scholarly journals S-Equol Protects Chondrocytes against Sodium Nitroprusside-Caused Matrix Loss and Apoptosis through Activating PI3K/Akt Pathway

2021 ◽  
Vol 22 (13) ◽  
pp. 7054
Author(s):  
Li-Wen Huang ◽  
Tzu-Ching Huang ◽  
Yu-Chen Hu ◽  
Bau-Shan Hsieh ◽  
Hsiao-Ling Cheng ◽  
...  
Keyword(s):  
Sodium Nitroprusside ◽  
Akt Pathway ◽  
No Production ◽  
Matrix Degradation ◽  
Common Chronic Disease ◽  
Akt Activation ◽  
Primary Chondrocytes ◽  
Aging Populations ◽  
Matrix Loss ◽  
Co Addition

Osteoarthritis (OA) is a common chronic disease with increasing prevalence in societies with more aging populations, therefore, it is causing more concern. S-Equol, a kind of isoflavones, was reported to be bioavailable and beneficial to humans in many aspects, such as improving menopausal symptoms, osteoporosis and prevention of cardiovascular disease. This study investigated the effects of S-Equol on OA progress in which rat primary chondrocytes were treated with sodium nitroprusside (SNP) to mimic OA progress with or without the co-addition of S-Equol for the evaluation of S-Equol’s efficacy on OA. Results showed treatment of 0.8 mM SNP caused cell death, and increased oxidative stress (NO and H2O2), apoptosis, and proteoglycan loss. Furthermore, the expressions of MMPs of MMP-2, MMP-3, MMP-9, and MMP-13 and p53 were increased. The addition of 30 μM S-Equol could lessen those caused by SNP. Moreover, S-Equol activates the PI3K/Akt pathway, which is an upstream regulation of p53 and NO production and is associated with apoptosis and matrix degradation. As a pretreatment of phosphoinositide 3-kinases (PI3K) inhibitor, all S-Equol protective functions against SNP decrease or disappear. In conclusion, through PI3K/Akt activation, S-Equol can protect chondrocytes against SNP-induced matrix degradation and apoptosis, which are commonly found in OA, suggesting S-Equol is a potential for OA prevention.

scholarly journals Protein kinase Cδ regulates endothelial nitric oxide synthase expression via Akt activation and nitric oxide generation

2008 ◽  
Vol 294 (3) ◽  
pp. L582-L591 ◽  
Author(s):  
Neetu Sud ◽  
Stephen Wedgwood ◽  
Stephen M. Black
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Promoter Activity ◽  
Dominant Negative ◽  
No Production ◽  
Enos Expression ◽  
Akt Activation ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

In this study, we explore the roles of the delta isoform of PKC (PKCδ) in the regulation of endothelial nitric oxide synthase (eNOS) activity in pulmonary arterial endothelial cells isolated from fetal lambs (FPAECs). Pharmacological inhibition of PKCδ with either rottlerin or with the peptide, δV1-1, acutely attenuated NO production, and this was associated with a decrease in phosphorylation of eNOS at Ser1177 (S1177). The chronic effects of PKCδ inhibition using either rottlerin or the overexpression of a dominant negative PKCδ mutant included the downregulation of eNOS gene expression that was manifested by a decrease in both eNOS promoter activity and protein expression after 24 h of treatment. We also found that PKCδ inhibition blunted Akt activation as observed by a reduction in phosphorylated Akt at position Ser473. Thus, we conclude that PKCδ is actively involved in the activation of Akt. To determine the effect of Akt on eNOS signaling, we overexpressed a dominant negative mutant of Akt and determined its effect of NO generation, eNOS expression, and phosphorylation of eNOS at S1177. Our results demonstrated that Akt inhibition was associated with decreased NO production that correlated with reduced phosphorylation of eNOS at S1177, and decreased eNOS promoter activity. We next evaluated the effect of endogenously produced NO on eNOS expression by incubating FPAECs with the eNOS inhibitor 2-ethyl-2-thiopseudourea (ETU). ETU significantly inhibited NO production, eNOS promoter activity, and eNOS protein levels. Together, our data indicate involvement of PKCδ-mediated Akt activation and NO generation in maintaining eNOS expression.

scholarly journals A p53-Phosphoinositide Signalosome Regulates Nuclear Akt Activation

