 2 of human MB135 myoblasts differentiation. A mitochondria-targeted antioxidant SkQ1 was used to elucidate the effect of mtROS on mitochondria. KEY FINDINGS: In immortalized human MB135 myoblasts, mitochondrial fragmentation began on day 1 of differentiation before the myoblast fusion. This fragmentation was preceded by dephosphorylation of p-Drp1 (Ser-637). On day 2, an increase in the content of some mitochondrial proteins was observed, indicating mitochondrial biogenesis stimulation. Furthermore, we found that myogenic differentiation, even on day 1, was accompanied both by an increased production of mtROS, and lipid peroxidation of the inner mitochondrial membrane. SkQ1 blocked these effects and partially reduced the level of mitochondrial fragmentation, but did not affect the dephosphorylation of p-Drp1 (Ser-637). Importantly, mitochondrial fragmentation at early stages of MB135 differentiation was not accompanied by depolarization, as an important stimulus for mitochondrial fragmentation. SIGNIFICANCE: Mitochondrial fragmentation during early myogenic differentiation depends on mtROS production rather than mitochondrial depolarization. SkQ1 only partially inhibited mitochondrial fragmentation, without significant effects on mitophagy or early myogenic differentiation.
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Diferenciación Celular , Peroxidación de Lípido , Mitocondrias , Mioblastos , Especies Reactivas de Oxígeno , Humanos , Especies Reactivas de Oxígeno/metabolismo , Diferenciación Celular/efectos de los fármacos , Mioblastos/metabolismo , Mioblastos/citología , Mioblastos/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Desarrollo de Músculos/fisiología , Desarrollo de Músculos/efectos de los fármacos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Dinaminas/metabolismo , Fosforilación , Línea CelularRESUMEN
Naringenin is a flavonoid with significant anti-inflammatory and antioxidant properties. Mitochondrial dynamics, the mitochondrial respiratory chain, and mtROS are closely related to each other and regulate various biological processes. Ferroptosis is closely related to inflammatory responses and immune function in multiple tissues and organs. However, whether naringenin can alleviate LPS-induced inflammation and immune disorders in the chicken thymus via mtROS/ferroptosis has not been reported. Therefore, in this study, we constructed chicken thymus and MSB-1 cell models of LPS and naringenin based on screening for naringenin concentrations that have positive effects on inflammation and immune function to further investigate the anti-inflammatory, antiferroptosis, and maintenance of the immune function of naringenin. The results showed that 40 mg/kg naringenin alleviated LPS-induced tissue damage, elevated serum inflammatory factors, and decreased serum immune factors. The mechanism by which naringenin attenuates mtROS release by alleviating the imbalance of mitochondrial dynamics and the blockage of the respiratory chain. The effect of naringenin on alleviating LPS-induced lipid peroxidation, disruption of the GSH/GSSG system, iron overload, and GPx4 inactivation, thereby attenuating ferroptosis in thymus tissue, was inhibited by the addition of mtROS activators. In conclusion, naringenin alleviates LPS-induced ferroptosis in chicken thymus by attenuating mtROS release.
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Infiltration of monocyte-derived macrophages plays a crucial role in cardiac remodeling and dysfunction. The serum and glucocorticoid-inducible protein kinase 3 (SGK3) is a downstream factor of PI3K signaling, regulating various biological processes via an AKT-independent signaling pathway. SGK3 has been implicated in cardiac remodeling. However, the contribution of macrophagic SGK3 to hypertensive cardiac remodeling remains unclear. A cardiac remodeling model was established by angiotensin II (Ang II) infusion in SGK3-Lyz2-CRE (f/f, +) and wild-type mice to assess the function of macrophagic SGK3. Additionally, a co-culture system of SGK3-deficient or wild-type macrophages and neonatal rat cardiomyocytes (CMs) or neonatal rat fibroblasts (CFs) was established to evaluate the effects of SGK3 and the underlying mechanisms. SGK3 levels were significantly elevated in both peripheral blood mononuclear cells and serum from patients with heart failure. Macrophage SGK3 deficiency attenuated Ang II-induced macrophage infiltration, myocardial hypertrophy, myocardial fibrosis, and mitochondrial oxidative stress. RNA sequencing suggested Ndufa13 as the candidate gene in the effect of SGK3 on Ang II-induced cardiac remolding. Downregulation of Ndufa13 in CMs and CFs prevented the suppression of cardiac remodeling caused by SGK3 deficiency in macrophages. Mechanistically, the absence of SGK3 led to a reduction in IL-1ß secretion by inhibiting the NLRP3/Caspase-1/IL-1ß pathway in macrophages, consequently suppressing upregulated Ndufa13 expression and mitochondrial oxidative stress in CMs and CFs. This study provides new evidence that SGK3 is a potent contributor to the pathogenesis of hypertensive cardiac remodeling, and targeting SGK3 in macrophages may serve as a potential therapy for cardiac remodeling.
