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Autophagy is required in diverse paradigms of lifespan extension, leading to the prevailing notion that autophagy is beneficial for longevity. However, why autophagy is harmful in certain contexts remains unexplained. Here, we show that mitochondrial permeability defines the impact of autophagy on aging. Elevated autophagy unexpectedly shortens lifespan in C. elegans lacking serum/glucocorticoid regulated kinase-1 (sgk-1) because of increased mitochondrial permeability. In sgk-1 mutants, reducing levels of autophagy or mitochondrial permeability transition pore (mPTP) opening restores normal lifespan. Remarkably, low mitochondrial permeability is required across all paradigms examined of autophagy-dependent lifespan extension. Genetically induced mPTP opening blocks autophagy-dependent lifespan extension resulting from caloric restriction or loss of germline stem cells. Mitochondrial permeability similarly transforms autophagy into a destructive force in mammals, as liver-specific Sgk knockout mice demonstrate marked enhancement of hepatocyte autophagy, mPTP opening, and death with ischemia/reperfusion injury. Targeting mitochondrial permeability may maximize benefits of autophagy in aging.
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Envejecimiento/metabolismo , Proteínas de Transporte de Membrana Mitocondrial/fisiología , Membranas Mitocondriales/fisiología , Animales , Autofagia/fisiología , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/fisiología , Restricción Calórica , Células HEK293 , Humanos , Longevidad/fisiología , Masculino , Ratones , Ratones Noqueados , Mitocondrias , Proteínas de Transporte de Membrana Mitocondrial/metabolismo , Poro de Transición de la Permeabilidad Mitocondrial , Permeabilidad , Cultivo Primario de Células , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/fisiología , Daño por Reperfusión/metabolismo , Transducción de SeñalRESUMEN
Nitric oxide (NO) from endothelial NO synthase (eNOS) importantly contributes to vascular homeostasis. Reduced NO production or increased scavenging during disease conditions with oxidative stress contribute to endothelial dysfunction and NO deficiency. In addition to the classical enzymatic NOS system, NO can also be generated via the nitrate-nitrite-NO pathway. Dietary and pharmacological approaches aimed at increasing NO bioactivity, especially in the cardiovascular system, have been the focus of much research since the discovery of this small gaseous signaling molecule. Despite wide appreciation of the biological role of NOS/NO signaling, questions still remain about the chemical nature of NOS-derived bioactivity. Recent studies show that NO-like bioactivity can be efficiently transduced by mobile NO-ferroheme species which can transfer between proteins, partition into a hydrophobic phase, and directly activate the sGC-cGMP-PKG pathway without intermediacy of free NO. Moreover, interaction between red blood cells and the endothelium in the regulation of vascular NO homeostasis have gained much attention, especially in conditions with cardiometabolic disease. In this review we discuss both classical and non-classical pathways for NO generation in the cardiovascular system, and how these can be modulated for therapeutic purposes. Significance Statement After four decades of intensive research, questions persist about the transduction and control of NO synthase bioactivity. Here we discuss NO signaling in cardiovascular health and disease, highlighting new findings, such as the important role of red blood cells in cardiovascular NO homeostasis. Non-classical signaling modes, like the nitrate-nitrite-NO pathway, and therapeutic opportunities related to the NO system are discussed. Existing and potential pharmacological treatments/strategies, as well as dietary components influencing NO generation and signaling are covered.
