Abstract 15873: Novel Contributions of Neutrophil-derived Myeloperoxidase and Hypochlorous Acid to 20-hydroxyeicosatetraenoic Acid Production That Drives Post-ischemic Angiogenesis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Juan A Azcona ◽  
Samantha Tang ◽  
Thomas M Jeitner ◽  
Michal Schwartzman ◽  
Austin M Guo
Keyword(s):  
Protein Expression ◽  
Hypochlorous Acid ◽  
Hypoxia Inducible Factor ◽  
Limb Ischemia ◽  
Tissue Perfusion ◽  
Underlying Mechanism ◽  
Arachidonic Acid Metabolite ◽  
Micro Vessel Density ◽  
First Time ◽  
Adequate Tissue

Introduction: Compensatory angiogenic response to ischemia is often insufficient in maintaining adequate tissue perfusion resulting in critical limb ischemia and amputation. Identifying a novel mechanism by which angiogenesis occurs in these conditions is clinically relevant. We recently uncovered that an increase in 20-HETE, an arachidonic acid metabolite of CYP4A/F ω-hydroxylases, regulates post-ischemic angiogenesis. However, the underlying mechanism resulting in this increase is unknown. Hypothesis: Neutrophil-derived myeloperoxidase (MPO) and hypochlorous acid (HOCl) critically contribute to post-ischemic 20-HETE increases that drive angiogenesis. Methods: Hindlimb ischemia was established in mice depleted of neutrophils, macrophages, and MPO (MPO -/- ). Angiogenesis was assessed by laser doppler perfusion imaging and micro-vessel density quantitation in the hindlimb gracilis muscles. MPO and HOCl were detected in these tissues using immunohistochemistry and a HOCl-specific fluorophore. We also determined the effects of MPO and HOCl on 20-HETE production, the expression of 20-HETE synthase CYP4A11, and hypoxia inducible factor-1α in cultured endothelial cells (EC) using LC/MS/MS, real time-PCR and western blot analysis, respectively. Results: We found that ischemia failed to increase 20-HETE production in mice depleted of neutrophils and MPO (13 ± 1.5 vs 35 ± 5 and ~2 ± .25 vs 35 ± 5 pg/mg of protein, respectively), accompanied with a decreased post-ischemic angiogenic phenotype. We also detected the formation of MPO and HOCl in post-ischemic gracilis muscles. MPO and HOCl also significantly stimulate CYP4A11 expression and 20-HETE production (40±12 vs 8±5 pg/mg of protein) in EC. Furthermore, HOCl quickly induces CYP4A11 mRNA/protein expression (2-fold,) and the protein expression of HIF-1α (2-fold) in as little as 15 min. Conclusion: Our studies establish for the first time that neutrophil-derived MPO and HOCl are responsible for promoting 20-HETE increases that critically drive angiogenesis post ischemia. Thus, identifying these novel mediators can further future therapeutic strategies to balance angiogenic responses during ischemia as well as treating diseases that are associated with abnormal angiogenesis.

scholarly journals Targeting hypoxia-inducible factor 1 to stimulate tissue vascularization

2016 ◽  
Vol 64 (2) ◽  
pp. 361-363 ◽  
Author(s):  
Gregg L Semenza
Keyword(s):  
Growth Factor ◽  
Transplant Rejection ◽  
Hypoxia Inducible Factor ◽  
Limb Ischemia ◽  
Tissue Perfusion ◽  
Therapeutic Benefit ◽  
Limb Amputation ◽  
Loss Of Function ◽  
Chemical Inducers ◽  
Hypoxia Inducible Factor 1

When tissue perfusion is impaired, the resulting reduction in O2 availability activates hypoxia-inducible factor 1 (HIF-1), which mediates increased transcription of genes encoding multiple angiogenic factors including vascular endothelial growth factor, stromal-derived factor 1, placental growth factor, and angiopoietins, leading to the mobilization of bone marrow-derived angiogenic cells, increased angiogenesis, and arterial remodeling. These HIF- 1-dependent responses are impaired by aging or loss of function mutations at the locus encoding the HIF-1α subunit. in mouse models of limb ischemia and lung transplant rejection, the augmentation of HIF-1 activity by gene therapy or chemical inducers was associated with maintenance of tissue perfusion that prevented limb amputation and allograft rejection, respectively. Thus, targeting HIF-1 may be of therapeutic benefit in these clinical contexts and others in which impaired tissue perfusion plays a role in disease pathogenesis.

scholarly journals IL-33-Induced Transcriptional Activation of LPIN1 Accelerates Breast Tumorigenesis

