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Fermented pineapple juice consumption limits metabolic disorders associated to sugary drinks on high-fat diet-fed mice. Mol Nutr Food Res 2023:e2200670. [PMID: 36949666 DOI: 10.1002/mnfr.202200670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 03/17/2023] [Indexed: 03/24/2023]
Abstract
Lactic acid fermentation modulates the composition of food, leading to changes in safety, sensory and nutritional properties. The effects of lactic fermented pineapple juice supplementation on energetic metabolism of high-fat diet (HFD) fed mice were compared with either water (control), sweetened water, bacteria in sweetened water and pineapple juice supplementation. Drink consumption and body weight were measured during the six weeks of experiment, whereas glycaemia and lipid content were determined at the beginning and at the end of the experiment. Total energy intake was similar between all groups though the volume of juice consumed was lower than that of sweetened waters. Weight gain was higher for mice provided with sugary drinks (5.65±1.32 g to 7.74±2.98 g) compared to water (4.68±0.93 g). The fermented pineapple juice was less detrimental to blood carbohydrate regulation than other sugary drinks. Triglyceride and total cholesterol content were not modified following fermented juice or water consumption, contrarily to other sugary drinks. Whatever the drink, intestinal permeability was preserved. Lactic acid bacterium (LAB) population in feces was not affected by the beverage but species composition was modified. From a health perspective, fermented pineapple juice was preferable to other sugary drinks to limit metabolic disorders related to HFD. This article is protected by copyright. All rights reserved.
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Distribution of Adiponectin Receptors in the Brain of Adult Mouse: Effect of a Single Dose of the Adiponectin Receptor Agonist, AdipoRON, on Ischemic Stroke. Brain Sci 2022; 12:brainsci12050680. [PMID: 35625066 PMCID: PMC9139333 DOI: 10.3390/brainsci12050680] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/08/2022] [Accepted: 05/16/2022] [Indexed: 12/10/2022] Open
Abstract
Adiponectin exhibits pleiotropic effects, including anti-inflammatory, anti-apoptotic, anti-oxidant, and neuroprotective ones. Although some studies have documented brain expression in different rodent models of its receptors, AdipoR1 and AdipoR2, their global distribution remains incomplete. Here, we demonstrated that both AdipoR are widely distributed in the brains of adult mice. Furthermore, by double immunostaining studies, we showed that AdipoR1 and AdipoR2 are mainly expressed in neurons and blood vessels. Then, considering the wide distribution of both receptors and the neuroprotective effects of adiponectin, we tested the therapeutic effect of a single injection of the adiponectin receptor agonist, AdipoRON (5 mg.kg−1), 24 h after stroke in a model of middle cerebral artery occlusion technique (MCAO). Under our experimental conditions, we demonstrated that AdipoRON did not modulate the infarct volume, cell death, neuroinflammatory parameters including microglia activation and oxidative stress. This study suggests that a protocol based on multiple injections of AdipoRON at a higher dose after MCAO could be considered to promote the therapeutic properties of AdipoRON on the brain repair mechanism and recovery.
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Author Correction: The SARS-CoV-2 spike residues 616/644 and 1138/1169 delineate two antibody epitopes in COVID-19 mRNA COMIRNATY vaccine (Pfizer/BioNTech). Sci Rep 2022; 12:6498. [PMID: 35444227 PMCID: PMC9019531 DOI: 10.1038/s41598-022-10885-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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The SARS-CoV-2 spike residues 616/644 and 1138/1169 delineate two antibody epitopes in COVID-19 mRNA COMINARTY vaccine (Pfizer/BioNTech). Sci Rep 2022; 12:5999. [PMID: 35397679 PMCID: PMC8994064 DOI: 10.1038/s41598-022-10057-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 03/16/2022] [Indexed: 01/07/2023] Open
Abstract
The newly identified coronavirus SARS-CoV-2 is responsible for the worldwide pandemic COVID-19. Considerable efforts have been devoted for the development of effective vaccine strategies against COVID-19. The SARS-CoV-2 spike protein has been identified as the major antigen candidate for the development of COVID-19 vaccines. The Pfizer-BioNTech COVID-19 vaccine comirnaty is a lipid nanoparticle-encapsulated mRNA encoding a full-length and prefusion-stabilized SARS-CoV-2 spike protein. In the present study, synthetic peptide-based ELISA assays were performed to identify linear B-cell epitopes into the spike protein that contribute to elicitation of antibody response in comirnaty-vaccinated individuals. The synthetic S2P6 peptide containing the spike residues 1138/1169 and to a lesser extent, the synthetic S1P4 peptide containing the spike residues 616/644 were recognized by the immune sera from comirnaty vaccine recipients but not COVID-19 recovered patients. We assume that the synthetic S2P6 peptide and to a lesser extent the synthetic S1P4 peptide, could be of interest to measure the dynamic of antibody response to COVID-19 mRNA vaccines. The S2P6 peptide has been identified as immunogenic in adult BALB/c mice that received protein-peptide conjugates in a prime-boost schedule. This raises the question on the role of the B-cell epitope peptide containing the SARS-CoV-2 spike residues 1138/1169 in protective efficacy of the Pfizer-BioNTech COVID-19 vaccine comirnaty.
