Bio-Rad Apoptosis Assays - Manual (Page 3)

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Introduction
Apoptosis refers to a genetically controlled process by which cells die
following a programmed physiological state or pathological condition.
The balance between pro- and anti-apoptotic processes is delicate,
and dysregulation is observed in a wide range of pathological conditions
(Rutledge 2002). Excessive apoptosis is implicated in neurodegenerative
and autoimmune diseases, myocardial infarction, stroke, and viral infection. In
contrast, insufficient apoptosis is linked to almost every known human cancer.
Cell death activation is thought to be regulated by the Bcl-2 family of proteins,
which consists of both pro-apoptotic and anti-apoptotic members. At least 17
human proteins with Bcl-2 homology have already been identified. Although
much has been studied about Bcl-2 family–mediated apoptosis, there is clearly
more to discover, specifically the mechanism by which heterodimerization
regulates both pro- and anti-apoptotic proteins (Rutledge 2002).
Apoptosis is induced by at least two distinct signaling pathways. The extrinsic
pathway is triggered by cell signaling through death receptors such as Fas,
followed by downstream activation of caspase-8 and caspase-3. The
intrinsic pathway is triggered by cytotoxic stress, which leads to translocation
of pro-apoptotic Bcl-2 proteins such as Bax and Bak to the mitochondrial
membrane. This causes release of cytochrome C into the cytosol, where it
promotes apoptosome formation and final activation of caspase-3.
Bio-Plex Pro
™
RBM Apoptosis Assays
The Bio-Plex Pro RBM apoptosis assays enable researchers to quantify
multiple intracellular proteins involved in the commitment, onset, and
induction of apoptosis by the intrinsic pathway. Compatible sample types
include cell lysates and tissue homogenates.
The use of magnetic (MagPlex) beads allows researchers to automate
wash steps on a Bio-Plex Pro (or similar) wash station. Magnetic separation
offers greater convenience, productivity, and reproducibility compared to
vacuum filtration.
References
Rutledge SE et al. (2002). A view to a kill: ligands for Bcl-2 family proteins.
Current Opinion in Chemical Biology (6), 479-485.