scholarly journals RUNX1/core binding factor A2 regulates platelet 12-lipoxygenase gene (ALOX12): studies in human RUNX1 haplodeficiency

Blood ◽  
2010 ◽  
Vol 115 (15) ◽  
pp. 3128-3135 ◽  
Author(s):  
Gurpreet Kaur ◽  
Gauthami Jalagadugula ◽  
Guangfen Mao ◽  
A. Koneti Rao
Keyword(s):  
Expression Profiling ◽  
Region Of Interest ◽  
Luciferase Reporter ◽  
Direct Transcriptional Target ◽  
Erythroleukemia Cells ◽  
12 Lipoxygenase ◽  
Sirna Knockdown ◽  
Induced Aggregation ◽  
Transcriptional Target

Abstract Haploinsufficiency of RUNX1 (also known as CBFA2/AML1) is associated with familial thrombocytopenia, platelet dysfunction, and predisposition to acute leukemia. We have reported on a patient with thrombocytopenia and impaired agonist-induced aggregation, secretion, and protein phosphorylation associated with a RUNX1 mutation. Expression profiling of platelets revealed approximately 5-fold decreased expression of 12-lipoxygenase (12-LO, gene ALOX12), which catalyzes 12-hydroxyeicosatetraenoic acid production from arachidonic acid. We hypothesized that ALOX12 is a direct transcriptional target gene of RUNX1. In present studies, agonist-induced platelet 12-HETE production was decreased in the patient. Four RUNX1 consensus sites were identified in the 2-kb promoter region of ALOX12 (at −1498, −1491, −708, −526 from ATG). In luciferase reporter studies in human erythroleukemia cells, mutation of each site decreased activity; overexpression of RUNX1 up-regulated promoter activity, which was abolished by mutation of RUNX1 sites. Gel shift studies, including with recombinant protein, revealed RUNX1 binding to each site. Chromatin immunoprecipitation revealed in vivo RUNX1 binding in the region of interest. siRNA knockdown of RUNX1 decreased RUNX1 and 12-LO proteins. ALOX12 is a direct transcriptional target of RUNX1. Our studies provide further proof of principle that platelet expression profiling can elucidate novel alterations in platelets with inherited dysfunction.

Abstract 33: Platelet 12-lipoxygenase is a Key Regulator of Platelet Reactivity and Thrombus Formation in vivo

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Reheman Adili ◽  
Katherine Mast ◽  
Theodore R Holman ◽  
Michael Holinstat
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Platelet Reactivity ◽  
Thrombus Formation ◽  
High Shear ◽  
Vessel Occlusion ◽  
12 Lipoxygenase ◽  
Induced Aggregation

Background: Platelet reactivity is required to maintain hemostasis, however high platelet reactivity leads to thrombus formation, myocardial infarction, and stroke. Platelet 12-lipoxygenase (12-LOX) has been demonstrated by our lab and others to regulate agonist-mediated platelet reactivity suggesting a role for 12-LOX in regulation of in vivo thrombosis. The ability to target 12-LOX in vivo has not been established to date. Therefore, we sought to determine if 12-LOX regulates platelet reactivity and thrombus formation in vivo using the selective 12-LOX inhibitor ML355 to determine whether platelet 12-LOX is an effective target for anti-platelet therapeutics. Methods: ML355 effects on human platelet function was assessed in vitro by platelet aggregometry, ex vivo by perfusion chamber, and in vivo by thrombus formation and vessel occlusion in small and large vessels in 12-LOX -/- , WT mice, and mice treated with ML355 via intravital microscopy using the FeCl 3 and laser injury models. Results: In in vitro platelet aggregation, ML355 dose-dependently inhibited agonist-induced aggregation. In ex vivo flow chamber assays, platelet adhesion and thrombus formation on collagen-coated surfaces at high shear was attenuated in both mouse and human whole blood after incubation with ML355. Further, platelet aggregation and thrombus growth in 12-LOX -/- mice were impaired in both laser and FeCl 3 -induced mesenteric, carotid artery and cremaster arteriole thrombosis models. Thrombi in 12-LOX -/- mice were unstable and frequently formed emboli, which resulted in impaired vessel occlusion or reopening. Additionally, thrombus formation and vessel occlusion was impaired in ML355 treated WT mice. Conclusions: The 12-LOX inhibitor ML355 inhibits platelet aggregation induced by a number of platelet agonists. Ex vivo high shear conditions in both mice and human was attenuated in the presence of ML355. Thrombus formation and vessel occlusion were impaired in mice deficient in 12-LOX. Finally, ML355 attenuates thrombus formation and prevents vessel occlusion in vivo . Our data strongly indicates 12-LOX is an important determinant of platelet reactivity and inhibition of platelet 12-LOX may represent a new target for anti-platelet therapeutics.

Linking the Glycolytic Enzyme HK3 to Neutrophil Differentiation of APL Cells Via PU.1

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2425-2425
Author(s):  
Elena A. Federzoni ◽  
Peter Valk ◽  
Bob Löwenberg ◽  
Martin F. Fey ◽  
Mario P. Tschan
Keyword(s):  
Cell Lines ◽  
Expression Profiling ◽  
Myeloid Cell ◽  
Mrna Levels ◽  
Knockdown Cell ◽  
Protein Levels ◽  
Healthy Donors ◽  
Neutrophil Differentiation ◽  
Transcriptional Target

Abstract Abstract 2425 Objectives: Identification and characterization of hexokinase 3 (HK3), as novel transcriptional target of the myeloid master regulator PU.1, with a role in APL cell differentiation and survival. Materials: HK3 and PU.1 quantitative RT-PCR in primary AML patient samples (n=170) and granulocytes isolated from healthy donors (n=20). Gene expression profiling in PU.1-knockout and PU.1-restored myeloid cell lines. Generation of NB4 and HT93 PU.1 as well as HK3 knockdown cell lines. ATRA-induced differentiation of these cell lines was assessed by CD11b and CEBPE expression. In vivo binding of PU.1 and PML-RARA to the HK3 promoter was shown by ChIP assays. Viability of NB4 cell lines was assessed by Alamar Blue staining. Results: We identified HK3 as putative transcriptional target of PU.1 by gene expression profiling in PU.1-knockout and PU.1-restored myeloid cell lines. Unlike the other three hexokinase family members (HK1, HK2 and HK4), HK3 expression is limited to hematopoietic cells, where it is mainly expressed in the myeloid lineage. We found 50-times lower HK3 mRNA levels in primary non-APL patients as compared to granulocytes from healthy donors. Most interestingly, we found that HK3 expression in APL patients with the t(15;17) translocation was 400-times lower (p<0.0001) than compared to granulocytes. Given the particularly low HK3 and PU.1 expression in APL patients, we decided to investigate the role of HK3 and its possible regulation by PU.1 during all-trans retinoic acid (ATRA)-induced neutrophil differentiation of NB4 and HT93 APL cell lines. Firstly, we observed a 5500- and 1100-fold increase of HK3 mRNA levels during neutrophil differentiation of NB4 and HT93, respectively. This was paralleled by markedly increased HK3 protein levels. No increased HK3 levels were observed in ATRA-resistant NB4-R2 cell lines. HK1 and HK2 mRNA expression was not markedly increased during neutrophil differentiation pointing to a particular role for HK3 in neutrophil differentiation. Regulation of the liver specific HK4 was not investigated. Next, we observed significantly decreased HK3 expression, both at the mRNA and protein levels, in all PU.1 knockdown cell lines upon ATRA-induced differentiation. In vivo PU.1 binding to three different regions of the HK3 promoter was found. Given our findings in primary APL patients, we decided to test if PML-RARa binds to the HK3 promoter, and indeed, PML-RARA binds to the same promoter regions as PU.1. Knocking down HK3 in APL cell lines resulted in significantly reduced neutrophil differentiation as measured by CD11b and CEBPE expression. Also, we observed that NB4 HK3 knockdown cell lines treated with ATRA were less viable compared to control cells. Conclusions: Our results strongly suggest that HK3 is a novel PU.1 transcriptional target functionally involved in neutrophil differentiation and cell viability of APL cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Hemgn is a direct transcriptional target of HOXB4 and induces expansion of murine myeloid progenitor cells

Blood ◽  
2010 ◽  
Vol 116 (5) ◽  
pp. 711-719 ◽  
Author(s):  
Jie Jiang ◽  
Hui Yu ◽  
Yan Shou ◽  
Geoffrey Neale ◽  
Sheng Zhou ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Target Genes ◽  
Bone Marrow Cells ◽  
Ex Vivo ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Direct Transcriptional Target ◽  
Myeloid Progenitor ◽  
Transcriptional Target

HOXB4, a member of the Homeobox transcription factor family, promotes expansion of hematopoietic stem cells and hematopoietic progenitor cells in vivo and ex vivo when overexpressed. However, the molecular mechanisms underlying this effect are not well understood. To identify direct target genes of HOXB4 in primary murine hematopoietic progenitor cells, we induced HOXB4 function in lineage-negative murine bone marrow cells, using a tamoxifen-inducible HOXB4-ERT2 fusion protein. Using expression microarrays, 77 probe sets were identified with differentially changed expression in early response to HOXB4 induction. Among them, we show that Hemogen (Hemgn), encoding a hematopoietic-specific nuclear protein of unknown function, is a direct transcriptional target of HOXB4. We show that HOXB4 binds to the promoter region of Hemgn both ex vivo and in vivo. When we overexpressed Hemgn in bone marrow cells, we observed that Hemgn promoted cellular expansion in liquid cultures and increased self-renewal of myeloid colony-forming units in culture, partially recapitulating the effect of HOXB4 overexpression. Furthermore, down-regulation of Hemgn using an shRNA strategy proved that Hemgn contributes to HOXB4-mediated expansion in our myeloid progenitor assays. Our results identify a functionally relevant, direct transcriptional target of HOXB4 and identify other target genes that may also participate in the HOXB4 genetic network.

scholarly journals Id3 Is a Direct Transcriptional Target of Pax7 in Quiescent Satellite Cells

2009 ◽  
Vol 20 (14) ◽  
pp. 3170-3177 ◽  
Author(s):  
Deepak Kumar ◽  
Jennifer L. Shadrach ◽  
Amy J. Wagers ◽  
Andrew B. Lassar
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Direct Transcriptional Target ◽  
Helix Loop Helix ◽  
Maximal Induction ◽  
Inhibitor Of Dna Binding ◽  
Bhlh Proteins ◽  
Transcriptional Target

Pax7 is a key regulator of skeletal muscle stem cells and is required along with Pax3 to generate skeletal muscle precursors. We have identified a collection of genes induced by either Pax3 or Pax7 in C2C12 muscle cells. Two notable Pax3/7 targets are the inhibitory helix-loop-helix (HLH) proteins inhibitor of DNA binding (Id) 2 and Id3, both of which are coordinately expressed with Pax7 in quiescent satellite cells and are induced in quiescent C2C12 myogenic cells after ectopic expression of either Pax3 or Pax7. Ectopic Pax7 activates expression of a luciferase reporter driven by the Id3 promoter, and maximal induction of this reporter requires a conserved Pax7 binding site located upstream of the Id3 gene. Chromatin immunoprecipitation indicated that Pax7 is bound upstream of the Id3 promoter in quiescent satellite cells. In addition, short hairpin RNA-mediated knockdown of Pax7 expression in cultured satellite cells coordinately decreased both Id2 and Id3 expression. Together, these findings indicate that Id3 is a direct transcriptional target for Pax7 in quiescent satellite cells, and they suggest that Pax7 acts to block premature differentiation of quiescent satellite cells by inducing the expression of Id2 and Id3, which in turn may act to block either the precocious induction of myogenic basic (b)HLH proteins, the activity of myogenic bHLH proteins, or both.

