ABSTRACT
Thoracic aortic aneurysm/dissection (TAAD) is a lethal vascular disease, and several pathological factors participate in aortic medial degeneration. We previously discovered that the complement C3a-C3aR axis in smooth muscle cells promotes the development of thoracic aortic dissection (TAD) through regulation of matrix metalloproteinase 2. However, discerning the specific complement pathway that is activated and elucidating how inflammation of the aortic wall is initiated remain unknown. We ascertained that the plasma levels of C3a and C5a were significantly elevated in patients with TAD and that the levels of C3a, C4a, and C5a were higher in acute TAD than in chronic TAD. We also confirmed the activation of the complement in a TAD mouse model. Subsequently, knocking out Cfb (Cfb) or C4 in mice with TAD revealed that the alternative pathway and Cfb played a significant role in the TAD process. Activation of the alternative pathway led to generation of the anaphylatoxins C3a and C5a, and knocking out their receptors reduced the recruitment of inflammatory cells to the aortic wall. Moreover, we used serum from wild-type mice or recombinant mice Cfb as an exogenous source of Cfb to treat Cfb KO mice and observed that it exacerbated the onset and rupture of TAD. Finally, we knocked out Cfb in the FBN1C1041G/+ Marfan-syndrome mice and showed that the occurrence of TAA was reduced. In summary, the alternative complement pathway promoted the development of TAAD by recruiting infiltrating inflammatory cells. Targeting the alternative pathway may thus constitute a strategy for preventing the development of TAAD.NEW & NOTEWORTHY The alternative complement pathway promoted the development of TAAD by recruiting infiltrating inflammatory cells. Targeting the alternative pathway may thus constitute a strategy for preventing the development of TAAD.
Subject(s)
Aortic Aneurysm, Thoracic , Aortic Dissection , Azides , Deoxyglucose/analogs & derivatives , Humans , Mice , Animals , Complement Pathway, Alternative , Matrix Metalloproteinase 2 , Aortic Aneurysm, Thoracic/genetics , Aortic Aneurysm, Thoracic/metabolism , Aortic Aneurysm, Thoracic/pathology , Aortic Dissection/genetics , InflammationABSTRACT
MicroRNAs (miRNAs) are a class of endogenous noncoding small RNAs that play important roles in various biological processes and diseases. Direct determination of miRNAs is a cost-efficient and accurate method for analysis. Herein, we established a novel method for the analysis of miRNAs based on a narrow constant-inner-diameter mass spectrometry emitter. We utilized the gravity-assisted sleeving etching method to prepare a constant-inner-diameter mass spectrometry emitter with a capillary inner diameter of 5.5 µm, coupled it with a high-voltage power supply and a high-resolution mass spectrometer, and used it for miRNA direct detection. The method showed high sensitivity and reproducibility for the analysis of four miRNAs, with a limit of detection of 100 nmol/L (170 amol) for the Hsa-miR-1290 analysis. Compared with commercial ion sources, our method achieved higher sensitivity for miRNA detection. In addition, we analyzed the total miRNAs in the A549 cells. The result indicated that both spiked and endogenous miRNAs could be quantified with high accuracy. As a result, this method offers a promising platform for highly sensitive and accurate miRNA analysis. Furthermore, this approach can be extended to the analysis of other small oligonucleotides and holds the potential for studying clinical samples and facilitating disease diagnosis.
