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Using a translational approach with an ST-segment myocardial infarction (STEMI) cohort and mouse model of myocardial infarction, we highlighted the role of the secreted IL-6 and MCP-1 cytokines and the STAT3 pathway in heart macrophage recruitment and activation. Cardiac myocytes secrete IL-6 and MCP-1 in response to hypoxic stress, leading to a recruitment and/or polarization of anti-inflammatory macrophages via the STAT3 pathway. In our preclinical model of myocardial infarction, neutralization of IL-6 and MCP-1 or STAT3 pathway reduced infarct size. Together, our data demonstrate that anti-inflammatory macrophages can be deleterious in the acute phase of STEMI.
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Myocardial infarction (MI) is a serious acute cardiovascular syndrome that causes myocardial injury due to blood flow obstruction to a specific myocardial area. Under ischemic-reperfusion settings, a burst of reactive oxygen species is generated, leading to redox imbalance that could be attributed to several molecules, including myoglobin. Myoglobin is dynamic and exhibits various oxidation-reduction states that have been an early subject of attention in the food industry, specifically for meat consumers. However, rarely if ever have the myoglobin optical properties been used to measure the severity of MI. In the current study, we develop a novel imaging pipeline that integrates tissue clearing, confocal and light sheet fluorescence microscopy, combined with imaging analysis, and processing tools to investigate and characterize the oxidation-reduction states of myoglobin in the ischemic area of the cleared myocardium post-MI. Using spectral imaging, we have characterized the endogenous fluorescence of the myocardium and demonstrated that it is partly composed by fluorescence of myoglobin. Under ischemia-reperfusion experimental settings, we report that the infarcted myocardium spectral signature is similar to that of oxidized myoglobin signal that peaks 3 h post-reperfusion and decreases with cardioprotection. The infarct size assessed by oxidation-reduction imaging at 3 h post-reperfusion was correlated to the one estimated with late gadolinium enhancement MRI at 24 h post-reperfusion. In conclusion, this original work suggests that the redox state of myoglobin can be used as a promising imaging biomarker for characterizing and estimating the size of the MI during early phases of reperfusion.
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Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Miocárdio , Mioglobina , Oxirredução , Mioglobina/metabolismo , Animais , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/diagnóstico por imagem , Traumatismo por Reperfusão Miocárdica/patologia , Masculino , Microscopia de Fluorescência , Modelos Animais de Doenças , Microscopia ConfocalRESUMO
BACKGROUND: Macrophages release not only cytokines but also extracellular vesicles (EVs). which are small membrane-derived nanovesicles with virus-like properties transferring cellular material between cells. Until now, the consequences of macrophage plasticity on the release and the composition of EVs have been poorly explored. In this study, we determined the impact of high-glucose (HG) concentrations on macrophage metabolism, and characterized their derived-EV subpopulations. Finally, we determined whether HG-treated macrophage-derived EVs participate in immune responses and in metabolic alterations of skeletal muscle cells. METHODS: THP1-macrophages were treated with 15mM (MG15) or 30mM (MG30) glucose. Then, M1/M2 canonical markers, pro- and anti-inflammatory cytokines, activities of proteins involved in glycolysis or oxidative phosphorylation were evaluated. Macrophage-derived EVs were characterized by TEM, NTA, MRSP, and 1H-Nuclear magnetic resonance spectroscopy for lipid composition. Macrophages or C2C12 muscle cells were used as recipients of MG15 and MG30-derived EVs. The lipid profiles of recipient cells were determined, as well as proteins and mRNA levels of relevant genes for macrophage polarization or muscle metabolism. RESULTS: Untreated macrophages released small and large EVs (sEVs, lEVs) with different lipid distributions. Proportionally to the glucose concentration, glycolysis was induced in macrophages, associated to mitochondrial dysfunction, triacylglycerol and cholesterol accumulation. In addition, MG15 and MG30 macrophages had increased level of CD86 and increase release of pro-inflammatory cytokines. HG also affected macrophage sphingolipid and phospholipid compositions. The differences in the lipid profiles between sEVs and lEVs were abolished and reflected the lipid alterations in MG15 and MG30 macrophages. Interestingly, MG15 and MG30 macrophages EVs induced the expression of CD163, Il-10 and increased the contents of triacylglycerol and cholesterol in recipient macrophages. MG15 lEVs and sEVs induced insulin-induced AKT hyper-phosphorylation and accumulation of triacylglycerol in myotubes, a state observed in pre-diabetes. Conversely, MG30 lEVs and sEVs induced insulin-resistance in myotubes. CONCLUSIONS: As inflammation involves first M1 macrophages, then the activation of M2 macrophages to resolve inflammation, this study demonstrates that the dialog between macrophages through the EV route is an intrinsic part of the inflammatory response. In a hyperglycemic context, EV macrophages could participate in the development of muscle insulin-resistance and chronic inflammation.