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Lack of Neuroprotective Effects of High-Density Lipoprotein Therapy in Stroke under Acute Hyperglycemic Conditions. Molecules 2021; 26:molecules26216365. [PMID: 34770774 PMCID: PMC8588473 DOI: 10.3390/molecules26216365] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 01/01/2023] Open
Abstract
Introduction: The pleiotropic protective effects of high-density lipoproteins (HDLs) on cerebral ischemia have never been tested under acute hyperglycemic conditions. The aim of this study is to evaluate the potential neuroprotective effect of HDL intracarotid injection in a mouse model of middle cerebral artery occlusion (MCAO) under hyperglycemic conditions. Methods: Forty-two mice were randomized to receive either an intracarotid injection of HDLs or saline. Acute hyperglycemia was induced by an intraperitoneal injection of glucose (2.2 g/kg) 20 min before MCAO. Infarct size (2,3,5-triphenyltetrazolium chloride (TTC)-staining), blood–brain barrier leakage (IgG infiltration), and hemorrhagic changes (hemoglobin assay by ELISA and hemorrhagic transformation score) were analyzed 24 h post-stroke. Brain tissue inflammation (IL-6 by ELISA, neutrophil infiltration and myeloperoxidase by immunohisto-fluorescence) and apoptosis (caspase 3 activation) were also assessed. Results: Intraperitoneal D-glucose injection allowed HDL- and saline-treated groups to reach a blood glucose level of 300 mg/dl in the acute phase of cerebral ischemia. HDL injection did not significantly reduce mortality (19% versus 29% in the saline-injected group) or cerebral infarct size (p = 0.25). Hemorrhagic transformations and inflammation parameters were not different between the two groups. In addition, HDL did not inhibit apoptosis under acute hyperglycemic conditions. Conclusion: We observed a nonsignificant decrease in cerebral infarct size in the HDL group. The deleterious consequences of reperfusion such as hemorrhagic transformation or inflammation were not improved by HDL infusion. In acute hyperglycemia, HDLs are not potent enough to counteract the adverse effects of hyperglycemia. The addition of antioxidants to therapeutic HDLs could improve their neuroprotective capacity.
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PCSK9 (Proprotein Convertase Subtilisin Kexin Type 9) Inhibition in Hyperglycemic Mice Increases the Risk of Hemorrhagic Transformation of Ischemic Stroke. Stroke 2021; 52:e545-e547. [PMID: 34315254 DOI: 10.1161/strokeaha.121.035677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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High-Fat Diet Aggravates Cerebral Infarct, Hemorrhagic Transformation and Neuroinflammation in a Mouse Stroke Model. Int J Mol Sci 2021; 22:4571. [PMID: 33925459 PMCID: PMC8123851 DOI: 10.3390/ijms22094571] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Stroke in context of type 2 diabetes (T2D) is associated with a poorer outcome than in non-diabetic conditions. We aimed at creating a new reproducible mouse model of stroke in impaired glucose tolerance conditions induced by high-fat diet. METHODS Adult C57BL6 mice were fed for 2 months with either normal diet (ND) or high-fat diet (HFD). We used a model of Middle Cerebral Artery Occlusion (MCAO) for 90 min. Oral Glucose Tolerance Test (OGTT) and Insulin Tolerance Test (ITT) were used to assess pre-diabetic status. Brain infarct volume, hemorrhagic transformation (HT) as well as systemic and cerebral inflammatory markers were evaluated. RESULTS HFD was associated with an increased body weight and glycemia following OGTT. The HFD group presented a significant increase in brain infarct volume (38.7 (IQR 30-46.7%) vs. 28.45 (IQR 21-30%); p = 0.016) and HT (HFD: 2 (IQR 1-5) vs. ND: 0 (IQR 0-1); p = 0.012) and higher levels of IL-6 and MCP-1 in infarcted hemisphere compared to the ND group. CONCLUSION Two months of HFD in adult mice were sufficient to alter the lipid profile and the control of hyperglycemia. These metabolic perturbations were significantly associated with increased infarct volume and hemorrhagic complications.