A technique for protecting delicate specimens during processing

1989 ◽  
Vol 47 ◽  
pp. 982-983
Author(s):  
R.J. Mount ◽  
R.V. Harrison
Keyword(s):  
Basilar Membrane ◽  
Low Cost ◽  
Organ Of Corti ◽  
Region Of Interest ◽  
Sensory Epithelium ◽  
Physical Damage ◽  
Air Drying ◽  
Specimen Handling ◽  
Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

Inhibition of Amyloid β Aggregation Using Optimized Nano-Encapsulated Formulations of Plant Extracts with High Metal Chelator Activities

2020 ◽  
Vol 21 (8) ◽  
pp. 681-701
Author(s):  
Fatma Kazdal ◽  
Fatemeh Bahadori ◽  
Burak Celik ◽  
Abdulselam Ertas ◽  
Gulacti Topcu
Keyword(s):  
Plant Extracts ◽  
Amyloid Β ◽  
Toxic Metal ◽  
In Vivo Studies ◽  
Total Phenolic ◽  
Metal Chelator ◽  
Apo E ◽  
High Metal ◽  
Induced Aggregation

Background: The role of Fe+2, Cu+2 and Zn+2 in facilitating aggregation of Amyloid β (Aβ) and consequently, the progression of Alzheimer's disease (AD) is well established. Objective: Development of non-toxic metal chelators is an emerging era in the treatment of AD, in which complete success has not been fully achieved. The purpose of this study was to determine plant extracts with high metal chelator and to encapsulate them in nano-micellar systems with the ability to pass through the Blood Brain Barrier (BBB). Method: Extracts of 36 different Anatolian plants were prepared, total phenolic and flavonoid contents were determined, and the extracts with high content were examined for their Fe+2, Cu+2 and Zn+2 chelating activities. Apolipoprotein E4 (Apo E) decorated nano-formulations of active extracts were prepared using Poly (Lactide-co-Glycolide) (PLGA) (final product ApoEPLGA) to provide BBB penetrating property. Results: Verbascum flavidum aqueous extract was found as the most active sample, incubation of which, with Aβ before and after metal-induced aggregation, resulted in successful inhibition of aggregate formation, while re-solubilization of pre-formed aggregates was not effectively achieved. The same results were obtained using ApoEPLGA. Conclusion: An optimized metal chelator nano-formulation with BBB penetrating ability was prepared and presented for further in-vivo studies.

scholarly journals TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Mechanistic Model ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Tissue Samples ◽  
Reporter Assays

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.

scholarly journals Marker for the pre-clinical development of bone substitute materials

2017 ◽  
Vol 3 (2) ◽  
pp. 711-715
Author(s):  
Michael de Wild ◽  
Simon Zimmermann ◽  
Marcel Obrecht ◽  
Michel Dard
Keyword(s):  
Bone Graft ◽  
Mechanical Stability ◽  
Clinical Performance ◽  
Ex Vivo ◽  
Region Of Interest ◽  
Defect Site ◽  
Novel Approach ◽  
Bone Substitute Materials ◽  
Clinical Experiments

AbstractThin mechanically stable Ti-cages have been developed for the in-vivo application as X-ray and histology markers for the optimized evaluation of pre-clinical performance of bone graft materials. A metallic frame defines the region of interest during histological investigations and supports the identification of the defect site. This standardization of the procedure enhances the quality of pre-clinical experiments. Different models of thin metallic frameworks were designed and produced out of titanium by additive manufacturing (Selective Laser Melting). The productibility, the mechanical stability, the handling and suitability of several frame geometries were tested during surgery in artificial and in ex-vivo bone before a series of cages was preclinically investigated in the female Göttingen minipigs model. With our novel approach, a flexible process was established that can be adapted to the requirements of any specific animal model and bone graft testing.

scholarly journals In vitro and in vivo assessment of the protective effect of sufentanil in acute lung injury

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098635
Author(s):  
Qi Gao ◽  
Ningqing Chang ◽  
Donglian Liu
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Protective Effect ◽  
High Mobility ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Hmgb1 Protein

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.

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