JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Real-time assessment of possible electromagnetic-field-induced changes in protein conformation and thermal stability.
Bioelectromagnetics
PUBLISHED: 08-14-2014
Show Abstract
Hide Abstract
Previous studies on possible interactions of radiofrequency electromagnetic fields (RF EMFs) with proteins have suggested that RF EMFs might affect protein structure and folding kinetics. In this study, the isolated thermosensor protein GrpE of the Hsp70 chaperone system of Escherichia coli was exposed to EMFs of various frequencies and field strengths under strictly controlled conditions. Circular dichroism spectroscopy was used to monitor possible structural changes. Simultaneously, temperature was recorded at each point of observation. The coiled-coil part of GrpE has been reported to undergo a well-defined and fully reversible folding/unfolding transition, thus facilitating the differentiation between thermal and non-thermal effects of RF EMFs. Any direct effect of EMF on the conformation and/or stability would result in a shift of the conformational equilibrium of the protein at a given temperature. Possible immediate (t???0.1?s) and delayed (t???30?s) effects of RF EMFs were investigated with sinusoidal signals of 0.1, 1.0, and 1.9?GHz at various field strengths up to 5.0?kV/m and with GSM signals at 0.3?kV/m in the protein solution. Taking the overall uncertainty of the experimental system into account, possible RF EMF-induced shifts in the conformational equilibrium of less than 1% of its total range might have been detected. The results obtained with the different experimental protocols indicate, however, that the conformational equilibrium of GrpE is insensitive to electromagnetic fields in the tested range of frequency and field strength.
Related JoVE Video
The Nuclear Receptor Constitutive Androstane Receptor/NR1I3 Enhances the Profibrotic Effects of Transforming Growth Factor ? and Contributes to the Development of Experimental Dermal Fibrosis.
PUBLISHED: 08-05-2014
Show Abstract
Hide Abstract
Nuclear receptors regulate cell growth, differentiation, and homeostasis. Selective nuclear receptors promote fibroblast activation, which leads to tissue fibrosis, the hallmark of systemic sclerosis (SSc). This study was undertaken to investigate the effects of constitutive androstane receptor (CAR)/NR1I3, an orphan nuclear receptor, on fibroblast activation and experimental dermal fibrosis.
Related JoVE Video
S100A4 amplifies TGF-?-induced fibroblast activation in systemic sclerosis.
Ann. Rheum. Dis.
PUBLISHED: 04-09-2014
Show Abstract
Hide Abstract
S100A4 is a calcium binding protein with regulatory functions in cell homeostasis, proliferation and differentiation that has been shown to promote cancer progression and metastasis. In the present study, we evaluated the role of S100A4 in fibroblast activation in systemic sclerosis (SSc).
Related JoVE Video
Related JoVE Video
Impedance flow cytometry gauges proliferative capacity by detecting TRPC1 expression.
Cytometry A
PUBLISHED: 03-03-2014
Show Abstract
Hide Abstract
When examined, the expansion of many stem cell classes has been shown to be facilitated by mechanically-regulated calcium entry from the extracellular space that also helps direct their developmental programs towards mechanosensitive tissues such as muscle, bone, and connective tissues. Cation channels of the transient receptor potential C class (TRPC) are the predominant conduit for calcium entry into proliferating myoblasts. Nonetheless, methods to non-invasively study this calcium-entry pathway are still in their infancy. Here we show that a microfluidic configuration of impedance-based flow cytometry (IFC) provides a method to detect TRP channel expression in cells at high throughput. Using this technology we discern changes in the IFC signal that correlates with the functional expression of TRPC1 channels and coincides with cell proliferation. Pharmacological agents, mechanical conditions or malignant states that alter the expression of TRPC1 channels are reflected in the IFC signal accordingly, whereas pharmacological agents that alter cation-permeation through TRPC1 channels, or ionophores that independently increase calcium entry across the membrane, have little effect. Our results suggest that IFC detects changes in whole-cell membrane organization associated with TRPC1 activation and surface expression, rather than cation permeation through the channel per se. IFC-based technologies thus have the potential to identify living stem cells in their earliest stages of expansion without staining or chemical fixation.
Related JoVE Video
Stimulation of the soluble guanylate cyclase (sGC) inhibits fibrosis by blocking non-canonical TGF? signalling.
Ann. Rheum. Dis.
PUBLISHED: 02-26-2014
Show Abstract
Hide Abstract
We have previously described the antifibrotic role of the soluble guanylate cyclase (sGC). The mode of action, however, remained elusive. In the present study, we describe a novel link between sGC signalling and transforming growth factor ? (TGF?) signalling that mediates the antifibrotic effects of the sGC.
Related JoVE Video
Signature of circulating microRNAs in osteoarthritis.
Ann. Rheum. Dis.
PUBLISHED: 02-10-2014
Show Abstract
Hide Abstract
Osteoarthritis is the most common form of arthritis and a major socioeconomic burden. Our study is the first to explore the association between serum microRNA levels and the development of severe osteoarthritis of the knee and hip joint in the general population.
Related JoVE Video
Deciphering the pro-fibrotic phenotype of fibroblasts in systemic sclerosis.
Exp. Dermatol.
