scholarly journals Tanshinol Attenuates the Deleterious Effects of Oxidative Stress on Osteoblastic Differentiation via Wnt/FoxO3a Signaling

2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Yajun Yang ◽  
Yanjie Su ◽  
Dongtao Wang ◽  
Yahui Chen ◽  
Tie Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Target Genes ◽  
Underlying Mechanism ◽  
Osteoblastic Differentiation ◽  
Dependent Manner ◽  
Protective Effects ◽  
Beneficial Effects ◽  
Cycle Arrest ◽  
Deleterious Consequence ◽  
Wnt Signal

There is now increasing evidence which suggests a pivotal role for oxidative stress in the development and progression of osteoporosis. We confirm herein the protective effects of natural antioxidant Tanshinol against oxidative stress in osteoblastic differentiation and the underlying mechanism. Our results show that hydrogen peroxide (H2O2) leads to accumulation of reactive oxygen species (ROS), decrease in cell viability, cell cycle arrest and apoptosis in a caspase-3-dependent manner, and inhibition of osteoblastic differentiation. Tanshinol reverses these deleterious consequence triggered by oxidative stress. Moreover, under the condition of oxidative stress, Tanshinol suppresses the activation of FoxO3a transcription factor and expressions of its target genesGadd45aandcatalase (CAT)and simultaneously counteracts the inhibition of Wnt signalling and expressions of target genesAxin2,alkaline phosphatase (ALP), andOsteoprotegerin (OPG). The findings are further consolidated using FoxO3a siRNA interference and overexpression of Tcf4. The results illustrate that Tanshinol attenuates oxidative stress via down-regulation of FoxO3a signaling, and rescues the decrease of osteoblastic differentiation through upregulation of Wnt signal under oxidative stress. The present findings suggest that the beneficial effects of Tanshinol may be adopted as a novel therapeutic approach in recently recognized conditions of niche targeting osteoporosis.

Klotho Deficiency Aggravates Tacrolimus-Induced Renal Injury via the Phosphatidylinositol 3-Kinase-Akt-Forkhead Box Protein O Pathway

2016 ◽  
Vol 43 (5) ◽  
pp. 357-365 ◽  
Author(s):  
Jian Jin ◽  
Long Jin ◽  
Sun Woo Lim ◽  
Chul Woo Yang
Keyword(s):  
Oxidative Stress ◽  
Experimental Model ◽  
Renal Injury ◽  
Manganese Superoxide Dismutase ◽  
Target Genes ◽  
Dependent Manner ◽  
Protective Effects ◽  
Phosphatidylinositol 3 Kinase ◽  
Forkhead Box ◽  
Phosphatidylinositol 3

Background: Klotho is highly expressed in the kidney, is present in the circulation and urine, and has protective effects against various renal injuries. We examined whether reduced Klotho expression affects tacrolimus (Tac)-induced renal injury in an experimental model of chronic Tac nephropathy. Methods: First, we evaluated the association between the Tac dose and Klotho expression by giving different doses of Tac (0.25, 0.5, and 1 mg/kg) to wild-type (WT) mice for 4 weeks. Second, we compared Klotho levels, renal function, fibrosis, and apoptosis between WT mice and Klotho heterozygous (HT) mice in an experimental model of chronic Tac nephropathy. Third, we examined whether the oxidative stress and signaling pathway are involved in the protection by Klotho against Tac-induced renal injury. Results: Klotho levels in renal tissue and urine were reduced in a dose-dependent manner in Tac-treated WT mice. Tac-treated HT mice showed lower levels of Klotho in the renal cortex and urine, and higher serum creatinine level, fibrosis, and apoptosis compared with WT mice. Treatment of Tac to WT mice increased markers of oxidative stress such as phosphatidylinositol 3-kinase (PI3K)-Akt and Forkhead box protein O (FoxO) 3a phosphorylation but decreased FoxO1 dephosphorylation. These effects were greater in HT mice. HT mice exhibited a much lower level of manganese superoxide dismutase level and higher level of Bim, target genes of FoxOs, compared with the levels in WT mice. Conclusion: Reduced Klotho expression aggravates Tac-induced renal injury via the PI3K-Akt-FoxO pathway.

scholarly journals Inhalation of Hydrogen of Different Concentrations Ameliorates Spinal Cord Injury in Mice by Protecting Spinal Cord Neurons from Apoptosis, Oxidative Injury and Mitochondrial Structure Damages

2018 ◽  
Vol 47 (1) ◽  
pp. 176-190 ◽  
Author(s):  
Xiao Chen ◽  
Jin Cui ◽  
Xiao Zhai ◽  
Jun Zhang ◽  
Zhengrong Gu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Spinal Cord ◽  
Target Genes ◽  
Ros Generation ◽  
Hydrogen Treatment ◽  
Dependent Manner ◽  
Protective Effects ◽  
Spinal Cord Neurons ◽  
Cord Injury

Background/Aims: Hydrogen selectively neutralizes reactive oxygen species (ROS) and ameliorates various ROS-induced injuries. Spinal cord injury (SCI) is a serious injury to the central nervous system, and secondary SCI is closely related to excessive ROS generation. We hypothesized that hydrogen inhalation ameliorates SCI, and the mechanism of action may be related to the protective effects of hydrogen against oxidative stress, apoptosis, and mitochondrial damage. Methods: Mechanically injured spinal cord neurons were incubated with different concentrations of hydrogen in vitro. Immunofluorescence staining and transmission electron microscopy were used to confirm the protective effects of hydrogen. ROS and related proteins were detected with dihydroethidium fluorescence staining, enzyme-linked immunosorbent assays, and western blotting. Terminal deoxynucleotidyl transferase dUTP nick end labeling assays, flow cytometry, and western blotting were used to detect neuronal apoptosis. ATP concentrations, Janus Green B staining, and mitochondrial permeability transition pore (mPTP) status were assessed to investigate mitochondrial damage. RNA sequencing was performed to screen potential target genes of hydrogen application. Hydrogen was administered to mice after spinal cord contusion injury was established for 42 days. The Basso Mouse Scale (BMS) and footprint analyses were used to assess locomotor functions, and immunofluorescence staining of the injured spinal cord segments was performed to detect oxidative stress status. Results: Spinal cord neurons were preserved by hydrogen administration after mechanical injury in a dose-dependent manner. ROS generation, oxidative stress injury-related markers, and the number of apoptotic neurons were significantly reduced after hydrogen treatment. The ATP production and mPTP function in injured neurons were preserved by hydrogen incubation. The expression levels of Cox8b, Cox6a2, Cox7a1, Hspb7, and Atp2a1 were inhibited by hydrogen treatment. BMS scores and the footprint assessment of mice with SCI were improved by hydrogen inhalation. Conclusions: Hydrogen inhalation (75%) ameliorated SCI in vivo and attenuated neuronal mechanical injuries in vitro, and its protective effect on spinal cord neurons was exerted in a dose-dependent manner. The underlying mechanisms included reducing ROS generation and oxidative stress, inhibiting neuronal apoptosis, and restoring mitochondrial construction and function. Cox8b, Cox6a2, Cox7a1, Hspb7, and Atp2a1 were identified as potential target genes of hydrogen treatment.

scholarly journals Hesperetin inhibits foam cell formation and promotes cholesterol efflux in THP-1-derived macrophages by activating LXRα signal in an AMPK-dependent manner

2021 ◽  
Author(s):  
Xuanjing Chen ◽  
Dezhi Zou ◽  
Xiaoling Chen ◽  
Huanlin Wu ◽  
Danping Xu
Keyword(s):  
Cholesterol Efflux ◽  
Target Genes ◽  
Therapeutic Potential ◽  
Foam Cell ◽  
Cell Formation ◽  
Underlying Mechanism ◽  
Foam Cell Formation ◽  
Dependent Manner ◽  
Protective Effects ◽  
Macrophage Foam Cell

AbstractCholesterol efflux from macrophages is the first step of reverse cholesterol transport (RCT), whose increase inhibits cholesterol accumulation and foam cell formation to suppress atherogenesis. Hesperetin has been reported to exert several protective effects on cardiovascular diseases, while little is known about the role of hesperetin and its underlying mechanism in macrophage foam cell formation. In this study, we sought to investigate the potential effects of hesperetin on foam cell formation and cholesterol efflux by using human macrophages, focusing on liver X receptor alpha (LXRα) and AMPK. We found that hesperetin treatment reduced foam cell formation, intracellular cholesterol levels and the cholesterol esterification rate, and increased cholesterol efflux in THP-1 macrophages. Hesperetin increased the levels of LXRα protein and its targets, including ABCA1, ABCG1, SR-BI, and phosphorylated-AMPK. Meanwhile, the hesperetin-induced increase in LXRα expression was further increased by the AMPK agonist and inhibited by an AMPK inhibitor. Meanwhile, hesperetin increased the levels of LXRα mRNA and its target genes, all of which were decreased in cells transfected with the AMPKα1/α2 small interfering RNA (siRNA). Furthermore, the hesperetin-induced inhibition of foam cell formation and promotion of cholesterol efflux were decreased by transfection of AMPKα1/α2 siRNA. In conclusions, We are the first to report that hesperetin activate AMPK in THP-1-derived macrophages. This activation upregulats LXRα and its targets, including ABCA1, ABCG1 and SR-BI, which significantly inhibits foam cell formation and promotes cholesterol efflux. Our results highlight the therapeutic potential of hesperetin to possibly reduce foam cell formation. This new mechanism might contribute the anti-atherogenic effects of hesperetin.

scholarly journals Hydroxyl-radical scavenging activity of hydrogen does not significantly contribute to its biological function

2021 ◽  
Author(s):  
Qinjian Li ◽  
Fei Xie ◽  
Yang Yi ◽  
Pengxiang Zhao ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Hydroxyl Radicals ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Published Data ◽  
Oh Radicals ◽  
Dependent Manner ◽  
Protective Effects ◽  
Beneficial Effects ◽  
Wide Range ◽  
Depth Study

AbstractSince Ohsawa et al. reported a biological antioxidant function of hydrogen in 2007, researchers have now shown it to exert protective effects in a wide range of human and animal disease models. Clinical observations and scientific arguments suggest that a selective scavenging property of H2 cannot adequately explain the beneficial effects of hydrogen. However, there is no experiment challenging the original published data, which suggested that molecular hydrogen dissolved in solution reacts with hydroxyl radicals in cell-free systems. Here we report that a hydrogen-saturated solution (0.6 mM) did not significantly reduce hydroxyl radicals in the Fenton system using 1 mM H2O2. We replicated the same condition as Ohsawa’s study (i.e. 5 μM H2O2), and observed a decrease in •OH radicals in both the H2-rich and N2-rich solutions, which may be caused by a decreased dissolved oxygen concentration. Finally, we determined the effect of hydrogen on a high-valence iron enzyme, horseradish peroxidase (HRP), and found that hydrogen could directly increase HRP activity in a dose-dependent manner. Overall, these results indicate that although H2 and •OH can react, the reaction rate is too low to have physiological function. The target of hydrogen is more complex, and its interaction with enzymes or other macro-molecules deserve more attention and in-depth study.

scholarly journals Notoginsenoside R1 Ameliorates Diabetic Retinopathy through PINK1-Dependent Activation of Mitophagy

Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 213 ◽  
Author(s):  
Ping Zhou ◽  
Weijie Xie ◽  
Xiangbao Meng ◽  
Yadong Zhai ◽  
Xi Dong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetic Retinopathy ◽  
Oral Treatment ◽  
Müller Cells ◽  
Panax Notoginseng ◽  
Protective Effects ◽  
Muller Cells ◽  
Beneficial Effects ◽  
Pre Treatment ◽  
Lc3 Puncta

: Accumulating evidence has indicated that inflammation, oxidative stress, apoptosis, and autophagy in retinal Müller cells are involved in diabetic retinopathy (DR). Notoginsenoside R1 (NGR1), a novel saponin extracted from Panax notoginseng, posesses pharmacological properties, including treating diabetic encephalopathy and improving microcirculatory disorders. Nevertheless, its beneficial effects on DR and the potential mechanism remain to be elucidated. In this study, we found retinal vascular degeneration, reduced retinal thickness, and impaired retinal function in db/db mice were all dramatically attenuated by oral treatment with NGR1 (30 mg/kg) for 12 weeks. NGR1 pretreatment also significantly inhibited apoptosis, markedly suppressed the VEGF expression, markedly increased PEDF expression and markedly inhibited oxidative stress and inflammation in rat retinal Müller cells (rMC-1) subjected to high glucose (HG) and in the retinas of db/db mice. Furthermore, NGR1 pre-treatment upregulated the level of PINK1 and Parkin, increased the LC3-II/LC3-I ratio, and downregulated the level of p62/SQSTM1 in rMC-1 cells induced by HG and in the retinas of db/db mice. Moreover, NGR1 administration enhanced the co-localization of GFP-LC3 puncta and MitoTracker in rMC-1 cells. Importantly, knockdown of PINK1 abolished the protective effects of NGR1. In conclusion, these phenomena suggested that NGR1 prevented DR via PINK1-dependent enhancement of mitophagy.

scholarly journals Poly-ADP-Ribosylation of Estrogen Receptor-Alpha by PARP1 Mediates Antiestrogen Resistance in Human Breast Cancer Cells

Cancers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 43 ◽  
Author(s):  
Nicholas Pulliam ◽  
Jessica Tang ◽  
Weini Wang ◽  
Fang Fang ◽  
Riddhi Sood ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Oxidative Stress ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Tamoxifen Resistance ◽  
Tamoxifen Treatment ◽  
Dependent Manner ◽  
Tamoxifen Resistant

Therapeutic targeting of estrogen receptor-α (ERα) by the anti-estrogen tamoxifen is standard of care for premenopausal breast cancer patients and remains a key component of treatment strategies for postmenopausal patients. While tamoxifen significantly increases overall survival, tamoxifen resistance remains a major limitation despite continued expression of ERα in resistant tumors. Previous reports have described increased oxidative stress in tamoxifen resistant versus sensitive breast cancer and a role for PARP1 in mediating oxidative damage repair. We hypothesized that PARP1 activity mediated tamoxifen resistance in ERα-positive breast cancer and that combining the antiestrogen tamoxifen with a PARP1 inhibitor (PARPi) would sensitize tamoxifen resistant cells to tamoxifen therapy. In tamoxifen-resistant vs. -sensitive breast cancer cells, oxidative stress and PARP1 overexpression were increased. Furthermore, differential PARylation of ERα was observed in tamoxifen-resistant versus -sensitive cells, and ERα PARylation was increased by tamoxifen treatment. Loss of ERα PARylation following treatment with a PARP inhibitor (talazoparib) augmented tamoxifen sensitivity and decreased localization of both ERα and PARP1 to ERα-target genes. Co-administration of talazoparib plus tamoxifen increased DNA damage accumulation and decreased cell survival in a dose-dependent manner. The ability of PARPi to overcome tamoxifen resistance was dependent on ERα, as lack of ERα-mediated estrogen signaling expression and showed no response to tamoxifen-PARPi treatment. These results correlate ERα PARylation with tamoxifen resistance and indicate a novel mechanism-based approach to overcome tamoxifen resistance in ER+ breast cancer.

Pleiotropic effects of laminar flow and statins depend on the Krüppel-like factor-induced lncRNA MANTIS

2019 ◽  
Vol 40 (30) ◽  
pp. 2523-2533 ◽  
Author(s):  
Matthias S Leisegang ◽  
Sofia-Iris Bibli ◽  
Stefan Günther ◽  
Beatrice Pflüger-Müller ◽  
James A Oo ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factors ◽  
Laminar Flow ◽  
Therapeutic Potential ◽  
Statin Treatment ◽  
Telomerase Activity ◽  
Dependent Manner ◽  
Protective Effects ◽  
Monocyte Adhesion ◽  
Beneficial Effects

Abstract Aims To assess the functional relevance and therapeutic potential of the pro-angiogenic long non-coding RNA MANTIS in vascular disease development. Methods and results RNA sequencing, CRISPR activation, overexpression, and RNAi demonstrated that MANTIS, especially its Alu-element, limits endothelial ICAM-1 expression in different types of endothelial cells. Loss of MANTIS increased endothelial monocyte adhesion in an ICAM-1-dependent manner. MANTIS reduced the binding of the SWI/SNF chromatin remodelling factor BRG1 at the ICAM-1 promoter. The expression of MANTIS was induced by laminar flow and HMG-CoA-reductase inhibitors (statins) through mechanisms involving epigenetic rearrangements and the transcription factors KLF2 and KLF4. Mutation of the KLF binding motifs in the MANTIS promoter blocked the flow-induced MANTIS expression. Importantly, the expression of MANTIS in human carotid artery endarterectomy material was lower compared with healthy vessels and this effect was prevented by statin therapy. Interestingly, the protective effects of statins were mediated in part through MANTIS, which was required to facilitate the atorvastatin-induced changes in endothelial gene expression. Moreover, the beneficial endothelial effects of statins in culture models (spheroid outgrowth, proliferation, telomerase activity, and vascular organ culture) were lost upon knockdown of MANTIS. Conclusion MANTIS is tightly regulated by the transcription factors KLF2 and KLF4 and limits the ICAM-1 mediated monocyte adhesion to endothelial cells and thus potentially atherosclerosis development in humans. The beneficial effects of statin treatment and laminar flow are dependent on MANTIS.

Effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts

2019 ◽  
Vol 38 (7) ◽  
pp. 833-845
Author(s):  
X Zhou ◽  
Z Chen ◽  
W Zhong ◽  
R Yu ◽  
L He
Keyword(s):  
Oxidative Stress ◽  
Er Stress ◽  
Signaling Pathway ◽  
Nuclear Import ◽  
Target Genes ◽  
Dental Fluorosis ◽  
Related Factor ◽  
Dependent Manner ◽  
Nrf2 Signaling Pathway ◽  
Glutamylcysteine Synthetase

In the development of dental fluorosis, oxidative stress is considered as the key mechanism. Endoplasmic reticulum (ER) stress can induce oxidative stress and activate the important antioxidative factor nuclear factor erythroid 2-related factor 2 (Nrf2) in a PKR-like ER kinase (PERK)-dependent manner, but combining ER stress and oxidative stress, the role of PERK-Nrf2 signaling pathway involved in fluoride-regulated ameloblasts is not fully defined. Here, we studied the effect of fluoride on PERK-Nrf2 signaling pathway in mouse ameloblasts. We found that low-dose and continuous fluoride exposure increased binding immunoglobulin protein expression and activated PERK–activating transcription factor 4 signaling pathway. Meanwhile, the expression of Nrf2 and its target genes (glutamylcysteine synthetase and glutathione S-transferase-P1) enhanced following ER stress. Tunicamycin increased the expression of PERK, leading to Nrf2 nuclear import, and tauroursodeoxycholate suppressed Nrf2 activation through PERK during ER stress, indicating that PERK activation is required for Nrf2 nuclear entry. Furthermore, tert-butylhydroquinone triggered the overexpression of Nrf2 to reduce ER stress, but luteolin inhibited Nrf2 nuclear localization to elevate ER stress. In summary, this study proved that fluoride under certain dose can induce ER stress and promote Nrf2 nuclear import via PERK activation and suggested that antioxidation mechanism mediated by PERK-Nrf2 can alleviate fluoride-induced ER stress effectively.

scholarly journals Isoliquiritigenin Ameliorates Acute Pancreatitis in Mice via Inhibition of Oxidative Stress and Modulation of the Nrf2/HO-1 Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xinnong Liu ◽  
Qingtian Zhu ◽  
Min Zhang ◽  
Tao Yin ◽  
Rong Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Acute Pancreatitis ◽  
Tissue Injury ◽  
Pancreatic Tissue ◽  
Zinc Protoporphyrin ◽  
Dependent Manner ◽  
Protective Effects ◽  
Stress Injury ◽  
Oxidative Stress Injury ◽  
Flavonoid Monomer

Oxidative stress plays a crucial role in the pathogenesis of acute pancreatitis (AP). Isoliquiritigenin (ISL) is a flavonoid monomer with confirmed antioxidant activity. However, the specific effects of ISL on AP have not been determined. In this study, we aimed to investigate the protective effect of ISL on AP using two mouse models. In the caerulein-induced mild acute pancreatitis (MAP) model, dynamic changes in oxidative stress injury of the pancreatic tissue were observed after AP onset. We found that ISL administration reduced serum amylase and lipase levels and alleviated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. Meanwhile, ISL decreased the oxidative stress injury and increased the protein expression of the Nrf2/HO-1 pathway. In addition, after administering a Nrf2 inhibitor (ML385) or HO-1 inhibitor (zinc protoporphyrin) to block the Nrf2/HO-1 pathway, we failed to observe the protective effects of ISL on AP in mice. Furthermore, we found that ISL mitigated the severity of pancreatic tissue injury and pancreatitis-associated lung injury in a severe acute pancreatitis model induced by L-arginine. Taken together, our data for the first time confirmed the protective effects of ISL on AP in mice via inhibition of oxidative stress and modulation of the Nrf2/HO-1 pathway.

scholarly journals Dehydroepiandrosterone Prevents H2O2-Induced BRL-3A Cell Oxidative Damage through Activation of PI3K/Akt Pathways rather than MAPK Pathways

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Longlong Li ◽  
Yao Yao ◽  
Zhihao Jiang ◽  
Jinlong Zhao ◽  
Ji Cao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Protein Expression ◽  
Signaling Pathways ◽  
Hormone Receptors ◽  
Mapk Signaling ◽  
Ros Generation ◽  
Protective Effects ◽  
Pi3k Inhibitor Ly294002 ◽  
Beneficial Effects

Dehydroepiandrosterone (DHEA) is a popular dietary supplement that has well-known benefits in animals and humans, but there is not enough information about the mechanisms underlying its effects. The present study aimed at investigating these mechanisms through in vitro experiments on the effects of DHEA on rat liver BRL-3A cells exposed to oxidative stress through H2O2. The findings showed that DHEA increased the antioxidant enzyme activity, decreased ROS generation, and inhibited apoptosis in H2O2-treated cells. These effects of DHEA were not observed when the cells were pretreated with known antagonists of sex hormones (Trilostane, Flutamide, or Fulvestrant). Furthermore, treatment with estradiol and testosterone did not have the same protective effects as DHEA. Thus, the beneficial effects of DHEA were associated with mechanisms that were independent of steroid hormone pathways. With regard to the mechanism underlying the antiapoptotic effect of DHEA, pretreatment with DHEA was found to induce a significant decrease in the protein expression of Bax and caspase-3 and a significant increase in the protein expression of PI3K and p-Akt in H2O2-treated BRL-3A cells. These effects of DHEA were abolished when the cells were pretreated with the PI3K inhibitor LY294002. No changes were observed on the p-ERK1/2, p-p38, and p-JNK protein levels in H2O2-induced BRL-3A cells pretreated with DHEA. In conclusion, our data demonstrate that DHEA protects BRL-3A cells against H2O2-induced oxidative stress and apoptosis through mechanisms that do not involve its biotransformation into steroid hormones or the activation of sex hormone receptors. Importantly, the protective effect of DHEA on BRL-3A cells was mainly associated with PI3K/Akt signaling pathways, rather than MAPK signaling pathways.

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