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Vesículas Extracelulares , Insulinas , Humanos , Macrófagos/metabolismo , Citocinas/metabolismo , Inflamação/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Vesículas Extracelulares/metabolismo , Lipídeos , Homeostase , Triglicerídeos/metabolismo , Colesterol/metabolismo , Insulinas/metabolismoRESUMO
Background: The immune system, composed of organs, tissues, cells, and proteins, is the key to protecting the body from external biological attacks and inflammation. The latter occurs in several pathologies, such as cancers, type 1 diabetes, and human immunodeficiency virus infection. Immunophenotyping by flow cytometry is the method of choice for diagnosing these pathologies. Under inflammatory conditions, the peripheral blood mononuclear cells (PBMCs) are partially activated and generate intracellular pathways involving Ca2+-dependent signaling cascades leading to transcription factor expression. Ca2+ signaling is typically studied by microscopy in cell lines but can present some limitations to explore human PBMCs, where flow cytometry can be a good alternative. Objective: In this review, we dived into the research field of inflammation and Ca2+ signaling in PBMCs. We aimed to investigate the structure and evolution of this field in a physio-pathological context, and then we focused our review on flow cytometry analysis of Ca2+ fluxes in PBMCs. Methods: From 1984 to 2022, 3865 articles on inflammation and Ca2+ signaling in PBMCs were published, according to The Clarivate Web of Science (WOS) database used in this review. A bibliometric study was designed for this collection and consisted of a co-citation and bibliographic coupling analysis. Results: The co-citation analysis was performed on 133 articles: 4 clusters highlighted the global context of Ca2+ homeostasis, including chemical probe development, identification of the leading players in Ca2+ signaling, and the link with chemokine production in immune cell function. Next, the bibliographic coupling analysis combined 998 articles in 8 clusters. This analysis outlined the mechanisms of PBMC activation, from signal integration to cellular response. Further explorations of the bibliographic coupling network, focusing on flow cytometry, revealed 21 articles measuring cytosolic Ca2+ in PBMCs, with only 5 since 2016. This final query showed that Ca2+ signaling analysis in human PBMCs using flow cytometry is still underdeveloped and investigates mainly the cytosolic Ca2+ compartment. Conclusion: Our review uncovers remaining knowledge gaps of intracellular players involved in Ca2+ signaling in PBMCs, such as reticulum and mitochondria, and presents flow cytometry as a solid option to supplement gold-standard microscopy studies.
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Leucócitos Mononucleares , Transdução de Sinais , Humanos , Leucócitos Mononucleares/metabolismo , Citometria de Fluxo/métodos , Linhagem Celular , Inflamação/metabolismoRESUMO
The Ca2+ release in microdomains formed by intercompartmental contacts, such as mitochondria-associated endoplasmic reticulum membranes (MAMs), encodes a signal that contributes to Ca2+ homeostasis and cell fate control. However, the composition and function of MAMs remain to be fully defined. Here, we focused on the transient receptor potential vanilloid 1 (TRPV1), a Ca2+-permeable ion channel and a polymodal nociceptor. We found TRPV1 channels in the reticular membrane, including some at MAMs, in a rat cardiomyoblast cell line (SV40-transformed H9c2) by Western blotting, immunostaining, cell fractionation, and proximity ligation assay. We used chemical and genetic probes to perform Ca2+ imaging in four cellular compartments: the endoplasmic reticulum (ER), cytoplasm, mitochondrial matrix, and mitochondrial surface. Our results showed that the ER Ca2+ released through TRPV1 channels is detected at the mitochondrial outer membrane and transferred to the mitochondria. Finally, we observed that prolonged TRPV1 modulation for 30 min alters the intracellular Ca2+ equilibrium and influences the MAM structure or the hypoxia/reoxygenation-induced cell death. Thus, our study provides the first evidence that TRPV1 channels contribute to MAM Ca2+ exchanges.