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BACKGROUND: Exercise-induced physiological cardiac growth regulators may protect the heart from ischemia/reperfusion (I/R) injury. Homeobox-containing 1 (Hmbox1), a homeobox family member, has been identified as a putative transcriptional repressor and is downregulated in the exercised heart. However, its roles in exercise-induced physiological cardiac growth and its potential protective effects against cardiac I/R injury remain largely unexplored. METHODS: We studied the function of Hmbox1 in exercise-induced physiological cardiac growth in mice after 4 weeks of swimming exercise. Hmbox1 expression was then evaluated in human heart samples from deceased patients with myocardial infarction and in the animal cardiac I/R injury model. Its role in cardiac I/R injury was examined in mice with adeno-associated virus 9 (AAV9) vector-mediated Hmbox1 knockdown and in those with cardiac myocyte-specific Hmbox1 ablation. We performed RNA sequencing, promoter prediction, and binding assays and identified glucokinase (Gck) as a downstream effector of Hmbox1. The effects of Hmbox1 together with Gck were examined in cardiomyocytes to evaluate their cell size, proliferation, apoptosis, mitochondrial respiration, and glycolysis. The function of upstream regulator of Hmbox1, ETS1, was investigated through ETS1 overexpression in cardiac I/R mice in vivo. RESULTS: We demonstrated that Hmbox1 downregulation was required for exercise-induced physiological cardiac growth. Inhibition of Hmbox1 increased cardiomyocyte size in isolated neonatal rat cardiomyocytes and human embryonic stem cell-derived cardiomyocytes but did not affect cardiomyocyte proliferation. Under pathological conditions, Hmbox1 was upregulated in both human and animal postinfarct cardiac tissues. Furthermore, both cardiac myocyte-specific Hmbox1 knockout and AAV9-mediated Hmbox1 knockdown protected against cardiac I/R injury and heart failure. Therapeutic effects were observed when sh-Hmbox1 AAV9 was administered after I/R injury. Inhibition of Hmbox1 activated the Akt/mTOR/P70S6K pathway and transcriptionally upregulated Gck, leading to reduced apoptosis and improved mitochondrial respiration and glycolysis in cardiomyocytes. ETS1 functioned as an upstream negative regulator of Hmbox1 transcription, and its overexpression was protective against cardiac I/R injury. CONCLUSIONS: Our studies unravel a new role for the transcriptional repressor Hmbox1 in exercise-induced physiological cardiac growth. They also highlight the therapeutic potential of targeting Hmbox1 to improve myocardial survival and glucose metabolism after I/R injury.
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Oxidative phosphorylation is regulated by mitochondrial calcium (Ca2+) in health and disease. In physiological states, Ca2+ enters via the mitochondrial Ca2+ uniporter and rapidly enhances NADH and ATP production. However, maintaining Ca2+ homeostasis is critical: insufficient Ca2+ impairs stress adaptation, and Ca2+ overload can trigger cell death. In this review, we delve into recent insights further defining the relationship between mitochondrial Ca2+ dynamics and oxidative phosphorylation. Our focus is on how such regulation affects cardiac function in health and disease, including heart failure, ischemia-reperfusion, arrhythmias, catecholaminergic polymorphic ventricular tachycardia, mitochondrial cardiomyopathies, Barth syndrome, and Friedreich's ataxia. Several themes emerge from recent data. First, mitochondrial Ca2+ regulation is critical for fuel substrate selection, metabolite import, and matching of ATP supply to demand. Second, mitochondrial Ca2+ regulates both the production and response to reactive oxygen species (ROS), and the balance between its pro- and antioxidant effects is key to how it contributes to physiological and pathological states. Third, Ca2+ exerts localized effects on the electron transport chain (ETC), not through traditional allosteric mechanisms but rather indirectly. These effects hinge on specific transporters, such as the uniporter or the Na+/Ca2+ exchanger, and may not be noticeable acutely, contributing differently to phenotypes depending on whether Ca2+ transporters are acutely or chronically modified. Perturbations in these novel relationships during disease states may either serve as compensatory mechanisms or exacerbate impairments in oxidative phosphorylation. Consequently, targeting mitochondrial Ca2+ holds promise as a therapeutic strategy for a variety of cardiac diseases characterized by contractile failure or arrhythmias.
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Calcio , Mitocondrias Cardíacas , Humanos , Animales , Calcio/metabolismo , Mitocondrias Cardíacas/metabolismo , Fosforilación Oxidativa , Especies Reactivas de Oxígeno/metabolismo , Miocardio/metabolismo , Cardiopatías/metabolismoRESUMEN
Liver transplantation has evolved into a mature clinical field but scarcity of usable organs poses a unique challenge. Expanding the donor pool requires novel approaches for protecting hepatic physiology and cellular homeostasis. Here we define hepatocellular injury during transplantation, with an emphasis on modifiable cell death pathways as future therapeutics.