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Angiotensina II , Macrófagos , Miocitos Cardíacos , Estrés Oxidativo , Proteínas Serina-Treonina Quinasas , Remodelación Ventricular , Animales , Angiotensina II/farmacología , Macrófagos/metabolismo , Estrés Oxidativo/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Ratones , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Ratas , Humanos , Masculino , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Transducción de Señal , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Cardiomegalia/metabolismo , Cardiomegalia/patología , Cardiomegalia/inducido químicamente , Cardiomegalia/genética , Ratones Noqueados , Células CultivadasRESUMEN
Aging and regeneration are opposite cellular processes. Aging refers to progressive dysfunction in most cells and tissues, and regeneration refers to the replacement of damaged or dysfunctional cells or tissues with existing adult or somatic stem cells. Various studies have shown that aging is accompanied by decreased regenerative abilities, indicating a link between them. The performance of any cellular process needs to be supported by the energy that is majorly produced by mitochondria. Thus, mitochondria may be a link between aging and regeneration. It should be interesting to discuss how mitochondria behave during aging and regeneration. The changes of mitochondria in aging and regeneration discussed in this review can provide a timely and necessary study of the causal roles of mitochondrial homeostasis in longevity and health.
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AIM: Chronic hypoxia is a common cause of pulmonary hypertension (PH). We test the hypothesis that microRNA-210 (miR-210) mediates hypoxia-induced PH by targeting mitochondrial metabolism and increasing reactive oxygen species (mtROS) production in the lungs. METHODS: Adult wildtype (WT) or miR-210 knockout (KO) mice were exposed to hypoxia (10.5% O2) or normoxia for 4 weeks. We measured miR-210 levels, right ventricular systolic pressure (RVSP), and histological changes in heart and lung tissues. Mitochondrial bioenergetics and mtROS production were assessed in isolated lung mitochondria. RESULTS: Hypoxia increased right ventricular wall thickness and pulmonary vessel wall muscularization in WT, but not miR-210 KO mice. No sex differences were observed. In male mice, hypoxia increased miR-210 levels in the lung and RVSP, which were abrogated by miR-210 deficiency. Hypoxia upregulated mitochondrial oxygen consumption rate and mtROS flux, which were negated in miR-210 KO animals. In addition, chronic hypoxia increased macrophage accumulation in lungs of WT, but not miR-210 KO mice. Moreover, miR-210 overexpression in lungs of WT animals recapitulated the effects of hypoxia and increased mitochondrial oxygen consumption rate, mtROS flux, right ventricular wall thickness, pulmonary vessel wall muscularization and RVSP. MitoQ revoked the effects of miR-210 on lung mitochondrial bioenergetics, right ventricular and pulmonary vessel remodeling and RVSP. CONCLUSION: Our findings with loss-of-function and gain-of-function approaches provide explicit evidence that miR-210 mediates hypoxia-induced PH by upregulating mitochondrial bioenergetics and mtROS production in a murine model, revealing new insights into the mechanisms and therapeutic targets for treatment of PH.