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Antineoplásicos , Canais de Potencial de Receptor Transitório , Animais , Ratos , Mitocôndrias , Retículo Endoplasmático , Linhagem Celular , Estresse do Retículo EndoplasmáticoRESUMO
Background: The inflammatory process underlying atrial myopathy may affect the inflammatory response activated in acute ischemic stroke (AIS). Objectives: We aimed to assess whether left atrial enlargement (LAE) as a marker of atrial myopathy is associated with a different profile of circulating inflammatory markers in AIS patients. Methods: HIBISCUS-STROKE is a cohort study including anterior circulation AIS patients treated with mechanical thrombectomy following MRI. Ten circulating inflammatory markers were measured at admission and 6, 24, and 48â h after admission. LAE was defined as a left atrial volume index (LAVi) ≥34â ml/m2. A multiple logistic regression model was performed to detect an independent association between the area under the curve (AUC) of these markers and LAE. Results: We included 143 patients. Of them, 85 (59.4%) had LAE. On univariable analysis, we found that patients with LAE had higher soluble form suppression of tumorigenicity 2 (sST2), soluble tumor necrosis factor receptor I (sTNFR1), and vascular cellular adhesion molecule-1 (VCAM-1) AUC, were older, mostly female, had a higher National Institutes of Health Stroke Scale (NIHSS) score and blood glucose level at admission, had more often hypertension, and a cardioembolic source of AIS, such as atrial fibrillation, while they were less frequently current smokers and had a lower rate of tandem occlusion than patients without LAE. On multivariable analysis, we found that among circulating inflammatory markers, only high VCAM-1 (OR: 9.13, 95% CI: 3.21-25.9) and sST2 (OR: 3.40, 95% CI: 1.68-6.86) AUC remained associated with LAE. Conclusions: High VCAM-1 and sST2 levels within the first 48â h are associated with LAE in AIS patients.
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Despite advances in cardioprotection, new therapeutic strategies capable of preventing ischemia-reperfusion injury of patients are still needed. Here, we discover that sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA2) phosphorylation at serine 663 is a clinical and pathophysiological event of cardiac function. Indeed, the phosphorylation level of SERCA2 at serine 663 is increased in ischemic hearts of patients and mouse. Analyses on different human cell lines indicate that preventing serine 663 phosphorylation significantly increases SERCA2 activity and protects against cell death, by counteracting cytosolic and mitochondrial Ca2+ overload. By identifying the phosphorylation level of SERCA2 at serine 663 as an essential regulator of SERCA2 activity, Ca2+ homeostasis and infarct size, these data contribute to a more comprehensive understanding of the excitation/contraction coupling of cardiomyocytes and establish the pathophysiological role and the therapeutic potential of SERCA2 modulation in acute myocardial infarction, based on the hotspot phosphorylation level of SERCA2 at serine 663 residue.