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Cardiovascular diseases (CVDs) are the leading cause of death worldwide, accounting for 31% of all deaths globally. Myocardial ischemia-reperfusion injury (IRI), a common complication of CVDs, is a major cause of mortality and morbidity. Studies have shown efficacious use of mesenchymal stem cells-derived small extracellular vesicles (MSCs-EVs) to mitigate IRI in animals, but few research has been done on human-related models. In this study, human embryonic stem cell-derived chambered cardiac organoid (CCO) was used as a model system to study the effects of MSC-EVs on myocardial IRI. The results revealed that MSC-EVs treatment reduced apoptosis and improved contraction resumption of the CCOs. Metabolomics analysis showed that this effect could be attributed to EVs' ability to prevent the accumulation of unsaturated very long-chain fatty acids (VLCFAs). This was corroborated when inhibition of fatty acid synthase, which was reported to reduce VLCFAs, produced a similar protective effect to EVs. Overall, this study uncovered the mechanistic role of MSC-EVs in mitigating IRI that involves preventing the accumulation of unsaturated VLCFA, decreasing cell death, and improving contraction resumption in CCOs.
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Apoptosis , Vesículas Extracelulares , Células Madre Mesenquimatosas , Organoides , Humanos , Vesículas Extracelulares/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Organoides/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/prevención & control , Ácidos Grasos/metabolismo , Cardiotónicos/metabolismo , Cardiotónicos/farmacologíaRESUMEN
Hepatic ischemia-reperfusion injury (HIRI) represents a major risk factor in liver transplantation and resection surgeries. Kupffer cells (KCs) produce proinflammatory cytokines and lead to hepatic neutrophil infiltration in the liver, which is one of the leading causes of HIRI. Mid1 is involved in immune infiltration, but the role of Mid1 remains poorly understood. Herin, our study aimed to investigate the effect of Mid1 on HIRI progression. Male C57BL/6 mice aged 6 weeks were used for the HIRI model established. The function of Mid1 on liver injury and hepatic inflammation was evaluated. In vitro, KCs were used to investigate the function and mechanism of Mid1 in modulating KC inflammation upon lipopolysaccharide (LPS) stimulation. We found that Mid1 expression was up-regulated upon HIRI. Mid1 inhibition alleviated liver damage, as evidenced by neutrophil infiltration, intrahepatic inflammation, and hepatocyte apoptosis. In vitro experiments further revealed that Mid1 knockdown reduced the secretion of proinflammatory cytokines and chemokines in KCs. Moreover, silenced-Mid1 suppressed proinflammatory responses by the inhibition of NF-κB, JNK, and p38 signaling pathways. Taken together, Mid1 contributes to HIRI via regulating the proinflammatory response of KCs and inducing neutrophil infiltration. Targeting Mid1 may be a promising strategy to protect against HIRI.
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Macrófagos del Hígado , Hígado , Ratones Endogámicos C57BL , Daño por Reperfusión , Animales , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Daño por Reperfusión/inmunología , Ratones , Masculino , Macrófagos del Hígado/metabolismo , Hígado/patología , Hígado/metabolismo , Infiltración Neutrófila , Citocinas/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , FN-kappa B/metabolismo , Apoptosis , Inflamación/metabolismo , Inflamación/patología , Transducción de SeñalRESUMEN
Renal ischemia-reperfusion injury (IRI) is an integral process in renal transplantation, which results in compromised graft survival. Macrophages play an important role in both the early inflammatory period and late fibrotic period in response to IRI. In this study, we investigated whether scutellarin (SCU) could protect against renal IRI by regulating macrophage polarization. Mice were given SCU (5-50 mg/kg) by gavage 1 h earlier, followed by a unilateral renal IRI. Renal function and pathological injury were assessed 24 h after reperfusion. The results showed that administration of 50 mg/kg SCU significantly improved renal function and renal pathology in IRI mice. In addition, SCU alleviated IRI-induced apoptosis. Meanwhile, it reduced macrophage infiltration and inhibited pro-inflammatory macrophage polarization. Moreover, in RAW 264.7 cells and primary bone marrow-derived macrophages (BMDMs) exposed to SCU, we found that 150 µM SCU inhibited these cells to polarize to an inflammatory phenotype induced by lipopolysaccharide (LPS) and interferon-γ (IFN-γ). However, SCU has no influence on anti-inflammatory macrophage polarization in vivo and in vitro induced by in interleukin-4 (IL-4). Finally, we explored the effect of SCU on the activation of the mitogen-activated protein kinase (MAPK) pathway both in vivo and in vitro. We found that SCU suppressed the activation of the MAPK pathway, including the extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK), and p38. Our results demonstrated that SCU protects the kidney against IRI by inhibiting macrophage infiltration and polarization toward pro-inflammatory phenotype via the MAPK pathway, suggesting that SCU may be therapeutically important in treatment of IRI.
