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.
Global metabolite profiling of mice with high-fat diet-induced obesity chronically treated with AMPK activators R118 or metformin reveals tissue-selective alterations in metabolic pathways.
BMC Res Notes
PUBLISHED: 06-18-2014
Show Abstract
Hide Abstract
The novel small molecule R118 and the biguanide metformin, a first-line therapy for type 2 diabetes (T2D), both activate the critical cellular energy sensor 5'-AMP-activated protein kinase (AMPK) via modulation of mitochondrial complex I activity. Activation of AMPK results in both acute responses and chronic adaptations, which serve to restore energy homeostasis. Metformin is thought to elicit its beneficial effects on maintenance of glucose homeostasis primarily though impacting glucose and fat metabolism in the liver. Given the commonalities in their mechanisms of action and that R118 also improves glucose homeostasis in a murine model of T2D, the effects of both R118 and metformin on metabolic pathways in vivo were compared in order to determine whether R118 elicits its beneficial effects through similar mechanisms.
Related JoVE Video
Partial suppression of M1 microglia by Janus kinase 2 inhibitor does not protect against neurodegeneration in animal models of amyotrophic lateral sclerosis.
J Neuroinflammation
PUBLISHED: 05-28-2014
Show Abstract
Hide Abstract
BackgroundAccumulating evidence has shown that the inflammatory process participates in the pathogenesis of amyotrophic lateral sclerosis (ALS), suggesting a therapeutic potential of anti-inflammatory agents. Janus kinase 2 (JAK2), one of the key molecules in inflammation, transduces signals downstream of various inflammatory cytokines, and some Janus kinase inhibitors have already been clinically applied to the treatment of inflammatory diseases. However, the efficacy of JAK2 inhibitors in treatment of ALS remains to be demonstrated. In this study, we examined the role of JAK2 in ALS by administering a selective JAK2 inhibitor, R723, to an animal model of ALS (mSOD1G93A mice).FindingsOrally administered R723 had sufficient access to spinal cord tissue of mSOD1G93A mice and significantly reduced the number of Ly6c positive blood monocytes, as well as the expression levels of IFN-¿ and nitric oxide synthase 2, inducible (iNOS) in the spinal cord tissue. R723 treatment did not alter the expression levels of Il-1ß, Il-6, TNF, and NADPH oxidase 2 (NOX2), and suppressed the expression of Retnla, which is one of the markers of neuroprotective M2 microglia. As a result, R723 did not alter disease progression or survival of mSOD1G93A mice.ConclusionsJAK2 inhibitor was not effective against ALS symptoms in mSOD1G93A mice, irrespective of suppression in several inflammatory molecules. Simultaneous suppression of anti-inflammatory microglia with a failure to inhibit critical other inflammatory molecules might explain this result.
Related JoVE Video
Exercise performance and peripheral vascular insufficiency improve with AMPK activation in high-fat diet-fed mice.
Am. J. Physiol. Heart Circ. Physiol.
PUBLISHED: 02-21-2014
Show Abstract
Hide Abstract
Intermittent claudication is a form of exercise intolerance characterized by muscle pain during walking in patients with peripheral artery disease (PAD). Endothelial cell and muscle dysfunction are thought to be important contributors to the etiology of this disease, but a lack of preclinical models that incorporate these elements and measure exercise performance as a primary end point has slowed progress in finding new treatment options for these patients. We sought to develop an animal model of peripheral vascular insufficiency in which microvascular dysfunction and exercise intolerance were defining features. We further set out to determine if pharmacological activation of 5'-AMP-activated protein kinase (AMPK) might counteract any of these functional deficits. Mice aged on a high-fat diet demonstrate many functional and molecular characteristics of PAD, including the sequential development of peripheral vascular insufficiency, increased muscle fatigability, and progressive exercise intolerance. These changes occur gradually and are associated with alterations in nitric oxide bioavailability. Treatment of animals with an AMPK activator, R118, increased voluntary wheel running activity, decreased muscle fatigability, and prevented the progressive decrease in treadmill exercise capacity. These functional performance benefits were accompanied by improved mitochondrial function, the normalization of perfusion in exercising muscle, increased nitric oxide bioavailability, and decreased circulating levels of the endogenous endothelial nitric oxide synthase inhibitor asymmetric dimethylarginine. These data suggest that aged, obese mice represent a novel model for studying exercise intolerance associated with peripheral vascular insufficiency, and pharmacological activation of AMPK may be a suitable treatment for intermittent claudication associated with PAD.