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2174
Author(s):  
Jin-Young Kim ◽  
Garam Kim ◽  
Sung-Chul Lim ◽  
Hong-Seok Choi
Keyword(s):  
Protein Expression ◽  
Signaling Pathway ◽  
Transcriptional Activation ◽  
Breast Cancer Cells ◽  
Regulatory Mechanism ◽  
Mammary Tumorigenesis ◽  
Underlying Mechanism ◽  
Breast Tumorigenesis ◽  
Mrna And Protein Expression ◽  
First Time

Phospholipids are crucial materials that are not only required for cell membrane construction but also play significant roles as signaling molecules. LPIN1 is an enzyme that displays phosphatidate phosphatase activity in the triglyceride and phospholipid synthesis pathway. Recent studies have shown that overexpression of LPIN1 is involved in breast tumorigenesis, but the underlying mechanism regulating LPIN1 expression has not been elucidated yet. In the present study, we showed that the IL-33-induced COT-JNK1/2 signaling pathway regulates LPIN1 mRNA and protein expression by recruiting c-Jun to the LPIN1 promoter in breast cancer cells. IL-33 dose-dependently and time-dependently increased LPIN1 mRNA and protein expression. Moreover, IL-33 promoted colony formation and mammary tumorigenesis via induction of LPIN1 expression, while inhibition of LPIN1 disturbed IL-33-induced cell proliferation and mammary tumorigenesis. IL-33-driven LPIN1 expression was mediated by the COT-JNK1/2 signaling pathway, and inhibition of COT or JNK1/2 reduced LPIN1 expression. COT-JNK1/2-mediated IL-33 signaling activated c-Jun and promoted its binding to the promoter region of LPIN1 to induce LPIN1 expression. These findings demonstrated the regulatory mechanism of LPIN1 transcription by the IL-33-induced COT/JNK1/2 pathway for the first time, providing a potential mechanism underlying the upregulation of LPIN1 in cancer.

scholarly journals Overexpression of CRABP2 inhibits dexamethasone-induced apoptosis in human osteoblast cells

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Haiping Zhang ◽  
Ziliang Yu ◽  
Farui Sun ◽  
Jin Jin
Keyword(s):  
Protein Expression ◽  
Underlying Mechanism ◽  
R Package ◽  
Treated Group ◽  
Gene Expression Omnibus ◽  
Human Osteoblast ◽  
Osteoblast Cells ◽  
Gene And Protein Expression ◽  
Osteoblast Apoptosis ◽  
Induced Apoptosis

Abstract Background The purpose of the current study was to explore the role and underlying mechanism of cellular retinoic acid binding protein 2 (CRABP2) in dexamethasone (DEX)-induced apoptosis in human osteoblast cells. Methods GSE10311 was downloaded from the Gene Expression Omnibus (GEO) database to identify the differentially expressed genes (DEGs) by the limma/R package. Primary human osteoblast was isolated and treated with different concentration of DEX (0, 10-8, 10-7, 10-6, 10-5, and 10-4 mol/L), and cell viability and flow cytometry were used to detect cell proliferation and apoptosis. A CRABP2 overexpression plasmid (oe-CRABP2) was used to overexpress CRABP2, and western blotting was conducted to detect protein expression. Results We found that CRABP2 was downregulated in the DEX-treated group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that DEGs were associated with PI3K/Akt signaling pathway. DEX downregulated CRABP2 gene and protein expression, inhibited viability, and induced human osteoblast apoptosis. Overexpression of CRABP2 reversed DEX-induced apoptosis in human osteoblast. Moreover, overexpression of CRABP2 delayed the progression of DEX-induced osteonecrosis of the femoral head (ONFH) animal model. Conclusion In conclusion, CRABP2 is effective at inhibiting DEX-induced human osteoblast apoptosis and delayed ONFH progression.

scholarly journals lncRNA CASC19 Contributes to Radioresistance of Nasopharyngeal Carcinoma by Promoting Autophagy via AMPK-mTOR Pathway

2021 ◽  
Vol 22 (3) ◽  
pp. 1407
Author(s):  
Hongxia Liu ◽  
Wang Zheng ◽  
Qianping Chen ◽  
Yuchuan Zhou ◽  
Yan Pan ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Malignant Tumors ◽  
Underlying Mechanism ◽  
Mtor Pathway ◽  
Rna Seq ◽  
Cellular Autophagy ◽  
First Time

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.

Prognostic impact of β-2-microglobulin expression in colorectal cancers stratified by mismatch repair status

2012 ◽  
Vol 65 (11) ◽  
pp. 996-1002 ◽  
Author(s):  
Viktor Hendrik Koelzer ◽  
Kristi Baker ◽  
Daniela Kassahn ◽  
Daniel Baumhoer ◽  
Inti Zlobec
Keyword(s):  
Protein Expression ◽  
Mismatch Repair ◽  
Immune Cell ◽  
Prognostic Significance ◽  
Clinicopathological Features ◽  
Prognostic Impact ◽  
Mismatch Repair Status ◽  
First Time ◽  
Intra Class Correlation Coefficient

Backgroundβ-2-microglobulin (B2M) is essential for antigen presentation, yet may also possess proto-oncogenic properties.AimTo determine the prognostic impact of B2M in patients with mismatch repair (MMR) proficient and deficient colorectal cancer (CRC) and to investigate whether this effect on outcome is dependent on the local immune response. MethodsB2M protein expression and tumour-infiltrating immune cells (CD3, CD16, CD163, CD20, CD4, CD45RO, CD56, CD68, CD8, FoxP3, GranzymeB, iNOS, mast cell tryptase, MUM1, PD1, TIA-1) were evaluated in a well characterised tissue microarray of 408 CRCs. The predictive value for clinicopathological features and the prognostic significance of B2M expression were analysed, stratified by MMR status and the immunohistological characteristics of immune cell infiltrates. ResultsInterobserver agreement for B2M staining was high (intra-class correlation coefficient=0.91). Complete B2M loss was more frequent in MMR-deficient (19.4%) compared to MMR-proficient (7.1%) tumours (p<0.001). In MMR-deficient cases, B2M loss predicted rare local recurrence (p=0.034), infrequent nodal-positivity (p=0.035), absence of distant metastasis (p=0.048; sensitivity=100%) and a trend towards favourable survival (p=0.124) independent of immune infiltrates. No associations between B2M and clinicopathological features were observed in MMR-proficient cases.ConclusionsOur data show for the first time that absence of B2M protein expression identifies MMR-deficient cancers with a favourable clinical course and absence of metastatic disease. Validation of B2M protein expression for sub-classification of MMR-deficient CRC is recommended for future clinical trials.

scholarly journals A MicroRNA Signature of Hypoxia

2006 ◽  
Vol 27 (5) ◽  
pp. 1859-1867 ◽  
Author(s):  
Ritu Kulshreshtha ◽  
Manuela Ferracin ◽  
Sylwia E. Wojcik ◽  
Ramiro Garzon ◽  
Hansjuerg Alder ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Hypoxia Inducible Factor ◽  
Tumor Formation ◽  
Low Oxygen ◽  
Functional Link ◽  
Factors Affecting ◽  
Cellular Processes ◽  
Hypoxic Environment ◽  
Tumorigenic Transformation ◽  
First Time

ABSTRACT Recent research has identified critical roles for microRNAs in a large number of cellular processes, including tumorigenic transformation. While significant progress has been made towards understanding the mechanisms of gene regulation by microRNAs, much less is known about factors affecting the expression of these noncoding transcripts. Here, we demonstrate for the first time a functional link between hypoxia, a well-documented tumor microenvironment factor, and microRNA expression. Microarray-based expression profiles revealed that a specific spectrum of microRNAs (including miR-23, -24, -26, -27, -103, -107, -181, -210, and -213) is induced in response to low oxygen, at least some via a hypoxia-inducible-factor-dependent mechanism. Select members of this group (miR-26, -107, and -210) decrease proapoptotic signaling in a hypoxic environment, suggesting an impact of these transcripts on tumor formation. Interestingly, the vast majority of hypoxia-induced microRNAs are also overexpressed in a variety of human tumors.

Evaluation of Tissue Perfusion by Wound Blush and 2D Color-Coded Digital Subtraction Angiography During Endovascular Intervention and Its Impact on Limb Salvage in Critical Limb Ischemia

2021 ◽  
pp. 152660282110659
Author(s):  
Hassan Lotfy ◽  
Ahmed Abou El-Nadar ◽  
Wael Shaalan ◽  
Ali El Emam ◽  
Akram Ibrahim ◽  
...  
Keyword(s):  
Wound Healing ◽  
Digital Subtraction Angiography ◽  
Limb Salvage ◽  
Critical Limb Ischemia ◽  
Limb Ischemia ◽  
Tissue Perfusion ◽  
Technical Failure ◽  
Digital Subtraction ◽  
Reliable Technique ◽  
Significant Difference