PUBLISHED: 01-31-2014
Show Abstract
Hide Abstract
LeRoy's seminal work on the phenotypic features of scleroderma fibroblasts has been directing fibrosis research in the field of systemic sclerosis (SSc, scleroderma) for the past 30 years. His principal experiment, to culture skin fibroblasts from patients with SSc and study their pro-fibrotic phenotype in comparison with skin fibroblasts from healthy individuals, has been used by most basic and translational fibrosis studies in SSc. LeRoy's findings have revolutionized our understanding of the disease pathogenesis and guided the development of novel antifibrotic therapies towards fibroblast-specific approaches.
Related JoVE Video
Vitamin D receptor regulates TGF-? signalling in systemic sclerosis.
Ann. Rheum. Dis.
PUBLISHED: 01-23-2014
Show Abstract
Hide Abstract
Vitamin D receptor (VDR) is a member of the nuclear receptor superfamily. Its ligand, 1,25-(OH)2D, is a metabolically active hormone derived from vitamin D3. The levels of vitamin D3 are decreased in patients with systemic sclerosis (SSc). Here, we aimed to analyse the role of VDR signalling in fibrosis.
Related JoVE Video
Combined inhibition of morphogen pathways demonstrates additive antifibrotic effects and improved tolerability.
Ann. Rheum. Dis.
PUBLISHED: 01-20-2014
Show Abstract
Hide Abstract
The morphogen pathways Hedgehog, Wnt and Notch are attractive targets for antifibrotic therapies in systemic sclerosis. Interference with stem cell regeneration, however, may complicate the use of morphogen pathway inhibitors. We therefore tested the hypothesis that combination therapies with low doses of Hedgehog, Wnt and Notch inhibitors maybe safe and effective for the treatment of fibrosis.
Related JoVE Video
Inhibition of casein kinase II reduces TGF? induced fibroblast activation and ameliorates experimental fibrosis.
Ann. Rheum. Dis.
PUBLISHED: 01-17-2014
Show Abstract
Hide Abstract
Casein kinase II (CK2) is a constitutively active serine/threonine protein kinase that plays a key role in cellular transformation and tumorigenesis. The purpose of the study was to characterise whether CK2 contributes to the pathologic activation of fibroblasts in patients with SSc and to evaluate the antifibrotic potential of CK2 inhibition.
Related JoVE Video
Inactivation of evenness interrupted (EVI) reduces experimental fibrosis by combined inhibition of canonical and non-canonical Wnt signalling.
Ann. Rheum. Dis.
PUBLISHED: 11-20-2013
Show Abstract
Hide Abstract
Canonical as well as non-canonical Wnt signalling pathways have emerged as core pathways of fibrosis. Their profibrotic effects are mediated via distinct intracellular cascades independently of each other. Thus, inhibition of both pathways may have additive antifibrotic effects. Here, we knocked down evenness interrupted (EVI) to simultaneously target for the first time canonical and non-canonical Wnt signalling in experimental fibrosis.
Related JoVE Video
The Wnt antagonists DKK1 and SFRP1 are downregulated by promoter hypermethylation in systemic sclerosis.
Ann. Rheum. Dis.
PUBLISHED: 05-22-2013
Show Abstract
Hide Abstract
OBJECTIVE: Activated Wnt signalling with decreased expression of endogenous inhibitors has recently been characterised as a central pathomechanism in systemic sclerosis (SSc). Aberrant epigenetic modifications also contribute to the persistent activation of SSc fibroblasts. We investigated whether increased Wnt signalling and epigenetic changes in SSc are causally linked via promoter hypermethylation-induced silencing of Wnt antagonists. METHODS: The methylation status of endogenous Wnt antagonists in leucocytes and fibroblasts was evaluated by methylation-specific PCR. 5-aza-2-deoxycytidine was used to inhibit DNA methyltransferases (Dnmts) in cultured fibroblasts and in the mouse model of bleomycin-induced skin fibrosis. Activation of Wnt signalling was assessed by analysing Axin2 mRNA levels and by staining for ?-catenin. RESULTS: The promoters of DKK1 and SFRP1 were hypermethylated in fibroblasts and peripheral blood mononuclear cells of patients with SSc. Promoter hypermethylation resulted in impaired transcription and decreased expression of DKK1 and SFRP1 in SSc. Treatment of SSc fibroblasts or bleomycin-challenged mice with 5-aza prevented promoter methylation-induced silencing and increased the expression of both genes to normal levels. Reactivation of DKK1 and SFRP1 transcription by 5-aza inhibited canonical Wnt signalling in vitro and in vivo and effectively ameliorated experimental fibrosis. CONCLUSIONS: We demonstrate that hypermethylation of the promoters of DKK1 and SFRP1 contributes to aberrant Wnt signalling in SSc and that Dnmt inhibition effectively reduces Wnt signalling. These data provide a novel link between epigenetic alterations and increased Wnt signalling in SSc and also have translational implications because Dnmt inhibitors are already approved for clinical use.
Related JoVE Video
Computed tomographic angiography as a useful adjunct in the diagnosis of brain death.
J Trauma Acute Care Surg
PUBLISHED: 04-24-2013
Show Abstract
Hide Abstract
Because of its widespread accessibly, computed tomographic angiography (CT-A) is a promising technique in the detection of intracranial circulatory arrest in brain death (BD). Several studies assessed this tool, but neither have standardized evaluation parameters been developed nor has information about specificity become available.
Related JoVE Video
Blockade of canonical Wnt signalling ameliorates experimental dermal fibrosis.
Ann. Rheum. Dis.
PUBLISHED: 04-17-2013
Show Abstract
Hide Abstract
Fibrosis is a major socioeconomic burden, but effective antifibrotic therapies are not available in the clinical routine. There is growing evidence for a central role of Wnt signalling in fibrotic diseases such as systemic sclerosis, and we therefore evaluated the translational potential of pharmacological Wnt inhibition in experimental dermal fibrosis.
Related JoVE Video
Experimental system for real-time assessment of potential changes in protein conformation induced by electromagnetic fields.
Bioelectromagnetics
PUBLISHED: 04-03-2013
Show Abstract
Hide Abstract
A novel experimental system to distinguish between potential thermal and non-thermal effects of electromagnetic fields (EMFs) on the conformational equilibrium and folding kinetics of proteins is presented. The system comprises an exposure chamber installed within the measurement compartment of a spectropolarimeter and allows real-time observation of the circular dichroism (CD) signal of the protein during EMF exposure. An optical temperature probe monitors the temperature of the protein solution at the site of irradiation. The electromagnetic, thermal, and fluid-dynamic behavior of the system is characterized by numerical and experimental means. The number of repeated EMF on/off cycles needed for achieving a certain detection limit is determined on the basis of the experimentally assessed precision of the CD measurements. The isolated thermosensor protein GrpE of the Hsp70 chaperone system of Eschericha coli serves as the test protein. Long-term experiments show high thermal reproducibility as well as thermal stability of the experimental setup.
Related JoVE Video
Modeling nuclear molecule release during in vitro cell death.
Autoimmunity
PUBLISHED: 01-16-2013
Show Abstract
Hide Abstract
The extracellular release of nuclear molecules occurs prominently during cell death and can determine the immune properties of dead and dying cells. Depending on inciting events and environmental conditions, cells can die by apoptosis or necrosis, although these processes differ in their immunological consequences. Whereas apoptosis is immunologically silent, necrosis leads to inflammation, possibly reflecting the array of "danger" molecules released. To investigate these processes, the extracellular release of HMGB1 during necrosis was characterized in vitro using Jurkat T cell leukemia cells treated to induce necrosis by freeze-thaw, heat, hydrogen peroxide or ethanol. HMGB1 is a non-histone nuclear protein that represents a prototype alarmin; the pro-inflammatory activity of HMGB1, however, depends on past-translational modifications and association with other molecules including cytokines. As results of these studies showed, the extent and kinetics of HMGB1 release from necrotic cells varies markedly depending on its induction. Among treatments tested, freeze-thaw produced the highest levels of extracellular HMGB1; levels with ethanol treatment were very low and in the range of untreated controls. Similar results were obtained with DNA, with freeze-thaw leading to significant amounts of extracellular DNA although this DNA was subject to rapid nuclease digestion. Together, these findings suggest that the rapid release of nuclear molecules is not an invariable feature of necrosis and that the characterization of the immune properties of dead and dying cells should use systems in which the content and stability of extracellular components are well defined.
Related JoVE Video
Morphogen pathways in systemic sclerosis.
Curr Rheumatol Rep
PUBLISHED: 01-08-2013
Show Abstract
Hide Abstract
The morphogen pathways Wnt, hedgehog, and Notch are key regulators of organ development and tissue homeostasis. In adults, the tightly regulated activity of morphogen pathways is essential for cell renewal and tissue regeneration. Loss of control and persistent activation of morphogen pathways, however, can lead to a variety of diseases, including malignancy and fibrotic disorders. In recent years, pathological activation of Wnt, hedgehog, and Notch pathways have been described in systemic sclerosis (SSc) and other fibrotic diseases. Experimental models reveal that morphogen pathways drive fibroblast activation and collagen release. In these model systems, genetic or pharmacological blockade of morphogen pathways inhibits collagen release and reduces experimental fibrosis. Importantly, inhibitors for Wnt, hedgehog, and Notch are already in clinical evaluation, thereby emphasizing the translational implications of these findings. Further experimental studies, however, should deepen our knowledge before initiating clinical trials with inhibitors of morphogen pathways.
Related JoVE Video
Activation of pregnane X receptor inhibits experimental dermal fibrosis.
Ann. Rheum. Dis.
PUBLISHED: 01-04-2013
Show Abstract
Hide Abstract
To assess the antifibrotic effects of pregnane X receptors (PXRs) in experimental dermal fibrosis.
Related JoVE Video
Low intensity and frequency pulsed electromagnetic fields selectively impair breast cancer cell viability.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs) to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1) cytotoxicity to breast cancer cells and; 2) that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatment.
Related JoVE Video
IgG4 immune response in Churg-Strauss syndrome.
Ann. Rheum. Dis.
PUBLISHED: 11-25-2011
Show Abstract
Hide Abstract
T-helper type 2 responses are crucial in Churg-Strauss syndrome (CSS) and may enhance the production of IgG4 antibodies. The authors assessed the IgG4 immune response in CSS patients.
Related JoVE Video
Inhibition of glycogen synthase kinase 3? induces dermal fibrosis by activation of the canonical Wnt pathway.
Ann. Rheum. Dis.
PUBLISHED: 08-25-2011
Show Abstract
Hide Abstract
Glycogen synthase kinase 3? (GSK-3) regulates the phosphorylation and subsequent degradation of ?-catenin, thereby preventing aberrant activation of the canonical Wnt pathway. A study was undertaken to define the role of GSK-3 in fibroblast activation and in experimental models of systemic sclerosis (SSc).
Related JoVE Video
Platelet-derived serotonin links vascular disease and tissue fibrosis.
J. Exp. Med.
PUBLISHED: 04-25-2011
Show Abstract
Hide Abstract
Vascular damage and platelet activation are associated with tissue remodeling in diseases such as systemic sclerosis, but the molecular mechanisms underlying this association have not been identified. In this study, we show that serotonin (5-hydroxytryptamine [5-HT]) stored in platelets strongly induces extracellular matrix synthesis in interstitial fibroblasts via activation of 5-HT(2B) receptors (5-HT(2B)) in a transforming growth factor ? (TGF-?)-dependent manner. Dermal fibrosis was reduced in 5-HT(2B)(-/-) mice using both inducible and genetic models of fibrosis. Pharmacologic inactivation of 5-HT(2B) also effectively prevented the onset of experimental fibrosis and ameliorated established fibrosis. Moreover, inhibition of platelet activation prevented fibrosis in different models of skin fibrosis. Consistently, mice deficient for TPH1, the rate-limiting enzyme for 5-HT production outside the central nervous system, showed reduced experimental skin fibrosis. These findings suggest that 5-HT/5-HT(2B) signaling links vascular damage and platelet activation to tissue remodeling and identify 5-HT(2B) as a novel therapeutic target to treat fibrotic diseases.
Related JoVE Video
Notch signalling regulates fibroblast activation and collagen release in systemic sclerosis.
Ann. Rheum. Dis.
PUBLISHED: 03-30-2011
Show Abstract
Hide Abstract
Dermal fibroblasts from patients with systemic sclerosis (SSc) release excessive amounts of collagen resulting in tissue fibrosis. The molecular mechanisms underlying this pathological activation are incompletely understood.
Related JoVE Video
Inactivation of the transcription factor STAT-4 prevents inflammation-driven fibrosis in animal models of systemic sclerosis.
Arthritis Rheum.
PUBLISHED: 03-02-2011
Show Abstract
Hide Abstract
The transcription factor STAT-4 has recently been identified as a genetic susceptibility factor in systemic sclerosis (SSc) and other autoimmune diseases. The aim of this study was to investigate the contribution of STAT-4 in the development of a fibrotic phenotype in 2 different mouse models of experimental dermal fibrosis.
Related JoVE Video
Inhibition of Notch signaling prevents experimental fibrosis and induces regression of established fibrosis.
Arthritis Rheum.
PUBLISHED: 02-12-2011
Show Abstract
Hide Abstract
Tissue fibrosis caused by pathologic activation of fibroblasts with increased synthesis of extracellular matrix components is a major hallmark of systemic sclerosis (SSc). Notch signaling regulates tissue differentiation, and abnormal activation of Notch signaling has been implicated in the pathogenesis of various malignancies. The present study was undertaken to investigate the role of Notch signaling in SSc and to evaluate the therapeutic potential of Notch inhibition for the treatment of fibrosis.
Related JoVE Video
EUSTAR biobanking: recommendations for the collection, storage and distribution of biospecimens in scleroderma research.
Ann. Rheum. Dis.
PUBLISHED: 02-01-2011
Show Abstract
Hide Abstract
The European League Against Rheumatism Scleroderma Trials and Research Group (EUSTAR) has established an online database with clinical data of currently more than 8200 patients with systemic sclerosis (SSc). In addition to clinical research, EUSTAR fosters biomolecular studies to develop novel biomarkers and therapies for SSc. High-quality biospecimens are the basis for successful biomolecular studies. The EUSTAR biobanking group has therefore developed recommendations to standardise the collection, storage and distribution of SSc biospecimens at EUSTAR centres. These recommendations consider the scientific challenges associated with biomolecular research in SSc and the organisational requirements of EUSTAR. They were approved by the EUSTAR executive committee as well as the EUSTAR board. Once they become effective, these recommendations will be the basis for international EUSTAR studies with large numbers of SSc biospecimens. These recommendations might also be followed by other SSc consortia to enable exchange of biosamples between different SSc initiatives and might serve as a template for biobanking initiatives in other rheumatic diseases.
Related JoVE Video
Pharmacotherapy: concepts of pathogenesis and emerging treatments. Novel targets in bone and cartilage.
Best Pract Res Clin Rheumatol
PUBLISHED: 08-25-2010
Show Abstract
Hide Abstract
The spectrum of arthritis ranges from erosive (e.g., rheumatoid arthritis) to ossifying disease with formation of new bone (e.g., ankylosing spondylitis and osteoarthritis). The molecular basis for these different patterns of arthritis had long been unclear. In the last few years, however, characterisation of catabolic and anabolic molecular pathways in different forms of arthritis led to a better understanding of joint remodelling and revealed novel therapeutic targets. Recent findings show that catabolic and anabolic molecular pathways govern bone and cartilage remodelling in healthy and arthritic joints. The predominance of catabolic molecular pathways (e.g., receptor activator of nuclear factor-kappaB ligand (RANKL)/RANK and cathepsin K) causes erosive disease whereas anabolic signalling (e.g., Wnt and fibroblast growth factor (FGF)18) favours the formation of new bone including bony spurs and subchondral sclerosis. Other pathways may have a dual function in arthritis (e.g., hedgehog) leading to either catabolic or anabolic joint remodelling dependent on other factors. Key mediators within these signalling pathways may serve as novel targets for treating pathological remodelling of bone and cartilage in arthritis. Molecular pathways govern remodelling processes of bone and cartilage in arthritic joints. Future therapies will likely target the pathologic activity of these molecular pathways to specifically block either catabolic or anabolic joint remodelling in arthritis.
Related JoVE Video
Are tyrosine kinase inhibitors promising for the treatment of systemic sclerosis and other fibrotic diseases?
Swiss Med Wkly
PUBLISHED: 04-27-2010
Show Abstract
Hide Abstract
Tissue fibrosis causes organ failure and death in patients with systemic sclerosis (SSc), but clearly effective anti-fibrotic therapies are not available. The tyrosine kinase inhibitor (TKI) imatinib, which blocks the pro-fibrotic c-Abl kinase and PDGF receptor, is currently evaluated in clinical proof-of-concept trials for the treatment of patients with SSc. In experimental models, imatinib efficiently prevented and reduced tissue fibrosis. First clinical case studies demonstrated anti-fibrotic effects of imatinib in selected patients with SSc and other fibrotic diseases, and observational studies in sclerotic chronic graft-versus-host disease showed promising results. Besides imatinib, the two novel TKIs of c-Abl and PDGF receptor nilotinib and dasatinib have recently proven efficacy in experimental models of SSc. The potential of TKIs of the VEGF receptor (e.g., semaxinib, vatalanib, sutent, and sorafenib) and the EGF receptor (e.g., erlotinib, gefitinib, lapatinib, and canertinib) as anti-fibrotic treatments are also discussed in this review. Prior to clinical use, however, controlled trials need to address efficacy as well as tolerability of TKIs in patients with different fibrotic diseases.
Related JoVE Video
The scientific basis for novel treatments of systemic sclerosis.
F1000 Med Rep
PUBLISHED: 12-09-2009
Show Abstract
Hide Abstract
In recent years, many potential antifibrotic treatment strategies have emerged from molecular studies of systemic sclerosis. Few biologicals have already entered clinical trials and these may hopefully prove to be effective in this progressive, profibrotic disease.
Related JoVE Video
The role of microparticles in the pathogenesis of rheumatic diseases.
Nat Rev Rheumatol
PUBLISHED: 12-01-2009
Show Abstract
Hide Abstract
Microparticles (MPs) are small membrane-bound vesicles that are emerging as important elements in the pathogenesis of rheumatic diseases owing to their pleiotropic effects on thrombosis, vascular reactivity, angiogenesis and inflammation. Released from cells during activation and apoptosis, MPs carry proteins, lipids and nucleic acids, and serve as platforms for enzymatic processes in thrombosis. Furthermore, MPs can transfer cytokines, receptors, RNA and DNA to modulate the properties of target cells. As MPs appear in the blood in increased numbers during rheumatic disease, they represent novel biomarkers that can be used to assess events in otherwise inaccessible tissues. Future research will define further the pathogenetic role of MPs and explore therapeutic strategies to block their release or signaling properties.
Related JoVE Video
Hypoxia. Hypoxia in the pathogenesis of systemic sclerosis.
Arthritis Res. Ther.
PUBLISHED: 04-21-2009
Show Abstract
Hide Abstract
Autoimmunity, microangiopathy and tissue fibrosis are hallmarks of systemic sclerosis (SSc). Vascular alterations and reduced capillary density decrease blood flow and impair tissue oxygenation in SSc. Oxygen supply is further reduced by accumulation of extracellular matrix (ECM), which increases diffusion distances from blood vessels to cells. Therefore, severe hypoxia is a characteristic feature of SSc and might contribute directly to the progression of the disease. Hypoxia stimulates the production of ECM proteins by SSc fibroblasts in a transforming growth factor-beta-dependent manner. The induction of ECM proteins by hypoxia is mediated via hypoxia-inducible factor-1alpha-dependent and -independent pathways. Hypoxia may also aggravate vascular disease in SSc by perturbing vascular endothelial growth factor (VEGF) receptor signalling. Hypoxia is a potent inducer of VEGF and may cause chronic VEGF over-expression in SSc. Uncontrolled over-expression of VEGF has been shown to have deleterious effects on angiogenesis because it leads to the formation of chaotic vessels with decreased blood flow. Altogether, hypoxia might play a central role in pathogenesis of SSc by augmenting vascular disease and tissue fibrosis.
Related JoVE Video
Morphogen pathways as molecular targets for the treatment of fibrosis in systemic sclerosis.
Arch. Dermatol. Res.
Show Abstract
Hide Abstract
Wnt-, Hedgehog- and Notch-signaling cascades are morphogen pathways that play crucial roles in development and tissue homeostasis. While morphogen pathways are tightly regulated at multiple levels, inappropriate activation of Wnt, Hedgehog and Notch signaling has been implicated into the pathogenesis of various diseases. In particular, Wnt, Hedgehog and Notch signaling have emerged as central players in the pathogenesis of fibrotic diseases. Here, we will review the pro-fibrotic effects of Wnt, Hedgehog and Notch signaling in systemic sclerosis (SSc), prototypical systemic fibrotic disease. Wnt, Hedgehog and Notch pathways are activated in SSc. They potently stimulate fibroblasts to differentiate into myofibroblasts and to release collagen and other extracellular matrix components. Genetic or pharmacological inhibition of morphogen pathways effectively prevents experimental fibrosis in different preclinical models and induces regression of pre-established fibrosis. As several inhibitors of Wnt, Hedgehog and Notch have recently been developed with first ones being already approved for clinical trials, morphogen pathways maybe a novel approach for the treatment of fibrosis.
Related JoVE Video
Inactivation of tankyrases reduces experimental fibrosis by inhibiting canonical Wnt signalling.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Canonical Wnt signalling has recently emerged as a key mediator of fibroblast activation and tissue fibrosis in systemic sclerosis. Here, we investigated tankyrases as novel molecular targets for inhibition of canonical Wnt signalling in fibrotic diseases.
Related JoVE Video
Technical aids in the diagnosis of brain death: a comparison of SEP, AEP, EEG, TCD and CT angiography.
Dtsch Arztebl Int
Show Abstract
Hide Abstract
The use of technical aids to confirm brain death is a controversial matter. Angiography with the intra-arterial administration of contrast medium is the international gold standard, but it is not allowed in Germany except in cases where it provides a potential mode of treatment. The currently approved tests in Germany are recordings of somatosensory evoked potentials (SSEP), brain perfusion scintigraphy, transcranial Doppler ultrasonography (TCD), and electroencephalography (EEG). CT angiography (CTA), a promising new alternative, is being increasingly used as well.
Related JoVE Video
Autophagy regulates TNF?-mediated joint destruction in experimental arthritis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Autophagy is a homeostatic process to recycle dispensable and damaged cell organelles. Dysregulation of autophagic pathways has recently been implicated in the pathogenesis of various diseases. Here, we investigated the role of autophagy during joint destruction in arthritis.
Related JoVE Video
Inhibition of hedgehog signaling for the treatment of murine sclerodermatous chronic graft-versus-host disease.
Blood
Show Abstract
Hide Abstract
Chronic graft-versus-host disease (cGVHD) is a prognosis limiting complication of allogeneic stem cell transplantation. The molecular mechanisms underlying cGVHD are incompletely understood, and targeted therapies are not yet established for clinical use. Here we examined the role of the hedgehog pathway in sclerodermatous cGVHD. Hedgehog signaling was activated in human and murine cGVHD with increased expression of sonic hedgehog and accumulation of the transcription factors Gli-1 and Gli-2. Treatment with LDE223, a highly selective small-molecule antagonist of the hedgehog coreceptor Smoothened (Smo), abrogated the activation of hedgehog signaling and protected against experimental cGVHD. Preventive therapy with LDE223 almost completely impeded the development of clinical and histologic features of sclerodermatous cGVHD. Treatment with LDE223 was also effective, when initiated after the onset of clinical manifestations of cGVHD. Hedgehog signaling stimulated the release of collagen from cultured fibroblasts but did not affect leukocyte influx in murine cGVHD, suggesting direct, leukocyte-independent stimulatory effects on fibroblasts as the pathomechanism of hedgehog signaling in cGVHD. Considering the high morbidity of cGVHD, the current lack of efficient molecular therapies for clinical use, and the availability of well-tolerated inhibitors of Smo, targeting hedgehog signaling might be a novel strategy for clinical trials in cGVHD.
Related JoVE Video
Inhibition of H3K27 histone trimethylation activates fibroblasts and induces fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Epigenetic modifications such as DNA methylation and histone acetylation have been implicated in the pathogenesis of systemic sclerosis. However, histone methylation has not been investigated so far. We therefore aimed to evaluate the role of the trimethylation of histone H3 on lysine 27 (H3K27me3) on fibroblast activation and fibrosis.
Related JoVE Video
Inactivation of fatty acid amide hydrolase exacerbates experimental fibrosis by enhanced endocannabinoid-mediated activation of CB1.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Selective targeting of the cannabinoid receptors CB1 and CB2 by synthetic compounds has revealed opposing roles of both receptors in fibrosis.
Related JoVE Video
Inhibition of sumoylation prevents experimental fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Fibrosis is a predominant cause of death in systemic sclerosis (SSc). First epigenetic modifications have recently been shown to contribute to activation of SSc fibroblasts. Here, we investigated inhibition of sumoylation as a novel antifibrotic approach.
Related JoVE Video
Pomalidomide is effective for prevention and treatment of experimental skin fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Tissue fibrosis is a major hallmark and a leading cause of death in systemic sclerosis (SSc). Here, we investigated the antifibrotic effects of pomalidomide, an analogue of thalidomide with potent immunomodulatory effects, in preclinical models of skin fibrosis.
Related JoVE Video
Liver X receptors orchestrate osteoblast/osteoclast crosstalk and counteract pathologic bone loss.
J. Bone Miner. Res.
Show Abstract
Hide Abstract
Osteoporosis is characterized by enhanced differentiation of bone-resorbing osteoclasts, resulting in a rapid loss of functional trabecular bone. Bone-forming osteoblasts and osteoblast-derived osteocytes perform a key role in the regulation of osteoclast development by providing both the pro-osteoclastogenic cytokine receptor activator of NF-?B ligand (RANKL) and its natural decoy receptor osteoprotegerin (OPG). By regulating the RANKL/OPG ratio, osteoblasts hence determine the rate of both osteoclast differentiation and bone turnover. Here, we describe a novel role for liver X receptors (LXRs) during the crosstalk of bone-forming osteoblasts and bone-resorbing osteoclasts. By using a system of osteoblast/osteoclast cocultures, we identify LXRs as regulator of RANKL expression and the RANKL/OPG ratio in osteoblasts. Activation of LXRs drastically reduced the RANKL/OPG ratio and interfered with osteoblast-mediated osteoclast differentiation in vitro. During an ovariectomy (OVX)-induced model of postmenopausal osteoporosis, the application of an LXR agonist shifted the RANKL/OPG ratio in vivo, ameliorated the enhanced osteoclast differentiation, and provided complete protection from OVX-induced bone loss. These results reveal an unexpected involvement of LXRs in the regulation of bone turnover and highlight a potential role for LXRs as novel targets in the treatment of osteoporosis and related diseases.
Related JoVE Video
Tyrosine kinase signaling in fibrotic disorders: Translation of basic research to human disease.
Biochim. Biophys. Acta
Show Abstract
Hide Abstract
Tyrosine kinases regulate a broad variety of physiological cell processes, including metabolism, growth, differentiation and apoptosis. Abnormal tyrosine kinase activity disturbs the physiological cell homeostasis and can lead to cancer, vascular disease, and fibrosis. In regard to fibrosis, different tyrosine kinases have been identified as determinants of disease progression and potential targets for anti-fibrotic therapies. This includes both receptor tyrosine kinases (e.g., PDGF receptor, VEGF receptor, EGF receptor, and JAK kinases) as well as non-receptor tyrosine kinases (e.g., c-Abl, c-Kit, and Src kinases). Given their central role in the pathogenesis of fibrosis, researchers of our field study the anti-fibrotic effects of monoclonal antibodies or small-molecule inhibitors to block the aberrant tyrosine kinase activity and treat fibrosis in preclinical models of various fibrotic diseases (e.g., idiopathic pulmonary fibrosis, renal fibrosis, liver fibrosis, and dermal fibrosis). The results of these studies were promising and prompted clinical trials with different compounds in fibrotic diseases. So far, results from studies with intedanib in idiopathic pulmonary fibrosis and imatinib in idiopathic pulmonary fibrosis and systemic sclerosis have been reported. Although none of these studies reported a positive primary outcome, promising trends in anti-fibrotic efficacy awaken our hopes for a new class of effective anti-fibrotic targeted therapies. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.
Related JoVE Video
JAK-2 as a novel mediator of the profibrotic effects of transforming growth factor ? in systemic sclerosis.
Arthritis Rheum.
Show Abstract
Hide Abstract
To investigate whether JAK-2 contributes to the pathologic activation of fibroblasts in patients with systemic sclerosis (SSc) and to evaluate the antifibrotic potential of JAK-2 inhibition for the treatment of SSc.
Related JoVE Video
CT angiography as a confirmatory test in brain death.
Acta Neurochir. Suppl.
Show Abstract
Hide Abstract
From recent studies, it remains unclear whether CT angiography could be an alternative to other established ancillary tests for the diagnosis of brain death. We examined intracranial contrast enhancement in CT angiography after clinically established brain death and compared the results with EEG and TCD findings.
Related JoVE Video
Innovative antifibrotic therapies in systemic sclerosis.
Curr Opin Rheumatol
Show Abstract
Hide Abstract
Fibrosis is a key feature of systemic sclerosis (SSc) and arises from excessive release of collagens by pathologically activated fibroblasts. Affecting the skin and many internal organs, fibrosis represents a major cause for the high morbidity and mortality in SSc. So far, effective therapies to treat fibrosis in SSc and other fibrotic diseases are not available in clinical routine. Nevertheless, promising antifibrotic agents are emerging from translational studies with some having already entered clinical trials.
Related JoVE Video
Activation of canonical Wnt signalling is required for TGF-?-mediated fibrosis.