Related JoVE Video
Involvement of Toso in activation of monocytes, macrophages, and granulocytes.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 01-28-2013
Show Abstract
Hide Abstract
Rapid activation of immune responses is necessary for antibacterial defense, but excessive immune activation can result in life-threatening septic shock. Understanding how these processes are balanced may provide novel therapeutic potential in treating inflammatory disease. Fc receptors are crucial for innate immune activation. However, the role of the putative Fc receptor for IgM, known as Toso/Faim3, has to this point been unclear. In this study, we generated Toso-deficient mice and used them to uncover a critical regulatory function of Toso in innate immune activation. Development of innate immune cells was intact in the absence of Toso, but Toso-deficient neutrophils exhibited more reactive oxygen species production and reduced phagocytosis of pathogens compared with controls. Cytokine production was also decreased in Toso(-/-) mice compared with WT animals, rendering them resistant to septic shock induced by lipopolysaccharide. However, Toso(-/-) mice also displayed limited cytokine production after infection with the bacterium Listeria monocytogenes that was correlated with elevated presence of Listeria throughout the body. Accordingly, Toso(-/-) mice succumbed to infections of L. monocytogenes, whereas WT mice successfully eliminated the infection. Taken together, our data reveal Toso to be a unique regulator of innate immune responses during bacterial infection and septic shock.
Related JoVE Video
AMPK Activation through Mitochondrial Regulation Results in Increased Substrate Oxidation and Improved Metabolic Parameters in Models of Diabetes.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Modulation of mitochondrial function through inhibiting respiratory complex I activates a key sensor of cellular energy status, the 5-AMP-activated protein kinase (AMPK). Activation of AMPK results in the mobilization of nutrient uptake and catabolism for mitochondrial ATP generation to restore energy homeostasis. How these nutrient pathways are affected in the presence of a potent modulator of mitochondrial function and the role of AMPK activation in these effects remain unclear. We have identified a molecule, named R419, that activates AMPK in vitro via complex I inhibition at much lower concentrations than metformin (IC50 100 nM vs 27 mM, respectively). R419 potently increased myocyte glucose uptake that was dependent on AMPK activation, while its ability to suppress hepatic glucose production in vitro was not. In addition, R419 treatment of mouse primary hepatocytes increased fatty acid oxidation and inhibited lipogenesis in an AMPK-dependent fashion. We have performed an extensive metabolic characterization of its effects in the db/db mouse diabetes model. In vivo metabolite profiling of R419-treated db/db mice showed a clear upregulation of fatty acid oxidation and catabolism of branched chain amino acids. Additionally, analyses performed using both (13)C-palmitate and (13)C-glucose tracers revealed that R419 induces complete oxidation of both glucose and palmitate to CO2 in skeletal muscle, liver, and adipose tissue, confirming that the compound increases mitochondrial function in vivo. Taken together, our results show that R419 is a potent inhibitor of complex I and modulates mitochondrial function in vitro and in diabetic animals in vivo. R419 may serve as a valuable molecular tool for investigating the impact of modulating mitochondrial function on nutrient metabolism in multiple tissues and on glucose and lipid homeostasis in diabetic animal models.
Related JoVE Video
R723, a selective JAK2 inhibitor, effectively treats JAK2V617F-induced murine myeloproliferative neoplasm.
Blood
PUBLISHED: 04-29-2011
Show Abstract
Hide Abstract
The activating mutations in JAK2 (including JAK2V617F) that have been described in patients with myeloproliferative neoplasms (MPNs) are linked directly to MPN pathogenesis. We developed R723, an orally bioavailable small molecule that inhibits JAK2 activity in vitro by 50% at a concentration of 2nM, while having minimal effects on JAK3, TYK2, and JAK1 activity. R723 inhibited cytokine-independent CFU-E growth and constitutive activation of STAT5 in primary hematopoietic cells expressing JAK2V617F. In an anemia mouse model induced by phenylhydrazine, R723 inhibited erythropoiesis. In a leukemia mouse model using Ba/F3 cells expressing JAK2V617F, R723 treatment prolonged survival and decreased tumor burden. In V617F-transgenic mice that closely mimic human primary myelofibrosis, R723 treatment improved survival, hepatosplenomegaly, leukocytosis, and thrombocytosis. R723 preferentially targeted the JAK2-dependent pathway rather than the JAK1- and JAK3-dependent pathways in vivo, and its effects on T and B lymphocytes were mild compared with its effects on myeloid cells. Our preclinical data indicate that R723 has a favorable safety profile and the potential to become an efficacious treatment for patients with JAK2V617F-positive MPNs.
Related JoVE Video
R428, a selective small molecule inhibitor of Axl kinase, blocks tumor spread and prolongs survival in models of metastatic breast cancer.
Cancer Res.
PUBLISHED: 02-09-2010
Show Abstract
Hide Abstract
Accumulating evidence suggests important roles for the receptor tyrosine kinase Axl in cancer progression, invasion, metastasis, drug resistance, and patient mortality, highlighting Axl as an attractive target for therapeutic development. We have generated and characterized a potent and selective small-molecule inhibitor, R428, that blocks the catalytic and procancerous activities of Axl. R428 inhibits Axl with low nanomolar activity and blocked Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production. Pharmacologic investigations revealed favorable exposure after oral administration such that R428-treated tumors displayed a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. In support of an earlier study, R428 inhibited angiogenesis in corneal micropocket and tumor models. R428 administration reduced metastatic burden and extended survival in MDA-MB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P < 0.05) mouse models of breast cancer metastasis. Additionally, R428 synergized with cisplatin to enhance suppression of liver micrometastasis. Our results show that Axl signaling regulates breast cancer metastasis at multiple levels in tumor cells and tumor stromal cells and that selective Axl blockade confers therapeutic value in prolonging survival of animals bearing metastatic tumors.
Related JoVE Video
The current status and the future of JAK2 inhibitors for the treatment of myeloproliferative diseases.
Int. J. Hematol.
PUBLISHED: 02-07-2010
Show Abstract
Hide Abstract
Janus kinases (JAKs) are critical components of cytokine signaling pathways which regulate immunity, inflammation, hematopoiesis, growth, and development. The recent discovery of JAK2-activating mutations as a causal event in the majority of patients with Philadelphia chromosome negative (Ph-) myeloproliferative disorders (MPDs) prompted many pharmaceutical companies to develop JAK2-selective inhibitors for the treatment of MPDs. JAK2 inhibitors effectively reduce JAK2-driven phosphorylation of signal transducer and activator of transcription 5, and cell proliferation and cell survival in JAK2-activated cells in vitro and in vivo. Most inhibitors are currently being evaluated in patients with one form of MPD, myelofibrosis. Patients treated with these inhibitors experienced a rapid reduction of splenomegaly, significant improvement of constitutional symptoms, and increased daily activity with few adverse events. A partial reduction of JAK2V617F disease burden during the treatment with JAK2 inhibitors was also observed. The inhibitors appear to have a therapeutic benefit in the treatment of these disorders. The results of ongoing clinical trials will allow further evaluation of clinical benefits and safety of these compounds. In this review, the authors summarize the status of JAK2 inhibitors in development and discuss their benefits and challenges.
Related JoVE Video
Discovery and development of an aurora kinase inhibitor clinical candidate using an image-based assay for measuring proliferation, apoptosis, and DNA content.
Assay Drug Dev Technol
PUBLISHED: 06-10-2009
Show Abstract
Hide Abstract
Measurement of antiproliferative capacity of a compound is central to early oncology drug discovery, with information about the precise mechanism of compound action typically being acquired during later downstream assays. Here we describe the development and validation of an in vitro image-based assay that simultaneously measures tumor cell count, late apoptotic morphology, and nuclear DNA content (termed the proliferation, apoptosis, and DNA content [PAD] assay) by using a DNA binding fluorescent dye. The PAD assay determines whether a compounds antiproliferative effect occurs via cell cycle arrest or induction of apoptosis, replacing downstream assays for 1/50(th) the cost. We used this assay to screen a kinase inhibitor-biased library and discovered an Aurora kinase inhibitor, and we also used it to drive structure-activity relationship to clinical candidate Investigational New Drug filing within 2 years. The simplicity of the PAD assay was critical to the rapid time frame within which this candidate was identified and progressed. This inhibitor is currently beginning Phase II clinical trials.
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.