Purpose: Critical limb ischemia (CLI) is an entity with high mortality if not properly treated. The primary aim of CLI revascularization is to enhance wound healing, which greatly depends on microvascular circulation. The available tools for assessment of revascularization success are deficient in the evaluation of local microvascular tissue perfusion, that wound blush (WB) reflects. A reliable technique that assesses capillary flow to foot lesions is needed. This study aims to assess WB angiographically at sites of interest in the foot after revascularization and its impact on limb salvage in CLI. Materials and Methods: 198 CLI patients (Rutherford category 5/6) with infrainguinal atherosclerotic lesions amenable for endovascular revascularization (EVR) were included. Limbs were directly or indirectly revascularized by EVR. Direct revascularization meant that successful revascularization of the area of interest according to the angiosome concept was achieved. A completion angiographic run was taken to assess WB. Patients were divided into 2 groups; positive and negative WB groups. In the event of a disagreement between the observational investigators, the digital subtraction angiography (DSA) series was analyzed for hemodynamic changes with a computerized 2D color-coded DSA (Syngo iFlow). Results: 176 limbs had successful revascularization in 157 patients. The successful revascularization rate was 88.9% (176/198), with technical failure encountered in 22 limbs. 121 patients had positive WB and 55 patients had negative WB. Direct revascularization of target areas was obtained in 98 limbs (55.7%). There was a significant difference in the rate of achieving direct flow to the lesion between the positive WB and negative WB groups (36.4% vs 19.3%, p≤0.001). We noticed a nonsignificant difference between patients who had direct revascularization of the foot lesion(s) and those who had indirect revascularization as regards limb salvage. Patients were followed up for 25.2 ± 12.7 months. By the end of the first year, limb salvage rate was significantly higher in patients who had positive WB (98% vs 63%, p<0.001, after 2 years (97% vs 58%, p<0.001) and after 3 years (94% vs 51.5%, p<0.001). Conclusions: WB is an important predictor and a prognostic factor for wound healing in CLI patients with soft tissue lesions.

scholarly journals Hypoxia increases KIAA1199/CEMIP expression and enhances cell migration in pancreatic cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takuya Oba ◽  
Norihiro Sato ◽  
Yasuhiro Adachi ◽  
Takao Amaike ◽  
Yuzan Kudo ◽  
...  
Keyword(s):  
Cell Migration ◽  
Protein Expression ◽  
Hypoxia Inducible Factor ◽  
Ductal Adenocarcinoma ◽  
Rt Pcr ◽  
Transwell Migration Assay ◽  
Migration Assay ◽  
Hypoxic Conditions ◽  
Mrna And Protein Expression ◽  
Interfering Rna

AbstractPancreatic ductal adenocarcinoma (PDAC) is characterised by dense desmoplasia and hypoxic microenvironment. Our previous reports demonstrated that hyaluronan (HA), especially low-molecular-weight HA, provides a favourable microenvironment for PDAC progression. However, the effect of hypoxia on HA metabolism remains unknown. Using quantitative real-time RT-PCR and western blot analysis, we analysed the changes in the expression of HA-synthesizing enzymes (HAS2 and HAS3) and HA-degrading enzymes (HYAL1, KIAA1199/CEMIP) in PDAC cell lines under hypoxic conditions. Hypoxia increased the mRNA and protein expression of KIAA1199, whereas it decreased HYAL1 expression. The expression of HAS3 was increased and HAS2 remained unchanged in response to hypoxia. The effect of KIAA1199 on hypoxia-induced cell migration was determined using a transwell migration assay and small-interfering RNA (siRNA). Hypoxia enhanced the migratory ability of PDAC cells, which was inhibited by KIAA1199 knockdown. We also used immunohistochemistry to analyse the protein expression of hypoxia inducible factor (HIF) 1α and KIAA1199 in PDAC tissues. There was a significant immunohistochemically positive correlation between KIAA1199 and HIF1α. These findings suggest that hypoxia-induced KIAA1199 expression may contribute to enhanced motility in PDAC.

scholarly journals Marrying Medicine and Materials: Artemisinin (Qinghaosu) Particle is Soft Enough for Scratching Hard SiC Wafer in Water

2016 ◽  
Author(s):  
Yu-rong Zhu ◽  
Dan Zhang ◽  
Yang Gan ◽  
Fei-hu Zhang
Keyword(s):  
Pure Water ◽  
High Hardness ◽  
Underlying Mechanism ◽  
Molecular Solids ◽  
High Brightness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Chemical Inertness ◽  
Sic Wafer ◽  
First Time

<p>Silicon carbide (SiC) single crystals, along with sapphire and silicon, are one of most important substrates for high-brightness LED fabrications. Owing to extremely high hardness (Mohs&rsquo; scale of 9.5) and chemical inertness, the polishing rate of SiC with conventional chemical mechanical polishing (CMP) methods is not high, and surface scratches are also inevitable because of using slurry containing hard abrasives such as silica particles. Here artemisinin (Qinghaosu) crystals, very soft molecular solids, were found, for the first time to the best of our knowledge, to effectively polish SiC wafers even in pure water as demonstrated by proof-of-concept scratching experiments using atomic force microscopy (AFM). The underlying mechanism is attributed to activated oxidation of SiC by mechanically released reactive &middot;OH free radicals from the endoperoxide bridges. The preliminary results reported here have important implications for developing novel alternative green and scratch-free polishing methods for hard-brittle substrates including SiC and others.</p>

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