Nat Commun
Show Abstract
Hide Abstract
The transforming growth factor-? (TGF-?) signalling pathway is a key mediator of fibroblast activation that drives the aberrant synthesis of extracellular matrix in fibrotic diseases. Here we demonstrate a novel link between transforming growth factor-? and the canonical Wnt pathway. TGF-? stimulates canonical Wnt signalling in a p38-dependent manner by decreasing the expression of the Wnt antagonist Dickkopf-1. Tissue samples from human fibrotic diseases show enhanced expression of Wnt proteins and decreased expression of Dickkopf-1. Activation of the canonical Wnt pathway stimulates fibroblasts in vitro and induces fibrosis in vivo. Transgenic overexpression of Dickkopf-1 ameliorates skin fibrosis induced by constitutively active TGF-? receptor type I signalling and also prevents fibrosis in other TGF-?-dependent animal models. These findings demonstrate that canonical Wnt signalling is necessary for TGF-?-mediated fibrosis and highlight a key role for the interaction of both pathways in the pathogenesis of fibrotic diseases.
Related JoVE Video
Inhibition of hedgehog signalling prevents experimental fibrosis and induces regression of established fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Tissue fibrosis is a leading cause of death in patients with systemic sclerosis (SSc). Effective antifibrotic treatments are not available. Here, the authors investigated inhibition of hedgehog signalling by targeting Smoothened (Smo) as a novel antifibrotic approach.
Related JoVE Video
The extracellular release of DNA and HMGB1 from Jurkat T cells during in vitro necrotic cell death.
Innate Immun
Show Abstract
Hide Abstract
In innate immunity, dead and dying cells release internal constituents that can serve as damage-associated molecular patterns (DAMPs) or alarmins. This release occurs more abundantly during necrosis than apoptosis and may account for the differences in the immunologic properties of these death forms. To elucidate DAMP release in necrosis, we compared the levels of two nuclear molecules (DNA and HMGB1, a non-histone protein with alarmin activity) in media following necrosis of Jurkat T cells by freeze-thawing, ethanol, heat or hydrogen peroxide treatment. In our experiments, DNA release was measured by fluorimetry with the dye PicoGreen, while HMGB1 was measured by Western blotting. As the results of our study show, each form of necrosis is associated with a distinct pattern of DNA and HMGB1 release with respect to kinetics and amounts. Of these, freeze-thawing produced the highest and most rapid increase in HMGB1 and DNA levels, although the released DNA was subject to nuclease digestion; in addition, freeze-thawing led to the production of particles measured by flow cytometry. Together, these results indicate that experimental necrosis leads to diverse patterns of nuclear molecule release which could affect their immunologic activity.
Related JoVE Video
Genome-wide transcription analysis of Escherichia coli in response to extremely low-frequency magnetic fields.
Bioelectromagnetics
Show Abstract
Hide Abstract
The widespread use of electricity raises the question of whether or not 50 Hz (power line frequency in Europe) magnetic fields (MFs) affect organisms. We investigated the transcription of Escherichia coli K-12 MG1655 in response to extremely low-frequency (ELF) MFs. Fields generated by three signal types (sinusoidal continuous, sinusoidal intermittent, and power line intermittent; all at 50 Hz, 1 mT) were applied and gene expression was monitored at the transcript level using an Affymetrix whole-genome microarray. Bacterial cells were grown continuously in a chemostat (dilution rate D = 0.4 h(-1)) fed with glucose-limited minimal medium and exposed to 50 Hz MFs with a homogenous flux density of 1 mT. For all three types of MFs investigated, neither bacterial growth (determined using optical density) nor culturable counts were affected. Likewise, no statistically significant change (fold-change > 2, P ? 0.01) in the expression of 4,358 genes and 714 intergenic regions represented on the gene chip was detected after MF exposure for 2.5 h (1.4 generations) or 15 h (8.7 generations). Moreover, short-term exposure (8 min) to the sinusoidal continuous and power line intermittent signal neither affected bacterial growth nor showed evidence for reliable changes in transcription. In conclusion, our experiments did not indicate that the different tested MFs (50 Hz, 1 mT) affected the transcription of E. coli.
Related JoVE Video
?-catenin is a central mediator of pro-fibrotic Wnt signaling in systemic sclerosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Pathologic fibroblast activation drives fibrosis of the skin and internal organs in patients with systemic sclerosis (SSc). ?-catenin is an integral part of adherens junctions and a central component of canonical Wnt signaling. Here, the authors addressed the role of ?-catenin in fibroblasts for the development of SSc dermal fibrosis.
Related JoVE Video
Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage.
Br J Neurosurg
Show Abstract
Hide Abstract
Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow.
Related JoVE Video
Stimulation of soluble guanylate cyclase reduces experimental dermal fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
Fibrosis and vascular disease are cardinal features of systemic sclerosis (SSc). Stimulators of soluble guanylate cyclase (sGC) are vasoactive drugs that are currently being evaluated in phase III clinical trials for pulmonary arterial hypertension.
Related JoVE Video
Jun N-terminal kinase as a potential molecular target for prevention and treatment of dermal fibrosis.
Ann. Rheum. Dis.
Show Abstract
Hide Abstract
The hallmark of systemic sclerosis (SSc) is the accumulation of extracellular matrix proteins by pathologically activated fibroblasts. This study analysed the antifibrotic effects of the selective c-Jun N-terminal kinase (JNK) inhibitor, CC-930, which recently entered first clinical trials as a novel antifibrotic approach.
Related JoVE Video

What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.