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Apigenina , Glucuronatos , Sistema de Señalización de MAP Quinasas , Macrófagos , Daño por Reperfusión , Animales , Masculino , Ratones , Apigenina/farmacología , Apoptosis/efectos de los fármacos , Glucuronatos/farmacología , Glucuronatos/uso terapéutico , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Inflamación/prevención & control , Inflamación/patología , Riñón/metabolismo , Riñón/efectos de los fármacos , Riñón/patología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones Endogámicos C57BL , Células RAW 264.7 , Daño por Reperfusión/tratamiento farmacológico , Daño por Reperfusión/metabolismoRESUMEN
Liver transplantation (LT) is the only effective method to treat end-stage liver disease. Hepatic ischemia-reperfusion injury (IRI) continues to limit the prognosis of patients receiving LT. Histone deacetylase 6 (HDAC6) is a unique HDAC member involved in inflammation and apoptosis. However, its role and mechanism in hepatic IRI have not yet been reported. We examined HDAC6 levels in liver tissue from LT patients, mice challenged with liver IRI, and hepatocytes subjected to hypoxia/reoxygenation (H/R). In addition, HDAC6 global-knockout (HDAC6-KO) mice, adeno-associated virus-mediated liver-specific HDAC6 overexpressing (HDAC6-LTG) mice, and their corresponding controls were used to construct hepatic IRI models. Hepatic histology, inflammatory responses, and apoptosis were detected to assess liver injury. The molecular mechanisms of HDAC6 in hepatic IRI were explored in vivo and in vitro. Moreover, the HDAC6-selective inhibitor tubastatin A was used to detect the therapeutic effect of HDAC6 on liver IRI. Together, our results showed that HDAC6 expression was significantly upregulated in liver tissue from LT patients, mice subjected to hepatic I/R surgery, and hepatocytes challenged by hypoxia/reoxygenation (H/R) treatment. Compared with control mice, HDAC6 deficiency mitigated liver IRI by inhibiting inflammatory responses and apoptosis, whereas HDAC6-LTG mice displayed the opposite phenotype. Further molecular experiments show that HDAC6 bound to and deacetylated AKT and HDAC6 deficiency improved liver IRI by activating PI3K/AKT/mTOR signaling. In conclusion, HDAC6 is a key mediator of hepatic IRI that functions to promote inflammation and apoptosis via PI3K/AKT/mTOR signaling. Targeting hepatic HDAC6 inhibition may be a promising approach to attenuate liver IRI.
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Proteínas Proto-Oncogénicas c-akt , Daño por Reperfusión , Animales , Humanos , Ratones , Apoptosis , Histona Desacetilasa 6/metabolismo , Hipoxia/metabolismo , Inflamación/metabolismo , Isquemia/metabolismo , Hígado/metabolismo , Ratones Endogámicos C57BL , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Daño por Reperfusión/metabolismo , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
OBJECTIVE: ASPP1 (apoptosis stimulating of p53 protein 1) is critical in regulating cell apoptosis as a cofactor of p53 to promote its transcriptional activity in the nucleus. However, whether cytoplasmic ASPP1 affects p53 nuclear trafficking and its role in cardiac diseases remains unknown. This study aims to explore the mechanism by which ASPP1 modulates p53 nuclear trafficking and the subsequent contribution to cardiac ischemia/reperfusion (I/R) injury. METHODS AND RESULTS: The immunofluorescent staining showed that under normal condition ASPP1 and p53 colocalized in the cytoplasm of neonatal mouse ventricular cardiomyocytes, while they were both upregulated and translocated to the nuclei upon hypoxia/reoxygenation treatment. The nuclear translocation of ASPP1 and p53 was interdependent, as knockdown of either ASPP1 or p53 attenuated nuclear translocation of the other one. Inhibition of importin-ß1 resulted in the cytoplasmic sequestration of both p53 and ASPP1 in neonatal mouse ventricular cardiomyocytes with hypoxia/reoxygenation stimulation. Overexpression of ASPP1 potentiated, whereas knockdown of ASPP1 inhibited the expression of Bax (Bcl2-associated X), PUMA (p53 upregulated modulator of apoptosis), and Noxa, direct apoptosis-associated targets of p53. ASPP1 was also increased in the I/R myocardium. Cardiomyocyte-specific transgenic overexpression of ASPP1 aggravated I/R injury as indicated by increased infarct size and impaired cardiac function. Conversely, knockout of ASPP1 mitigated cardiac I/R injury. The same qualitative data were observed in neonatal mouse ventricular cardiomyocytes exposed to hypoxia/reoxygenation injury. Furthermore, inhibition of p53 significantly blunted the proapoptotic activity and detrimental effects of ASPP1 both in vitro and in vivo. CONCLUSIONS: Binding of ASPP1 to p53 triggers their nuclear cotranslocation via importin-ß1 that eventually exacerbates cardiac I/R injury. The findings imply that interfering the expression of ASPP1 or the interaction between ASPP1 and p53 to block their nuclear trafficking represents an important therapeutic strategy for cardiac I/R injury.
