Blogs for August 2017

Application guide: Methods to monitor Autophagy

Tuesday, August 29, 2017 - 15:50

Autophagy is an essential process that cells utilize to degrade and recycle damaged material and fuel metabolism, especially under stress.  The process is evolutionarily conserved and complex, relying on over 20 key proteins. Induction of autophagy is mediated by the formation of the

Novel Insights into Hypoxia Induced AKT Signaling

Thursday, August 24, 2017 - 10:51

Hypoxia is a common feature of most tumors and is a product of rapid cell growth and poor vascularization1. When oxygen availability is low in the tumor environment, the hypoxia inducing transcription factors (HIFs) regulate a variety of signaling programs that can affect the balance between tumor cell apoptosis2 and autophagy3.  In normoxia, HIFs are bound by the von Hippel-Lindau protein (VHL) in the cytosol where it is degraded by the proteasome, however, under hypoxia HIFs are translocated to the nucleus where they activate survival signals. Additionally, HIF mediated signaling can increase the metastatic capabilities of tumor cells and facilitate the pro-metastatic phenotypes of epithelial to mesenchymal transition (EMT), alter tumor cell metabolism, increase vascularization and angiogenesis, as well as suppress immune reactivity1. Together these HIF regulated pathways help cancer cells to thrive and activate pro-...

pSIVA a Biological Switch and Sensor of Apoptosis

Monday, August 21, 2017 - 09:27

Altered cellular membrane integrity is one of the earliest signs of apoptosis.1,2 One key change during this event is the movement of phosphatidylserine (PS) from the inner leaflet of the cell membrane towards the cell surface. This process, due to the inactivation of flippase- and activation of scramblase-enzymes, is inducible, reversible and dependent upon calcium release from the endoplasmic reticulum.1 Exposure of PS acts as an "eat me" signal, prompting phagocytosis of apoptotic cells.3 In the absence of PS exposure during apoptosis, dying cells would escape the immune system ensuing an inflammatory response.2 Thus, PS externalization has emerged as a useful event and target for monitoring the progression of apoptosis in real-time.

The discovery of a natural ligand, Annexin A5, which binds reversibly, selectively and with high-affinity to exposed PS prompted its development as a biological tool for the...

Applications Focus: 5 tips for Flow Cytometry Panel Design

Monday, August 14, 2017 - 13:14

1. Know your cytometer

The configuration of flow cytometers including light sources (lasers) and optics (mirrors, filters, and detectors) vary and a few, such as the Propel ZE5 Cell Analyzer, can detect up to 30 parameters in thousands to millions of cells. Lasers excite fluorochromes at fixed wavelengths and the emitted fluorescence is captured by optical detectors called photomultiplier tubes (PMTs). Setting PMT voltages correctly is important because a low setting can compromise signal detection. Furthermore, some instruments have interchangeable/swappable filters offering more flexibility when designing flow cytometry experiments.

2. Optimize antibody selections

To prevent complications during your experiment, take time to choose your antibodies and optimize their working conditions. Best practices dictate lowly expressed proteins or those with rare epitopes should be paired with antibodies conjugated to...

Article Review: Glucose-induced transcriptional regulation in cancer

Tuesday, August 8, 2017 - 14:20

Epigenetic mechanisms have been implicated in many physiological and pathophysiological processes. Among these, histone modifications including methylation, phosphorylation, acetylation and ubiquitination, significantly modify gene expression. In cancer, specific abnormal epigenetic changes are thought to impart tumor cells with properties that facilitate their survival.1 Recently, a new study uncovered a novel mechanism regulating epigenetic changes of importance in cancer. Briefly, a sequence of post-translational modifications triggered by changes in glucose levels were identified to positively impact tumor sphere formation and tumor engraftment.2

Histone acetylation is generally associated with an increase in gene transcription.3 Formation of this epigenetic mark is catalyzed by...

Application Focus: New targets for immunostaining analysis of microglia

Tuesday, August 1, 2017 - 09:35

Microglia are resident macrophages in the central nervous system (CNS) that play roles in immune defense, inflammatory response, neurodegenerative disease and development. Identification of microglia has confounded researchers aiming to understand their biological function in the CNS, as they are molecularly and morphologically similar to other myeloid cells. For example, morphologically, microglia are indistinguishable from infiltrating blood derived macrophages.1 Additionally, microglia are commonly purified for study based on their expression of molecular markers, such as CD11bHigh and CD45Low; although, these may change in disease states.2,3

To fully understand and uncover the roles of microglia in the CNS, specific markers that accurately identify these cells are needed. Recently, investigators have embarked in efforts to elucidate specific...

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