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Infarto do Miocárdio , Miocárdio , Animais , Humanos , Camundongos , Cálcio/metabolismo , Homeostase , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , Fosforilação , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismoRESUMO
Reperfusion therapies in acute ischemic stroke have demonstrated their efficacy in promoting clinical recovery. However, ischemia/reperfusion injury and related inflammation remain a major challenge in patient clinical management. We evaluated the spatio-temporal evolution of inflammation using sequential clinical [11C]PK11195 PET-MRI in a non-human primate (NHP) stroke model mimicking endovascular thrombectomy (EVT) with a neuroprotective cyclosporine A (CsA) treatment. The NHP underwent a 110-min transient endovascular middle cerebral artery occlusion. We acquired [11C]PK11195 dynamic PET-MR imaging at baseline, 7 and 30 days after intervention. Individual voxel-wise analysis was performed thanks to a baseline scan database. We quantified [11C]PK11195 in anatomical regions and in lesioned areas defined on per-occlusion MR diffusion-weighted imaging and perfusion [15O2]H2OPET imaging. [11C]PK11195 parametric maps showed a clear uptake overlapping the lesion core at D7, which further increased at D30. Voxel-wise analysis identified individuals with significant inflammation at D30, with voxels located within the most severe diffusion reduction area during occlusion, mainly in the putamen. The quantitative analysis revealed that thalamic inflammation lasted until D30 and was significantly reduced in the CsA-treated group compared to the placebo. In conclusion, we showed that chronic inflammation matched ADC decrease at occlusion time, a region exposed to an initial burst of damage-associated molecular patterns, in an NHP stroke model mimicking EVT. We described secondary thalamic inflammation and the protective effect of CsA in this region. We propose that major ADC drop in the putamen during occlusion may identify individuals who could benefit from early personalized treatment targeting inflammation.
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Isquemia Encefálica , Encefalite , AVC Isquêmico , Acidente Vascular Cerebral , Animais , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/cirurgia , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/tratamento farmacológico , Trombectomia/métodos , Primatas , Inflamação/diagnóstico por imagem , Isquemia Encefálica/terapia , Isquemia Encefálica/tratamento farmacológico , Resultado do TratamentoRESUMO
RATIONALE: Mitochondria are key organelles involved in cell survival and death during the acute phenomena of myocardial ischemia-reperfusion (i.e., myocardial infarction). To investigate the functions of isolated mitochondria such as calcium retention capacity, oxidative phosphorylation, and reactive oxygen species (ROS) production, already established methods are based on extramitochondrial measurements of the whole mitochondria population. OBJECTIVE: The aim of this study was to develop a reliable and well-characterized method for multiparametric analysis of isolated single mitochondrion by flow cytometry (FC) in the context of myocardial infarction. The advantage of FC is the possibility to give a simultaneous analysis of morphological parameters (side and forward scatters: SSC and FSC) for each mitochondrion, combined with intramitochondrial measurements of several biological markers, such as ROS production or membrane potential (Δφm), using specific fluorescent probes. METHODS AND RESULTS: For this study, a rat model of ischemia-reperfusion and a protective approach of post-conditioning using low reperfusion pressure was used. Thanks to the use of specific probes (NAO, MTR, TMRM, DilC1, and DHR123) combined with flow cytometry, we propose a method: (i) to identify mitochondrial populations of interest based on quality criteria (NAO/TMRM double staining); (ii) to monitor their morphological criteria, especially during swelling due to calcium overload; and (iii) to compare mitochondrial functions (membrane potential and ROS production) in different experimental groups. Applied to mitochondria from ischemic hearts, these measurements revealed that individual mitochondria are altered and that cardioprotection by low-pressure reperfusion reduces damage, as expected. CONCLUSIONS: Our results highlight FC as a reliable and sensitive method to investigate changes in mitochondrial functions and morphology in pathological conditions that disrupts their activity such as the case in ischemia-reperfusion. This methodological approach can be extended to other pathologies involving mitochondrial dysfunctions. Moreover, FC offers the possibility to work with very small amounts of isolated mitochondria, a factor that may limit the use of classical methods.