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Proteínas Adaptadoras Transductoras de Señales , Daño por Reperfusión , Proteína p53 Supresora de Tumor , Animales , Ratones , Apoptosis/fisiología , Hipoxia/metabolismo , Isquemia/metabolismo , Carioferinas , Miocitos Cardíacos/metabolismo , Daño por Reperfusión/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteínas Adaptadoras Transductoras de Señales/genéticaRESUMEN
Chronic kidney disease (CKD) has emerged as a significant global public health concern. Recent epidemiological studies have highlighted the link between exposure to fine particulate matter (PM2.5) and a decline in renal function. PM2.5 exerts harmful effects on various organs through oxidative stress and inflammation. Acute kidney injury (AKI) resulting from ischaemia-reperfusion injury (IRI) involves biological processes similar to those involved in PM2.5 toxicity and is a known risk factor for CKD. The objective of this study was to investigate the impact of PM2.5 exposure on IRI-induced AKI. Through a unique environmentally controlled setup, mice were exposed to urban PM2.5 or filtered air for 12 weeks before IRI followed by euthanasia 48 h after surgery. Animals exposed to PM2.5 and IRI exhibited reduced glomerular filtration, impaired urine concentration ability, and significant tubular damage. Further, PM2.5 aggravated local innate immune responses and mitochondrial dysfunction, as well as enhancing cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway activation. This increased renal senescence and suppressed the anti-ageing protein klotho, leading to early fibrotic changes. In vitro studies using proximal tubular epithelial cells exposed to PM2.5 and hypoxia/reoxygenation revealed heightened activation of the STING pathway triggered by cytoplasmic mitochondrial DNA, resulting in increased tubular damage and a pro-inflammatory phenotype. In summary, our findings imply a role for PM2.5 in sensitising proximal tubular epithelial cells to IRI-induced damage, suggesting a plausible association between PM2.5 exposure and heightened susceptibility to CKD in individuals experiencing AKI. Strategies aimed at reducing PM2.5 concentrations and implementing preventive measures may improve outcomes for AKI patients and mitigate the progression from AKI to CKD. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
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Lesión Renal Aguda , Ratones Endogámicos C57BL , Material Particulado , Daño por Reperfusión , Animales , Lesión Renal Aguda/patología , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/etiología , Lesión Renal Aguda/metabolismo , Daño por Reperfusión/patología , Material Particulado/efectos adversos , Material Particulado/toxicidad , Ratones , Masculino , Contaminación del Aire/efectos adversos , Modelos Animales de Enfermedad , Riñón/patología , Riñón/metabolismo , Transducción de Señal , Tasa de Filtración GlomerularRESUMEN
Skeletal muscle ischemia-reperfusion (IR) injury poses significant challenges due to its local and systemic complications. Traditional studies relying on two-dimensional (2D) cell culture or animal models often fall short of faithfully replicating the human in vivo environment, thereby impeding the translational process from animal research to clinical applications. Three-dimensional (3D) constructs, such as skeletal muscle spheroids with enhanced cell-cell interactions from human pluripotent stem cells (hPSCs) offer a promising alternative by partially mimicking human physiological cellular environment in vivo processes. This study aims to establish an innovative in vitro model, human skeletal muscle spheroids based on sphere differentiation from hPSCs, to investigate human skeletal muscle developmental processes and IR mechanisms within a controlled laboratory setting. By eticulously recapitulating embryonic myogenesis through paraxial mesodermal differentiation of neuro-mesodermal progenitors, we successfully established 3D skeletal muscle spheroids that mirror the dynamic colonization observed during human skeletal muscle development. Co-culturing human skeletal muscle spheroids with spinal cord spheroids facilitated the formation of neuromuscular junctions, providing functional relevance to skeletal muscle spheroids. Furthermore, through oxygen-glucose deprivation/re-oxygenation treatment, 3D skeletal muscle spheroids provide insights into the molecular events and pathogenesis of IR injury. The findings presented in this study significantly contribute to our understanding of skeletal muscle development and offer a robust platform for in vitro studies on skeletal muscle IR injury, holding potential applications in drug testing, therapeutic development, and personalized medicine within the realm of skeletal muscle-related pathologies.