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Metabolismo Energético , Hipertensión Pulmonar , Hipoxia , Ratones Noqueados , MicroARNs , Mitocondrias , Especies Reactivas de Oxígeno , Animales , MicroARNs/metabolismo , MicroARNs/genética , Hipertensión Pulmonar/metabolismo , Hipertensión Pulmonar/genética , Hipoxia/metabolismo , Masculino , Ratones , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Femenino , Ratones Endogámicos C57BL , Pulmón/metabolismo , Pulmón/patologíaRESUMEN
Diabetic retinopathy (DR) is characterized by chronic, low-grade inflammation. This state may be related to the heightened production of neutrophil extracellular traps (NETs) induced by high glucose (HG). Human cathelicidin antimicrobial peptide (LL37) is an endogenous ligand of G protein-coupled chemoattractant receptor formyl peptide receptor 2 (FPR2), expressed on neutrophils and facilitating the formation and stabilization of the structure of NETs. In this study, we detected neutrophils cultured under different conditions, the retinal tissue of diabetic mice, and fibrovascular epiretinal membranes (FVM) samples of patients with proliferative diabetic retinopathy (PDR) to explore the regulating effect of LL37/FPR2 on neutrophil in the development of NETs during the process of DR. Specifically, HG or NG with LL37 upregulates the expression of FPR2 in neutrophils, induces the opening of mitochondrial permeability transition pore (mPTP), promotes the increase of reactive oxygen species and mitochondrial ROS, and then leads to the rise of NET production, which is mainly manifested by the release of DNA reticular structure and the increased expression of NETs-related markers. The PI3K/AKT signaling pathway was activated in neutrophils, and the phosphorylation level was enhanced by FPR2 agonists in vitro. In vivo, increased expression of NETs markers was detected in the retina of diabetic mice and in FVM, vitreous fluid, and serum of PDR patients. Transgenic FPR2 deletion led to decreased NETs in the retina of diabetic mice. Furthermore, in vitro, inhibition of the LL37/FPR2/mPTP axis and PI3K/AKT signaling pathway decreased NET production induced by high glucose. These results suggested that FPR2 plays an essential role in regulating the production of NETs induced by HG, thus may be considered as one of the potential therapeutic targets.
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Péptidos Catiónicos Antimicrobianos , Catelicidinas , Retinopatía Diabética , Trampas Extracelulares , Ratones Endogámicos C57BL , Neutrófilos , Receptores de Formil Péptido , Retinopatía Diabética/metabolismo , Retinopatía Diabética/patología , Trampas Extracelulares/metabolismo , Animales , Receptores de Formil Péptido/metabolismo , Receptores de Formil Péptido/genética , Humanos , Neutrófilos/metabolismo , Ratones , Péptidos Catiónicos Antimicrobianos/metabolismo , Masculino , Receptores de Lipoxina/metabolismo , Receptores de Lipoxina/genética , Diabetes Mellitus Experimental/metabolismo , Transducción de Señal , Especies Reactivas de Oxígeno/metabolismo , Femenino , Persona de Mediana EdadRESUMEN
Aflatoxin B1 (AFB1) is highly toxic to the liver and can cause excessive production of mitochondrial reactive oxygen species (mtROS) in hepatocytes, leading to oxidative stress, inflammation, fibrosis, cirrhosis, and even liver cancer. The overproduction of mtROS can induce mitophagy, but whether mtROS and mitophagy are involved in the liver injury induced by AFB1 in ducks remains unclear. In this study, we first demonstrated that overproduction of mtROS and mitophagy occurred during liver injury induced by AFB1 exposure in ducks. Then, by inhibiting mtROS and mitophagy, we found that the damage caused by AFB1 in ducks was significantly alleviated, and the overproduction of mtROS induced by AFB1 exposure could mediate the occurrence of mitophagy. These results suggested that mtROS-mediated mitophagy is involved in AFB1-induced duck liver injury, and they may be the prevention and treatment targets of AFB1 hepatotoxicity.