2021 ◽  
Author(s):  
Mo Chen ◽  
Suyong Choi ◽  
Tianmu Wen ◽  
Changliang Chen ◽  
Narendra Thapa ◽  
...  
Keyword(s):  
Genotoxic Stress ◽  
Akt Pathway ◽  
Mutant P53 ◽  
Tumor Suppressor P53 ◽  
Wild Type ◽  
Akt Activation ◽  
Pi3k Inhibitors ◽  
Phosphoinositide 3 Kinase ◽  
Induced Apoptosis ◽  
Dependent Mechanism

The tumor suppressor p53 and the phosphoinositide 3-kinase (PI3K)-Akt pathway have fundamental roles in regulating cell growth, apoptosis and are frequently mutated in cancer. Here, we show that genotoxic stress induces nuclear Akt activation by a p53-dependent mechanism that is independent from the canonical membrane-localized PI3K-Akt pathway. Upon genotoxic stress a nuclear p53-PI3,4,5P3 complex is generated in regions devoid of membranes by a nuclear PI3K, and this complex recruits all the kinases required to activate Akt and phosphorylate FOXOs, inhibiting DNA damage-induced apoptosis. Wild-type p53 activates nuclear Akt in an on/off fashion upon stress, whereas mutant p53 stimulates high basal Akt activity, indicating a fundamental difference. The nuclear p53-phosphoinositide signalosome is distinct from the canonical membrane-localized pathway and insensitive to PI3K inhibitors currently in the clinic, underscoring its therapeutic relevance.

scholarly journals Pan-cancer analysis reveals TAp63-regulated oncogenic lncRNAs that promote cancer progression through AKT activation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Marco Napoli ◽  
Xiaobo Li ◽  
Hayley D. Ackerman ◽  
Avani A. Deshpande ◽  
Ivan Barannikov ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Tumour Progression ◽  
Genetic Alterations ◽  
Mammary Adenocarcinoma ◽  
Akt Pathway ◽  
Metastasis Suppressor ◽  
P53 Family ◽  
Akt Activation ◽  
Human Cancers ◽  
Pan Cancer

Abstract The most frequent genetic alterations across multiple human cancers are mutations in TP53 and the activation of the PI3K/AKT pathway, two events crucial for cancer progression. Mutations in TP53 lead to the inhibition of the tumour and metastasis suppressor TAp63, a p53 family member. By performing a mouse-human cross species analysis between the TAp63 metastatic mammary adenocarcinoma mouse model and models of human breast cancer progression, we identified two TAp63-regulated oncogenic lncRNAs, TROLL-2 and TROLL-3. Further, using a pan-cancer analysis of human cancers and multiple mouse models of tumour progression, we revealed that these two lncRNAs induce the activation of AKT to promote cancer progression by regulating the nuclear to cytoplasmic translocation of their effector, WDR26, via the shuttling protein NOLC1. Our data provide preclinical rationale for the implementation of these lncRNAs and WDR26 as therapeutic targets for the treatment of human tumours dependent upon mutant TP53 and/or the PI3K/AKT pathway.

PI3K/AKT Pathway as a Potential Therapeutic Target In Myelodysplastic Syndrome

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1871-1871
Author(s):  
Denise C Rezende ◽  
Lorena Zaida Pacheco ◽  
Luis Arthur F. Pelloso ◽  
Maria L. Chauffaille ◽  
Marçal C.A Silva ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Therapeutic Potential ◽  
Leukemia Cell ◽  
Jurkat Cells ◽  
Leukemic Cells ◽  
Leukemia Cell Line ◽  
Akt Pathway ◽  
Akt Activation ◽  
Cd34 Cells

