Sphingosine kinase 1 regulates lysyl oxidase through STAT3 in hyperoxia-mediated neonatal lung injury

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-216469
Author(s):  
Alison W Ha ◽  
Tao Bai ◽  
David L Ebenezer ◽  
Tanvi Sethi ◽  
Tara Sudhadevi ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lysyl Oxidase ◽  
Critical Role ◽  
Sphingosine Kinase ◽  
In Vivo Studies ◽  
Sphingosine Kinase 1 ◽  
Neonatal Lung ◽  
Neonatal Lung Injury

IntroductionNeonatal lung injury as a consequence of hyperoxia (HO) therapy and ventilator care contribute to the development of bronchopulmonary dysplasia (BPD). Increased expression and activity of lysyl oxidase (LOX), a key enzyme that cross-links collagen, was associated with increased sphingosine kinase 1 (SPHK1) in human BPD. We, therefore, examined closely the link between LOX and SPHK1 in BPD.MethodThe enzyme expression of SPHK1 and LOX were assessed in lung tissues of human BPD using immunohistochemistry and quantified (Halo). In vivo studies were based on Sphk1−/− and matched wild type (WT) neonatal mice exposed to HO while treated with PF543, an inhibitor of SPHK1. In vitro mechanistic studies used human lung microvascular endothelial cells (HLMVECs).ResultsBoth SPHK1 and LOX expressions were increased in lungs of patients with BPD. Tracheal aspirates from patients with BPD had increased LOX, correlating with sphingosine-1-phosphate (S1P) levels. HO-induced increase of LOX in lungs were attenuated in both Sphk1−/− and PF543-treated WT mice, accompanied by reduced collagen staining (sirius red). PF543 reduced LOX activity in both bronchoalveolar lavage fluid and supernatant of HLMVECs following HO. In silico analysis revealed STAT3 as a potential transcriptional regulator of LOX. In HLMVECs, following HO, ChIP assay confirmed increased STAT3 binding to LOX promoter. SPHK1 inhibition reduced phosphorylation of STAT3. Antibody to S1P and siRNA against SPNS2, S1P receptor 1 (S1P1) and STAT3 reduced LOX expression.ConclusionHO-induced SPHK1/S1P signalling axis plays a critical role in transcriptional regulation of LOX expression via SPNS2, S1P1 and STAT3 in lung endothelium.

scholarly journals Ventilator-induced lung-injury in mouse models: Is there a trap?

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Jon Petur Joelsson ◽  
Saevar Ingthorsson ◽  
Jennifer Kricker ◽  
Thorarinn Gudjonsson ◽  
Sigurbergur Karason
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Mouse Models ◽  
Mechanical Strain ◽  
Acute Injury ◽  
In Vivo Studies ◽  
Cellular Interactions ◽  
Ventilator Induced Lung Injury

AbstractVentilator-induced lung injury (VILI) is a serious acute injury to the lung tissue that can develop during mechanical ventilation of patients. Due to the mechanical strain of ventilation, damage can occur in the bronchiolar and alveolar epithelium resulting in a cascade of events that may be fatal to the patients. Patients requiring mechanical ventilation are often critically ill, which limits the possibility of obtaining patient samples, making VILI research challenging. In vitro models are very important for VILI research, but the complexity of the cellular interactions in multi-organ animals, necessitates in vivo studies where the mouse model is a common choice. However, the settings and duration of ventilation used to create VILI in mice vary greatly, causing uncertainty in interpretation and comparison of results. This review examines approaches to induce VILI in mouse models for the last 10 years, to our best knowledge, summarizing methods and key parameters presented across the studies. The results imply that a more standardized approach is warranted.

scholarly journals Impaired Brain Mitochondrial Bioenergetics in the Ts65Dn Mouse Model of Down Syndrome Is Restored by Neonatal Treatment with the Polyphenol 7,8-Dihydroxyflavone

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Daniela Valenti ◽  
Fiorenza Stagni ◽  
Marco Emili ◽  
Sandra Guidi ◽  
Renata Bartesaghi ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Mouse Model ◽  
Critical Role ◽  
Hippocampal Neurogenesis ◽  
In Vivo Studies ◽  
Mitochondrial Bioenergetics ◽  
Ts65dn Mouse ◽  
Atp Production

Down syndrome (DS), a major genetic cause of intellectual disability, is characterized by numerous neurodevelopmental defects. Previous in vitro studies highlighted a relationship between bioenergetic dysfunction and reduced neurogenesis in progenitor cells from the Ts65Dn mouse model of DS, suggesting a critical role of mitochondrial dysfunction in neurodevelopmental alterations in DS. Recent in vivo studies in Ts65Dn mice showed that neonatal supplementation (Days P3–P15) with the polyphenol 7,8-dihydroxyflavone (7,8-DHF) fully restored hippocampal neurogenesis. The current study was aimed to establish whether brain mitochondrial bioenergetic defects are already present in Ts65Dn pups and whether early treatment with 7,8-DHF positively impacts on mitochondrial function. In the brain and cerebellum of P3 and P15 Ts65Dn pups we found a strong impairment in the oxidative phosphorylation apparatus, resulting in a deficit in mitochondrial ATP production and ATP content. Administration of 7,8-DHF (dose: 5 mg/kg/day) during Days P3–P15 fully restored bioenergetic dysfunction in Ts65Dn mice, reduced the levels of oxygen radicals and reinstated the hippocampal levels of PGC-1α. No pharmacotherapy is available for DS. From current findings, 7,8-DHF emerges as a treatment with a good translational potential for improving mitochondrial bioenergetics and, thus, mitochondria-linked neurodevelopmental alterations in DS.

Circulating CD62E Occurs in Soluble Form as Well as Bound to Endothelial Microparticles (EMP): Functional Differences in Platelet Aggregation in Thrombotic Thrombocytopenic Purpura (TTP).

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2624-2624
Author(s):  
Joaquin J. Jimenez ◽  
Wenche Jy ◽  
Lucia M. Mauro ◽  
Michael N. Markou ◽  
George W. Burke ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Endothelial Cells ◽  
Platelet Aggregation ◽  
Acute Phase ◽  
Critical Role ◽  
In Vivo Studies ◽  
Soluble Form ◽  
Dependent Manner

Abstract Injured endothelial cells (EC) are believed to play a critical role in the pathophysiology of TTP. Soluble markers of endothelial disturbance measured by enzyme-linked immunoassay (ELISA) have been found elevated in TTP. We have recently demonstrated an increase in the release of CD31/42b- EMP, and CD62E+ EMP. Moreover, we have observed that CD62E+ EMP also express vWF. The aim of this study was to quantitate soluble (s) vs. EMP-bound CD62E (bCD62E) in vitro and in vivo, in relation to the functional activity of vWF+ EMP. METHODS: Brain and renal microvascular endothelial cells (MVEC) were cultured and treated with 10ng/mL TNF-α to induce activation, or deprived of serum and growth factors (GFD) to induce apoptosis. Culture supernatants were collected and evaluated in a time-dependent manner. For in vivo studies, platelet-poor plasma was obtained from 4 TTP patients during the acute phase and upon remission. Filtration through 0.1μm, which retains most EMP, was employed to discriminate between (s) and bCD62E. sCD62E was measured by ELISA post-filtration and bCD62E by ELISA pre-filtration. Additionally, CD62E+ and CD62E+/vWF+ EMP were measured by flow cytometry. To assess pro-aggregatory function, EMP were added to washed platelets in the presence of 1 mg/mL ristocetin and aggregates were measured by flow cytometry. RESULTS: In vitro: Activation did not induce release of sCD62E at 3 hours, although bCD62E was present (1.5±0.5X106 EMP/mL). At 6 hours, some sCD62E was detected in the filtrate (0.09±0.02 ng/mL), but most was present in the unfiltered medium (3.5±0.85 ng/mL), signifying that the majority was bCD62E, confirmed by a doubling of CD62E+ EMP (3.0±0.6X106/mL). Subsequently, sCD62E levels were 1.0±0.2 ng/mL at 12 hr, 3.5±0.7 ng/mL at 18 hr, and 5±0.9 ng/mL at 24 hr. In contrast, EMP counts at 12, 18 and 24 hours were 4.6±1, 7±1.3 and 9±1.8 X106/mL (p=0.01, p=0.01, p=0.02, respectively). For all time periods, 40-60% of CD62E were positive for vWF. In control or GFD cultures, there was not a significant increase in sCD62E or CD62E+ EMP at any time period. MVEC from renal gave similar results. In acute TTP plasma samples, CD62E measured by ELISA was significantly increased (65±22 ng/mL) vs. remission (30±6 ng/mL). bCD62E accounted for 50% in acute and 15% in remission. CD62E+/vWF+ EMP were significantly elevated in plasma from acute TTP patients vs. remission (15±4.5 vs. 3±0.5, p=0.01). Sample filtration resulted in a decrease of >95% EMP in both acute and remission TTP plasma. MVEC-derived CD62E+/vWF+ EMP resulted in a dose-dependent increase in platelet aggregation. Additionally, plasma from 4 TTP patients with elevated CD62E+/vWF+ EMP obtained during the acute phase enhanced the formation of platelet aggregates by 48±12% (p=0.02) above remission plasma with low EMP counts. CONCLUSIONS: The results demonstrate that CD62E heretofore regarded as a soluble marker of endothelial dysfunction, in reality exists in both a soluble and EMP-bound form. Indeed, this distinction is highly relevant because CD62E+ EMP also express vWF and are pro-aggregatory to platelets. These EMP have been shown to be elevated during the acute phase of TTP and decrease upon remission. Thus, CD62E+/vWF+ EMP may be active participants in the formation of platelet-rich thrombi in TTP.

scholarly journals Basal and angiopoietin-1–mediated endothelial permeability is regulated by sphingosine kinase-1

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3489-3497 ◽  
Author(s):  
Xiaochun Li ◽  
Milena Stankovic ◽  
Claudine S. Bonder ◽  
Christopher N. Hahn ◽  
Michelle Parsons ◽  
...  
Keyword(s):  
Endothelial Permeability ◽  
Sphingosine Kinase ◽  
Dominant Negative ◽  
Sphingosine Kinase 1 ◽  
Sphingosine 1 Phosphate ◽  
Functional States ◽  
Interfering Rna ◽  
Angiopoietin 1

Abstract Endothelial cells (ECs) regulate the barrier function of blood vessels. Here we show that basal and angiopoietin-1 (Ang-1)–regulated control of EC permeability is mediated by 2 different functional states of sphingosine kinase-1 (SK-1). Mice depleted of SK-1 have increased vascular leakiness, whereas mice transgenic for SK-1 in ECs show attenuation of leakiness. Furthermore, Ang-1 rapidly and transiently stimulates SK-1 activity and phosphorylation, and induces an increase in intracellular sphingosine-1-phosphate (S1P) concentration. Overexpression of SK-1 resulted in inhibition of permeability similar to that seen for Ang-1, whereas knockdown of SK-1 by small interfering RNA blocked Ang-1-mediated inhibition of permeability. Transfection with SKS225A, a nonphosphorylatable mutant of SK-1, inhibited basal leakiness, and both SKS225A and a dominant-negative SK-1 mutant removed the capacity of Ang-1 to inhibit permeability. These effects were independent of extracellular S1P as knockdown or inhibition of S1P1, S1P2, or S1P3, did not affect the Ang-1 response. Thus, SK-1 levels in ECs powerfully regulate basal permeability in vitro and in vivo. In addition, the Ang-1–induced inhibition of leakiness is mediated through activation of SK-1, defining a new signaling pathway in the Ang-1 regulation of permeability.

scholarly journals Molecular Docking and Admet Analyses of Photochemicals from Nigella sativa (blackseed), Trigonella foenum-graecum (Fenugreek) and Anona muricata (Soursop) on SARS-CoV-2 Target

2020 ◽  
Author(s):  
OLUWASEUN TAOFEEK
Keyword(s):  
Molecular Docking ◽  
Electrostatic Interactions ◽  
Nigella Sativa ◽  
Critical Role ◽  
In Vivo Studies ◽  
Viral Gene ◽  
Discovery Studio ◽  
Trigonella Foenum Graecum

The novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) responsible for the 2019 coronavirus disease (COVID-19) has caused a global health challenge. The SARS-COV-2 main protease, 3CLpro/Mpro plays a critical role in the viral gene expression and replication and has been a major target for inhibiting viral maturation and enhancing host innate immune responses against COVID-19. In this study, we screened a library of 38 phytochemicals from Nigella sativa (blackseed), Trigonella foenum-graecum (Fenugreek) and Anona muricata (Soursop) potent medicinal plants with reported antiviral properties - in a molecular docking protocol on 3CLpro using Autodock4.0 tool implanted in PyRx followed by docking validation and insilico absorption, distribution, metabolism, excretion, and toxicology (ADMET) evaluations. The docking results were visualized using Accelrys Discovery Studio and Pymol software. Among the 38 ligands screened, 19 showed significant interaction through non-covalent hydrogen bonding, hydrophobic, and electrostatic interactions with binding affinities from -5.3kcal/mol to -8.1kcal/mol indicating significant binding interactions at the active site binding pocket. Another important interaction observed in the study which mostly involve the transfer of charges was pi-interactions such as Pi-Pi interaction, Pi-Alkyl interaction, Pi-Sulfur interaction, Pi- Sigma, and Pi-Pi stacking. The docking results revealed that phytochemicals from T. foenum-graecum showed more 3CLpro inhibitory potential compared to those from N. sativa and A. muricata. Insilico ADMET evaluations for drug-like and lead-like characteristics however demonstrated that only 8 ligands - apigenin, kaempferol, luteolin, dithymoquinone, naringenine, nornuciferine, quercetin and nigellidine were actually drug-like; showed best activities against 3CLpro, and lack hepatotoxicity effects while none was lead-like. Insilico results of this study further suggested that drug repurposing candidates, remdesivir, indinavir,hydroxychloroquine, chloroquine and ritonavir,exhibited various interactions with 3CLpro. Hence, further in vitro and in vivo studies are proposed.

scholarly journals Novel estradiol analogue induces apoptosis and autophagy in esophageal carcinoma cells

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Elize Wolmarans ◽  
Thandi Mqoco ◽  
Andre Stander ◽  
Sandra Nkandeu ◽  
Katherine Sippel ◽  
...  
Keyword(s):  
Cell Death ◽  
Esophageal Carcinoma ◽  
Ex Vivo ◽  
Apoptotic Cell ◽  
Critical Role ◽  
Carcinoma Cells ◽  
In Vivo Studies ◽  
Apoptotic Pathway

AbstractCancer is the second leading cause of death in South Africa. The critical role that microtubules play in cell division makes them an ideal target for the development of chemotherapeutic drugs that prevent the hyperproliferation of cancer cells. The new in silico-designed estradiol analogue 2-ethyl-3-O-sulfamoylestra-1,3,5(10)16-tetraene (ESE-16) was investigated in terms of its in vitro antiproliferative effects on the esophageal carcinoma SNO cell line at a concentration of 0.18 μM and an exposure time of 24 h. Polarization-optical differential interference contrast and triple fluorescent staining (propidium iodide, Hoechst 33342 and acridine orange) revealed a decrease in cell density, metaphase arrest, and the occurrence of apoptotic bodies in the ESE-16-treated cells when compared to relevant controls. Treated cells also showed an increase in the presence of acidic vacuoles and lysosomes, suggesting the occurrence of autophagic processes. Cell death via autophagy was confirmed using the Cyto-ID autophagy detection kit and the aggresome detection assay. Results showed an increase in autophagic vacuole and aggresome formation in ESE-16 treated cells, confirming the induction of cell death via autophagy. Cell cycle progression demonstrated an increase in the sub-G1 fraction (indicative of the presence of apoptosis). In addition, a reduction in mitochondrial membrane potential was also observed, which suggests the involvement of apoptotic cell death induced by ESE-16 via the intrinsic apoptotic pathway. In this study, it was demonstrated that ESE-16 induces cell death via both autophagy and apoptosis in esophageal carcinoma cells. This study paves the way for future investigation into the role of ESE-16 in ex vivo and in vivo studies as a possible anticancer agent.

Role of sphingosine kinase 1 (SphK1) on cetuximab resistance in colorectal cancer models.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13509-e13509
Author(s):  
Roberto Bianco ◽  
Roberta Rosa ◽  
Lucia Nappi ◽  
Luigi Formisano ◽  
Vincenzo Damiano ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Anticancer Agents ◽  
Acquired Resistance ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Mutational Status ◽  
Resistant Cells

e13509 Background: Although EGFR inhibitors, such as the mAb cetuximab, represent an effective strategy in colorectal cancer (CRC), the clinical use of these agents is limited by intrinsic or acquired resistance. Alterations in the ‘sphingolipid rheostat’, or the balance between the proapoptotic molecule ceramide and the mitogenic factor sphingosine-1-phosphate (S1P), due to overactivation of sphingosine kinase 1 (SphK1), have been involved in the regulation of resistance to anticancer agents. Since some studies described cross-talks between SphK1 and EGFR-dependent signalling pathways, we investigated the contribution of SphK1 to cetuximab resistance in CRC models. Methods: We used CRC cell lines with both intrinsic or acquired resistance to cetuximab. In these models, we analyzed SphK1 expression/activation by using different tools, including the available drug fingolimod (FTY720), both in vitro and in vivo. We confirmed our data through a tissue microarray (TMA)-based analysis on CRC tissues. Results: SphK1 is overexpressed in CRC cells resistant to cetuximab. Higher doses of N,N-dimethylsphingosine (DMS), a potent competitive inhibitor of SphK1, are needed to achieve complete enzyme saturation and survival inhibition in resistant cells. Moreover, ceramide induces apoptosis less efficiently in resistant than in sensitive cells, consistently with the idea that increased SphK1 levels mediate S1P synthesis by ceramide in resistant cells. SphK1 contribution to resistance is supported by the demonstration that SphK1 inhibition by DMS or silencing via siRNA in resistant cells restores sensitivity to cetuximab, whereas exogenous SphK1 overexpression in wild-type cells confers resistance. Re-sensitization to cetuximab is observed after treatment with fingolimod, a S1P receptor inhibitor, both in vitro and in nude mice xenografted with CRC cells. Finally, a TMA-based analysis on CRC tissues revealed that SphK1 expression is related to K-Ras mutational status, a well-known determinant of cetuximab resistance. Conclusions: Our data could clarify the role of SphK1 in the onset of resistance to cetuximab, thus suggesting SphK1 inhibition as a part of novel targeting strategies for resistant cancer patients.

scholarly journals Small Interference RNA Targeting TLR4 Gene Effectively Attenuates Pulmonary Inflammation in a Rat Model

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Feixiang Wu ◽  
Yantao Liu ◽  
Xin Lv ◽  
Xuerong Miao ◽  
Yuming Sun ◽  
...  
Keyword(s):  
Lung Injury ◽  
Critical Role ◽  
Saline Control ◽  
Control Group ◽  
Tlr4 Expression ◽  
Small Interference Rna ◽  
Tlr4 Gene ◽  
Interference Rna

Objective. The present study was to investigate the feasibility of adenovirus-mediated small interference RNA (siRNA) targeting Toll-like receptor 4 (TLR4) gene in ameliorating lipopolysaccharide- (LPS-) induced acute lung injury (ALI).Methods.In vitro, alveolar macrophages (AMs) were treated with Ad-siTLR4 and Ad-EFGP, respectively, for 12 h, 24 h, and 48 h, and then with LPS (100 ng/mL) for 2 h, and the function and expression of TLR4 were evaluated.In vivo, rats received intratracheal injection of 300 μL of normal saline (control group), 300 μL of Ad-EGFP (Ad-EGFP group), or 300 μL of Ad-siTLR4 (Ad-siTLR4 group) and then were intravenously treated with LPS (50 mg/kg) to induce ALI.Results. Ad-siTLR4 treatment significantly reduced TLR4 expression and production of proinflammatory cytokines following LPS treatment bothin vitroandin vivo. Significant alleviation of tissue edema, microvascular protein leakage, and neutrophil infiltration was observed in the AdsiTLR4-treated animals.Conclusion. TLR4 plays a critical role in LPS-induced ALI, and transfection of Ad-siTLR4 can effectively downregulate TLR4 expressionin vitroandin vivo, accompanied by alleviation of LPS-induced lung injury. These findings suggest that TLR4 may serve as a potential target in the treatment of ALI and RNA interfering targeting TLR4 expression represents a therapeutic strategy.

scholarly journals Kaempferol Inhibits Zearalenone-Induced Oxidative Stress and Apoptosis via the PI3K/Akt-Mediated Nrf2 Signaling Pathway: In Vitro and In Vivo Studies

2020 ◽  
Vol 22 (1) ◽  
pp. 217
Author(s):  
Peramaiyan Rajendran ◽  
Rebai Ben Ammar ◽  
Fatma J. Al-Saeedi ◽  
Maged E. Mohamed ◽  
Medhat A. ElNaggar ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Critical Role ◽  
In Vivo Studies ◽  
Marker Enzyme ◽  
Dependent Manner ◽  
In Vivo Models ◽  
Antioxidant Genes ◽  
Nrf2 Signaling Pathway

In this study, kaempferol (KFL) shows hepatoprotective activity against zearalenone (ZEA)-induced oxidative stress and its underlying mechanisms in in vitro and in vivo models were investigated. Oxidative stress plays a critical role in the pathophysiology of various hepatic ailments and is normally regulated by reactive oxygen species (ROS). ZEA is a mycotoxin known to exert toxicity via inflammation and ROS accumulation. This study aims to explore the protective role of KFL against ZEA-triggered hepatic injury via the PI3K/Akt-regulated Nrf2 pathway. KFL augmented the phosphorylation of PI3K and Akt, which may stimulate antioxidative and antiapoptotic signaling in hepatic cells. KFL upregulated Nrf2 phosphorylation and the expression of antioxidant genes HO-1 and NQO-1 in a dose-dependent manner under ZEA-induced oxidative stress. Nrf2 knockdown via small-interfering RNA (siRNA) inhibited the KFL-mediated defence against ZEA-induced hepatotoxicity. In vivo studies showed that KFL decreased inflammation and lipid peroxidation and increased H2O2 scavenging and biochemical marker enzyme expression. KFL was able to normalize the expression of liver antioxidant enzymes SOD, CAT and GSH and showed a protective effect against ZEA-induced pathophysiology in the livers of mice. These outcomes demonstrate that KFL possesses notable hepatoprotective roles against ZEA-induced damage in vivo and in vitro. These protective properties of KFL may occur through the stimulation of Nrf2/HO-1 cascades and PI3K/Akt signaling.

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