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1.
Crisis ; 44(3): 189-197, 2023 May.
Article in English | MEDLINE | ID: mdl-35086355

ABSTRACT

Background: Better Off With You is a peer-to-peer, digital suicide prevention campaign pilot designed to challenge the idea of perceived burdensomeness; the schema experienced by many people contemplating suicide that they are a burden on others. Aims: To investigate the safety, acceptability, and initial effectiveness of the campaign. Method: This mixed methods pilot involved a general community sample (N = 157), from targeted sites within two Australian communities. Data were collected at baseline and after 1-week exposure to the campaign videos and website. Qualitative interviews were conducted with a subset of participants (N = 15). Results: Participants rated the campaign as highly engaging and relevant to local communities. In interviews, participants identified the campaign as being unique, safe, and impactful. Overall, exposure to Better Off With You did not result in any notable changes in perceived burdensomeness, psychological distress, or help-seeking. Limitations: The pilot involved a community sample. As such, outcome measurement scores were low at baseline. Conclusion: This pilot provides new insights about the safety, engagement and initial effectiveness of the Better Off With You campaign. Future research is needed to explore its impact on people experiencing suicidal ideation.


Subject(s)
Suicide Prevention , Suicide , Humans , Australia , Suicide/psychology , Suicidal Ideation , Interpersonal Relations , Psychological Theory , Risk Factors
2.
JMIR Form Res ; 5(3): e23892, 2021 Mar 03.
Article in English | MEDLINE | ID: mdl-33656441

ABSTRACT

BACKGROUND: The Interpersonal Theory of Suicide posits that there are three key elements of suicidal behavior: perceived burdensomeness, thwarted belongingness, and the acquired capability for suicide. The digital campaign Better Off With You was developed to directly challenge the idea of perceived burdensomeness among people who are contemplating suicide in 2 communities within Australia. OBJECTIVE: The aim of this study is to explore the needs and preferences of people with lived experience of suicidal thoughts and actions to inform the development of Better Off With You. METHODS: This study involved a series of focus groups that aimed to discuss campaign messaging, scope, and approach. People with lived experience of suicidal thoughts and actions attended the focus groups. After the completion of initial focus groups, the results informed the creation of campaign collateral by creative agencies. Early versions of the campaign collateral were then presented in the user testing sessions. Transcriptions were analyzed via thematic analysis. RESULTS: In total, 13 participants attended the focus groups and 14 attended the user testing sessions. The following three overarching themes were presented: acceptability, safety, and resonance. Participants believed that suicide is a serious and ongoing issue in their communities and welcomed a localized suicide prevention focus via peer-to-peer storytelling. The idea of perceived burdensomeness required clarification but was perceived as acceptable and relevant. Participants seemed drawn toward peer narratives that they perceived to be authentic, genuine, and believable as given by real people with lived experience. Campaign messaging needs to be clear and empathetic while directly talking about suicide. Participants did not anticipate any significant negative or harmful impact from any campaign videos and highlighted the importance of providing appropriate help-seeking information. CONCLUSIONS: This iterative study provided important insights and knowledge about peer-to-peer storytelling in suicide prevention campaigns. Future campaigns should involve simple messaging, be validating and empathetic, and consider including a lived experience perspective.

3.
Plant Biotechnol J ; 18(3): 743-755, 2020 03.
Article in English | MEDLINE | ID: mdl-31465620

ABSTRACT

For future food security, it is important that wheat, one of the most widely consumed crops in the world, can survive the threat of abiotic and biotic stresses. New genetic variation is currently being introduced into wheat through introgressions from its wild relatives. For trait discovery, it is necessary that each introgression is homozygous and hence stable. Breeding programmes rely on efficient genotyping platforms for marker-assisted selection (MAS). Recently, single nucleotide polymorphism (SNP)-based markers have been made available on high-throughput Axiom® SNP genotyping arrays. However, these arrays are inflexible in their design and sample numbers, making their use unsuitable for long-term MAS. SNPs can potentially be converted into Kompetitive allele-specific PCR (KASP™) assays that are comparatively cost-effective and efficient for low-density genotyping of introgression lines. However, due to the polyploid nature of wheat, KASP assays for homoeologous SNPs can have difficulty in distinguishing between heterozygous and homozygous hybrid lines in a backcross population. To identify co-dominant SNPs, that can differentiate between heterozygotes and homozygotes, we PCR-amplified and sequenced genomic DNA from potential single-copy regions of the wheat genome and compared them to orthologous copies from different wild relatives. A panel of 620 chromosome-specific KASP assays have been developed that allow rapid detection of wild relative segments and provide information on their homozygosity and site of introgression in the wheat genome. A set of 90 chromosome-nonspecific assays was also produced that can be used for genotyping introgression lines. These multipurpose KASP assays represent a powerful tool for wheat breeders worldwide.


Subject(s)
Chromosome Mapping , Homozygote , Plant Breeding , Triticum/genetics , Chromosomes, Plant/genetics , Genotype , Polymorphism, Single Nucleotide
4.
Cardiovasc Eng Technol ; 9(2): 141-150, 2018 06.
Article in English | MEDLINE | ID: mdl-28236165

ABSTRACT

Calcific aortic valve disease (CAVD) is a major cause of morbidity in the aging population, but the underlying mechanisms of its progression remain poorly understood. Aortic valve calcification preferentially occurs on the fibrosa, which is subjected to disturbed flow. The side-specific progression of the disease is characterized by inflammation, calcific lesions, and extracellular matrix (ECM) degradation. Here, we explored the role of mechanosensitive microRNA-181b and its downstream targets in human aortic valve endothelial cells (HAVECs). Mechanistically, miR-181b is upregulated in OS and fibrosa, and it targets TIMP3, SIRT1, and GATA6, correlated with increased gelatinase/MMP activity. Overexpression of miR-181b led to decreased TIMP3 and exacerbated MMP activity as shown by gelatinase assay, and miR-181b inhibition decreased gelatinase activity through the repression of TIMP3 levels. Luciferase assay showed specific binding of miR-181b to the TIMP3 gene. Overexpression of miR-181b in HAVECs subjected to either LS or OS increased MMP activity, and miR-181b inhibition abrogated shear-sensitive MMP activity. These studies suggest that targeting this shear-dependent miRNA may provide a novel noninvasive treatment for CAVD.


Subject(s)
Aortic Valve/metabolism , Calcinosis/metabolism , Endothelial Cells/metabolism , Extracellular Matrix/metabolism , Heart Valve Diseases/metabolism , Mechanotransduction, Cellular , Tissue Inhibitor of Metalloproteinase-3/metabolism , 3' Untranslated Regions , Aortic Valve/pathology , Binding Sites , Calcinosis/genetics , Calcinosis/pathology , Cells, Cultured , Endothelial Cells/pathology , Gelatinases/metabolism , Gene Expression Regulation , Heart Valve Diseases/genetics , Heart Valve Diseases/pathology , Humans , MicroRNAs/genetics , Stress, Mechanical , Tissue Inhibitor of Metalloproteinase-3/genetics
5.
Arterioscler Thromb Vasc Biol ; 38(2): 335-343, 2018 02.
Article in English | MEDLINE | ID: mdl-29269512

ABSTRACT

OBJECTIVE: Accumulating evidence suggests a role of semaphorins in vascular homeostasis. Here, we investigate the role of Sema7A (semaphorin 7A) in atherosclerosis and its underlying mechanism. APPROACH AND RESULTS: Using genetically engineered Sema7A-/-ApoE-/- mice, we showed that deletion of Sema7A attenuates atherosclerotic plaque formation primarily in the aorta of ApoE-/- mice on a high-fat diet. A higher level of Sema7A in the atheroprone lesser curvature suggests a correlation of Sema7A with disturbed flow. This notion is supported by elevated Sema7A expression in human umbilical venous endothelial cells either subjected to oscillatory shear stress or treated with the PKA (protein kinase A)/CREB (cAMP response element-binding protein) inhibitor H89 (N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide·2HCl hydrate). Further studies using the partial carotid artery ligation model showed that disturbed flow in the left carotid artery of Sema7A+/+ApoE-/- mice promoted the expression of endothelial Sema7A and cell adhesion molecules, leukocyte adhesion, and plaque formation, whereas such changes were attenuated in Sema7A-/-ApoE-/- mice. Further studies showed that blockage of ß1 integrin, a known Sema7A receptor, or inhibition of FAK (focal adhesion kinase), MEK1/2 (mitogen-activated protein kinase kinase 1/2), or NF-κB (nuclear factor-κB) significantly reduced the expression of cell adhesion molecules and THP-1 (human acute monocytic leukemia cell line) monocyte adhesion in Sema7A-overexpressing human umbilical venous endothelial cells. Studies using chimeric mice suggest that vascular, most likely endothelial, Sema7A plays a major role in atherogenesis. CONCLUSIONS: Our findings indicate a significant role of Sema7A in atherosclerosis by mediating endothelial dysfunction in a ß1 integrin-dependent manner.


Subject(s)
Antigens, CD/metabolism , Aortic Diseases/metabolism , Atherosclerosis/metabolism , Carotid Artery Diseases/metabolism , Endothelial Cells/metabolism , Integrin beta1/metabolism , Mechanotransduction, Cellular , Semaphorins/metabolism , Animals , Antigens, CD/genetics , Aortic Diseases/genetics , Aortic Diseases/pathology , Atherosclerosis/genetics , Atherosclerosis/pathology , Carotid Artery Diseases/genetics , Carotid Artery Diseases/pathology , Cell Adhesion , Cell Adhesion Molecules/metabolism , Disease Models, Animal , Endothelial Cells/pathology , Focal Adhesion Protein-Tyrosine Kinases/metabolism , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , Human Umbilical Vein Endothelial Cells , Humans , Leukocyte Rolling , MAP Kinase Kinase Kinases/metabolism , Mice, Inbred C57BL , Mice, Knockout, ApoE , NF-kappa B/metabolism , Plaque, Atherosclerotic , Regional Blood Flow , Semaphorins/deficiency , Semaphorins/genetics , THP-1 Cells , Up-Regulation
6.
Redox Biol ; 9: 244-253, 2016 10.
Article in English | MEDLINE | ID: mdl-27591403

ABSTRACT

Oxidative stress represents excessive intracellular levels of reactive oxygen species (ROS), which plays a major role in the pathogenesis of cardiovascular disease. Besides having a critical impact on the development and progression of vascular pathologies including atherosclerosis and diabetic vasculopathy, oxidative stress also regulates physiological signaling processes. As a cell permeable ROS generated by cellular metabolism involved in intracellular signaling, hydrogen peroxide (H2O2) exerts tremendous impact on cardiovascular pathophysiology. Under pathological conditions, increased oxidase activities and/or impaired antioxidant systems results in uncontrolled production of ROS. In a pro-oxidant environment, vascular smooth muscle cells (VSMC) undergo phenotypic changes which can lead to the development of vascular dysfunction such as vascular inflammation and calcification. Investigations are ongoing to elucidate the mechanisms for cardiovascular disorders induced by oxidative stress. This review mainly focuses on the role of H2O2 in regulating physiological and pathological signals in VSMC.


Subject(s)
Cardiovascular Diseases/etiology , Cardiovascular Diseases/metabolism , Oxidation-Reduction , Signal Transduction , Animals , Antioxidants/metabolism , Cardiovascular Diseases/physiopathology , Humans , Hydrogen Peroxide/metabolism , Inflammation/etiology , Inflammation/metabolism , Mitochondria, Muscle/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Oxidative Stress , Reactive Oxygen Species/metabolism
7.
Sci Rep ; 6: 25397, 2016 05 06.
Article in English | MEDLINE | ID: mdl-27151744

ABSTRACT

Aortic valve (AV) calcification is an inflammation driven process that occurs preferentially in the fibrosa. To explore the underlying mechanisms, we investigated if key microRNAs (miRNA) in the AV are differentially expressed due to disturbed blood flow (oscillatory shear (OS)) experienced by the fibrosa compared to the ventricularis. To identify the miRNAs involved, endothelial-enriched RNA was isolated from either side of healthy porcine AVs for microarray analysis. Validation using qPCR confirmed significantly higher expression of 7 miRNAs (miR-100, -130a, -181a/b, -199a-3p, -199a-5p, and -214) in the fibrosa versus the ventricularis. Upon bioinformatics analysis, miR-214 was selected for further investigation using porcine AV leaflets in an ex vivo shear system. Fibrosa and ventricularis sides were exposed to either oscillatory or unidirectional pulsatile shear for 2 days and 3 &7 days in regular and osteogenic media, respectively. Higher expression of miR-214, increased thickness of the fibrosa, and calcification was observed when the fibrosa was exposed to OS compared to the ventricularis. Silencing of miR-214 by anti-miR-214 in whole AV leaflets with the fibrosa exposed to OS significantly increased the protein expression of TGFß1 and moderately increased collagen content but did not affect AV calcification. Thus, miR-214 is identified as a side- and shear-dependent miRNA that regulates key mechanosensitive gene in AV such as TGFß1.


Subject(s)
Aortic Valve/pathology , Atherosclerosis/pathology , MicroRNAs/analysis , Animals , Disease Models, Animal , Microarray Analysis , Real-Time Polymerase Chain Reaction , Stress, Mechanical , Swine
8.
Antioxid Redox Signal ; 25(7): 401-14, 2016 09 01.
Article in English | MEDLINE | ID: mdl-26651130

ABSTRACT

SIGNIFICANCE: Currently, calcific aortic valve disease (CAVD) is only treatable through surgical intervention because the specific mechanisms leading to the disease remain unclear. In this review, we explore the forces and structure of the valve, as well as the mechanosensors and downstream signaling in the valve endothelium known to contribute to inflammation and valve dysfunction. RECENT ADVANCES: While the valvular structure enables adaptation to dynamic hemodynamic forces, these are impaired during CAVD, resulting in pathological systemic changes. Mechanosensing mechanisms-proteins, sugars, and membrane structures-at the surface of the valve endothelial cell relay mechanical signals to the nucleus. As a result, a large number of mechanosensitive genes are transcribed to alter cellular phenotype and, ultimately, induce inflammation and CAVD. Transforming growth factor-ß signaling and Wnt/ß-catenin have been widely studied in this context. Importantly, NADPH oxidase and reactive oxygen species/reactive nitrogen species signaling has increasingly been recognized to play a key role in the cellular response to mechanical stimuli. In addition, a number of valvular microRNAs are mechanosensitive and may regulate the progression of CAVD. CRITICAL ISSUES: While numerous pathways have been described in the pathology of CAVD, no treatment options are available to avoid surgery for advanced stenosis and calcification of the aortic valve. More work must be focused on this issue to lead to successful therapies for the disease. FUTURE DIRECTIONS: Ultimately, a more complete understanding of the mechanisms within the aortic valve endothelium will lead us to future therapies important for treatment of CAVD without the risks involved with valve replacement or repair. Antioxid. Redox Signal. 25, 401-414.


Subject(s)
Aortic Valve/metabolism , Endothelium/metabolism , Gene Expression Regulation , Mechanotransduction, Cellular , Shear Strength , Animals , Aortic Valve/anatomy & histology , Aortic Valve/cytology , Aortic Valve/pathology , Aortic Valve Stenosis/etiology , Aortic Valve Stenosis/metabolism , Aortic Valve Stenosis/pathology , Aortic Valve Stenosis/therapy , Biomarkers , Calcinosis/etiology , Calcinosis/metabolism , Calcinosis/pathology , Calcinosis/therapy , Hemodynamics , Humans , Mechanoreceptors/metabolism , Stress, Mechanical
9.
Arterioscler Thromb Vasc Biol ; 35(1): 175-83, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25378413

ABSTRACT

OBJECTIVE: Vascular calcification is a characteristic feature of atherosclerosis, diabetes mellitus, and end-stage renal disease. We have demonstrated that activation of protein kinase B (AKT) upregulates runt-related transcription factor 2 (Runx2), a key osteogenic transcription factor that is crucial for calcification of vascular smooth muscle cells (VSMC). Using mice with SMC-specific deletion of phosphatase and tensin homolog (PTEN), a major negative regulator of AKT, the present studies uncovered a novel molecular mechanism underlying PTEN/AKT/FOXO (forkhead box O)-mediated Runx2 upregulation and VSMC calcification. APPROACH AND RESULTS: SMC-specific PTEN deletion mice were generated by crossing PTEN floxed mice with SM22α-Cre transgenic mice. The PTEN deletion resulted in sustained activation of AKT that upregulated Runx2 and promoted VSMC calcification in vitro and arterial calcification ex vivo. Runx2 knockdown did not affect proliferation but blocked calcification of the PTEN-deficient VSMC, suggesting that PTEN deletion promotes Runx2-depedent VSMC calcification that is independent of proliferation. At the molecular level, PTEN deficiency increased the amount of Runx2 post-transcriptionally by inhibiting Runx2 ubiquitination. AKT activation increased phosphorylation of FOXO1/3 that led to nuclear exclusion of FOXO1/3. FOXO1/3 knockdown in VSMC phenocopied the PTEN deficiency, demonstrating a novel function of FOXO1/3, as a downstream signaling of PTEN/AKT, in regulating Runx2 ubiquitination and VSMC calcification. Using heterozygous SMC-specific PTEN-deficient mice and atherogenic ApoE(-/-) mice, we further demonstrated AKT activation, FOXO phosphorylation, and Runx2 ubiquitination in vascular calcification in vivo. CONCLUSIONS: Our studies have determined a new causative effect of SMC-specific PTEN deficiency on vascular calcification and demonstrated that FOXO1/3 plays a crucial role in PTEN/AKT-modulated Runx2 ubiquitination and VSMC calcification.


Subject(s)
Aortic Diseases/metabolism , Atherosclerosis/metabolism , Forkhead Transcription Factors/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Vascular Calcification/metabolism , Animals , Aorta/metabolism , Aorta/pathology , Aortic Diseases/genetics , Aortic Diseases/pathology , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Atherosclerosis/genetics , Atherosclerosis/pathology , Cells, Cultured , Core Binding Factor Alpha 1 Subunit/metabolism , Disease Models, Animal , Enzyme Activation , Forkhead Box Protein O1 , Forkhead Box Protein O3 , Forkhead Transcription Factors/genetics , Gene Expression Regulation , Genotype , Integrases/genetics , Mice, Knockout , Microfilament Proteins/genetics , Muscle Proteins/genetics , Muscle, Smooth, Vascular/pathology , Myocytes, Smooth Muscle/pathology , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Phenotype , Phosphorylation , Protein Transport , Proto-Oncogene Proteins c-akt/metabolism , RNA Interference , Signal Transduction , Time Factors , Transfection , Ubiquitination , Vascular Calcification/genetics , Vascular Calcification/pathology
10.
Circ Res ; 114(7): 1094-102, 2014 Mar 28.
Article in English | MEDLINE | ID: mdl-24526702

ABSTRACT

RATIONALE: Vascular calcification is a serious cardiovascular complication that contributes to the increased morbidity and mortality of patients with diabetes mellitus. Hyperglycemia, a hallmark of diabetes mellitus, is associated with increased vascular calcification and increased modification of proteins by O-linked N-acetylglucosamine (O-GlcNAcylation). OBJECTIVE: We sought to determine the role of protein O-GlcNAcylation in regulating vascular calcification and the underlying mechanisms. METHODS AND RESULTS: Low-dose streptozotocin-induced diabetic mice exhibited increased aortic O-GlcNAcylation and vascular calcification, which was also associated with impaired aortic compliance in mice. Elevation of O-GlcNAcylation by administration of Thiamet-G, a potent inhibitor for O-GlcNAcase that removes O-GlcNAcylation, further accelerated vascular calcification and worsened aortic compliance of diabetic mice in vivo. Increased O-GlcNAcylation, either by Thiamet-G or O-GlcNAcase knockdown, promoted calcification of primary mouse vascular smooth muscle cells. Increased O-GlcNAcylation in diabetic arteries or in the O-GlcNAcase knockdown vascular smooth muscle cell upregulated expression of the osteogenic transcription factor Runx2 and enhanced activation of AKT. O-GlcNAcylation of AKT at two new sites, T430 and T479, promoted AKT phosphorylation, which in turn enhanced vascular smooth muscle cell calcification. Site-directed mutation of AKT at T430 and T479 decreased O-GlcNAcylation, inhibited phosphorylation of AKT at S473 and binding of mammalian target of rapamycin complex 2 to AKT, and subsequently blocked Runx2 transactivity and vascular smooth muscle cell calcification. CONCLUSIONS: O-GlcNAcylation of AKT at 2 new sites enhanced AKT phosphorylation and activation, thus promoting vascular calcification. Our studies have identified a novel causative effect of O-GlcNAcylation in regulating vascular calcification in diabetes mellitus and uncovered a key molecular mechanism underlying O-GlcNAcylation-mediated activation of AKT.


Subject(s)
Acetylglucosamine/metabolism , Diabetes Mellitus, Experimental/pathology , Proto-Oncogene Proteins c-akt/metabolism , Vascular Calcification/metabolism , Animals , Aorta/metabolism , Aorta/pathology , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Diabetes Mellitus, Experimental/metabolism , Glycosylation , Mechanistic Target of Rapamycin Complex 2 , Mice , Mice, Inbred C57BL , Multiprotein Complexes/metabolism , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Phosphorylation , Protein Binding , Proto-Oncogene Proteins c-akt/genetics , Pyrans/pharmacology , TOR Serine-Threonine Kinases/metabolism , Thiazoles/pharmacology , Vascular Calcification/pathology , beta-N-Acetylhexosaminidases/antagonists & inhibitors , beta-N-Acetylhexosaminidases/genetics , beta-N-Acetylhexosaminidases/metabolism
11.
Circ Res ; 111(5): 543-52, 2012 Aug 17.
Article in English | MEDLINE | ID: mdl-22773442

ABSTRACT

RATIONALE: Vascular calcification is a hallmark of atherosclerosis, a major cause of morbidity and mortality in the United States. We have previously reported that the osteogenic transcription factor Runx2 is an essential and sufficient regulator of calcification of vascular smooth muscle cells (VSMC) in vitro. OBJECTIVE: To determine the contribution of osteogenic differentiation of VSMC to the pathogenesis of vascular calcification and the function of VSMC-derived Runx2 in regulating calcification in vivo. METHODS AND RESULTS: SMC-specific Runx2-deficient mice, generated by breeding SM22α-Cre mice with the Runx2 exon 8 floxed mice, exhibited normal aortic gross anatomy and expression levels of SMC-specific marker genes. Runx2 deficiency did not affect basal SMC markers, but inhibited oxidative stress-reduced expression of SMC markers. High-fat-diet-induced vascular calcification in vivo was markedly inhibited in the Runx2-deficient mice in comparison with their control littermates. Runx2 deficiency inhibited the expression of receptor activator of nuclear factor κB ligand, which was accompanied by decreased macrophage infiltration and formation of osteoclast-like cells in the calcified lesions. Coculture of VSMC with bone marrow-derived macrophages demonstrated that the Runx2-deficient VSMC failed to promote differentiation of macrophages into osteoclast-like cells. CONCLUSIONS: These data have determined the importance of osteogenic differentiation of VSMC in the pathogenesis of vascular calcification in mice and defined the functional role of SMC-derived Runx2 in regulating vascular calcification and promoting infiltration of macrophages into the calcified lesion to form osteoclast-like cells. Our studies suggest that the development of vascular calcification is coupled with the formation of osteoclast-like cells, paralleling the bone remodeling process.


Subject(s)
Atherosclerosis/pathology , Calcinosis/pathology , Core Binding Factor Alpha 1 Subunit/genetics , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/physiology , Acid Phosphatase/metabolism , Animals , Atherosclerosis/physiopathology , Bone Remodeling/physiology , Calcinosis/physiopathology , Cell Differentiation/physiology , Cells, Cultured , Coculture Techniques , Core Binding Factor Alpha 1 Subunit/deficiency , Diet, High-Fat , Disease Models, Animal , Exons/genetics , Female , Isoenzymes/metabolism , Macrophages/cytology , Male , Mice , Mice, Knockout , Mutagenesis/physiology , Osteoclasts/cytology , RANK Ligand/genetics , RANK Ligand/metabolism , Tartrate-Resistant Acid Phosphatase
12.
Arterioscler Thromb Vasc Biol ; 31(6): 1387-96, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21454810

ABSTRACT

OBJECTIVE: Clinical and experimental studies demonstrate the important roles of vascular smooth muscle cells (VSMC) in the pathogenesis of atherosclerosis. We have previously determined that the osteogenic transcription factor Runx2 is essential for VSMC calcification. The present study characterized Runx2-regulated signals and their potential roles in vascular calcification. METHODS AND RESULTS: In vivo studies with atherogenic apolipoprotein E(-/-) mice demonstrated that increased oxidative stress was associated with upregulation of Runx2 and receptor activator of nuclear factor κB ligand (RANKL), which colocalized in the calcified atherosclerotic lesions and were juxtaposed to infiltrated macrophages and osteoclast-like cells that are positively stained for an osteoclast marker, tartrate-resistant acid phosphatase. Mechanistic studies using RNA interference, a luciferase reporter system, chromatin immunoprecipitation, and electrophoretic mobility shift assays indicated that Runx2 regulated the expression of RANKL via a direct binding to the 5'-flanking region of the RANKL. Functional characterization revealed that RANKL did not induce VSMC calcification, nor was RANKL required for oxidative stress-induced VSMC calcification. Using a coculture system, we demonstrated that VSMC-expressed RANKL induced migration as well as differentiation of bone marrow-derived macrophages into multinucleated, tartrate-resistant acid phosphatase-positive osteoclast-like cells. These effects were inhibited by the RANKL antagonist osteoprotegerin and with VSMC deficient in Runx2 or RANKL. CONCLUSION: We demonstrate that Runx2 directly binds to the promoter and controls the expression of RANKL, which mediates the crosstalk between calcifying VSMC and migration and differentiation of macrophages into osteoclast-like cells in the atherosclerotic lesions. Our studies provide novel mechanistic insights into the regulation and function of VSMC-derived RANKL in the pathogenesis of atherosclerosis and vascular calcification.


Subject(s)
Calcinosis/etiology , Core Binding Factor Alpha 1 Subunit/physiology , Macrophages/physiology , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/physiology , Osteoclasts/cytology , RANK Ligand/physiology , Vascular Diseases/etiology , Acid Phosphatase/analysis , Animals , Atherosclerosis/etiology , Calcinosis/metabolism , Cell Differentiation , Cell Movement , Gene Expression Regulation , Isoenzymes/analysis , Macrophages/cytology , Mice , Mice, Inbred C57BL , Muscle, Smooth, Vascular/physiology , Oxidative Stress , Promoter Regions, Genetic , Protein Binding , RANK Ligand/genetics , Tartrate-Resistant Acid Phosphatase , Vascular Diseases/metabolism
13.
Mol Ther ; 18(1): 143-50, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19724265

ABSTRACT

Integrating lentiviral vectors based on the human immunodeficiency virus type-1 (HIV-1) can transduce quiescent cells, which in lung account for almost 95% of the epithelial cell population. Pseudotyping lentiviral vectors with the envelope glycoprotein from the Ebola Zaire virus, the lymphocytic choriomeningitis virus (LCMV), the Mokola virus, and the vesicular stomatitis virus (VSV-G) resulted in transduction of mouse alveolar epithelium, but gene expression in the lung of C57BL/6 and BALB/c mice waned within 90 days of vector injection. Intratracheal delivery of the four pseudotyped lentiviral vectors resulted in transgene-specific T-cell activation in both mouse strains, albeit lower than that achieved by intramuscular injection of the vectors. We performed an adoptive transfer of luciferase-specific T cells, isolated from spleen or lung of donor mice injected with VSV-G-pseudotyped lentivirus vector expressing luciferase into the muscle or lung, respectively, into recipient recombination-activating gene (RAG)-deficient mice transduced in lung with adenovirus expressing firefly luciferase (ffluc2). Gene expression declined within 7 days of adoptive transfer approaching background levels by day 36. Taken together, our results suggest that the loss of transduced cells in lung is due to VSV-G.HIV vector-mediated activation of transgene-specific T cells rather than as result of normal turnover of airway cells.


Subject(s)
Lentivirus/genetics , Lung/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transgenes/genetics , Adoptive Transfer , Animals , Genetic Vectors , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Lung/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Spleen/immunology , Spleen/metabolism , Transduction, Genetic
14.
Mol Ther ; 17(12): 2078-87, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19638960

ABSTRACT

Physicochemical properties of gene transfer vectors play an important role in both transduction efficiency and biodistribution following airway delivery. Adeno-associated virus (AAV) vectors are currently used in many gene transfer applications; however, the respiratory epithelium remains a challenging target. We synthesized two cationic sterol-based lipids, dexamethasone-spermine (DS) and disubstituted spermine (D(2)S) for pulmonary gene targeting. Scanning and transmission electron micrographs (TEM) confirmed that AAV/lipid formulations produced submicron-sized clusters. When AAV2/9 or AAV2/6.2 were formulated with these cationic lipids, the complexes had positive zeta potential (zeta) and the transduction efficiency in cultured A549 cells increased by sevenfold and sixfold, respectively. Transduction of cultured human airway epithelium with AAV2/6.2-lipid formulations also showed approximately twofold increase in green fluorescence protein (GFP) positive cells as quantified by flow cytometry. Intranasal administration of 10(11) genome copies (GC) of AAV2/9 and AAV2/6.2 coformulated with lipid formulations resulted in an average fourfold increase in transgene expression for both vectors. Formulation of AAV2/9 with DS changed the tropism of this vector for the alveolar epithelium, resulting in successful transduction of conducting airway epithelium. Our results suggest that formulating AAV2/9 and AAV2/6.2 with DS and D(2)S can lead to improved physicochemical characteristics for in vivo gene delivery to lung.