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Diferenciación Celular , Músculo Esquelético , Células Madre Pluripotentes , Daño por Reperfusión , Esferoides Celulares , Humanos , Daño por Reperfusión/patología , Daño por Reperfusión/metabolismo , Músculo Esquelético/citología , Células Madre Pluripotentes/citología , Células Madre Pluripotentes/metabolismo , Esferoides Celulares/citología , Desarrollo de Músculos , Técnicas de Cocultivo/métodos , Células Cultivadas , Técnicas de Cultivo de Célula/métodosRESUMEN
Four-and-a-half LIM domains protein 2 (FHL2) is an adaptor protein that may interact with hypoxia inducible factor 1α (HIF-1α) or ß-catenin, two pivotal protective signaling in acute kidney injury (AKI). However, little is known about the regulation and function of FHL2 during AKI. We found that FHL2 was induced in renal tubular cells in patients with acute tubular necrosis and mice model of ischemia-reperfusion injury (IRI). In cultured renal proximal tubular cells (PTCs), hypoxia induced FHL2 expression and promoted the binding of HIF-1 to FHL2 promoter. Compared with control littermates, mice with PTC-specific deletion of FHL2 gene displayed worse renal function, more severe morphologic lesion, more tubular cell death and less cell proliferation, accompanying by downregulation of AQP1 and Na, K-ATPase after IRI. Consistently, loss of FHL2 in PTCs restricted activation of HIF-1 and ß-catenin signaling simultaneously, leading to attenuation of glycolysis, upregulation of apoptosis-related proteins and downregulation of proliferation-related proteins during IRI. In vitro, knockdown of FHL2 suppressed hypoxia-induced activation of HIF-1α and ß-catenin signaling pathways. Overexpression of FHL2 induced physical interactions between FHL2 and HIF-1α, ß-catenin, GSK-3ß or p300, and the combination of these interactions favored the stabilization and nuclear translocation of HIF-1α and ß-catenin, enhancing their mediated gene transcription. Collectively, these findings identify FHL2 as a direct downstream target gene of HIF-1 signaling and demonstrate that FHL2 could play a critical role in protecting against ischemic AKI by promoting the activation of HIF-1 and ß-catenin signaling through the interactions with its multiple protein partners.
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Lesión Renal Aguda , Túbulos Renales Proximales , Proteínas con Homeodominio LIM , Proteínas Musculares , Daño por Reperfusión , Factores de Transcripción , beta Catenina , Animales , Proteínas con Homeodominio LIM/metabolismo , Proteínas con Homeodominio LIM/genética , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/patología , Lesión Renal Aguda/genética , Humanos , Túbulos Renales Proximales/metabolismo , Túbulos Renales Proximales/patología , Daño por Reperfusión/metabolismo , Daño por Reperfusión/patología , Daño por Reperfusión/genética , Ratones , beta Catenina/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Masculino , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Transducción de Señal , Ratones Endogámicos C57BL , Ratones Noqueados , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Glucógeno Sintasa Quinasa 3 beta/genética , Proliferación Celular , ApoptosisRESUMEN
Ischemia reperfusion injury represents a common pathological condition that is triggered by the release of endogenous ligands. While neutrophils are known to play a critical role in its pathogenesis, the tissue-specific spatiotemporal regulation of ischemia-reperfusion injury is not understood. Here, using oxidative lipidomics and intravital imaging of transplanted mouse lungs that are subjected to severe ischemia reperfusion injury, we discovered that necroptosis, a nonapoptotic form of cell death, triggers the recruitment of neutrophils. During the initial stages of inflammation, neutrophils traffic predominantly to subpleural vessels, where their aggregation is directed by chemoattractants produced by nonclassical monocytes that are spatially restricted in this vascular compartment. Subsequent neutrophilic disruption of capillaries resulting in vascular leakage is associated with impaired graft function. We found that TLR4 signaling in vascular endothelial cells and downstream NADPH oxidase 4 expression mediate the arrest of neutrophils, a step upstream of their extravasation. Neutrophil extracellular traps formed in injured lungs and their disruption with DNase prevented vascular leakage and ameliorated primary graft dysfunction. Thus, we have uncovered mechanisms that regulate the initial recruitment of neutrophils to injured lungs, which result in selective damage to subpleural pulmonary vessels and primary graft dysfunction. Our findings could lead to the development of new therapeutics that protect lungs from ischemia reperfusion injury.
