scholarly journals ALDH2 Activity Reduces Mitochondrial Oxygen Reserve Capacity in Endothelial Cells and Induces Senescence Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
G. Nannelli ◽  
E. Terzuoli ◽  
V. Giorgio ◽  
S. Donnini ◽  
P. Lupetti ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Mitochondrial Respiration ◽  
Reserve Capacity ◽  
Flux Analysis ◽  
P53 Expression ◽  
Senescent Phenotype ◽  
Extracellular Flux ◽  
Age Related ◽  
And Migration ◽  
Endothelial Dysfunctions

Endothelial cells (ECs) are dynamic cells that turn from growth into senescence, the latter being associated with cellular dysfunction, altered metabolism, and age-related cardiovascular diseases. Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme metabolizing acetaldehyde and other toxic aldehydes, such as 4-hydroxynonenal (4-HNE). In conditions in which lipid peroxidation products and reactive oxygen species (ROS) are accumulated, ECs become dysfunctional and significantly contribute to the progression of vascular-dependent diseases. The aim of the present study has been to investigate whether inhibition of ALDH2 alters endothelial functions together with the impairment of bioenergetic functions, accelerating the acquisition of a senescent phenotype. HUVECs transfected with siRNA targeting ALDH2 or treated with daidzin, an ALDH2 inhibitor, were used in this study. We observed an alteration in cell morphology associated with endothelial dysfunctions. Loss of ALDH2 reduced cell proliferation and migration and increased paracellular permeability. To assess bioenergetic function in intact ECs, extracellular flux analysis was carried out to establish oxygen consumption rates (OCR). We observed a decrease in mitochondrial respiration and reserve capacity that coincided with SA-β-Gal accumulation and an increase in p21 and p53 expression in siALDH2 or daidzin-treated HUVECs. Treatment with N-acetyl-L-cysteine (NAC) reduced endothelial dysfunctions mediated by siALDH2, indicating that oxidative stress downstream to siALDH2 plays an instrumental role. Our results highlight that ALDH2 impairment accelerates the acquisition of a premature senescent phenotype, a change likely to be associated with the observed reduction of mitochondrial respiration and reserve capacity.

scholarly journals Retinoblastoma ( Rb ) promotes senescence of corneal endothelial cells by inhibiting the activation of E2F2

2020 ◽  
Author(s):  
Alan Jiang ◽  
longbing Mao ◽  
sujuan Duan ◽  
yanyan Zhang ◽  
xing Liu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Function ◽  
Corneal Endothelial Cells ◽  
Senescent Phenotype ◽  
Age Related ◽  
Passage Number ◽  
Fuchs Endothelial Dystrophy ◽  
Rb Gene ◽  
And Migration

Abstract Background Senescence-like changes occur in aging Corneal endothelial cells (CECs), and these changes are associated with decreased vision and age-related corneal diseases. such as Fuchs endothelial dystrophy (FED), chronic corneal allograft dysfunction (CCAD). Such changes have also been shown to cultured cell in vitro after passaging. Therefore, studying the mechanism of CEC senescence would aid in the development of anti-senescence treatment, which would benefit FED and CCAD. The tumor suppressor retinoblastoma (RB) gene product pRB triggers senescent growth arrest when inactivated. In this study, we used siRNA treatment to evaluate whether RB knockdown could suppress CEC senescence, and we investigated relevant molecular mechanisms.Methods RCECs were obtained and were cultured with or without siRb. Senescent cells were detected with a β-galactosidase senescence staining kit. The gene p21, which is associated with a senescent phenotype, was measured by RT-PCR. The morphology and migration of cultured RCECs were examined by phase-contrast microscopy. ZO-1 and N-Cadherin, which are involved in pump and barrier functions, were assessed by immunofluorescence. Cell cycle assessment was performed using a flow cytometer (BD FACSCalibur).Results As the cells were passaged, the number of senescent RCECs, the levels of the senescence-related gene p21, and the levels of senescence-associated secretory factors increased. SiRNA-mediated knockdown of RB led to suppression of cell senescence and the SASP. Furthermore, RB intervention increased the numbers of cells at the G2/M and S phase but did not influence the cell function or migratory ability. Knockdown of RB promoted the activation of E2F2.Conclusions We demonstrated that as the cells increased in passage number, the number of senescent RCECs, the levels of the senescence-related genes p21, and the levels of senescence-associated secretory factors increased. Retinoblastoma (Rb) promoted the senescence of corneal endothelial cells by inhibiting the activation of E2F2.