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Aflatoxina B1 , Enfermedad Hepática Inducida por Sustancias y Drogas , Patos , Mitofagia , Especies Reactivas de Oxígeno , Animales , Aflatoxina B1/toxicidad , Mitofagia/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Mitocondrias Hepáticas/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Mitocondrias Hepáticas/patología , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Estrés Oxidativo/efectos de los fármacosRESUMEN
Mitophagy is a distinct physiological process that can have beneficial or deleterious effects in particular tissues. Prior research suggests that mitophagic activity can be triggered by CaO2-PM-CsPbBr3 QDs, yet the specific role that mitophagy plays in hepatic injury induced by CaO2-PM-CsPbBr3 QDs has yet to be established. Accordingly, in this study a series of mouse model- and cell-based experiments were performed that revealed the ability of CaO2-PM-CsPbBr3 QDs to activate mitophagic activity. Golm1 was upregulated in response to CaO2-PM-CsPbBr3 QDs treatment, and overexpressing Golm1 induced autophagic flux in the murine liver and hepatocytes, whereas knocking down Golm1 had the opposite effect. CaO2-PM-CsPbBr3 QDs were also able to Golm1 expression, in turn promoting the degradation of P53 and decreasing the half-life of this protein. Overexpressing Golm1 was sufficient to suppress the apoptotic death of hepatocytes in vitro and in vivo, whereas the knockdown of Golm1 had the opposite effect. The ability of Golm1 to promote p53-mediated autophagy was found to be associated with the disruption of Beclin-1 binding to Bcl-2, and the Golm1 N-terminal domain was determined to be required for p53 interactions, inducing autophagic activity in a manner independent of helicase activity or RNA binding. Together, these results indicate that inhibiting Golm1 can promote p53-dependent autophagy via disrupting Beclin-1 binding to Bcl-2, highlighting a novel approach to mitigating liver injury induced by CaO2-PM-CsPbBr3 QDs.
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Apoptosis , Autofagia , Beclina-1 , Hepatocitos , Proteínas de la Membrana , Mitocondrias , Proteínas Proto-Oncogénicas c-bcl-2 , Puntos Cuánticos , Especies Reactivas de Oxígeno , Proteína p53 Supresora de Tumor , Animales , Hepatocitos/metabolismo , Hepatocitos/citología , Proteína p53 Supresora de Tumor/metabolismo , Beclina-1/metabolismo , Ratones , Especies Reactivas de Oxígeno/metabolismo , Mitocondrias/metabolismo , Puntos Cuánticos/química , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Humanos , Mitofagia , Masculino , Ratones Endogámicos C57BLRESUMEN
Pyxinol, an active metabolite of ginsenosides in human hepatocytes, exhibits various pharmacological activities. Here, a series of C-3 modified pyxinol derivatives was designed and virtually screened by molecular docking with the key inflammation-related proteins of the nuclear factor kappa B (NF-κB) pathway. Some of the novel derivatives were synthesized to assess their effects in inhibiting the production of nitric oxide (NO) and mitochondrial reactive oxygen species (MtROS) in lipopolysaccharide-triggered RAW264.7 cells. Derivative 2c exhibited the highest NO and MtROS inhibitory activities with low cytotoxicity. Furthermore, 2c decreased the protein levels of interleukin 1ß, tumor necrosis factor α, inducible nitric oxide synthase, and cyclooxygenase 2 and suppressed the activation of NF-κB signaling. Cellular thermal shift assays indicated that 2c could directly bind with p65 and p50 in situ. Molecular docking revealed that 2c's binding to the p65-p50 heterodimer and p50 homodimer was close to their DNA binding sites. In summary, pyxinol derivatives possess potential for development as NF-κB inhibitors.
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Antiinflamatorios , Simulación del Acoplamiento Molecular , FN-kappa B , Óxido Nítrico , FN-kappa B/metabolismo , FN-kappa B/antagonistas & inhibidores , Ratones , Animales , Células RAW 264.7 , Antiinflamatorios/farmacología , Antiinflamatorios/síntesis química , Antiinflamatorios/química , Óxido Nítrico/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos , Lipopolisacáridos/farmacología , Humanos , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Relación Estructura-ActividadRESUMEN
BACKGROUND: Programmed death ligand-1(PD-L1) has been postulated to play a crucial role in the regulation of barrier functions of the vascular endothelium, yet how this novel molecule mediates dysfunction in endothelial cells (ECs) during acute lung injury (ALI) remains largely unknown. METHODS: PD-L1 siRNA and plasmids were synthesized and applied respectively to down- or up-regulate PD-L1 expression in human lung microvascular endothelial cells (HMVECs). RNA sequencing was used to explore the differentially expressed genes following PD-L1 overexpression. The expression levels of tight junction proteins (ZO-1 and occludin) and the signaling pathways of NLRP-3/caspase-1/pyroptosis were analyzed. A mouse model of indirect ALI was established through hemorrhagic shock (HEM) followed by cecal ligation and puncture (CLP), enabling further investigation into the effects of intravenous delivery of PD-L1 siRNA. RESULTS: A total of 1502 differentially expressed genes were identified, comprising 532 down-regulated and 970 up-regulated genes in ECs exhibiting PD-L1overexpression. Enrichment of PD-L1-correlated genes were observed in the NOD-like receptor signaling pathway and the TNF signaling pathway. Western blot assays confirmed that PD-L1 overexpression elevated the expression of NLRP3, cleaved-caspase-1, ASC and GSDMD, and concurrently diminished the expression of ZO-1 and occludin. This overexpression also enhanced mitochondrial oxidative phosphorylation and mitochondrial reactive oxygen species (mtROS) production. Interestingly, mitigating mitochondrial dysfunction with mitoQ partially countered the adverse effects of PD-L1 on the functionality of ECs. Furthermore, intravenous administration of PD-L1 siRNA effectively inhibited the activation of the NLRP3 inflammasome and pyroptosis in pulmonary ECs, subsequently ameliorating lung injury in HEM/CLP mice. CONCLUSION: PD-L1-mediated activation of the inflammasome contributes significantly to the disruption of tight junction and induction of pyroptosis in ECs, where oxidative stress associated with mitochondrial dysfunction serves as a pivotal mechanism underpinning these effects.