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Background: The objective of this study was to demonstrate that synchrotron K-edge subtraction tomography (SKES-CT) can simultaneously track therapeutic cells and their encapsulating carrier, in vivo, in a rat model of focal brain injury using a dual-contrast agent approach. The second objective was to determine if SKES-CT could be used as a reference method for spectral photon counting tomography (SPCCT). Methods: Phantoms containing different concentrations of gold and iodine nanoparticles (AuNPS/INPs) were imaged with SKES-CT and SPCCT to assess their performances. A pre-clinical study was performed in rats with focal cerebral injury which intracerebrally received AuNPs-labelled therapeutic cells encapsulated in a INPs-labelled scaffold. Animals were imaged in vivo with SKES-CT and back-to-back with SPCCT. Results: SKES-CT revealed to be reliable for quantification of gold and iodine, whether alone or mixed. In the preclinical model, SKES-CT showed that AuNPs remained at the site of cell injection, while INPs expanded within and/or along the lesion border, suggesting dissociation of both components in the first days post-administration. Compared to SKES-CT, SPCCT was able to correctly locate gold, but not completely located iodine. When SKES-CT was used as reference, SPCCT gold quantification appeared very accurate both in vitro and in vivo. Iodine quantification by SPCCT was also quite accurate, albeit less so than for gold. Conclusion: We here provide the proof-of-concept that SKES-CT is a novel method of choice for performing dual-contrast agent imaging in the context of brain regenerative therapy. SKES-CT may also serve as ground truth for emerging technologies such as multicolour clinical SPCCT.
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Lesões Encefálicas , Iodo , Nanopartículas Metálicas , Ratos , Animais , Meios de Contraste , Ouro , Síncrotrons , Tomografia Computadorizada por Raios X/métodos , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/terapiaRESUMO
BACKGROUND AND OBJECTIVES: The objective of this study was to assess the relationship between blood biomarkers of inflammation and lesion growth within the penumbra in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). METHODS: The HIBISCUS-STROKE cohort enrolled patients admitted in the Lyon Stroke Center for an anterior circulation AIS treated with MT after brain MRI assessment. Lesion growth within the penumbra was assessed on day 6 MRI using a voxel-based nonlinear coregistration method and dichotomized into low and high according to the median value. C-reactive protein, interleukin (IL)-6, IL-8, IL-10, monocyte chemoattractant protein-1, soluble tumor necrosis factor receptor I, soluble form suppression of tumorigenicity 2 (sST2), soluble P-selectin, vascular cellular adhesion molecule-1, and matrix metalloproteinase-9 were measured in sera at 4 time points within the first 48 hours. Reperfusion was considered as successful if Thrombolysis in Cerebral Infarction score was 2b/2c/3. A multiple logistic regression model was performed to detect any association between area under the curve (AUC) of these biomarkers within the first 48 hours and a high lesion growth within the penumbra. RESULTS: Ninety patients were included. The median lesion growth within the penumbra was 2.3 (0.7-6.2) mL. On multivariable analysis, a high sST2 AUC (OR 3.77, 95% CI 1.36-10.46), a high baseline DWI volume (OR 3.65, 95% CI 1.32-10.12), and a lack of successful reperfusion (OR 0.19, 95% CI 0.04-0.92) were associated with a high lesion growth within the penumbra. When restricting analyses to patients with successful reperfusion (n = 76), a high sST2 AUC (OR 5.03, 95% CI 1.64-15.40), a high baseline DWI volume (OR 3.74, 95% CI 1.22-11.53), and a high penumbra volume (OR 3.25, 95% CI 1.10-9.57) remained associated with a high lesion growth within the penumbra. DISCUSSION: High sST2 levels within the first 48 hours are associated with a high lesion growth within the penumbra.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/cirurgia , Trombectomia/métodos , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/cirurgia , Resultado do Tratamento , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/cirurgia , Biomarcadores , Inflamação/diagnóstico por imagemRESUMO
Through a screen that combines functional and evolutionary analyses, we identified tripartite motif protein (Trim69), a poorly studied member of the Trim family, as a negative regulator of HIV-1 infection in interferon (IFN)-stimulated myeloid cells. Trim69 inhibits the early phases of infection of HIV-1, but also of HIV-2 and SIVMAC in addition to the negative and positive-strand RNA viruses vesicular stomatitis virus and severe acute respiratory syndrome coronavirus 2, with magnitudes that depend on the combination between cell type and virus. Mechanistically, Trim69 associates directly to microtubules and its antiviral activity is linked to its ability to promote the accumulation of stable microtubules, a program that we uncover to be an integral part of antiviral IFN-I responses in myeloid cells. Overall, our study identifies Trim69 as the antiviral innate defense factor that regulates the properties of microtubules to limit viral spread and highlights the cytoskeleton as an unappreciated battleground in the host-pathogen interactions that underlie viral infections.