scholarly journals Increased Susceptibility to Ethylmercury-Induced Mitochondrial Dysfunction in a Subset of Autism Lymphoblastoid Cell Lines

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Shannon Rose ◽  
Rebecca Wynne ◽  
Richard E. Frye ◽  
Stepan Melnyk ◽  
S. Jill James
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Cell Lines ◽  
Autism Spectrum ◽  
Reserve Capacity ◽  
Flux Analysis ◽  
Lymphoblastoid Cell Lines ◽  
Extracellular Flux ◽  
Respiratory Parameters ◽  
Increased Risk

The association of autism spectrum disorders with oxidative stress, redox imbalance, and mitochondrial dysfunction has become increasingly recognized. In this study, extracellular flux analysis was used to compare mitochondrial respiration in lymphoblastoid cell lines (LCLs) from individuals with autism and unaffected controls exposed to ethylmercury, an environmental toxin known to deplete glutathione and induce oxidative stress and mitochondrial dysfunction. We also tested whether pretreating the autism LCLs with N-acetyl cysteine (NAC) to increase glutathione concentrations conferred protection from ethylmercury. Examination of 16 autism/control LCL pairs revealed that a subgroup (31%) of autism LCLs exhibited a greater reduction in ATP-linked respiration, maximal respiratory capacity, and reserve capacity when exposed to ethylmercury, compared to control LCLs. These respiratory parameters were significantly elevated at baseline in the ethylmercury-sensitive autism subgroup as compared to control LCLs. NAC pretreatment of the sensitive subgroup reduced (normalized) baseline respiratory parameters and blunted the exaggerated ethylmercury-induced reserve capacity depletion. These findings suggest that the epidemiological link between environmental mercury exposure and an increased risk of developing autism may be mediated through mitochondrial dysfunction and support the notion that a subset of individuals with autism may be vulnerable to environmental influences with detrimental effects on development through mitochondrial dysfunction.

scholarly journals The profiles of mitochondrial respiration and glycolysis using extracellular flux analysis in porcine enterocyte IPEC-J2

2015 ◽  
Vol 1 (3) ◽  
pp. 239-243 ◽  
Author(s):  
Bie Tan ◽  
Hao Xiao ◽  
Fengna Li ◽  
Liming Zeng ◽  
Yulong Yin
Keyword(s):  
Mitochondrial Respiration ◽  
Flux Analysis ◽  
Extracellular Flux

scholarly journals Mitochondrial Respiration in Female Zucker Rats: Effects of Obesity and Short-Term Metformin Treatment

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1682-1682
Author(s):  
Shannon Rose ◽  
Eugenia Carvalho ◽  
David Irby ◽  
Sirish Bennuri ◽  
Alexandria Beebe ◽  
...  
Keyword(s):  
Mitochondrial Respiration ◽  
Coupling Efficiency ◽  
Zucker Rats ◽  
Proton Leak ◽  
Acid Oxidation ◽  
Flux Analysis ◽  
Metformin Treatment ◽  
Short Term ◽  
Funding Sources ◽  
Extracellular Flux