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Antígeno B7-H1 , Caspasa 1 , Endotelio Vascular , Proteína con Dominio Pirina 3 de la Familia NLR , Piroptosis , Transducción de Señal , Animales , Humanos , Masculino , Ratones , Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/patología , Lesión Pulmonar Aguda/genética , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Caspasa 1/metabolismo , Caspasa 1/genética , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Mitocondrias/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Piroptosis/genética , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Ferroptosis is a newly recognized type of programmed cell death that is implicated in the pathophysiological process of neurological disorders. Our previous studies have revealed that exposure to high concentrations of fluoride for long periods of time induces hippocampal neural injury and cognitive deficits. However, whether ferroptosis is involved in fluoride-induced neuronal death and the underlying mechanism remain unknown. In this study, the results indicated that exposure to high fluoride triggered ferroptosis in SH-SY5Y cells and in the hippocampus of mice. Fluoride exposure accelerated the lysosomal degradation of GPX4 and led to neuronal ferroptosis, while GPX4 overexpression protected SH-SY5Y cells against fluoride-induced neurotoxicity. Intriguingly, the enhanced chaperone-mediated autophagy (CMA) induced by fluoride stimulation was responsible for GPX4 degradation because the inhibition of CMA activity by LAMP2A knockdown effectively prevented fluoride-induced GPX4 loss. Furthermore, mitochondrial ROS (mtROS) accumulation caused by fluoride contributed to CMA activation-mediated GPX4 degradation and subsequent neuronal ferroptosis. Notably, the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) or the ROS scavenger N-acetyl-L-cysteine (NAC) alleviated fluoride-evoked hippocampal neuronal death and synaptic injury as well as cognitive deficits in mice. The present studies indicates that ferroptosis is a novel mechanism of fluoride-induced neurotoxicity and that chronic fluoride exposure facilitates GPX4 degradation via mtROS chaperone-mediated autophagy, leading to neuronal ferroptosis and cognitive impairment.
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Autofagia Mediada por Chaperones , Disfunción Cognitiva , Ferroptosis , Fluoruros , Neuronas , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Especies Reactivas de Oxígeno , Animales , Humanos , Ratones , Autofagia/efectos de los fármacos , Autofagia Mediada por Chaperones/fisiología , Autofagia Mediada por Chaperones/efectos de los fármacos , Disfunción Cognitiva/inducido químicamente , Ferroptosis/efectos de los fármacos , Ferroptosis/fisiología , Fluoruros/toxicidad , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Neuronas/efectos de los fármacos , Fosfolípido Hidroperóxido Glutatión Peroxidasa/efectos de los fármacos , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Macrophages restrain microbial infection and reinstate tissue homeostasis. The mitochondria govern macrophage metabolism and serve as pivot in innate immunity, thus acting as immunometabolic regulon. Metabolic pathways produce electron flows that end up in mitochondrial electron transport chain (mtETC), made of super-complexes regulating multitude of molecular and biochemical processes. Cell-intrinsic and extrinsic factors influence mtETC structure and function, impacting several aspects of macrophage immunity. These factors provide the macrophages with alternate fuel sources and metabolites, critical to gain functional competence and overcoming pathogenic stress. Mitochondrial reactive oxygen species (mtROS) and oxidative phosphorylation (OXPHOS) generated through the mtETC are important innate immune attributes, which help macrophages in mounting antibacterial responses. Recent studies have demonstrated the role of mtETC in governing mitochondrial dynamics and macrophage polarization (M1/M2). M1 macrophages are important for containing bacterial pathogens and M2 macrophages promote tissue repair and wound healing. Thus, mitochondrial bioenergetics and metabolism are intimately coupled with innate immunity. In this review, we have addressed mtETC function as innate rheostats that regulate macrophage reprogramming and innate immune responses. Advancement in this field encourages further exploration and provides potential novel macrophage-based therapeutic targets to control unsolicited inflammation.