Subject(s)
Mass Spectrometry , MicroRNAs , MicroRNAs/analysis , Humans , A549 Cells , Limit of DetectionABSTRACT
Studying the mechanisms of drug antitumor activity at the single-cell level can provide information about the responses of cell subpopulations to drug therapy, which is essential for the accurate treatment of cancer. Due to the small size of single cells and the low contents of metabolites, metabolomics-based approaches to studying the mechanisms of drug action at the single-cell level are lacking. Herein, we develop a label-free platform for studying the mechanisms of drug action based on single-cell metabolomics (sMDA-scM) by integrating intact living-cell electro-launching ionization mass spectrometry (ILCEI-MS) with metabolomics analysis. Using this platform, we reveal that non-small-cell lung cancer (NSCLC) cells treated by gefitinib can be clustered into two cell subpopulations with different metabolic responses. The glutathione metabolic pathway of the subpopulation containing 14.4% of the cells is not significantly affected by gefitinib, exhibiting certain resistance characteristics. The presence of these cells masked the judgment of whether cysteine and methionine metabolic pathway was remarkably influenced in the analysis of overall average results, revealing the heterogeneity of the response of single NSCLC cells to gefitinib treatment. The findings provide a basis for evaluating the early therapeutic effects of clinical medicines and insights for overcoming drug resistance in NSCLC subpopulations.
Subject(s)
Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/metabolism , Gefitinib/pharmacology , Lung Neoplasms/pathology , Cell Proliferation , Cell Line, Tumor , Drug Resistance, Neoplasm , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic useABSTRACT
The accumulation and spatial distribution of intracellular nanoplastic particles provide useful information about their spatiotemporal toxicological effects mediated by the physicochemical parameters of nanoplastics in living cells. In this study, a sample injection-transfer method was designed with an accuracy of up to femtoliters to attoliters to match the volume required for ultranarrow-bore open-tubular liquid chromatography. The separation and concentration quantification of mixed polystyrenes in different regions in living cells were achieved by directly transferring picoliter/femtoliter volumes of intracellular cytoplasm to an ultranarrow-bore open-tubular chromatographic column. The measurement of pollutant concentration in different areas of a small-volume target (single cell) was realized. This method is expected to be used in the qualitative and quantitative analyses of complex, mixed, and label-free nanoplastics (a few nm in size) in the subregions of living cells.
Subject(s)
Microplastics , Polystyrenes , Microplastics/analysis , Chromatography, Liquid/methods , Polystyrenes/analysis , Cytoplasm/chemistryABSTRACT
Small proline-rich protein 1A (SPRR1A) plays a critical role in regulating squamous cell differentiation. SPRR1A overexpression was reported to be closely related to the progression of some tumors, such as gastric cancer and colon cancer. However, the function of SPRR1A in lung adenocarcinoma (LUAD) has not been elucidated. Here, we first examined the expression pattern of SPRR1A in LUAD tissues, which indicated that the SPRR1A expression level was significantly elevated in LUAD tissues compared with normal lung tissues. High expression of SPRR1A was closely related to larger tumor size. LUAD patients with higher SPRR1A expression had poorer overall survival and SPRR1A was identified as an independent unfavorable prognosis factor. In addition, the effects of SPRR1A on lung cancer cells were tested through cellular experiments and the result demonstrated that knockdown of SPRR1A can suppress the proliferation and invasion capacities of tumor cells, while overexpressing SPRR1A exerted opposite effects. Finally, our findings were substantiated by the data obtained from in vivo xenografts using a mice model. In conclusion, LUAD patients with higher SPRR1A expression were more predisposed to poorer clinical outcomes and unfavorable prognoses, indicating the potential role of SPRR1A as a novel clinical biomarker and therapeutic target.
Subject(s)
Adenocarcinoma of Lung , Cornified Envelope Proline-Rich Proteins , Lung Neoplasms , Adenocarcinoma of Lung/metabolism , Animals , Cell Proliferation , Cornified Envelope Proline-Rich Proteins/metabolism , Gene Expression Regulation, Neoplastic , Humans , Lung/metabolism , Lung Neoplasms/pathology , MiceABSTRACT
A VO2-assisted temperature-controlled multifunctional metamaterial polarization converter with large asymmetric transmission (AT) is proposed by introducing a gold-VO2 grating. The converter can be switched between reflection mode and transmission mode by controlling the phase transition. When VO2 is in the metallic state, the converter works in reflection mode, converting the incident forward/backward linearly/circularly polarized waves into the cross-polarized waves, and the broadband polarization conversion rates (PCRs) can reach 90% with relative bandwidth of up to 91.1% and 87.5%, respectively; when VO2 is in the insulating state, the converter shows giant AT effect for circularly polarized waves at 0.64 THz and 1.28 THz. The multifunctional polarization converter holds great potential in the fields of communication and imaging, which provides a new way to design optical devices such as polarizers, isolators.