Abstract Objectives As childhood obesity rates climb, so has the incidence of type 2 diabetes among children and adolescents. Metformin, an FDA approved anti-hyperglycemic drug, is thought to target the mitochondria, but its effects on mitochondrial function in obesity have not been well studied. We used an obese Zucker rat model to investigate the effects of obesity and short-term metformin treatment on mitochondrial respiration. Methods Five-week old female Zucker rats (n = 16 lean, n = 16 obese) were fed AIN-93 G diet for 8 weeks before equally randomized to receive metformin (mixed in diet at 1 g/kg of feed); thus forming 4 groups with 8 rats each: lean +/– metformin and obese +/– metformin. Rats were sacrificed 10 weeks post-metformin treatment and spleens, perigonadal visceral adipose tissue (VAT) and skeletal muscle (SM; gracilis) collected. Mitochondrial respiration was measured in splenocytes by extracellular flux analysis and in VAT and SM fibers by high resolution respirometry. Results Effects of obesity on mitochondrial respiration were found in VAT and SM, but not splenocytes. In VAT, obese rats exhibited increased OXPHOS capacity over lean rats when octanoylcarnitine and malate were provided as substrates (obese vs lean: 1.33 vs 0.76 pmol O2/s/mg; SEdiff = 0.18, P = .005), and after subsequent additions of pyruvate (P = .012), glutamate (P = .009), and succinate (P = .045). In SM, OXPHOS capacity was increased when octanoylcarnitine and malate were provided as substrates (obese vs lean: 12.18 vs 5.45 pmol O2/s/mg; SEdiff = 2.31, P = .011) in obese vs lean rats. Metformin effects were observed only in splenocytes: coupling efficiency was decreased (metformin vs no metformin; 56.2% vs 69.8%; SEdiff = 4.1%, P = 0.005) and proton leak was increased (P < .001) in metformin treated rats as compared to rats not treated with metformin. Conclusions We found obesity was associated with increased mitochondrial respiration, particularly fatty acid oxidation, in VAT and SM. Short-term metformin treatment did not alter mitochondrial respiration in VAT or SM, but was found to increase proton leak and reduce coupling efficiency in splenocytes. Funding Sources Arkansas Children's Research Institute, Arkansas Biosciences Institute (R.H). S.R. and E.C. are also supported by the National Institute of General Medical Sciences of the National Institutes of Health.

scholarly journals HGF and VEGF-A and Their Receptors Show Expression and Angiogenic Effects on Human Choroidal Endothelial Cells: Implications for Treatments of Neovascular Age-Related Macular Degeneration

2021 ◽  
Vol 1 (1) ◽  
pp. 69-82
Author(s):  
Elizabeth A. Stewart ◽  
Claire L. Allen ◽  
Govindi J. Samaranayake ◽  
Thomas Stubington ◽  
Rukhsar Akhtar ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
In Vitro Assays ◽  
Prolonged Treatment ◽  
Vegf Receptor ◽  
Tubule Formation ◽  
Age Related ◽  
And Migration

Intraocular neovascularisation is associated with common blinding conditions including neovascular age-related macular degeneration (nAMD). Vascular endothelial growth factor (VEGF) is central in driving choroidal neovascularisation in this disease. Many clinical therapies target VEGF-A with intravitreal anti-VEGF drugs, which, however, have limited efficacy and require repeated, prolonged treatment. Other cytokines are known to be involved, including hepatocyte growth factor (HGF), which is shown to have a role in the early stages of nAMD. We investigated the effect of HGF and its co-operation with VEGF-A on human choroidal endothelial cells (CEC). The expression of HGF and related molecules in CEC was investigated using immunofluorescence, Western blotting and flow cytometry. In vitro assays for proliferation, tubule formation and migration were used to assess the potential role of HGF in neovascularisation. Primary human CEC expressed HGF, VEGF-A and their receptors MET and VEGF receptor 2 (VEGFR2). HGF increased CEC proliferation, tubule formation and migration; the increased proliferation and migration appeared to be additive with that achieved with VEGF-A. This study provides insight into growth factor co-operation in CEC signalling and indicates that simultaneous blockage of multiple growth factors or common downstream signalling pathways may provide a more sustained treatment response, enhancing treatments in nAMD.

Platelet-Derived Exosomes Affect the Proliferation and Migration of Human Umbilical Vein Endothelial Cells Via miR-126

2019 ◽  
Vol 17 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Yan Sun ◽  
Xiao-li Liu ◽  
Dai Zhang ◽  
Fang Liu ◽  
Yu-jing Cheng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Real Time ◽  
Umbilical Vein ◽  
Angiogenic Factors ◽  
Healthy Donors ◽  
And Migration ◽  
Umbilical Vein Endothelial Cells ◽  
Tgf Β1 ◽  
Proliferation And Migration

Background:Intraplaque angiogenesis, the process of generating new blood vessels mediated by endothelial cells, contributes to plaque growth, intraplaque hemorrhage, and thromboembolic events. Platelet-derived Exosomes (PLT-EXOs) affect angiogenesis in multiple ways. The ability of miR-126, one of the best-characterized miRNAs that regulates angiogenesis, carried by PLT-EXOs to influence angiogenesis via the regulation of the proliferation and migration of endothelial cells is unknown. In this study, we aimed to investigate the effects of PLT-EXOs on angiogenesis by Human Umbilical Vein Endothelial Cells (HUVECs).Methods:We evaluated the levels of miR-126 and angiogenic factors in PLT-EXOs from Acute Coronary Syndrome (ACS) patients and healthy donors by real-time Polymerase Chain Reaction (PCR) and western blotting. We incubated HUVECs with PLT-EXOs and measured cell proliferation and migration with the Cell Counting Kit-8 assay and scratch assay, respectively. We also investigated the expression of miR-126 and angiogenic factors in HUVECs after exposure to PLT-EXOs by western blotting and real-time PCR.Results:PLT-EXOs from ACS patients contained higher levels of miR-126 and angiogenic factors, including Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF), and Transforming Growth Factor Beta 1 (TGF-β1), than those from healthy donors (p<0.05). Moreover, the levels of exosomal miR-126 and angiogenic factors were increased after stimulation with thrombin (p<0.01). HUVEC proliferation and migration were promoted by treatment with activated PLT-EXOs (p<0.01); they were accompanied by the over-expression of miR-126 and angiogenic factors, including VEGF, bFGF, and TGF-β1 (p<0.01).Conclusion:Activated PLT-EXOs promoted the proliferation and migration of HUVECs, and the overexpression of miR-126 and angiogenic factors, thereby elucidating potential new therapeutic targets for intraplaque angiogenesis.

scholarly journals Regorafenib-Attenuated, Bleomycin-Induced Pulmonary Fibrosis by Inhibiting the TGF-β1 Signaling Pathway

2021 ◽  
Vol 22 (4) ◽  
pp. 1985
Author(s):  
Xiaohe Li ◽  
Ling Ma ◽  
Kai Huang ◽  
Yuli Wei ◽  
Shida Long ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Signaling Pathway ◽  
Transforming Growth Factor ◽  
Kinase Inhibitor ◽  
In Vivo Experiments ◽  
Age Related ◽  
And Migration ◽  
Tgf Β1

Idiopathic pulmonary fibrosis (IPF) is a fatal and age-related pulmonary disease. Nintedanib is a receptor tyrosine kinase inhibitor, and one of the only two listed drugs against IPF. Regorafenib is a novel, orally active, multi-kinase inhibitor that has similar targets to nintedanib and is applied to treat colorectal cancer and gastrointestinal stromal tumors in patients. In this study, we first identified that regorafenib could alleviate bleomycin-induced pulmonary fibrosis in mice. The in vivo experiments indicated that regorafenib suppresses collagen accumulation and myofibroblast activation. Further in vitro mechanism studies showed that regorafenib inhibits the activation and migration of myofibroblasts and extracellular matrix production, mainly through suppressing the transforming growth factor (TGF)-β1/Smad and non-Smad signaling pathways. In vitro studies have also indicated that regorafenib could augment autophagy in myofibroblasts by suppressing TGF-β1/mTOR (mechanistic target of rapamycin) signaling, and could promote apoptosis in myofibroblasts. In conclusion, regorafenib attenuates bleomycin-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway.

scholarly journals Age influences susceptibility of brain capillary endothelial cells to La Crosse virus infection and cell death

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Rahul Basu ◽  
Vinod Nair ◽  
Clayton W. Winkler ◽  
Tyson A. Woods ◽  
Iain D. C. Fraser ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Virus Infection ◽  
La Crosse Virus ◽  
Brain Capillary ◽  
Adult Mice ◽  
Age Related ◽  
Capillary Endothelial Cells ◽  
The Brain

Abstract Background A key factor in the development of viral encephalitis is a virus crossing the blood-brain barrier (BBB). We have previously shown that age-related susceptibility of mice to the La Crosse virus (LACV), the leading cause of pediatric arbovirus encephalitis in the USA, was associated with the ability of the virus to cross the BBB. LACV infection in weanling mice (aged around 3 weeks) results in vascular leakage in the olfactory bulb/tract (OB/OT) region of the brain, which is not observed in adult mice aged > 6–8 weeks. Thus, we studied age-specific differences in the response of brain capillary endothelial cells (BCECs) to LACV infection. Methods To examine mechanisms of LACV-induced BBB breakdown and infection of the CNS, we analyzed BCECs directly isolated from weanling and adult mice as well as established a model where these cells were infected in vitro and cultured for a short period to determine susceptibility to virus infection and cell death. Additionally, we utilized correlative light electron microscopy (CLEM) to examine whether changes in cell morphology and function were also observed in BCECs in vivo. Results BCECs from weanling, but not adult mice, had detectable infection after several days in culture when taken ex vivo from infected mice suggesting that these cells could be infected in vitro. Further analysis of BCECs from uninfected mice, infected in vitro, showed that weanling BCECs were more susceptible to virus infection than adult BCECs, with higher levels of infected cells, released virus as well as cytopathic effects (CPE) and cell death. Although direct LACV infection is not detected in the weanling BCECs, CLEM analysis of brain tissue from weanling mice indicated that LACV infection induced significant cerebrovascular damage which allowed virus-sized particles to enter the brain parenchyma. Conclusions These findings indicate that BCECs isolated from adult and weanling mice have differential viral load, infectivity, and susceptibility to LACV. These age-related differences in susceptibility may strongly influence LACV-induced BBB leakage and neurovascular damage allowing virus invasion of the CNS and the development of neurological disease.

scholarly journals Prominent Indomethacin-Induced Enteropathy in Fcgriib Defi-cient lupus Mice: An Impact of Macrophage Responses and Immune Deposition in Gut

2021 ◽  
Vol 22 (3) ◽  
pp. 1377
Author(s):  
Thansita Bhunyakarnjanarat ◽  
Kanyarat Udompornpitak ◽  
Wilasinee Saisorn ◽  
Bhumdhanin Chantraprapawat ◽  
Peerapat Visitchanakun ◽  
...  
Keyword(s):  
Cytokine Production ◽  
High Dose ◽  
Flux Analysis ◽  
Wild Type ◽  
Fc Gamma Receptor ◽  
Serum Cytokines ◽  
Extracellular Flux ◽  
Gamma Receptor ◽  
Gut Leakage ◽  
Gastrointestinal Permeability

A high dose of NSAIDs, a common analgesic, might induce lupus activity through several NSAIDs adverse effects including gastrointestinal permeability defect (gut leakage) and endotoxemia. Indomethacin (25 mg/day) was orally administered for 7 days in 24-wk-old Fc gamma receptor IIb deficient (FcgRIIb-/-) mice, an asymptomatic lupus model (increased anti-dsDNA without lupus nephritis), and age-matched wild-type (WT) mice. Severity of indomethacin-induced enteropathy in FcgRIIb-/- mice was higher than WT mice as demonstrated by survival analysis, intestinal injury (histology, immune-deposition, and intestinal cytokines), gut leakage (FITC-dextran assay and endotoxemia), serum cytokines, and lupus characteristics (anti-dsDNA, renal injury, and proteinuria). Prominent responses of FcgRIIb-/- macrophages toward lipopolysaccharide (LPS) compared to WT cells due to the expression of only activating-FcgRs without inhibitory-FcgRIIb were demonstrated. Extracellular flux analysis indicated the greater mitochondria activity (increased respiratory capacity and respiratory reserve) in FcgRIIb-/- macrophages with a concordant decrease in glycolysis activity when compared to WT cells. In conclusion, gut leakage-induced endotoxemia is more severe in indomethacin-administered FcgRIIb-/- mice than WT, possibly due to the enhanced indomethacin toxicity from lupus-induced intestinal immune-deposition. Due to a lack of inhibitory-FcgRIIb expression, mitochondrial function, and cytokine production of FcgRIIb-/- macrophages were more prominent than WT cells. Hence, lupus disease-activation from NSAIDs-enteropathy-induced gut leakage is possible.

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