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Ferroptosis has been shown to be involved in carbon tetrachloride (CCl4)-induced acute liver injury (ALI). The mitochondrion-targeted antioxidant MitoQ can eliminate the production of mitochondrial reactive oxygen species (mtROS). This study investigated the role of MitoQ in CCl4-induced hepatocytic ferroptosis and ALI. MDA and 4HNE were elevated in CCl4-induced mice. In vitro, CCl4 exposure elevated the levels of oxidized lipids in HepG2 cells. Alterations in the mitochondrial ultrastructure of hepatocytes were observed in the livers of CCl4-evoked mice. Ferrostatin-1 (Fer-1) attenuated CCl4-induced hepatic lipid peroxidation, mitochondrial ultrastructure alterations and ALI. Mechanistically, acyl-CoA synthetase long-chain family member 4 (ACSL4) was upregulated in CCl4-exposed human hepatocytes and mouse livers. The ACSL4 inhibitor rosiglitazone alleviated CCl4-induced hepatic lipid peroxidation and ALI. ACSL4 knockdown inhibited oxidized lipids in CCl4-exposed human hepatocytes. Moreover, CCl4 exposure decreased the mitochondrial membrane potential and OXPHOS subunit levels and increased the mtROS level in HepG2 cells. Correspondingly, MitoQ pretreatment inhibited the upregulation of ACSL4 in CCl4-evoked mouse livers and HepG2 cells. MitoQ attenuated lipid peroxidation in vivo and in vitro after CCl4 exposure. Finally, MitoQ pretreatment alleviated CCl4-induced hepatocytic ferroptosis and ALI. These findings suggest that MitoQ protects against hepatocyte ferroptosis in CCl4-induced ALI via the mtROS-ACSL4 pathway.
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Tetracloruro de Carbono , Enfermedad Hepática Inducida por Sustancias y Drogas , Coenzima A Ligasas , Ferroptosis , Hepatocitos , Ratones Endogámicos C57BL , Compuestos Organofosforados , Especies Reactivas de Oxígeno , Regulación hacia Arriba , Animales , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Regulación hacia Arriba/efectos de los fármacos , Células Hep G2 , Coenzima A Ligasas/metabolismo , Coenzima A Ligasas/genética , Ratones , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Ferroptosis/efectos de los fármacos , Tetracloruro de Carbono/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Masculino , Compuestos Organofosforados/farmacología , Ubiquinona/análogos & derivados , Ubiquinona/farmacología , Antioxidantes/farmacología , Peroxidación de Lípido/efectos de los fármacosRESUMEN
Gingival inflammation and alveolar bone loss are characteristic manifestations of periodontitis. Interleukin (IL)-1ß, the maturation of which is mainly regulated by NOD-like receptor protein (NLRP) 3 inflammasome, not only amplifies the inflammatory response but also triggers osteoclastogenesis, thereby accelerating the progression of periodontitis. Dioscin, a natural steroid saponin, has been shown to inhibit NLRP3 inflammasome. Nevertheless, research on the effectiveness of Dioscin for the management of periodontitis remains scarce. In this study, Dioscin was found to dramatically reduce the integral components of NLRP3 inflammasome, ultimately limiting IL-1ß secretion. Notably, the inhibitory impact of Dioscin on NLRP3 inflammasome might be exerted by curbing the generation of mitochondrial (mt) reactive oxygen species (ROS) and oxidized (ox) mtDNA, which were mediated by inhibition of K+ efflux. Furthermore, Dioscin effectively alleviated periodontitis in mice. Overall, the results established that Dioscin could alleviate periodontitis by inhibiting NLRP3 inflammasome via modulation of the K+ efflux-mtROS-ox-mtDNA pathway, holding the potential to treat periodontitis and other NLRP3-driven inflammatory diseases.