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Protective Effects of Antioxidant Polyphenols against Hyperglycemia-Mediated Alterations in Cerebral Endothelial Cells and a Mouse Stroke Model. Mol Nutr Food Res 2020; 64:e1900779. [PMID: 32447828 DOI: 10.1002/mnfr.201900779] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 03/08/2020] [Indexed: 12/15/2022]
Abstract
SCOPE Hyperglycemia alters cerebral endothelial cell and blood-brain barrier functions, aggravating cerebrovascular complications such as stroke during diabetes. Redox and inflammatory changes play a causal role. This study evaluates polyphenol protective effects in cerebral endothelial cells and a mouse stroke model during hyperglycemia. METHODS AND RESULTS Murine bEnd.3 cerebral endothelial cells and a mouse stroke model are exposed to a characterized, polyphenol-rich extract of Antirhea borbonica or its predominant constituent caffeic acid, during hyperglycemia. Polyphenol effects on redox, inflammatory and vasoactive markers, infarct volume, and hemorrhagic transformation are determined. In vitro, polyphenols improve reactive oxygen species levels, Cu/Zn superoxide dismutase activity, and both NAPDH oxidase 4 and nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression deregulated by high glucose. Polyphenols reduce Nrf2 nuclear translocation and counteract nuclear factor-ĸappa B activation, interleukin-6 secretion, and the altered production of vasoactive markers mediated by high glucose. In vivo, polyphenols reduce cerebral infarct volume and hemorrhagic transformation aggravated by hyperglycemia. Polyphenols attenuate redox changes, increase vascular endothelial-Cadherin production, and decrease neuro-inflammation in the infarcted hemisphere. CONCLUSION Polyphenols protect against hyperglycemia-mediated alterations in cerebral endothelial cells and a mouse stroke model. It is relevant to assess polyphenol benefits to improve cerebrovascular damages during diabetes.
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Expression of adiponectin receptors in the brain of adult zebrafish and mouse: Links with neurogenic niches and brain repair. J Comp Neurol 2019; 527:2317-2333. [DOI: 10.1002/cne.24669] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/18/2019] [Accepted: 02/26/2019] [Indexed: 12/17/2022]
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Comparative suppressing effects of black and green teas on the formation of advanced glycation end products (AGEs) and AGE-induced oxidative stress. Food Funct 2018; 8:4194-4209. [PMID: 29043349 DOI: 10.1039/c7fo01038a] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study aimed at investigating and comparing the anti-diabetic potential of black and green teas. Biochemical analyses indicate higher antioxidant potency, significantly correlated with the phytochemicals present, in green teas compared to black teas. Both extracts afforded a similar level of protection to erythrocytes against peroxyl radical-induced lysis. Non-cytotoxic concentration of green and black tea extracts significantly reduced the reactive oxygen species (ROS) production (P < 0.01), lowered the oxidation of proteins (P < 0.05) and decreased the IL-6 secretion (P < 0.01) induced by AGEs or H2O2 in 3T3-L1 preadipocytes. Both teas also inhibited the decline in the enzymatic activities of superoxide dismutase, catalase and glutathione peroxidase induced by the pro-oxidants. The teas further suppressed the glycation of BSA mediated by glucose, ribose and MGO by reducing fluorescent AGE, fructosamine, protein carbonyl and AOPP levels. Black and green teas also inhibited the activities of α-amylase (AA50: 589.86 ± 39.51 and 947.80 ± 18.20 μg mL-1, respectively) and α-glucosidase (AA50: 72.31 ± 4.23 and 100.23 ± 8.10 μg mL-1, respectively). The teas afforded a comparable level of protection at the cellular level and against glycation while black tea exerted the highest carbohydrate hydrolysing enzymes inhibitory activity. Our results clearly show that black and green teas represent an important source of antioxidants with anti-diabetic potential.
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Circulating Concentrations of Redox Biomarkers Do Not Improve the Prediction of Adverse Cardiovascular Events in Patients With Type 2 Diabetes Mellitus. J Am Heart Assoc 2018; 7:JAHA.117.007397. [PMID: 29478972 PMCID: PMC5866317 DOI: 10.1161/jaha.117.007397] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Despite pathophysiological relevance and promising experimental data, the usefulness of biomarkers of oxidative stress for cardiac risk prediction is unclear. The aim of our study was to investigate the prognostic value of 6 biomarkers exploring different pathways of oxidative stress for predicting adverse cardiovascular outcomes in patients with type 2 diabetes mellitus beyond established risk factors. Methods and Results The SURDIAGENE (Survie, Diabete de type 2 et Genetique) prospective cohort study consecutively recruited 1468 patients with type 2 diabetes mellitus. Assays were performed at baseline, and incident cases of major adverse cardiovascular events (MACE)—first occurrence of cardiovascular death, nonfatal myocardial infarction, or stroke—were recorded during a median of 64 months. Advanced oxidation protein products, oxidative hemolysis inhibition assay, ischemia‐modified albumin, and total reductive capacity of plasma were not associated with the risk of MACE in univariate analyses. Fluorescent advanced glycation end products and carbonyls were associated with MACE (hazard ratio=1.38 per SD, 95% confidence interval 1.24‐1.54, P<0.001 and hazard ratio=1.15 per SD, 95% confidence interval 1.04‐1.27, P=0.006, respectively) in univariate analysis, but when added to a multivariate predictive model including traditional risk factors for MACE, these markers did not significantly improve c‐statistics or integrated discrimination index of the model. Conclusions These plasma concentrations of 6 markers, which cover a broad spectrum of oxidative processes, were not significantly associated with MACE occurrence and were not able to improve MACE risk discrimination and classification beyond classical risk factors in type 2 diabetes mellitus patients.
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A hemorrhagic transformation model of mechanical stroke therapy with acute hyperglycemia in mice. J Comp Neurol 2018; 526:1006-1016. [PMID: 29277912 DOI: 10.1002/cne.24386] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 12/07/2017] [Accepted: 12/07/2017] [Indexed: 12/25/2022]
Abstract
Clinical benefit for mechanical thrombectomy (MT) in stroke was recently demonstrated in multiple large prospective studies. Acute hyperglycemia (HG) is an important risk factor of poor outcome in stroke patients, including those that underwent MT. The aim of this therapy is to achieve a complete reperfusion in a short time, given that reperfusion damage is dependent on the duration of ischemia. Here, we investigated the effects of acute HG in a mouse model of ischemic stroke induced by middle cerebral artery occlusion (MCAO). Hyperglycemic (intraperitoneal [ip] injection of glucose) and control (ip saline injection) 10-week male C57BL6 mice were subjected to MCAO (30, 90, and 180 min) followed by reperfusion obtained by withdrawal of the monofilament. Infarct volume, hemorrhagic transformation (HT), neutrophil infiltration, and neurological scores were assessed at 24 hr by performing vital staining, ELISA immunofluorescence, and behavioral test, respectively. Glucose injection led to transient HG (blood glucose = 250-390 mg/dL) that significantly increased infarct volume, HT, and worsened neurological outcome. In addition, we report that HG promoted blood-brain barrier disruption as shown by hemoglobin accumulation in the brain parenchyma and tended to increase neutrophil extravasation within the infarcted area. Acute HG increased neurovascular damage for all MCAO durations tested. HTs were observed as early as 90 min after ischemia under hyperglycemic conditions. This model mimics MT ischemia/reperfusion and allows the exploration of brain injury in hyperglycemic conditions.
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A hemorrhagic transformation model of mechanical stroke therapy with acute hyperglycemia in mice. Atherosclerosis 2017. [DOI: 10.1016/j.atherosclerosis.2017.06.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Glycated human albumin alters mitochondrial respiration in preadipocyte 3T3-L1 cells. Biofactors 2017; 43:577-592. [PMID: 28543688 DOI: 10.1002/biof.1367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 04/02/2017] [Accepted: 04/20/2017] [Indexed: 12/22/2022]
Abstract
Diabetes and obesity are strongly associated with increased levels of circulating advanced glycation end products (AGEs) and reactive oxygen species (ROS). These two molecular phenomena affect the physiology of adipose tissue, a biological driver of the metabolic syndrome, leading to an inflammatory profile and insulin resistance, which could contribute to obesity/diabetes-associated complications, such as cardiovascular diseases. Herein, we investigated the impact of AGEs on mitochondrial bioenergetics in murine preadipocyte cells (3T3-L1) and cellular redox homeostasis. We show that incubation of preadipocytes with AGEs stimulates mitochondrial activity and respiration while inducing oxidative stress. This AGE-induced intracellular ROS production was blocked by diphenylene iodonium, an NAD(P)H oxidase inhibitor. In parallel, antioxidant enzymes (catalase, superoxide dismutase, and glutathione peroxidase) were found to be activated upon AGE treatment. Our results suggest that AGE-induced oxidative stress is generated by NAD(P)H oxidase and leads to a cellular proliferation arrest associated with enhanced mitochondrial metabolism and biogenesis, and with increased levels of ROS-detoxifying enzymes, as well. These new data show how AGEs may be involved in hyperglycemia-induced oxidative damage in preadipocytes and their potential links to diabetes progression. © 2017 BioFactors, 43(4):577-592, 2017.
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Diabetes-induced hepatic oxidative stress: a new pathogenic role for glycated albumin. Free Radic Biol Med 2017; 102:133-148. [PMID: 27890722 DOI: 10.1016/j.freeradbiomed.2016.11.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/29/2016] [Accepted: 11/14/2016] [Indexed: 01/21/2023]
Abstract
Increased oxidative stress and advanced glycation end-product (AGE) formation are major contributors to the development of type 2 diabetes. Here plasma proteins e.g. albumin can undergo glycoxidation and play a key role in diabetes onset and related pathologies. However, despite recent progress linking albumin-AGE to increased oxidative stress and downstream effects, its action in metabolic organs such as the liver remains to be elucidated. The current study therefore investigated links between oxidative perturbations and biochemical/structural modifications of plasma albumin, and subsequent downstream effects in transgenic db/db mouse livers and HepG2 cells, respectively. Our data reveal increased oxidative stress biomarkers and lipid accumulation in plasma and livers of diabetic mice, together with albumin glycoxidation. Purified mouse albumin modifications resembled those typically found in diabetic patients, i.e. degree of glycation, carbonylation, AGE levels and in terms of chemical composition. Receptor for AGE expression and reactive oxygen species production were upregulated in db/db mouse livers, together with impaired proteolytic, antioxidant and mitochondrial respiratory activities. In parallel, acute exposure of HepG2 cells to glycated albumin also elicited intracellular free radical formation. Together this study demonstrates that AGE-modified albumin can trigger damaging effects on the liver, i.e. by increasing oxidative stress, attenuating antioxidant capacity, and by impairment of hepatic proteolytic and respiratory chain enzyme activities.
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Soluble expression of disulfide-bonded C-type lectin like domain of human CD93 in the cytoplasm of Escherichia coli. J Immunol Methods 2016; 439:67-73. [PMID: 27742562 DOI: 10.1016/j.jim.2016.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
CD93 belongs to the group XIV C-type lectin like domain (CTLD) and is closely related to thrombomodulin (CD141). Although CD93 is known to be involved in the regulation of cell adhesion and phagocytosis, its role in innate immunity remains to be fully investigated. Critically, published data about CD141 suggest that CD93 CTLD could be involved in the control of inflammation. In order to address further functional and structural analyses, we expressed human CD93 CTLD with several disulfide bonds in an E. coli expression system. As the E. coli cytoplasm is a reducing compartment, production of disulfide-bond proteins remains a challenge. Hence, we decided to over express CD93 CTLD in commercially available strains of E. coli and co-expressed a sulfhydryl oxidase (Erv1p) and a disulfide isomerase (DsbC). This strategy led to high yield expression of a native form of CD93 CTLD. NMR studies revealed that Ca2+ was not able to bind to CD93 CTLD. We also showed that the recombinant protein could alter LPS pro-inflammatory activity on THP1. This work provides new tool for further functional and structural studies to decipher the functions associated to the CTLD of CD93. This approach may also be used for others members of the group XIV C-type lectin like domain (CD141, CD248 and CLec14A).
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TLR4-dependant pro-inflammatory effects of HMGB1 on human adipocyte. Adipocyte 2016; 5:384-388. [PMID: 27994953 PMCID: PMC5160392 DOI: 10.1080/21623945.2016.1245818] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/03/2016] [Accepted: 10/03/2016] [Indexed: 10/20/2022] Open
Abstract
Chronic low grade inflammation is one of the major metabolic disorders in case of obesity and associated pathologies. By its important secretion function, the role of adipose tissue in this metabolic low grade inflammation is well known. Recently, it was demonstrated that the alarmin high mobility group box protein 1 (HMGB1) is involved in obesity-related pathologies by its increased serum levels in obese compared to normal weight individuals, and by its pro-inflammatory effects. However, the role of HMGB1 on adipocytes inflammation is poorly documented and we propose to investigate this point. Primary culture of human subcutaneous adipocytes were performed from human adipose tissue samples. Cells were treated with recombinant HMGB1 with/without anti-TLR4 antibody and inhibitors of NF-κB and P38 MAPK. Supernatants were collected for IL-6 and MCP-1 ELISA. HMGB1 initiates Toll-like receptor 4 (TLR4)-dependent activation of inflammation through the downstream NF-κB and P38 MAPK signaling pathway to upregulate the secretion of the pro-inflammatory cytokine IL-6. HMGB1 has pro-inflammatory effects on adipocytes. This reinforces the role of TLR4 in adipose tissue inflammation and antagonizing the HMGB1 inflammatory pathway could bring on new therapeutic targets to counteract obesity-associated pathologies.
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Glycation Alters Ligand Binding, Enzymatic, and Pharmacological Properties of Human Albumin. Biochemistry 2015; 54:3051-62. [DOI: 10.1021/acs.biochem.5b00273] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Recombinant human HSP60 produced in ClearColi™ BL21(DE3) does not activate the NFκB pathway. Cytokine 2015; 73:190-5. [PMID: 25771243 DOI: 10.1016/j.cyto.2015.01.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 01/14/2015] [Accepted: 01/22/2015] [Indexed: 12/29/2022]
Abstract
HSP60, an intracellular molecular chaperone has been largely described as an alarmin or damage-associated molecular pattern when released outside the cell. HSP60 has been reported as a possible ligand of TLR2 or TLR4 inducing NFκB-dependant signaling pathway leading to cytokine secretion. However, recent publications suggested that HSP60 could not act as an activator of TLR4 by itself. The observed effect could be due to the presence of endotoxin in HSP60 preparation especially LPS. In order to clarify the controversy, we produced recombinant human HSP60 in two different strains of Escherichia coli, standard strain for protein overproduction, BL21(DE3), and the new ClearColi BL21(DE3) strain which lacks LPS-activity through TLR4. Undoubtedly, we have shown that recombinant HSP60 by itself was not able to induce NFκB-dependant signaling pathway in a model of THP1 monocyte cell line. Our data suggest that HSP60 needs either pathogen-associated molecules, specific post-translational modification and/or other host factors to activate immune cells via NFκB activation.
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Oxidative damage in diabetics: insights from a graduate study in La Reunion University. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 42:435-442. [PMID: 25132514 DOI: 10.1002/bmb.20818] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 06/02/2014] [Accepted: 07/24/2014] [Indexed: 06/03/2023]
Abstract
Due to the growing incidence of diabetes in developed nations, there is a compelling case to be made for teaching graduate students more deeply about mechanisms underlying this disease. Diabetes is associated with enhanced oxidative stress and protein glycation via the covalent binding of glucose molecules. Albumin represents the major plasmatic protein and undergoes enhanced glycoxidative modifications in diabetic condition. La Réunion Island, a French department located in the Indian Ocean exhibit a growing incidence of diabetes. At the University of La Réunion, our research group named GEICO (Groupe d'Etude sur l'Inflammation Chronique et l'Obésité) participated to foster research and training in diabetes context and focuses on the impact of glycated albumin mediated oxidative stress on cell physiopathology. A laboratory course was designed by our group to introduce graduate students to cutting edge techniques in redox biology while providing insights into scientific processes and methods. This two weeks research laboratory training took place at CYROI, a local biotechnology center that provides advanced facilities for research, business, and education. Using histochemistry, molecular biology, biochemical techniques, student investigated oxidative damages in liver from leptin receptor deficient diabetic mice compared to control littermates. In addition, they used an in vitro model by assaying oxidative impact of glycated albumin on hepatoma carcinoma HepG2 cells. This article gives an overview of the organization and protocol used by the students during their two weeks training in the laboratory. Therefore, it may be helpful for teaching graduate students techniques used in research laboratory working on redox biology.
