Research tools aimed at exploring mitochondria are becoming more and more popular and cover multiple experimental applications. They go from primary antibodies validated for immuno-assays (see “10 Mitochondrial marker antibodies“) to fluorescent probes for mitochondria-related events monitor in living-cells (e.g. MitoPeDPP for live cell imaging, mitophagy or singlet Oxygen (1O2) detection…). Here I’d like to introduce 3 new molecules developed by Focus Biomolecules to further decipher mitochondrial biology.
The year 2015 was full of significant publications in the field of ophthalmology. Here’s a snapshot of 2 “proof-of-concept” studies suggesting that “Sterols” could be promising approaches to treat cataract.
Microbial metabolites are a source of unequalled elements for in vitro assays. Sometimes neglected, these active molecules naturally provide a large spectrum of structural diversity for Drug discovery and antibiotics development programs. In this post, 6 metabolites and their respective properties are highlighted with the hope of refreshing our minds, a little bit, of the importance of such molecules in innovative research discovery.
The FDA-approved drug Losartan is used to treat high blood pressure. By preventing the blood vessels from narrowing, Losartan improves blood flow reducing hypertension. Losartan is also used to reduce kidney damage in type 2 diabetes patients with high blood pressure. Losartan is now considered an attractive therapeutical solution to prevent epilepsy associated with vascular injury.
Practicing sport creates sudden pleasant “feelings” (euphoria, anxiolysis, analgesia, euphoria…) also known as the “runner’s high”.
For decades, increased levels of ß-endorphins in the blood were associated to this sport-induced positive perception. Today, German researchers (University Medical Center Hamburg-Eppendorf) reveal that, in mice, the brain’s endocannabinoids (like the lipid-soluble endocannabinoid called anandamide) might also contribute to this well-being mood after running exercise.
This conclusion has recently been published in the PNAS review: Fuss et al. “A runner’s high depends on cannabinoid receptors in mice”(2015) PNAS, vol. 112 no. 42, DOI: 10.1073/pnas.1514996112
Here are some research tools we’ve selected to study the endocannabinoid and endorphine systems in vitro:
Microtubules are key components of the cytoskeletal structure of eukaryotic cells. Composed of alpha- and beta- tubulin sub-units, microtubules are dynamic entities with pivotal cellular roles (e.g. division and mitosis). Because of these unique characteristics, the first microtubule-based anti-cancer drugs have been described in the early 70’s. Here, we will review the 6 most popular small compounds active on tubulin polymerization and microtubules which are regularly used in today’s microtubule-centred in vitro assays.
Microtubule depolymerizing/inhibitor agents
- Ansamitocin P3 (CAS# 66547-09-9) is a fungal metabolite from Actinosynnema pretiosum. Ansamitocin P3 is a maytansine analog which displays potent cytotoxicity against various human tumor cell lines. Maytansine (and analogs) cause extensive disassembly of microtubules by interacting with tubulin molecules.
- Colchicine (CAS# 64-86-8) is a naturally occurring alkaloid acting as an antimitotic agent. It binds to tubulin and depolymerizes microtubules. Colchine has been shown to induce apoptosis in a variety of cell lines.
- Nocodazole (CAS# 31430-18-9) is an anti-mitotic agent (cell cycle arrest at G2/M phase) disrupting microtubules by binding to ß-tubulin and thereby inhibiting microtubule dynamics. It causes a disruption of mitotic spindle function and fragmentation of the Golgi complex. Nocodazole also activates the JNK/SAPK signaling pathway and induces apoptosis in a variety of cell lines.
- Vinblastine sulfate (CAS# 143-67-9) is a semi-synthetic alkaloidal anticancer agent. It induces cell cycle arrest at G2/M phase by inhibiting mitotic spindle formation. Vinblastine sulfate inhibits normal microtubule assembly and induces aberant tubulin polymerization causing apoptosis. This compound also inhibits autophagosome maturation.
Microtubule stabilizing agents
- Docetaxel (CAS# 114977-28-5) is an antimitotic chemotherapeutic with reversible high-affinity binding to microtubules. It induces apoptosis in a variety of cancer cell lines. Nevertheless, tumor cells can quickly develop resistance to docetaxel via several mechanisms.
- Taxol (CAS# 33069-62-4) is a cancer chemotherapeutic agent (breast, non-small cell lung and ovarian cancers). It acts as a promoter of tubulin polymerization by stabilizing microtubules in vitro and in vivo leading to arrest of cells in the G2 and M phase of the cell cycle.
Looking for pure small molecules active on Microtubule and compatible with in vitro studies?
tebu-bio’s experts have selected high quality sources of active small molecules. Discover those related to tubulin and Microtubules right here.