Abstract Abstract 1871 Introduction: PI3K/AKT pathway is involved in cell growth, proliferation and apoptosis. A key downstream effector is the phosphorylated serine-threonine Akt (p-AKT). Constitutive activation of PI3K/AKT has been observed in solid tumours and leukemic cells. Inhibition of PI3K/AKT activity, results in apoptosis in cell lines (CL) after treatment with different compounds, e.g. deguelin, a natural product from the leguminous Mundulea sericea, with antitumour effects. Aims: To evaluate PI3K/AKT activation in MDS patients and its therapeutic potential in MDS. Methods: PI3K/AKT activation was evaluated by flow cytometry (FC) using an alexa-fluor 488-antibody Ser 473 p-AKT (Cell Signalling Technology). A triple immunostaining procedure using CD45-PerCP and CD34-PE was used for p-AKT expression in CD34+ primary samples. The p-AKT activity was determined using Kolmogorov-Smirnov test (D). CD34+ cells from healthy donors and Jurkat cells were used as negative and positive controls respectively. Apoptosis (determined by Annexin V and PI/7AAD) and cell cycle arrest (using RNAse and PI) were determined following treatments with LY294002 (50uM), and deguelin (100-500nM) in P-39 myeloid leukemia cell line, with constitutive PI3K/AKT activation. Apoptosis was determined in bone marrow mononuclear cells and CD34+ cells from MDS patients with the same treatments. To evaluate in vivo activity of deguelin, we used a xenotransplant model. Briefly, NODSCID mice were injected intrafemurally with P-39 CL and 12 days post transplant a three week-course of treatment, every other day, was started (deguelin 4mg/Kg, n=3 vs vehicle, n=3). Results: P-39 CL showed constitutive PI3K/AKT activation with levels significantly higher than in CD34+cells from controls (median±SD= 0.73. Disclosures: No relevant conflicts of interest to declare.

scholarly journals 17β-Estradiol abrogates apoptosis in murine skeletal muscle cells through estrogen receptors: role of the phosphatidylinositol 3-kinase/Akt pathway

2007 ◽  
Vol 196 (2) ◽  
pp. 385-397 ◽  
Author(s):  
Andrea Vasconsuelo ◽  
Lorena Milanesi ◽  
Ricardo Boland
Keyword(s):  
Skeletal Muscle ◽  
Protective Action ◽  
Muscle Cells ◽  
Cellular Systems ◽  
C2c12 Cells ◽  
Skeletal Muscle Cells ◽  
Akt Pathway ◽  
Akt Activation ◽  
17Β Estradiol ◽  
Murine Skeletal Muscle

Estrogens can regulate apoptosis in various cellular systems. The present study shows that 17β-estradiol (E2), at physiological concentrations, abrogates DNA damage, poly (ADP-ribose) polymerase cleavage, and mitochondrial cytochrome c release induced by H2O2 or etoposide in mouse skeletal muscle C2C12 cells. This protective action, which involved PI3K/Akt activation and Bcl-2 associated death agonist (BAD) phosphorylation, was inhibited by antibodies against the estrogen receptor (ER) α or β isoforms, or transfecting siRNA specific for each isoform. The inhibition of the antiapoptotic action of E2 at the mitochondrial level was more pronounced when ER-β was immunoneutralized or suppressed by mRNA silencing, whereas transfection of C2C12 cells with either ER-α siRNA or ER-β siRNA blocked the activation of Akt by E2, suggesting differential involvement of ER isoforms depending on the step of the apoptotic/survival pathway evaluated. These results indicate that E2 exerts antiapoptotic effects in skeletal muscle cells which are mediated by ER-β and ER-α and involve the PI3K/Akt pathway.

scholarly journals iNOS Associates With Poor Survival in Melanoma: A Role for Nitric Oxide in the PI3K-AKT Pathway Stimulation and PTEN S-Nitrosylation

2021 ◽  
Vol 11 ◽  
Author(s):  
Zhen Ding ◽  
Dai Ogata ◽  
Jason Roszik ◽  
Yong Qin ◽  
Sun-Hee Kim ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Expression ◽  
Nitrosative Stress ◽  
Akt Pathway ◽  
Melanoma Tumor ◽  
Inos Protein ◽  
Akt Activation ◽  
Inos Protein Expression ◽  
Patient Prognosis

We previously showed that inducible nitric oxide synthase (iNOS) protein expression in melanoma tumor cells is associated with poor patient prognosis. Here, we analyzed the association between iNOS and the oncogenic PI3K-AKT pathway. TCGA data show that iNOS and phospho-Akt Ser473 expression were associated significantly only in the subset of tumors with genetically intact PTEN. Employing a stage III melanoma TMA, we showed that iNOS protein presence is significantly associated with shorter survival only in tumors with PTEN protein expression. These findings led to our hypothesis that the iNOS product, nitric oxide (NO), suppresses the function of PTEN and stimulates PI3K-Akt activation. Melanoma cells in response to NO exposure in vitro exhibited enhanced AKT kinase activity and substrate phosphorylation, as well as attenuated PTEN phosphatase activity. Biochemical analysis showed that NO exposure resulted in a post-translationally modified S-Nitrosylation (SNO) PTEN, which was also found in cells expressing iNOS. Our findings provide evidence that NO-rich cancers may exhibit AKT activation due to post-translational inactivation of PTEN. This unique activation of oncogenic pathway under nitrosative stress may contribute to the pathogenesis of iNOS in melanoma. Significance: Our study shows that iNOS expression is associated with increased PI3K-AKT signaling and worse clinical outcomes in melanoma patients with wt (intact) PTEN. Mutated PTEN is already inactivated. We also demonstrate that NO activates the PI3K-AKT pathway by suppressing PTEN suppressor function concurrent with the formation of PTEN-SNO. This discovery provides insight into the consequences of inflammatory NO produced in human melanoma and microenvironmental cells. It suggests that NO–driven modification provides a marker of PTEN inactivation, and represents a plausible mechanism of tumor suppressor inactivation in iNOS expressing subset of cancers.

scholarly journals Effect of MnSOD (E. coli) on the relaxation caused by sodium nitroprusside on isolated rat renal artery

2004 ◽  
Vol 69 (11) ◽  
pp. 973-980 ◽  
Author(s):  
Slobodan Milovanovic ◽  
Zorana Orescanin ◽  
Snezana Spasic ◽  
Srdjan Miletic ◽  
Milica Prostran ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Renal Artery ◽  
Sodium Nitroprusside ◽  
Relaxation Effect ◽  
Renal Arteries ◽  
Nitric Oxide Donor ◽  
No Production ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Relaxation Effects

In this study themolecular foundation of nitric oxide induced relaxation of arteries, with or without endothelium, of normotensive and spontanously hypertensive ratswas re-examined. With this purpose in mind, the effects of the nitric oxide donor sodium nitroprusside (NaNP), with and without manganese containing superoxide dismutase (MnSOD E.C. 1.15.1.1), on rat renal artery relaxation was strudied. The results show that the relaxation effect of NaNP is two times higher in normotensive, compared to spontaneously hypertensive rats. Similar differences exist in the relaxation effects of NaNP on isolated renal arteries without endothelium, indicating that besides the difference in the function of an endothelium, concerning basal NO production in normotensive and hypertensive rats, there is a differencewith respect to NO relaxation in the smoothmuscle that is induced by hypertension. MnSOD decreased the relaxation effect of NaNP in all the examined renal arteries, more in normotensive than in hypertensive ones regardless of the presence of an endothelium. These results show that MnSOD, by modifying the chemical versatility of NO into redox active forms - nitrosonium (NO+) and nitroxyl (NO-), produces different relaxation effects in normotensive and hypertensive arteries of rats, with or without an endothelium, potentiating the role of nitroxyl induced relaxation in sponteneously hypertensive rats. The results prove the need for the synthesis of complex NO donors, as the mechanisms of artery relaxation are different due to an endothel and smooth mouscle changes in hypertensive, as compared to normotensive rats.

Vascular responses to sodium nitroprusside in the human fetal-placental circulation

1995 ◽  
Vol 7 (6) ◽  
pp. 1557 ◽  
Author(s):  
MA Read ◽  
WB Giles ◽  
IM Leitch ◽  
AL Boura ◽  
WA Walters
Keyword(s):  
Sodium Nitroprusside ◽  
Vascular Function ◽  
No Production ◽  
Low Oxygen ◽  
Experimental Conditions ◽  
Arterial Perfusion ◽  
Basal Tone ◽  
Intra Uterine Growth Retardation ◽  
Synthase Inhibitor