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Endotelio Vascular/metabolismo , Pulmón/metabolismo , Necroptosis , Infiltración Neutrófila , Neutrófilos/metabolismo , Daño por Reperfusión/metabolismo , Animales , Endotelio Vascular/lesiones , Humanos , Pulmón/irrigación sanguínea , Ratones , Ratones Noqueados , Daño por Reperfusión/genética , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
Ischemia-reperfusion injury (IRI) is a cumulation of pathophysiological processes that involves cell and organelle damage upon blood flow constraint and subsequent restoration. However, studies on overall immune infiltration and ferroptosis in liver ischemia-reperfusion injury (LIRI) are limited. This study explored immune cell infiltration and ferroptosis in LIRI using bioinformatics and experimental validation. The GSE151648 dataset, including 40 matched pairs of pre- and post- transplant liver samples was downloaded for bioinformatic analysis. Eleven hub genes were identified by overlapping differentially expressed genes (DEGs), iron genes, and genes identified through weighted gene co-expression network analysis (WGCNA). Subsequently, the pathway enrichment, transcription factor-target, microRNA-mRNA and protein-protein interaction networks were investigated. The diagnostic model was established by logistic regression, which was validated in the GSE23649 and GSE100155 datasets and verified using cytological experiments. Moreover, several drugs targeting these genes were found in DrugBank, providing a more effective treatment for LIRI. In addition, the expression of 11 hub genes was validated using quantitative real-time polymerase chain reaction (qRT-PCR) in liver transplantation samples and animal models. The expression of the 11 hub genes increased in LIRI compared with the control. Five genes were significantly enriched in six biological process terms, six genes showed high enrichment for LIRI-related signaling pathways. There were 56 relevant transcriptional factors and two central modules in the protein-protein interaction network. Further immune infiltration analysis indicated that immune cells including neutrophils and natural killer cells were differentially accumulated in the pre- and post-transplant groups, and this was accompanied by changes in immune-related factors. Finally, 10 targeted drugs were screened. Through bioinformatics and further experimental verification, we identified hub genes related to ferroptosis that could be used as potential targets to alleviate LIRI.
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Ischemia-reperfusion injury (IRI) is an inevitable pathophysiological phenomenon in kidney transplantation. Necroptosis is an undoubtedly important contributing mechanism in renal IRI. We first screened differentially expressed necroptosis-related genes (DENRGs) from public databases. Eight DENRGs were validated by independent datasets and verified by qRT-PCR in a rat IRI model. We used univariate and multivariate Cox regression analyses to establish a prognostic signature, and graft survival analysis was performed. Immune infiltrating landscape analysis and gene set enrichment analysis (GSEA) were performed to understand the underlying mechanisms of graft loss, which suggested that necroptosis may aggravate the immune response, resulting in graft loss. Subsequently, a delayed graft function (DGF) diagnostic signature was constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) and exhibited robust efficacy in validation datasets. After comprehensively analyzing DENRGs during IRI, we successfully constructed a prognostic signature and DGF predictive signature, which may provide clinical insights for kidney transplant.