The Murphy Roths Large-MRL engineered mouse strain spontaneously regenerates ears and even heart tissue. Such a regenerative process is known for amphibians; mammals generally forming scar tissue during the process of wound repair. The groups of Ellen Heber-Katz (The Wistar Institute, Philadelphia, PA) and Phillip B. Messersmith (Northwestern University, Evanston, IL) discovered these exceptional capabilities a few years ago. By using this unique model, the scientists have recently shown that Hypoxia-Inducible Factor-1 alpha (HIF-1alpha) is involved in mammalian tissue regeneration (Zhang Y. et al. “Drug-induced regeneration in adult mice”(2015) Sci. Transl. Med. DOI: 10.1126/scitranslmed.3010228).
The World Health Organization (WHO) estimated in 2008 that 1.4 billion adults worldwide were overweight and of these 500 million were obese with risks for developing type 2 diabetes, hypertension and cardio-vascular diseases. The discovery of the adipocyte hormone, Leptin, brought to light the possibility that its anorectic effect could be harnessed for treating the epidemic of obesity. However up until now Leptin resistance has been an unsurmountable problem and the use of this adipokine for suppressing food intake has failed. In a recent issue of Cell, Junli Liu and coworkers at Harvard Medical School report that Celastrol, a natural product isolated from the Thunder God Vine (Tripterygium Wilfordi), is a powerful antiobesity agent.
Dengue Virus (DenV) is transmitted by mosquito vectors. It infects 50-100 million people each year and is at the origin of Dengue Fever and the more lethal Dengue Hemorrhagic Fever (DHF) and Shock Syndrome (DSS) leading to an estimated 500,000 cases of DHF and 22 000 deaths. The World Health Organization (WHO) estimates that 40% of the world’s population is at risk of infection.
In the June issue of Journal of Biomolecular Screening, investigators at San Diego State University (Dept of Biology) and Institute Pasteur Korea (Seoul, South Korea) developed a multiplexed cell-based assay for the identification of modulators of pre-membrane processing as a target for the discovery of DenV inhibitors. (1)
The DenV pre-membrane protein (prM) is an essential chaperone for the viral envelope protein which prevents premature fusion with vesicles during viral export. Inhibition of pre-membrane protein cleavage restricts fusion and represents, thus, a novel druggable target.
The new in vitro assay developed in this study, is the first described cell-based assay that monitors DenVprM processing within the classical secretory pathway. In a pilot screen of 1,280 small molecules on that assay, Thiostrepton, a known cyclopeptide Antibiotic and FOXM1 inhibitor, was identified as a novel positive hit in this assay (IC50=4.94 µM).
The utility of this novel assay has been proven by the identification of Thiostrepton (available at Focus Biomolecules cat. nr 10-2108) which may be a novel lead compound for the discovery of new drugs effective against Dengue Virus.
1- Stolp Z.D. et al. “A Multiplexed Cell-Based Assay for the Identification of Modulators of Pre-Membrane Processing as a Target against Dengue Virus” (2015) J. Biomol. Screen. 20:616-626. DOI: 10.1177/1087057115571247.
|Dengue Fever||Cat. Nr||Product Name||Application|
|Antibody for Dengue Virus||157MAB4043||Dengue virus Types 1,2,3,4 monoclonal antibody, clone BDI419||Dot,IF,EIA|
|Antibodies for Envelope Protein||157MAB8901||Dengue virus E-D3 monoclonal antibody, clone 5j122||ELISA,WB-Re|
|Antibodies for NS1 protein||157MAB13532||Dengue virus NS1 monoclonal antibody, clone HM026||ELISA,IF,LFIA|
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One of the hottest news last month was the high resolution structure of the TRPA1 ion channel protein.
TRPA1 is a sensor for environmental noxious agents or signaling molecules produced endogenously. The structure was solved in the presence of agonist and antagonist ligands by using single-particle electron cryo-microscopy. (1)
This smart experimental method, which has revealed several unexpected TRPA1 structural features, shows that structural information thus discovered might greatly assist Life Researchers in the design of better antagonists which will represent the next generation analgesic and anti-inflammatory agents.
Interestingly, several TRPA1-related agents are now well characterized for further in vitro characterization.
Several useful agents for studying TRPA1 channels are available:
- TRPA1 antagonist HC-030031 inhibits the ion channel (cat. nr 21910-1065)
- TRPA1 antagonist A-967079 is a cell permeable TRPA1 blocker (cat. nr 21910-1055)
- TRPA1 antagonist AP-18 is a selective TRPA1 channel blocker (cat. nr 21910-1127)
- TRPA1 agonist Polygodial displays analgesic activity via desensitization of sensory neurons (cat. nr 21910-1145)
Thanks to our friends from Focus Biomolecules for this post !