Asunto(s)
Diosgenina/análogos & derivados , Inflamasomas , Periodontitis , Animales , Ratones , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Periodontitis/tratamiento farmacológico , Periodontitis/metabolismo , Mitocondrias/metabolismo , Homeostasis , ADN Mitocondrial/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Interleucina-1beta/metabolismoRESUMEN
BACKGROUND: As the demand and application of engineered nanomaterials have increased, their potential toxicity to the central nervous system has drawn increasing attention. Tunneling nanotubes (TNTs) are novel cell-cell communication that plays a crucial role in pathology and physiology. However, the relationship between TNTs and nanomaterials neurotoxicity remains unclear. Here, three types of commonly used engineered nanomaterials, namely cobalt nanoparticles (CoNPs), titanium dioxide nanoparticles (TiO2NPs), and multi-walled carbon nanotubes (MWCNTs), were selected to address this limitation. RESULTS: After the complete characterization of the nanomaterials, the induction of TNTs formation with all of the nanomaterials was observed using high-content screening system and confocal microscopy in both primary astrocytes and U251 cells. It was further revealed that TNT formation protected against nanomaterial-induced neurotoxicity due to cell apoptosis and disrupted ATP production. We then determined the mechanism underlying the protective role of TNTs. Since oxidative stress is a common mechanism in nanotoxicity, we first observed a significant increase in total and mitochondrial reactive oxygen species (namely ROS, mtROS), causing mitochondrial damage. Moreover, pretreatment of U251 cells with either the ROS scavenger N-acetylcysteine or the mtROS scavenger mitoquinone attenuated nanomaterial-induced neurotoxicity and TNTs generation, suggesting a central role of ROS in nanomaterials-induced TNTs formation. Furthermore, a vigorous downstream pathway of ROS, the PI3K/AKT/mTOR pathway, was found to be actively involved in nanomaterials-promoted TNTs development, which was abolished by LY294002, Perifosine and Rapamycin, inhibitors of PI3K, AKT, and mTOR, respectively. Finally, western blot analysis demonstrated that ROS and mtROS scavengers suppressed the PI3K/AKT/mTOR pathway, which abrogated TNTs formation. CONCLUSION: Despite their biophysical properties, various types of nanomaterials promote TNTs formation and mitochondrial transfer, preventing cell apoptosis and disrupting ATP production induced by nanomaterials. ROS/mtROS and the activation of the downstream PI3K/AKT/mTOR pathway are common mechanisms to regulate TNTs formation and mitochondrial transfer. Our study reveals that engineered nanomaterials share the same molecular mechanism of TNTs formation and intercellular mitochondrial transfer, and the proposed adverse outcome pathway contributes to a better understanding of the intercellular protection mechanism against nanomaterials-induced neurotoxicity.
Asunto(s)
Estructuras de la Membrana Celular , Nanotubos de Carbono , Nanotubos , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-akt/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Nanotubos de Carbono/toxicidad , Serina-Treonina Quinasas TOR/metabolismo , Neuroglía/metabolismo , Adenosina Trifosfato , ApoptosisRESUMEN
The functional and structural changes in the proximal tubule play an important role in the occurrence and development of diabetic kidney disease (DKD). Diabetes-induced metabolic changes, including lipid metabolism reprogramming, are reported to lead to changes in the state of tubular epithelial cells (TECs), and among all the disturbances in metabolism, mitochondria serve as central regulators. Mitochondrial dysfunction, accompanied by increased production of mitochondrial reactive oxygen species (mtROS), is considered one of the primary factors causing diabetic tubular injury. Most studies have discussed how altered metabolic flux drives mitochondrial oxidative stress during DKD. In the present study, we focused on targeting mitochondrial damage as an upstream factor in metabolic abnormalities under diabetic conditions in TECs. Using SS31, a tetrapeptide that protects the mitochondrial cristae structure, we demonstrated that mitochondrial oxidative damage contributes to TEC injury and lipid peroxidation caused by lipid accumulation. Mitochondria protected using SS31 significantly reversed the decreased expression of key enzymes and regulators of fatty acid oxidation (FAO), but had no obvious effect on major glucose metabolic rate-limiting enzymes. Mitochondrial oxidative stress facilitated renal Sphingosine-1-phosphate (S1P) deposition and SS31 limited the elevated Acer1, S1pr1 and SPHK1 activity, and the decreased Spns2 expression. These data suggest a role of mitochondrial oxidative damage in unbalanced lipid metabolism, including lipid droplet (LD) formulation, lipid peroxidation, and impaired FAO and sphingolipid homeostasis in DKD. An in vitro study demonstrated that high glucose drove elevated expression of cytosolic phospholipase A2 (cPLA2), which, in turn, was responsible for the altered lipid metabolism, including LD generation and S1P accumulation, in HK-2 cells. A mitochondria-targeted antioxidant inhibited the activation of cPLA2f isoforms. Taken together, these findings identify mechanistic links between mitochondrial oxidative metabolism and reprogrammed lipid metabolism in diabetic TECs, and provide further evidence for the nephroprotective effects of SS31 via influencing metabolic pathways.
Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Humanos , Metabolismo de los Lípidos , Mitocondrias , Estrés Oxidativo , Células Epiteliales , Glucosa , LípidosRESUMEN
Lead (Pb), a well-known environmental pollutant, could cause damage of microglia, the resident macrophages vitally regulating inflammation in brain. Previous studies have found that Pb exposure induces typical pro-inflammatory factors release, such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß), but what effects of Pb treatment below the dose causing these factors release are unknown. Thus, cytokines assay was performed to identify the factors released from Pb-treated BV-2 cells at 2.5 µM, causing no effects on TNF-α, IL-1ß, and IL-6 release and cell death. Cytokines assay identified low doses of Pb exposure mainly induce an increase in specific chemokines, including CXCL10, CCL2, and CXCL2, which were confirmed by ELISA. Subsequent assessment found Pb could damage mitochondria function and generate mitochondrial reactive oxygen species (mtROS), and Mito TEMPO, a specific inhibitor of mtROS, suppressed Pb-caused upregulation of CXCL10 and CCL2, but not CXCL2. Finally, we determined that mtROS mediated Pb-induced activation of NF-κB pathway, as Mito TEMPO treatment inhibited P-p65/p65 escalation during Pb treatment. Inhibition of NF-κB pathway by Bay11-7821 suppressed the release of CXCL10 and CCL2. Collectively, low dose of Pb induces the release of CXCL10 and CCL2 chemokines, but not TNF-α and IL-1ß, via mtROS/NF-κB activation in BV-2 cells.
Asunto(s)
Quimiocina CCL2 , FN-kappa B , FN-kappa B/metabolismo , Plomo/toxicidad , Factor de Necrosis Tumoral alfa/metabolismo , Citocinas/metabolismo , QuimiocinasRESUMEN
Diabetes cardiomyopathy (DCM) refers to myocardial dysfunction and disorganization resulting from diabetes. In this study, we investigated the effects of berberine on cardiac function in male db/db mice with metformin as a positive control. After treatment for 8 weeks, significant improvements in cardiac function and a reduction in collagen deposition were observed in db/db mice. Furthermore, inflammation and pyroptosis were seen to decrease in these mice, as evidenced by decreased expressions of p-mTOR, NOD-like receptor thermal protein domain associated protein 3 (NLRP3), IL-1ß, IL-18, caspase-1, and gasdermin D (GSDMD). In vitro experiments on H9C2 cells showed that glucose exposure at 33 mmol/L induced pyroptosis, whereas berberine treatment reduced the expression of p-mTOR and NLRP3 inflammasome components. Moreover, berberine treatment was seen to inhibit the generation of mitochondrial reactive oxygen species (mtROS) and effectively improve cell damage in high glucose-induced H9C2 cells. The mTOR inhibitor, Torin-1, showed a therapeutic effect similar to that of berberine, by reducing the expression of NLRP3 inflammasome components and inhibiting mtROS generation. However, the activation of mTOR by MHY1485 partially nullified berberine's protective effects during high glucose stress. Collectively, our study reveals the mechanism that berberine regulates the mTOR/mtROS axis to inhibit pyroptosis induced by NLRP3 inflammasome activation, thereby alleviating DCM.