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Cardio-metabolic effectsof HIV protease inhibitors (lopinavir/ritonavir). PLoS One 2013; 8:e73347. [PMID: 24098634 PMCID: PMC3787040 DOI: 10.1371/journal.pone.0073347] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 07/18/2013] [Indexed: 01/24/2023] Open
Abstract
Although antiretroviral treatment decreases HIV-AIDS morbidity/mortality, long-term side effects may include the onset of insulin resistance and cardiovascular diseases. However, the underlying molecular mechanisms responsible for highly active antiretroviral therapy (HAART)-induced cardio-metabolic effects are poorly understood. In light of this, we hypothesized that HIV protease inhibitor (PI) treatment (Lopinavir/Ritonavir) elevates myocardial oxidative stress and concomitantly inhibits the ubiquitin proteasome system (UPS), thereby attenuating cardiac function. Lopinavir/Ritonavir was dissolved in 1% ethanol (vehicle) and injected into mini-osmotic pumps that were surgically implanted into Wistar rats for 8 weeks vs. vehicle and sham controls. We subsequently evaluated metabolic parameters, gene/protein markers and heart function (ex vivo Langendorff perfusions). PI-treated rats exhibited increased serum LDL-cholesterol, higher tissue triglycerides (heart, liver), but no evidence of insulin resistance. In parallel, there was upregulation of hepatic gene expression, i.e. acetyl-CoA carboxylase β and 3-hydroxy-3-methylglutaryl-CoA-reductase, key regulators of fatty acid oxidation and cholesterol synthesis, respectively. PI-treated hearts displayed impaired cardiac contractile function together with attenuated UPS activity. However, there was no significant remodeling of hearts exposed to PIs, i.e. lack of ultrastructural changes, fibrosis, cardiac hypertrophic response, and oxidative stress. Western blot analysis of PI-treated hearts revealed that perturbed calcium handling may contribute to the PI-mediated contractile dysfunction. Here chronic PI administration led to elevated myocardial calcineurin, nuclear factor of activated T-cells 3 (NFAT3), connexin 43, and phosphorylated phospholamban, together with decreased calmodulin expression levels. This study demonstrates that early changes triggered by PI treatment include increased serum LDL-cholesterol levels together with attenuated cardiac function. Furthermore, PI exposure inhibits the myocardial UPS and leads to elevated calcineurin and connexin 43 expression that may be associated with the future onset of cardiac contractile dysfunction.
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Soluble HMGB1 is a novel adipokine stimulating IL-6 secretion through RAGE receptor in SW872 preadipocyte cell line: contribution to chronic inflammation in fat tissue. PLoS One 2013; 8:e76039. [PMID: 24073286 PMCID: PMC3779194 DOI: 10.1371/journal.pone.0076039] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 08/23/2013] [Indexed: 11/18/2022] Open
Abstract
Low-grade inflammation (LGI) is a central phenomenon in the genesis of obesity and insulin-resistance characterized by IL-6 in human serum. Whereas this LGI was initially thought to be mainly attributed to macrophage activation, it is now known that pre-adipocytes and adipocytes secrete several adipokines including IL-6 and participate to LGI and associated pathologies. In macrophages, HMGB1 is a nuclear yet secreted protein and acts as a cytokine to drive the production of inflammatory molecules through RAGE and TLR2/4. In this paper we tested the secretion of HMGB1 and the auto- and paracrine contribution to fat inflammation using the human preadipocyte cell line SW872 as a model. We showed that 1) human SW872 secreted actively HMGB1, 2) IL-6 production was positively linked to high levels of secreted HMGB1, 3) recombinant HMGB1 boosted IL-6 expression and this effect was mediated by the receptor RAGE and did not involve TLR2 or TLR4. These results suggest that HMGB1 is a major adipokine contributing to LGI implementation and maintenance, and can be considered as a target to develop news therapeutics in LGI associated pathologies such as obesity and type II diabetes.
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