Subject(s)
Dependovirus/genetics , Dexamethasone/chemistry , Genetic Vectors , Lipids/chemistry , Lung/metabolism , Spermine/chemistry , Animals , Dexamethasone/metabolism , Gene Transfer Techniques , Humans , Liposomes , Mice , Mice, Inbred C57BL , Respiratory System/cytology , Respiratory System/metabolism , Spermine/metabolism , beta-Galactosidase
15.
J Invest Dermatol ; 129(10): 2358-64, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19387480

ABSTRACT

The hair follicles (HFs) and the interfollicular epidermis (IFE) of intact mature skin are maintained by distinct stem cell populations. Upon wounding, however, emigration of HF keratinocytes to the IFE plays a role in acute stages of healing. In addition to this repair function, rapidly cycling cells of the upper HF have been observed transiting to the IFE in neonatal skin. Here we report that an absence of HF development leads to shortening and kinking of the mouse tail. These skeletal defects are reduced by stimulating keratinocyte proliferation, suggesting that they arise from impaired epidermal expansion. We confirm that rapidly cycling cells of the HF emigrate to the IFE of the neonatal tail. These results suggest that an absence of HFs results in impaired skin growth that is unable to keep pace with the rapidly elongating axial skeleton of the tail. Thus, in addition to their role in wound repair, HFs can make a significant contribution to lateral expansion of the IFE in the absence of trauma.


Subject(s)
Cell Movement/physiology , Cell Proliferation , Hair Follicle/physiology , Keratinocytes/cytology , Skin/cytology , Skin/growth & development , Animals , Animals, Newborn , Bone and Bones/pathology , Edar-Associated Death Domain Protein/genetics , Edar-Associated Death Domain Protein/metabolism , Keratinocytes/metabolism , Mice , Mice, Mutant Strains , Mutation/genetics , Skin/embryology , Tail/pathology , Wound Healing/physiology
16.
Am J Pathol ; 173(3): 844-55, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18688028

ABSTRACT

Decorin, a member of the small leucine-rich proteoglycan gene family, down-regulates members of the ErbB receptor tyrosine kinase family and attenuates their signaling, leading to growth inhibition. We investigated the effects of decorin on the growth of ErbB2-overexpressing mammary carcinoma cells in comparison with AG879, an established ErbB2 kinase inhibitor. Cell proliferation and anchorage-independent growth assays showed that decorin was a potent inhibitor of breast cancer cell growth and a pro-apoptotic agent. When decorin and AG879 were used in combination, the inhibitory effect was synergistic in proliferation assays but only additive in both colony formation and apoptosis assays. Active recombinant human decorin protein core, AG879, or a combination of both was administered systemically to mice bearing orthotopic mammary carcinoma xenografts. Primary tumor growth and metabolism were reduced by approximately 50% by both decorin and AG879. However, no synergism was observed in vivo. Decorin specifically targeted the tumor cells and caused a significant reduction of ErbB2 levels in the tumor xenografts. Most importantly, systemic delivery of decorin prevented metastatic spreading to the lungs, as detected by novel species-specific DNA detection and quantitative assays. In contrast, AG879 failed to have any effect. Our data support a role for decorin as a powerful and effective therapeutic agent against breast cancer due to its inhibition of both primary tumor growth and metastatic spreading.


Subject(s)
Adenocarcinoma/drug therapy , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Extracellular Matrix Proteins/pharmacology , Proteoglycans/pharmacology , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Animals , Apoptosis/drug effects , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation , Decorin , Drug Synergism , Enzyme Inhibitors/pharmacology , Female , Flow Cytometry , Fluorescent Antibody Technique , Glycoproteins/drug effects , Glycoproteins/metabolism , Humans , Image Processing, Computer-Assisted , Lung Neoplasms/drug therapy , Lung Neoplasms/secondary , Mice , Polymerase Chain Reaction , Positron-Emission Tomography , Rats , Receptor, ErbB-2
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