ABSTRACT
We propose super-resolution scanning imaging by using a metamaterial composed of a silver-silicon dioxide composite covered by a layer of chromium containing one slit and a silicon dioxide substrate. By simulating a distribution of energy flow in the metamaterial for an H-polarized wave, we find that the output beam exhibits focusing accompanied with good directional radiation, which is able to be designed as a super-resolution scanning probe. We also demonstrate numerically super-resolution imaging by scanning our designed metamaterial over a sub-wavelength object.
ABSTRACT
Bone marrow stromal cell antigen 2 (BST-2), also known as CD317 or tetherin, has been identified as a host restriction factor that suppresses the release of enveloped viruses from host cells by physically tethering viral particles to the cell surface; however, this host defense can be subverted by multiple viruses. For example, human immunodeficiency virus (HIV)-1 encodes a specific accessory protein, viral protein U (Vpu), to counteract BST-2 by binding to it and directing its lysosomal degradation. Thus, blocking the interaction between Vpu and BST-2 will provide a promising strategy for anti-HIV therapy. Here, we report a NanoLuc Binary Technology (NanoBiT)-based high-throughput screening assay to detect inhibitors that disrupt the Vpu-BST-2 interaction. Out of more than 1000 compounds screened, four inhibitors were identified with strong activity at nontoxic concentrations. In subsequent cell-based BST-2 degradation assays, inhibitor Y-39983 HCl restored the cell-surface and total cellular level of BST-2 in the presence of Vpu. Furthermore, the Vpu-mediated enhancement of pesudotyped viral particle production was inhibited by Y-39983 HCl. Our findings indicate that our newly developed assay can be used for the discovery of potential antiviral molecules with novel mechanisms of action.
Subject(s)
Anti-HIV Agents/pharmacology , HIV Infections/drug therapy , HIV-1/drug effects , High-Throughput Screening Assays/methods , Human Immunodeficiency Virus Proteins/antagonists & inhibitors , Protein Interaction Domains and Motifs/drug effects , Viral Regulatory and Accessory Proteins/antagonists & inhibitors , Antigens, CD/metabolism , GPI-Linked Proteins/antagonists & inhibitors , GPI-Linked Proteins/metabolism , HIV Infections/metabolism , HIV Infections/virology , HeLa Cells , Human Immunodeficiency Virus Proteins/metabolism , Humans , Nanotechnology/methods , Viral Regulatory and Accessory Proteins/metabolism , Virus ReplicationABSTRACT
Acute lung injury (ALI) is a life-threatening, diffuse heterogeneous lung injury characterized by acute onset, pulmonary edema, and respiratory failure. Lipopolysaccharide (LPS) is a leading cause for ALI and when administered to a mouse it induces a lung phenotype exhibiting some of the clinical characteristics of human ALI. This study focused on investigating whether microRNA-27b (miR-27b) affects ALI in a mouse model established by LPS-induction and to further explore the underlying mechanism. After model establishment, the mice were treated with miR-27b agomir, miR-27b antagomir, or D-ribofuranosylbenzimidazole (an inhibitor of nuclear factor-E2-related factor 2 [Nrf2]) to determine levels of miR-27b, Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells nuclear factor κB (NF-κB), p-NF-κB, and heme oxygenase-1 (HO-1). The levels of interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF) were determined. The results of luciferase activity suggested that Nrf2 was a target gene of miR-27b. It was indicated that the Nrf2 level decreased in lung tissues from ALI mice. The downregulation of miR-27b decreased the levels of IL-1ß, IL-6, and TNF-α in BALF of ALI mice. Downregulated miR-27b increased Nrf2 level, thus enhancing HO-1 level along with reduction of NF-κB level as well as the extent of NF-κB phosphorylation in the lung tissues of the transfected mice. Pathological changes were ameliorated in LPS-reduced mice elicited by miR-27b inhibition. The results of this study demonstrate that downregulated miR-27b couldenhance Nrf2 and HO-1 expressions, inhibit NF-κB signaling pathway, which exerts a protective effect on LPS-induced ALI in mice.