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Infecções por HIV , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Replicação Viral , Humanos , Imunidade Inata , Interferons/imunologia , Microtúbulos/metabolismo , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Infecções por HIV/imunologiaRESUMO
Inflammation is involved in small vessel disease (SVD). We aim to clarify whether inflammation related to white matter hyperintensities (WMH), a key component of SVD, may affect the inflammatory response in acute ischemic stroke (AIS) patients. For this, we sequentially measured 10 circulating inflammatory markers and assessed WMH burden on admission MRI in AIS patients treated with thrombectomy. Of 149 patients, 57 (38.3%) had a high WMH burden (Fazekas≥3). A high WMH burden was associated with 4 markers levels but this association did not remain following multivariable analyses. WMH burden is not associated with a specific inflammatory profile in AIS.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Substância Branca , Biomarcadores , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Humanos , Inflamação/complicações , Inflamação/diagnóstico por imagem , AVC Isquêmico/diagnóstico por imagem , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Substância Branca/diagnóstico por imagemRESUMO
White-matter injury leads to severe functional loss in many neurological diseases. Myelin staining on histological samples is the most common technique to investigate white-matter fibers. However, tissue processing and sectioning may affect the reliability of 3D volumetric assessments. The purpose of this study was to propose an approach that enables myelin fibers to be mapped in the whole rodent brain with microscopic resolution and without the need for strenuous staining. With this aim, we coupled in-line (propagation-based) X-ray phase-contrast tomography (XPCT) to ethanol-induced brain sample dehydration. We here provide the proof-of-concept that this approach enhances myelinated axons in rodent and human brain tissue. In addition, we demonstrated that white-matter injuries could be detected and quantified with this approach, using three animal models: ischemic stroke, premature birth and multiple sclerosis. Furthermore, in analogy to diffusion tensor imaging (DTI), we retrieved fiber directions and DTI-like diffusion metrics from our XPCT data to quantitatively characterize white-matter microstructure. Finally, we showed that this non-destructive approach was compatible with subsequent complementary brain sample analysis by conventional histology. In-line XPCT might thus become a novel gold-standard for investigating white-matter injury in the intact brain. This is Part I of a series of two articles reporting the value of in-line XPCT for virtual histology of the brain; Part II shows how in-line XPCT enables the whole-brain 3D morphometric analysis of amyloid- ß (A ß ) plaques.
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BACKGROUND: Aging is associated with a chronic low-grade inflammatory state. This condition may affect the acute inflammatory response involved in ST-segment-elevation myocardial infarction (STEMI) or acute ischemic stroke (AIS). We sought to compare the profile of a set of circulating inflammatory markers between young and older patients admitted for STEMI or AIS. METHODS: HIBISCUS-STEMI (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in ST Elevation Myocardial Infarction) and HIBISCUS-STROKE (Cohort of Patients to Identify Biological and Imaging Markers of Cardiovascular Outcomes in Stroke) are 2 cohort studies that enrolled patients with STEMI treated with primary percutaneous coronary intervention in the cardiac intensive care unit of Lyon and patients with AIS treated with mechanical thrombectomy in the Lyon Stroke Center, respectively from 2016 to 2019. Patients were classified as older if they were ≥65 years and as young if they were <65 years. In both cohorts, CRP (C-reactive protein), IL (interleukin)-6, IL-8, IL-10, MCP (monocyte chemoattractant protein), sTNF-RI (soluble tumor necrosis factor receptor I), sST2 (soluble form suppression of tumorigenicity 2), and VCAM-1 (vascular cellular adhesion molecule-1) were measured on serum collected at 5 time points using enzyme-linked immunosorbent assay. A multiple logistic regression model was performed to detect an association between area under the curve of circulating inflammatory markers within the first 48 hours and older age. RESULTS: A total of 260 patients with STEMI and 164 patients with AIS were included. Of them, there were 76 (29%) and 105 (64%) older patients with STEMI and AIS, respectively. Following multivariable analysis, a high area under the curve of IL-6 and sTNF-RI, a low lymphocyte count, and a high neutrophil-lymphocyte ratio at 24 hours were associated with older age in patients with STEMI and AIS. CONCLUSIONS: Older patients had higher IL-6 and sTFN-RI levels within the first 48 hours associated with a lower lymphocyte count and a higher neutrophil-lymphocyte ratio at 24 hours in both cohorts.