This study examined the activity of sodium nitroprusside (SNP) in the human fetal-placental circulation in vitro in pathological and experimental conditions in which vascular function may be impaired. SNP (13-3400 nM) caused a concentration-dependent reduction in fetal arterial perfusion pressure (FAP) in Krebs' perfused placental cotyledons, at basal tone and following pre-constriction with prostaglandin F2 alpha (PGF2 alpha). SNP-induced reduction in FAP in the PGF2 alpha pre-constricted fetal-placental circulation was enhanced approximately six-fold (5.85) in those placentae pre-treated with the nitric oxide (NO) synthase inhibitor N omega-nitro-L-arginine (100 microM). Reductions in FAP in the preconstricted fetal-placental vasculature caused by SNP were not altered by prior infusion of ouabain (100 nM) into the fetal circulation or during low oxygen perfusion (O2 tension < 50 mmHg). No differences were observed in the responses obtained to SNP in placentae obtained from women with normotensive pregnancies or those associated with (i) pregnancy-induced hypertension, (ii) intra-uterine growth retardation, or (iii) an elevated umbilical-artery Doppler-ultrasound systolic/diastolic ratio, in either preconstricted placentae or those at basal tone. These findings are consistent with an up-regulation of guanylate cyclase/cGMP-mediated vasodilatation in the fetal-placental vasculature following complete blockade of endogenous NO production.

The Anti-inflammatory Effects of Lignan Glycosides from Cistanche tubulosa stems on LPS/IFN-γ-induced RAW264.7 Macrophage Cells via PI3K/AKT Pathway

2020 ◽  
Vol 21 ◽  
Author(s):  
Jinhan Guo ◽  
Shuming Tang ◽  
Yuyang Miao ◽  
Lanlan Ge ◽  
Junfa Xu ◽  
...  
Keyword(s):  
Raw264.7 Cells ◽  
Akt Pathway ◽  
No Production ◽  
Dependent Manner ◽  
Ifn Γ ◽  
Cox 2 ◽  
Cistanche Tubulosa ◽  
Anti Inflammatory ◽  
Lignan Glycosides ◽  
Dose Dependent

Background: Cistanche tubulosa is a tonic in traditional Chinese medicines and has a broad spectrum of biological activity, including anti-inflammatory. However, its anti-inflammatory major constituents of C. tubulosa and their underlying mechanisms are still unknown. Objective: The aim of the current study was to explore the separation and structural characterization of lignan glycosides from C. tubulosa (Schenk) Wight., their anti-inflammatory activity and underlying mechanism. Materials and Methods: Fractionation and isolation of the 85% EtOH extract of C. tubulosa (Schenk) Wight. were carried out and the primary ingredients lignan glycosides (1-6) were structurally characterized. CCK8 methods were used to evaluate the cytotoxic effect of lignan glycosides (1-6). Effects of lignan glycosides (1-6) on NO production in LPS/IFN-γ-induced RAW264.7 macrophages cells were measured using Griess reagent by reaction with nitrite. The mRNA expression levels of iNOS, COX-2, IL-1β, IL-6, TNF-a, and TGF-β treated RAW264.7 cells with various concentrations (0, 25 and 50 μg/ml) of lignan glycosides (1, 4) in the presence of LPS (10 ng/ml) and IFN-γ (20 ng/ml) for 24 h were analyzed by quantitative RT-PCR. Also the protein expressions of iNOS, COX-2, PI3K, AKT, p-AKT and β-actin were determined using Western blot analysis. A molecular docking study was performed to investigate the interactions between the lignan glycosides and the PI3K using Autodock vina 1.1.2 package. Results: Six lignan glycosides (1-6) were isolated from stems of C. tubulosa. Among them, (+)-pinoresinol-4-O-β-D-glucopyranosyl- (1→6)-β-D- glucopyranoside (5) and eleutheroside E (6) were firstly isolated from C. tubulosa. Of these lignans, 1 and 4 exhibited pronounced inhibitions on NO production with the values of 33.63 ± 4.78 and 39.28 ± 5.52 % at 50 μg/ml, respectively. Additionally, LPS/IFN-γ-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-a (TNF-a) was significantly suppressed by pre-treatment of 1 and 4 in a dose-dependent manner. While 1 and 4 increased the mRNA levels of anti-inflammatory cytokines (TGF-β). Furthermore, 1 and 4 significantly inhibited the protein levels of PI3K and p-AKT in a dose-dependent manner. Conclusion: Taken together, these results suggest that 1 and 4 play an important role in the attenuation of LPS/IFN-γ-induced inflammatory responses in RAW264.7 cells and that the mechanisms involve down-regulation of the PI3K/AKT pathway.

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