Subject(s)
Acute Lung Injury/prevention & control , Antagomirs/pharmacology , Anti-Inflammatory Agents/pharmacology , Dichlororibofuranosylbenzimidazole/pharmacology , Lung/drug effects , MicroRNAs/antagonists & inhibitors , NF-E2-Related Factor 2/antagonists & inhibitors , NF-kappa B/metabolism , Acute Lung Injury/chemically induced , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Animals , Cytokines/metabolism , Disease Models, Animal , Down-Regulation , Heme Oxygenase-1/genetics , Heme Oxygenase-1/metabolism , Lipopolysaccharides , Lung/metabolism , Lung/pathology , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice, Inbred C57BL , MicroRNAs/genetics , MicroRNAs/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , NF-kappa B/genetics , Pulmonary Edema/chemically induced , Pulmonary Edema/metabolism , Pulmonary Edema/pathology , Pulmonary Edema/prevention & control , Signal TransductionABSTRACT
Reconfigurable design is an effective way to achieve multifunctional devices for system integration. Limited by the feeding network for multi-resonators, multimode absorbers with more than four modes are rarely reported. In this paper, a frequency-reconfigurable metamaterial absorber/reflector resonating at 3.05, 4.45 and 5.54 GHz is proposed. Based on a stereoscopic feeding network and a strategic arranged structure with loaded switching diodes, the proposed structure can realize the reconfigurable eight operating modes, including triple-band (111)/dual-band (110, 101, 011)/single-band (100, 010, 001) absorption and reflection (000) without re-optimizing and re-engineering the structure. The simulated results are confirmed by measuring a fabricated prototype. Our design provides a strategy to realize multifunction devices in microwave or even higher frequencies.
ABSTRACT
Inflammatory cells such as macrophages can play a pro-tumorigenic role in the tumor stroma. Tumor-associated macrophages (TAMs) generally display an M2 phenotype with tumor-promoting activity; however, the mechanisms regulating the TAM phenotype remain unclear. Complement 5a (C5a) is a cytokine-like polypeptide that is generated during complement system activation and is known to promote tumor growth. Herein, we investigated the role of C5a on macrophage polarization in colon cancer metastasis in mice. We found that deficiency of the C5a receptor (C5aR) severely impairs the metastatic ability of implanted colon cancer cells. C5aR was expressed on TAMs, which exhibited an M2-like functional profile in colon cancer liver metastatic lesions. Furthermore, C5a mediated macrophage polarization and this process relied substantially on activation of the nuclear factor-kappa B (NF-κB) pathway. Finally, analysis of human colon carcinoma indicated that C5aR expression is negatively associated with tumor differentiation grade. Our results demonstrate that C5aR has a central role in regulating the M2 phenotype of TAMs, which in turn, contributes to hepatic metastasis of colon cancer through NF-κB signaling. C5a is a potential novel marker for cancer prognosis and drugs targeting complement system activation, specifically the C5aR pathway, may offer new therapeutic opportunities for colon cancer management.