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AVC Isquêmico , Infarto do Miocárdio com Supradesnível do Segmento ST , Síndrome de Resposta Inflamatória Sistêmica , Idoso , Biomarcadores/análise , Proteína C-Reativa , Humanos , Interleucina-6 , AVC Isquêmico/imunologia , AVC Isquêmico/terapia , Pessoa de Meia-Idade , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST/imunologia , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Acidente Vascular Cerebral/terapia , Síndrome de Resposta Inflamatória Sistêmica/imunologiaRESUMO
Hypothermia provides an effective neuro and cardio-protection in clinical settings implying ischemia/reperfusion injury (I/R). At the onset of reperfusion, succinate-induced reactive oxygen species (ROS) production, impaired oxidative phosphorylation (OXPHOS), and decreased Ca2+ retention capacity (CRC) concur to mitochondrial damages. We explored the effects of temperature from 6 to 37 °C on OXPHOS, ROS production, and CRC, using isolated mitochondria from mouse brain and heart. Oxygen consumption and ROS production was gradually inhibited when cooling from 37 to 6 °C in brain mitochondria (BM) and heart mitochondria (HM). The decrease in ROS production was gradual in BM but steeper between 31 and 20 °C in HM. In respiring mitochondria, the gradual activation of complex II, in addition of complex I, dramatically enhanced ROS production at all temperatures without modifying respiration, likely because of ubiquinone over-reduction. Finally, CRC values were linearly increased by cooling in both BM and HM. In BM, the Ca2+ uptake rate by the mitochondrial calcium uniporter (MCU) decreased by 2.7-fold between 25 and 37 °C, but decreased by 5.7-fold between 25 and 37 °C in HM. In conclusion, mild cold (25-37 °C) exerts differential inhibitory effects by preventing ROS production, by reverse electron transfer (RET) in BM, and by reducing MCU-mediated Ca2+ uptake rate in BM and HM.
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Encéfalo , Mitocôndrias Cardíacas , Animais , Homeostase , Camundongos , Espécies Reativas de Oxigênio , RespiraçãoRESUMO
BACKGROUND & AIMS: Hepatic insulin resistance in obesity and type 2 diabetes was recently associated with endoplasmic reticulum (ER)-mitochondria miscommunication. These contact sites (mitochondria-associated membranes: MAMs) are highly dynamic and involved in many functions; however, whether MAM dysfunction plays a causal role in hepatic insulin resistance and steatosis is not clear. Thus, we aimed to determine whether and how organelle miscommunication plays a role in the onset and progression of hepatic metabolic impairment. METHODS: We analyzed hepatic ER-mitochondria interactions and calcium exchange in a time-dependent and reversible manner in mice with diet-induced obesity. Additionally, we used recombinant adenovirus to express a specific organelle spacer or linker in mouse livers, to determine the causal impact of MAM dysfunction on hepatic metabolic alterations. RESULTS: Disruption of ER-mitochondria interactions and calcium exchange is an early event preceding hepatic insulin resistance and steatosis in mice with diet-induced obesity. Interestingly, an 8-week reversal diet concomitantly reversed hepatic organelle miscommunication and insulin resistance in obese mice. Mechanistically, disrupting structural and functional ER-mitochondria interactions through the hepatic overexpression of the organelle spacer FATE1 was sufficient to impair hepatic insulin action and glucose homeostasis. In addition, FATE1-mediated organelle miscommunication disrupted lipid-related mitochondrial oxidative metabolism and induced hepatic steatosis. Conversely, reinforcement of ER-mitochondria interactions through hepatic expression of a synthetic linker prevented diet-induced glucose intolerance after 4 weeks' overnutrition. Importantly, ER-mitochondria miscommunication was confirmed in the liver of obese patients with type 2 diabetes, and correlated with glycemia, HbA1c and HOMA-IR index. CONCLUSIONS: ER-mitochondria miscommunication is an early causal trigger of hepatic insulin resistance and steatosis, and can be reversed by switching to a healthy diet. Thus, targeting MAMs could help to restore metabolic homeostasis. LAY SUMMARY: The literature suggests that interactions between the endoplasmic reticulum and mitochondria could play a role in hepatic insulin resistance and steatosis during chronic obesity. In the present study, we reappraised the time-dependent regulation of hepatic endoplasmic reticulum-mitochondria interactions and calcium exchange, investigating reversibility and causality, in mice with diet-induced obesity. We also assessed the relevance of our findings to humans. We show that organelle miscommunication is an early causal trigger of hepatic insulin resistance and steatosis that can be improved by nutritional strategies.
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Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Resistência à Insulina , Hepatopatias , Animais , Cálcio/metabolismo , Comunicação , Proteínas de Ligação a DNA/metabolismo , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/metabolismo , Retículo Endoplasmático/metabolismo , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Glucose/metabolismo , Humanos , Fígado/metabolismo , Hepatopatias/metabolismo , Camundongos , Mitocôndrias/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Mitochondria are real sensors of the physiological status of tissues. After the death of an animal, they maintain physiological activity for several days. This activity is highly dependent on the availability of nutrients in the tissue. In this study, flow cytometry was used to measure the membrane potential of mitochondria isolated from European seabass (Dicentrarchus labrax) red muscle stored in ice for seven days in order to characterize fish freshness. Two probes, TMRM and Rhodamine 123, were used to measure mitochondrial potential. During the first few days (D0 to D3), isolated mitochondria maintained high potential, and then lost their potential (from D3 to D5), but were always re-polarizable after addition of substrates (glutamate, malate and succinate). From D7, the mitochondria were more strongly depolarized and were difficult to repolarize by the substrates. Using flow cytometry, we demonstrated that mitochondria were an excellent marker to confirm seabass freshness.
Assuntos
Bass , Animais , Citometria de Fluxo , Mitocôndrias , Mitocôndrias Musculares , Alimentos Marinhos/análiseRESUMO
BACKGROUND: Soluble form suppression of tumorigenicity 2 (sST2) is known to have prognostic value in ST-elevation myocardial infarction (STEMI) and could impact mortality after acute ischemic stroke (AIS). However, before considering sST2 as a therapeutic target, the kinetics of release and its association with adverse clinical events in both STEMI and AIS patients have to be determined. METHODS: We prospectively enrolled 251 STEMI patients, treated with primary percutaneous coronary intervention, and 152 AIS patients treated with mechanical thrombectomy. We evaluated the level of sST2 in patient sera at five time point (admission, 4, 24, 48 h and 1 month from admission for STEMI patients and admission, 6, 24, 48 h and 3 months from admission for AIS patients). Major adverse clinical events (MACE) (all-cause death, acute myocardial infarction, stroke or hospitalization for heart failure) in STEMI patients and all-cause death in AIS patients were recorded during a 12-month follow-up. RESULTS: Mean age of the study population was 59 ± 12 and 69 ± 15 years in STEMI and AIS patients, respectively. In STEMI patients, sST2 peaked 24 h after admission (25.5 ng/mL interquartile range (IQR) [14.9-29.1]) whereas an earlier and lower peak was observed in AIS patients (16.8 ng/mL IQR [15.2-18.3] at 6 h). Twenty-five (10.0%) STEMI patients experienced a MACE and 12 (7.9%) AIS patients had all-cause death within the first 12 months. A high level of sST2 at 24 h was associated with MACE in STEMI patients (hazard ratio (HR) = 2.5; 95% confidence interval (CI) [1.1-5.6], p = 0.03) and all-cause death in AIS patients (HR = 11.7; 95% CI [3.8-36.2], p < 0.01) within the first 12 months. CONCLUSIONS: The study highlights that sST2 levels at 24 h are associated with an increased risk to adverse clinical events in both diseases.