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Trasplante de Riñón , Ratas , Animales , Trasplante de Riñón/efectos adversos , Funcionamiento Retardado del Injerto/diagnóstico , Funcionamiento Retardado del Injerto/genética , Necroptosis , Riñón , Supervivencia de Injerto/fisiologíaRESUMEN
Ischemia/reperfusion (I/R) injury after revascularization contributes â¼50% of infarct size and causes heart failure, for which no established clinical treatment exists. ß-hydroxybutyrate (ß-OHB), which serves as both an energy source and a signaling molecule, has recently been reported to be cardioprotective when administered immediately before I/R and continuously after reperfusion. This study aims to determine whether administering ß-OHB at the time of reperfusion with a single dose can alleviate I/R injury and, if so, to define the mechanisms involved. We found plasma ß-OHB levels were elevated during ischemia in STEMI patients, albeit not to myocardial protection level, and decreased after revascularization. In mice, compared with normal saline, ß-OHB administrated at reperfusion reduced infarct size (by 50%) and preserved cardiac function, as well as activated autophagy and preserved mtDNA levels in the border zone. Our treatment with one dose ß-OHB reached a level achievable with fasting and strenuous physical activity. In neonatal rat ventricular myocytes (NRVMs) subjected to I/R, ß-OHB at physiologic level reduced cell death, increased autophagy, preserved mitochondrial mass, function, and membrane potential, in addition to attenuating reactive oxygen species (ROS) levels. ATG7 knockdown/knockout abolished the protective effects of ß-OHB observed both in vitro and in vivo. Mechanistically, ß-OHB's cardioprotective effects were associated with inhibition of mTOR signaling. In conclusion, ß-OHB, when administered at reperfusion, reduces infarct size and maintains mitochondrial homeostasis by increasing autophagic flux (potentially through mTOR inhibition). Since ß-OHB has been safely tested in heart failure patients, it may be a viable therapeutic to reduce infarct size in STEMI patients.
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Insuficiencia Cardíaca , Daño por Reperfusión Miocárdica , Infarto del Miocardio con Elevación del ST , Ratones , Ratas , Animales , Humanos , Masculino , Ácido 3-Hidroxibutírico/farmacología , Ácido 3-Hidroxibutírico/metabolismo , Ácido 3-Hidroxibutírico/uso terapéutico , Infarto del Miocardio con Elevación del ST/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Mitocondrias/metabolismo , Autofagia , Serina-Treonina Quinasas TOR/metabolismo , Reperfusión , Insuficiencia Cardíaca/metabolismoRESUMEN
Myocardial ischemia-reperfusion injury (MIRI) is closely related to the final infarct size in acute myocardial infarction (AMI). Therefore, reducing MIRI can effectively improve the prognosis of AMI patients. At the same time, the healing process after AMI is closely related to the local inflammatory microenvironment. Regulatory T cells (Tregs) can regulate various physiological and pathological immune inflammatory responses and play an important role in regulating the immune inflammatory response after AMI. However, different subtypes of Tregs have different effects on MIRI, and the same subtype of Tregs may also have different effects at different stages of MIRI. This article systematically reviews the classification and function of Tregs, as well as the role of various subtypes of Tregs in MIRI. A comprehensive understanding of the role of each subtype of Tregs can help design effective methods to control immune reactions, reduce MIRI, and provide new potential therapeutic options for AMI.
Asunto(s)
Infarto del Miocardio , Daño por Reperfusión Miocárdica , Humanos , Daño por Reperfusión Miocárdica/patología , Linfocitos T Reguladores , Infarto del Miocardio/terapiaRESUMEN
In myocardial infarction, ischemia-reperfusion injury (IRI) poses a significant challenge due to a lack of effective treatments. Bilirubin, a natural compound known for its anti-inflammatory and antioxidant properties, has been identified as a potential therapeutic agent for IRI. Currently, there are no reports about proteomic studies related to IRI and bilirubin treatment. In this study, we explored the effects of bilirubin nanoparticles in a rat model of myocardial IRI. A total of 3616 protein groups comprising 76,681 distinct peptides were identified using LC-MS/MS, where we distinguished two kinds of protein groups: those showing increased expression in IRI and decreased expression in IRI with bilirubin treatment, and vice versa, accounting for 202 and 35 proteins, respectively. Our proteomic analysis identified significant upregulation in the Wnt and insulin signaling pathways and increased Golgi markers, indicating their role in mediating bilirubin nanoparticle's protective effects. This research contributes to the proteomic understanding of myocardial IRI and suggests bilirubin nanoparticles as a promising strategy for cardiac protection, warranting further investigation in human models.
RESUMEN
Myocardial ischemia-reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium-derived factor (PEDF), which belongs to the non-inhibitory serpin family, exhibits several physiological effects, including anti-angiogenesis, anti-inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34-mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34-mer, particularly regarding the Nrf2/HO-1 signalling pathway. Our results demonstrated that PEDF 34-mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO-1 signalling. These findings highlight the therapeutic potential of PEDF and 34-mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI.