scholarly journals Protective Role of Endogenous Kallistatin in Vascular Injury and Senescence by Inhibiting Oxidative Stress and Inflammation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Julie Chao ◽  
Youming Guo ◽  
Lee Chao

Kallistatin was identified in human plasma as a tissue kallikrein-binding protein and a serine proteinase inhibitor. Kallistatin exerts pleiotropic effects on angiogenesis, oxidative stress, inflammation, apoptosis, fibrosis, and tumor growth. Kallistatin levels are markedly reduced in patients with coronary artery disease, sepsis, diabetic retinopathy, inflammatory bowel disease, pneumonia, and cancer. Moreover, plasma kallistatin levels are positively associated with leukocyte telomere length in young African Americans, indicating the involvement of kallistatin in aging. In addition, kallistatin treatment promotes vascular repair by increasing the migration and function of endothelial progenitor cells (EPCs). Kallistatin via its heparin-binding site antagonizes TNF-α-induced senescence and superoxide formation, while kallistatin’s active site is essential for inhibiting miR-34a synthesis, thus elevating sirtuin 1 (SIRT1)/eNOS synthesis in EPCs. Kallistatin inhibits oxidative stress-induced cellular senescence by upregulating Let-7g synthesis, leading to modulate Let-7g-mediated miR-34a-SIRT1-eNOS signaling pathway in human endothelial cells. Exogenous kallistatin administration attenuates vascular injury and senescence in association with increased SIRT1 and eNOS levels and reduced miR-34a synthesis and NADPH oxidase activity, as well as TNF-α and ICAM-1 expression in the aortas of streptozotocin- (STZ-) induced diabetic mice. Conversely, endothelial-specific depletion of kallistatin aggravates vascular senescence, oxidative stress, and inflammation, with further reduction of Let-7g, SIRT1, and eNOS and elevation of miR-34a in mouse lung endothelial cells. Furthermore, systemic depletion of kallistatin exacerbates aortic injury, senescence, NADPH oxidase activity, and inflammatory gene expression in STZ-induced diabetic mice. These findings indicate that endogenous kallistatin displays a novel role in protection against vascular injury and senescence by inhibiting oxidative stress and inflammation.

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jiahong Xue ◽  
Jiali Fan ◽  
Yuan Li ◽  
Wenhuan Wu ◽  
Qing Yan ◽  
...  

Summary. Oxidative stress is an important factor that is related to endothelial dysfunction. ATP-binding cassette transporter G1 (ABCG1), a regulator of intracellular cholesterol efflux, has been found to prevent endothelial activation in vessel walls. To explore the role of ABCG1 in oxidative stress production in endothelial cells, HUAECs were exposed to H2O2 and transfected with the specific ABCG1 siRNA or ABCG1 overexpression plasmid. The results showed that overexpression of ABCG1 by ABCG1 plasmid or liver X receptor (LXR) agonist T0901317 treatment inhibited ROS production and MDA content induced by H2O2 in HUAECs. Furthermore, ABCG1 upregulation blunted the activity of prooxidant NADPH oxidase and the expression of Nox4, one of the NADPH oxidase subunits. Moreover, the increased migration of Nrf2 from the cytoplasm to the nucleus and antioxidant HO-1 expression were detected in HUAECs with upregulation of ABCG1. Conversely, ABCG1 downregulation by ABCG1 siRNA increased NADPH oxidase activity and Nox4 expression and abrogated the increase at Nrf2 nuclear protein levels. In addition, intracellular cholesterol load interfered with the balance between NADPH oxidase activity and HO-1 expression. It was suggested that ABCG1 attenuated oxidative stress induced by H2O2 in endothelial cells, which might be involved in the balance between decreased NADPH oxidase activity and increased Nrf2/OH-1 antioxidant defense signaling via its regulation for intracellular cholesterol accumulation.


2021 ◽  
Vol 11 (2) ◽  
pp. 164
Author(s):  
Jae-Hoon Jeong ◽  
Jung-Hoon Koo ◽  
Jang Soo Yook ◽  
Joon-Yong Cho ◽  
Eun-Bum Kang

Exercise and antioxidants have health benefits that improve cognitive impairment and may act synergistically. In this study, we examined the effects of treadmill exercise (TE) and mitochondria-targeted antioxidant mitoquinone (MitoQ), individually or combined, on learning and memory, mitochondrial dynamics, NADPH oxidase activity, and neuroinflammation and antioxidant activity in the hippocampus of D-galactose-induced aging rats. TE alone and TE combined with MitoQ in aging rats reduced mitochondrial fission factors (Drp1, Fis1) and increased mitochondrial fusion factors (Mfn1, Mfn2, Opa1). These groups also exhibited improved NADPH oxidase activity and antioxidant activity (SOD-2, catalase). TE or MitoQ alone decreased neuroinflammatory response (COX-2, TNF-α), but the suppression was greater with their combination. In addition, aging-increased neuroinflammation in the dentate gyrus was decreased in TE but not MitoQ treatment. Learning and memory tests showed that, contrarily, MitoQ alone demonstrated some similar effects to TE but not a definitive improvement. In conclusion, this study demonstrated that MitoQ exerted some positive effects on aging when used as an isolated treatment, but TE had a more effective role on cognitive impairment, oxidative stress, inflammation, and mitochondria dysfunction. Our findings suggest that the combination of TE and MitoQ exerted no synergistic effects and indicated regular exercise should be the first priority in neuroprotection of age-related cognitive decline.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Denise C Fernandes ◽  
Celio X Santos ◽  
Hanjoong Jo ◽  
Francisco R Laurindo

While anti-atherogenic effects of sustained laminar shear (LS) involve NO release from eNOS, increases in LS trigger transient superoxide production via NADPH oxidase. Recently, we showed that NADPH oxidase undergoes thiol-dependent regulation by the thioredoxin superfamily chaperone Protein Disulfide Isomerase (PDI). PDI is known to promote NO internalization via trans-nitrosation reactions. We hypothesized that PDI-dependent support of NADPH oxidase activity affects NO output during sustained LS. Cultured rabbit aortic endothelial cells (RAEC) submitted to LS (15 dynes/cm 2 ) in a cone-plate system for 18h exhibited (vs. static controls): Decreased (~50%) superoxide production (HPLC analysis of DHE oxidation); Decreased (~20%) NADPH-triggered hydrogen peroxide production in membrane fraction (Amplex Red assay); Decreased mRNA expression of Nox1 (67%) and Nox4 (45%) (real-time QPCR); Increased eNOS expression (~50%, western blot) and nitrite levels in culture medium (Δ = 7.1±2.5[SD] μM, NO Analyzer and Griess reaction); Decrease in total and membrane fraction PDI protein expression (~20%) without changes in membrane fraction/total ratio of PDI. RAEC were transfected with c-myc -tagged plasmid coding for wild-type (WT) PDI or PDI mutated in 4 thioredoxin-motif cysteine residues. Forced expression (2-fold) of mutated but not WT PDI led to increase in nitrite output after LS (18h) (Δmutated = 17.2±3.3 μM vs. ΔWT = 7.0±1.9 μM, n=3, p<0.02). Confocal microscopy indicated similar subcellular localization between WT and mutated PDI. PDI co-imunoprecipitated with p22phox NADPH oxidase subunit, but not with eNOS or caveolin-1, either in static condition or after LS. Fractionation studies in sucrose gradients showed that PDI is distributed throughout several fractions in static conditions, including caveolin-1-enriched fractions, but migrates to higher-density fractions, not containing caveolin-1, during sustained LS. These results suggest that PDI is involved in regulation of NO output during LS via its effects on NADPH oxidase activity.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Dongmei Liu ◽  
Lie Gao ◽  
Kurtis G Cornish ◽  
Irving H Zucker

In a previous study, we showed that Ang II type I receptor (AT1R) expression increased in the rostral ventrolateral medulla (RVLM) of chronic heart failure (CHF) rabbits and in normal rabbits infused with intracerebroventricular (ICV) Angiotensin II (AngII). The present study investigated if oxidative stress plays a role in Ang II induced AT1R upregulation and its relationship to the transcription factor activator protein 1 (AP1) in CHF rabbits and in the CATHa neuronal cell line. In neuronal cell cultures, Ang II significantly increased AT1R mRNA by 153 ± 22%, P <0.01; c-Jun mRNA by 90 ± 10%, P < 0.01; NADPH oxidase activity by 126 ± 43%, P < 0.01 versus untreated cells; Tempol, Apocynin and the AP 1 inhibitor Tanshinone II reversed the increased AT1R, c-Jun expression and NADPH oxidase activity induced by AngII. We examined the effect of ICV Tempol on expression of these proteins in the RVLM of CHF rabbits. Compared to untreated CHF rabbits Tempol significantly decreased AT1R protein expression (0.88±0.16 vs. 1.6±0.29, P <0.05), phosphorylated Jnk protein (0.10±0.02 vs. 0.31±0.10, P <0.05), and phosphorylated c-Jun (0.02±0.001 vs. 0.14±0.05, P <0.05). These data suggest that Ang II induces AT1R upregulation at the transcriptional level by activation of oxidative stress and AP1 in both cultured cells and in intact brain. Antioxidant agents may be beneficial in CHF by decreasing AT1R expression through the Jnk and AP1 pathway.


2015 ◽  
Vol 86 ◽  
pp. 352-361 ◽  
Author(s):  
Julio Madrigal-Matute ◽  
Carlos-Ernesto Fernandez-Garcia ◽  
Luis Miguel Blanco-Colio ◽  
Elena Burillo ◽  
Ana Fortuño ◽  
...  

2008 ◽  
Vol 295 (1) ◽  
pp. E103-E109 ◽  
Author(s):  
Adam Whaley-Connell ◽  
Javad Habibi ◽  
Shawna A. Cooper ◽  
Vincent G. DeMarco ◽  
Melvin R. Hayden ◽  
...  

Angiotensin II (Ang II) stimulation of the Ang type 1 receptor (AT1R) facilitates myocardial remodeling through NADPH oxidase-mediated generation of oxidative stress. Components of the renin-angiotensin system constitute an autocrine/paracrine unit in the myocardium, including renin, which is the rate-limiting step in the generation of Ang II. This investigation sought to determine whether cardiac oxidative stress and cellular remodeling could be attenuated by in vivo renin inhibition and/or AT1R blockade in a rodent model of chronically elevated tissue Ang II levels, the transgenic (mRen2)27 rat (Ren2). The Ren2 overexpresses the mouse renin transgene with resultant hypertension, insulin resistance, and cardiovascular damage. Young (6- to 7-wk-old) heterozygous (+/−) male Ren2 and age-matched Sprague-Dawley rats were treated with the renin inhibitor aliskiren, which has high preferential affinity for human and mouse renin, an AT1R blocker, irbesartan, or placebo for 3 wk. Myocardial NADPH oxidase activity and immunostaining for NADPH oxidase subunits and 3-nitrotyrosine were evaluated and remodeling changes assessed by light and transmission electron microscopy. Blood pressure, myocardial NADPH oxidase activity and subunit immunostaining, 3-nitrotyrosine, perivascular fibrosis, mitochondrial content, and markers of activity were significantly increased in Ren2 compared with SD littermates. Both renin inhibition and blockade of the AT1R significantly attenuated cardiac functional and structural alterations, although irbesartan treatment resulted in greater reductions of both blood pressure and markers of oxidative stress. Collectively, these data suggest that both reduce changes driven, in part, by Ang II-mediated increases in NADPH oxidase and, in part, increases in blood pressure.


Blood ◽  
2013 ◽  
Vol 121 (11) ◽  
pp. 2099-2107 ◽  
Author(s):  
Alex George ◽  
Suvarnamala Pushkaran ◽  
Diamantis G. Konstantinidis ◽  
Sebastian Koochaki ◽  
Punam Malik ◽  
...  

Key Points Sickle RBC ROS production is mediated in part by NADPH oxidase activity. Sickle RBC ROS production can be induced by plasma signaling molecules.


2018 ◽  
Vol 4 (1) ◽  
pp. 170-181
Author(s):  
Darrell A. Jackson ◽  
Fanny Astruc-Diaz ◽  
Nicole M. Byrnes ◽  
Phillip H. Beske

Most 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl) propanoic acid receptors (AMPARs) expressed on adult hippocampal pyramidal neurons contain the edited form of GluA2 (Q607R) and are thus impermeable to Ca2+/Zn2+ entry.  Following ischemic injury, these receptors undergo a subunit composition change, switching from a GluA2-containing Ca2+/Zn2+-impermeable AMPAR to a GluA2-lacking Ca2+/Zn2+-permeable AMPAR. Recent studies indicate that an oxidative stress signaling pathway is responsible for the I/R-induced changes in AMPAR subunit composition.  Studies suggest that nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase), a superoxide generator, is the source that initiates the oxidative stress-signaling cascade during post-ischemic reperfusion. The objective of the present study was to determine if suppression of NADPH oxidase activity prevents the increase in phosphorylation and subsequent internalization of the GluA2 AMPAR subunit during reperfusion of post-ischemic hippocampal slices. In this study, we demonstrated that exposure of adult rat hippocampal slices to oxygen glucose deprivation/reperfusion (OGD/R) results in an increase in Ser880 phosphorylation of the GluA2 subunit.  The increase in Ser880 phosphorylation resulted in the dissociation of GluA2 from the scaffolding proteins Glutamate receptor-interacting protein 1 (GRIP1) and AMPAR binding protein (ABP), thus enabling the association of GluA2 with protein interacting with C kinase 1 (PICK1). OGD/R also resulted in an increase in the association of activated protein kinase C ? (PKC?) with PICK1. We have found that pharmacological inhibition of NADPH oxidase with apocynin diminishes the OGD/R-induced increase in activated PKC? association with PICK1 and subsequent Ser880 phosphorylation of GluA2. Suppression of NADPH oxidase activity also blunted OGD/R-induced decreased association of GluA2 with the scaffolding proteins GRIP1 and ABP.  Protein phosphatase 2A (PP2A), which regulates PKC? activity by dephosphorylating the kinase, was inactivated by OGD/R-induced increase in tyrosine phosphorylation of the phosphatase (Y307). Inhibition of NADPH oxidase activity ameliorated OGD/R-induced PP2A phosphorylation and inactivation. Our findings are consistent with a model of OGD/R-induced Ser880 phosphorylation of GluA2 that implicates NADPH oxidase mediated inactivation of PP2A and sustained PKC? phosphorylation of GluA2.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Mark W Cunningham ◽  
Venkata Ramana Vaka ◽  
Lorena Amaral ◽  
Fan Fan ◽  
Tarek Ibrahim ◽  
...  

Preeclampsia (PE), hypertension in response to placental ischemia, is associated with angiotensin II type 1 receptor agonistic autoantibodies (AT1-AA), oxidative stress, and neurological complications, such as headaches, blurred vision, and seizures which could lead to stroke and death. We hypothesize that AT1AAs play a role in the cerebral pathology of PE. The objective of this study was to determine if administration of a specific peptide sequence to inhibit the AT1-AA from binding to the AT1 receptor, will improve blood pressure (MAP) and cerebral oxidative stress in the reduced uterine perfusion pressure (RUPP) rat model of PE. Pregnant Sprague Dawley rats were divided into 2 groups: RUPP (n=5) and RUPP+AT1-AA inhibitory peptide (7AA) (n=3). RUPP surgery was performed on gestational day (GD) 14 and the 7AA was administered (2ug/μl saline) via mini-osmotic pumps. On GD 19, MAP was determined and brains collected. Western blots were stained for Glial Fibrillary Acidic Protein (GFAP), endothelial NO synthase (eNOS), phosphorylated eNOS and NADPH oxidase activity was determined using chemilumenescence. MAP was decreased in RUPP+7AA vs. RUPP (95±2 vs. 130±6 mmHg). Brain/body weight ratio, which is indicative of edema, was reduced in RUPP+7AA (5.8±0.25 vs. 6.5±0.25 grams) vs. RUPP. NADPH oxidase activity was lower in RUPP+7AA (33275±3122 vs. 57408±10508 RLU/min/mg protein). Phosphorylated eNOS was 2 fold higher in the RUPP+7AA vs. RUPP (0.4±0.1 vs. 0.2±0.04 AU) and the phosphorylated eNOS/eNOS ratio was elevated (0.4±0.12 vs. 0.2±0.04 AU). GFAP a marker for activated astrocytes that increases during neurologic injury and serves as a compensatory mechanism for brain injury recovery was elevated in RUPP+7AA vs. RUPP (3.2±1.3 vs. 0.5±0.2 AU). Administration of AT1-AA inhibitory peptide to RUPP rats decreased blood pressure and improved markers of NO bioavailability, injury (GFAP), and cerebral swelling. In conclusion, our preliminary data suggests that AT1-AA inhibition could be a potential therapy to improve peripheral and neurological complications during PE. Research Supported by T32HL105324 (Cunningham), RO1HD067541-06 (LaMarca), DK-104184 (Roman), 050049 (Fan), P20-GM-104357 (cores B and C-Roman; Pilot-Fan) and AHA 16GRNT31200036 (Fan).


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