Subject(s)
Colonic Neoplasms/pathology , Complement C5a/metabolism , Liver Neoplasms/secondary , Macrophages/pathology , Receptor, Anaphylatoxin C5a/metabolism , Receptor, Anaphylatoxin C5a/physiology , Animals , Carcinogenesis , Colonic Neoplasms/genetics , Colonic Neoplasms/metabolism , Complement C5a/genetics , Cytokines/metabolism , Humans , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Macrophage Activation , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptor, Anaphylatoxin C5a/genetics , Signal Transduction , Tumor Cells, Cultured , Tumor MicroenvironmentABSTRACT
Based on the derived rational solutions of the nonautonomous nonlinear Schrödinger equation with varying coefficients, we present a simple scheme to generate a high-power pulse, pulse pair, and pulse train with non-oscillating amplitudes in dispersion exponentially decreasing fiber. Without requiring elimination of the background, the stable pulse train can be generated from the first-order Akhmediev breather, and the high-power pulse and pulse pair can be generated from the second-order Kuznetsov-Ma breather. Moreover, it is found that the characteristics of these pulses can be controlled by adjusting the eigenvalue parameter and fiber parameters. The results presented here are expected to be useful in large-capacity and high-power optical communication systems.
ABSTRACT
Thoracic aortic aneurysm and dissection (TAAD) is due to degeneration of the aorta and causes a high mortality rate, while molecular mechanisms for the development of TAAD are still not completely understood. In the present study, 3-aminopropionitrile (BAPN) treatment was used to induce TAAD mouse model. Through transcriptome analysis, we found the expression levels of genes associated with interleukin-3 (IL-3) signaling pathway were up-regulated during TAAD development in mouse, which were validated by real-time PCR. IL-3 positive cells were increased in TAAD mouse aortas, especially for smooth muscle cells (SMCs). IL-3 deficiency reduced BAPN-induced TAAD formation. We then examined the matrix metalloproteinases (MMPs) expression during TAAD formation in both wild-type and IL-3 deficient mice, showing that MMP12 were significantly down-regulated in IL-3 deficient aortas. Mechanistically, we found recombinant IL-3 could increase MMP12 production and activity from macrophages in vitro Silencing of IL-3 receptor ß, which was mainly expressed in macrophages but not SMCs, diminished the activation of c-Jun N terminal kinase (JNK)/extracellular-regulated protein kinases 1/2 (ERK1/2)/AP-1 signals, and decreased MMP12 expression in IL-3 stimulated macrophages. Moreover, both circulating and aortic inflammation were decreased in IL-3 deficient aortas. Taken together, our results demonstrated that IL-3 stimulated the production of MMP12 from macrophages by a JNK- and ERK1/2-dependent AP-1 pathway, contributing to TAAD formation. Thus, the IL-3/IL-3Rß/MMP12 signals activation may be an important pathological mechanism for progression of TAAD.
Subject(s)
Aorta, Thoracic/enzymology , Aortic Aneurysm, Thoracic/enzymology , Aortic Dissection/enzymology , Interleukin-3/metabolism , Macrophages/enzymology , Matrix Metalloproteinase 12/metabolism , Aminopropionitrile , Aortic Dissection/chemically induced , Aortic Dissection/genetics , Aortic Dissection/pathology , Animals , Aorta, Thoracic/pathology , Aortic Aneurysm, Thoracic/chemically induced , Aortic Aneurysm, Thoracic/genetics , Aortic Aneurysm, Thoracic/pathology , Cells, Cultured , Cytokine Receptor Common beta Subunit/genetics , Cytokine Receptor Common beta Subunit/metabolism , Dilatation, Pathologic , Disease Models, Animal , Elastin/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Interleukin-3/deficiency , Interleukin-3/genetics , JNK Mitogen-Activated Protein Kinases/metabolism , Macrophages/pathology , Matrix Metalloproteinase 12/genetics , Mice, Inbred C57BL , Mice, Knockout , Signal Transduction , Transcription Factor AP-1/metabolism , Up-RegulationABSTRACT
Background: Emerging evidence suggests that long non-coding RNAs (lncRNAs) can be used as potential biomarkers for a wide range of cancers. Herein, the prognostic value of lncRNA taurine upregulated gene (TUG1) was analyzed using meta-analysis in different kinds of cancers. Methods: Databases including Cochrane Library, PubMed, and Chinese National Knowledge Infrastructure were searched for epidemiological studies up to March 2018. Hazard ratio (HR) and its 95% confidence interval (CI) were calculated to probe the relationship between TUG1 expression and overall survival of various cancer patients. The odds ratio (OR) was calculated to measure the strength of the association between TUG1 expression and gender, distant metastasis, vascular invasion, lymph node metastasis, and vascular invasion using Rev Man 5.3 and STATA12.0 software. Results: A total of 24 studies involving 2,117 cancer cases were enrolled. Our results demonstrated that a high expression of TUG1 was not associated with patient gender (odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.72 - 1.25, p = 0.71), but was a significant risk factor for distant metastasis (OR = 4.18, 95% CI = 1.89 - 9.27, p = 0.0004), vascular invasion (OR = 12.19, 95% CI = 2.71 - 54.89, p = 0.001) and lymph node metastasis (OR = 1.80, 95% CI = 1.16 - 2.80, p = 0.009). Furthermore, hazard ratio (HR) analysis suggested that TUG1 expression was not significantly correlated with overall survival (HR: 0.15, 95% CI: -0.21 to 0.51, p = 0.406), except for patients with bladder cancer (HR: 1.01, 95% CI: 0.25 - 1.78, p = 0.01). In the subgroup analysis, cancer type, sample size, and TUG1 expression levels affected the association between TUG1 expression and cancer prognosis. No evidence of publication bias was detected. Conclusions: Our meta-analysis revealed that a high expression of the lncRNA TUG1 was significantly associated with poor prognosis in patients with various cancers. Therefore, lncRNA TUG1 could be considered as a potential prognostic factor in different cancer types.
Subject(s)
Biomarkers, Tumor/genetics , Gene Expression Regulation, Neoplastic , Neoplasms/genetics , RNA, Long Noncoding/genetics , Female , Humans , Lymphatic Metastasis , Male , Neoplasms/classification , Neoplasms/diagnosis , Odds Ratio , Prognosis , Risk Factors , Survival AnalysisABSTRACT
The degeneration of vascular smooth muscle cell(s) (SMC) is one of the key features of thoracic aortic aneurysm and dissection (TAAD). We and others have shown that elevated endoplasmic reticulum (ER) stress causes SMC loss and TAAD formation, however, the mechanism of how SMC dysfunction contributes to intimal damage, leading to TAAD, remains to be explored. In the present study, in vitro assay demonstrated that elevated mechanical stretch (18% elongation, 3600 cycles/h) stimulated the ER stress response and microparticle(s) (MP) production from both SMC and endothelial cell(s) (EC) in a time-dependent manner. Treatment of EC with isolated MP led to anoikis, which was determined by measuring the fluorescence of the ethidium homodimer (EthD-1) and Calcein AM cultured in hydrogel-coated plates and control plates. MP stimulation of EC also up-regulated the mRNA levels of inflammatory molecules (i.e. Vascular cellular adhesion molecular-1 (VCAM-1)), intercellular adhesion molecular-1 (ICAM-1), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6)). Use of an ER stress inhibitor or knockout of CHOP decreased mechanical stretch-induced MP production in SMC. In vivo, administration of an ER stress inhibitor or knockout of CHOP suppressed both apoptosis of EC and the infiltration of inflammatory cells. Moreover, TAAD formation was also suppressed by the administration of an ER stress inhibitor. In conclusion, our study demonstrates that elevated mechanical stretch induces MP formation in SMC leading to endothelial dysfunction, which is ER stress dependent. The inhibition of ER stress suppressed EC apoptosis, inflammation in the aorta, and TAAD development.
Subject(s)
Aortic Aneurysm, Thoracic/metabolism , Aortic Dissection/metabolism , Cell-Derived Microparticles/metabolism , Endoplasmic Reticulum Stress , Endoplasmic Reticulum/metabolism , Endothelial Cells/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Aminopropionitrile , Aortic Dissection/chemically induced , Aortic Dissection/genetics , Aortic Dissection/pathology , Animals , Anoikis , Aorta, Thoracic/metabolism , Aorta, Thoracic/pathology , Aortic Aneurysm, Thoracic/chemically induced , Aortic Aneurysm, Thoracic/genetics , Aortic Aneurysm, Thoracic/pathology , Cell-Derived Microparticles/pathology , Cells, Cultured , Disease Models, Animal , Endoplasmic Reticulum/pathology , Endothelial Cells/pathology , Gene Expression Regulation , Genetic Predisposition to Disease , Humans , Inflammation Mediators/metabolism , Male , Mechanotransduction, Cellular , Mice, Inbred C57BL , Mice, Knockout , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , Paracrine Communication , Phenotype , RNA, Messenger/genetics , Stress, Mechanical , Time Factors , Transcription Factor CHOP/genetics , Transcription Factor CHOP/metabolismABSTRACT
Thoracic aortic aneurysm/dissection (TAAD) is characterized by excessive smooth muscle cell (SMC) loss, extracellular matrix (ECM) degradation and inflammation. However, the mechanism whereby signaling leads to SMC loss is unclear. We used senescence-associated (SA)-ß-gal staining and analysis of expression of senescence-related proteins (p53, p21, p19) to show that excessive mechanical stretch (20% elongation, 3600cycles/h, 48h) induced SMC senescence. SMC senescence was also detected in TAAD specimens from both mice and humans. High-performance liquid chromatography and luciferin-luciferase-based assay revealed that excessive mechanical stretch increased adenosine diphosphate (ADP) release from SMCs both in vivo and in vitro. Elevated ADP induced SMC senescence while genetic knockout of the ADP receptor, P2Y G protein-coupled receptor 12 (P2ry12), in mice protected against SMC senescence and inflammation. Both TAAD formation and rupture were significantly reduced in P2ry12-/- mice. SMCs from P2ry12-/- mice were resistant to senescence induced by excessive mechanical stretch or ADP treatment. Mechanistically, ADP treatment sustained Ras activation, whereas pharmacological inhibition of Ras protected against SMC senescence and reduced TAAD formation. Taken together, excessive mechanical stress may induce a sustained release of ADP and promote SMC senescence via P2ry12-dependent sustained Ras activation, thereby contributing to excessive inflammation and degeneration, which provides insights into TAAD formation and progression.
Subject(s)
Adenosine Diphosphate/metabolism , Aortic Aneurysm, Thoracic/metabolism , Aortic Dissection/metabolism , Myocytes, Smooth Muscle/metabolism , Receptors, Purinergic P2Y12/metabolism , Signal Transduction , Aortic Dissection/diagnostic imaging , Aortic Dissection/etiology , Aortic Dissection/pathology , Animals , Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Aneurysm, Thoracic/etiology , Aortic Aneurysm, Thoracic/pathology , Biopsy , Cellular Senescence , Cytokines/metabolism , Disease Models, Animal , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Male , Matrix Metalloproteinases/metabolism , Mice , Mice, Knockout , Receptors, Purinergic P2Y12/deficiency , Receptors, Purinergic P2Y12/genetics , Stress, Mechanical , UltrasonographyABSTRACT
BACKGROUND/AIMS: Hypertension plays a critical role in the cardiac inflammation and injury. However, the mechanism of how hypertension causes the cardiac injury at a molecular level remains to be elucidated. METHODS: RNA-Seq has been demonstrated to be an effective approach for transcriptome analysis, which is essential to reveal the molecular constituents of cells and tissues. In this study, we investigated the global molecular events associated with the mechanism of hypertension induced cardiac injury using RNA-Seq analysis. RESULTS: Our results showed that totally 1,801 genes with different expression variations were identified after Ang II infusion at 1, 3 and 7 days. Go analysis showed that the top 5 high enrichment Go terms were response to stress, response to wounding, cellular component organization, cell activation and defense response. KEGG pathway analysis revealed the top 5 significantly overrepresented pathways were associated with ECM-receptor interaction, focal adhesion, protein digestion and absorption, phagosome and asthma. Moreover, protein-protein interaction network analysis indicated that ubiquitin C may play a key role in the processes of hypertension-induced cardiac injury. CONCLUSION: Our study provides a comprehensive understanding of the transcriptome events in hypertension-induced cardiac pathology.
Subject(s)
Gene Expression Profiling , Heart Injuries/genetics , Hypertension/genetics , Myocardium/pathology , Transcriptome , Animals , Fibrosis , Gene Expression Regulation , Gene Ontology , Heart Injuries/complications , Heart Injuries/metabolism , Heart Injuries/pathology , High-Throughput Nucleotide Sequencing , Hypertension/complications , Hypertension/metabolism , Hypertension/pathology , Inflammation/complications , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Mice , Myocardium/metabolism , Protein Interaction MapsABSTRACT
Thoracic aortic aneurysm/dissection (TAAD) is characterized by excessive smooth muscle cell (SMC) loss, extracellular matrix (ECM) degradation and inflammation. In response to certain stimuli, endoplasmic reticulum (ER) stress is activated and regulates apoptosis and inflammation. Excessive apoptosis promotes aortic inflammation and degeneration, leading to TAAD. Therefore, we studied the role of ER stress in TAAD formation. A lysyl oxidase inhibitor, 3-aminopropionitrile fumarate (BAPN), was administrated to induce TAAD formation in mice, which showed significant SMC loss (α-SMA level). Excessive apoptosis (TUNEL staining) and ER stress (ATF4 and CHOP), along with inflammation, were present in TAAD samples from both mouse and human. Transcriptional profiling of SMCs after mechanical stress demonstrated the expression of genes for ER stress and inflammation. To explore the causal role of ER stress in initiating degenerative signalling events and TAAD, we treated wild-type (CHOP(+/+)) or CHOP(-/-) mice with BAPN and found that CHOP deficiency protected against TAAD formation and rupture, as well as reduction in α-SMA level. Both SMC apoptosis and inflammation were significantly reduced in CHOP(-/-) mice. Moreover, SMCs isolated from CHOP(-/-) mice were resistant to mechanical stress-induced apoptosis. Taken together, our results demonstrated that mechanical stress-induced ER stress promotes SMCs apoptosis, inflammation and degeneration, providing insight into TAAD formation and progression.
Subject(s)
Aortic Aneurysm, Thoracic/pathology , Apoptosis , Endoplasmic Reticulum Stress , Signal Transduction , Activating Transcription Factor 4/genetics , Activating Transcription Factor 4/metabolism , Aminopropionitrile/pharmacology , Animals , Aorta/metabolism , Aortic Aneurysm, Thoracic/chemically induced , Aortic Aneurysm, Thoracic/metabolism , Cells, Cultured , Disease Models, Animal , Humans , Inflammation , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Myocytes, Smooth Muscle/metabolism , Transcription Factor CHOP/genetics , Transcription Factor CHOP/metabolismABSTRACT
A simple and accurate method was developed for determining silicon in gasoline using inductively coupled plasma optical emission spectroscopy (ICP-OES). For sample inroduction a Burgener nubulizer and a Cyclonic spray chamber were used. A gasoline sample was diluted with isooctane and then introduced into the cooled spray chamber of the ICP-OES. Good linearity was achieved in the silicon concentration range 0.1 - 10.0 mg x kg(-1), and the correlation coefficient was 0.999 96. The detection limit for silicon was 0.012 mg x kg(-1) and the silicon recoveries from gasoline samples were 95.8% - 98.4%, with relative standard deviations of less than 3.0% The method was proved to be simple, reliable and highly sensitive, and suitable for determining silicon in samples of motor gasoline, ethanol-gasoline and methanol-gasoline fuel mixtures those containing not more than 15% (V/V) oxygenates.