Background: Senescence is characterized by stable stress-induced proliferative arrest and resistance to mitogenic stimuli, as well as the secretion of proteins such as cytokines, growth factors and proteases. These secreted proteins comprise the senescence-associated secretory phenotype (SASP). Senescent cells are thought to accumulate as an organism ages, and contribute to age-related diseases, including cancer, through promotion of inflammation and disruption of normal cellular function (1,2).Because there is no single biomarker that can be used to definitively identify senescent cells, researchers must rely on a collection of biomarkers commonly associated with senescence. The Senescence Marker Antibody Sampler Kit provides a collection of antibodies to commonly used biomarkers of senescence-associated cell cycle arrest (p16 INK4A, p21 Waf1/Cip1), senescence-associated DNA damage (gamma-Histone H2A.X), and the SASP (HMGB1, IL-6, TNF-alpha, MMP3). The kit also includes an antibody to Lamin B1, which is frequently reduced in senescent cells.
Background: Senescence is characterized by stable stress-induced proliferative arrest and resistance to mitogenic stimuli, as well as the secretion of proteins such as cytokines, growth factors and proteases. These secreted proteins comprise the senescence-associated secretory phenotype (SASP). Senescent cells are thought to accumulate as an organism ages, and contribute to age-related diseases, including cancer, through promotion of inflammation and disruption of normal cellular function (1,2). The composition of the SASP varies, and SASP components can be either beneficial or deleterious in human disease, depending on the context (3).Senescence Associated Secretory Phenotype (SASP) Antibody Sampler Kit provides a collection of antibodies to various SASP components, including TNF-alpha, interleukin-6 (IL-6), the multifunctional cytokine IL-1beta, the chemokines CXCL10, RANTES/CCL5 and MCP-1, the matrix metalloprotease MMP3, and the serine-protease inhibitor PAI-1.
Background: The innate immune system works as the first line of defense in protection from pathogenic microbes and host-derived signals of cellular distress. One way in which these “danger” signals trigger inflammation is through activation of inflammasomes, which are multiprotein complexes that assemble in the cytosol after exposure to pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) and result in the activation of caspase-1 and subsequent cleavage of proinflammatory cytokines IL-1β and IL-18 (Reviewed in 1-6). Inflammasome complexes typically consist of a cytosolic pattern recognition receptor (PRR; a nucleotide-binding domain and leucine-rich-repeat [NLR] or AIM2-like receptor [ALR] family member), an adaptor protein (ASC/TMS1), and pro-caspase-1. A number of distinct inflammasome complexes have been identified, each with a unique PRR and activation triggers. The best characterized is the NLRP3 complex, which contains NLRP3, ASC/TMS1, and pro-caspase-1. The NLRP3 inflammasome is activated in a two-step process. First, NF-κB signaling is induced through PAMP- or DAMP-mediated activation of TLR4 or TNFR, resulting in increased expression of NLRP3, pro-IL-1β, and pro-IL-18 (priming step, signal 1). Next, indirect activation of NLRP3 occurs by a multitude of signals (whole pathogens, PAMPs/DAMPs, potassium efflux, lysosomal-damaging environmental factors [uric acid, silica, alum] and endogenous factors [amyloid-β, cholesterol crystals], and mitochondrial damage), leading to complex assembly and activation of caspase-1 (signal 2). The complex inflammasome structure is built via domain interactions among the protein components. Other inflammasomes are activated by more direct means: double-stranded DNA activates the AIM2 complex, anthrax toxin activates NLRP1, and bacterial flagellin activates NLRC4. Activated caspase-1 induces secretion of proinflammatory cytokines IL-1β and -18, but also regulates metabolic enzyme expression, phagosome maturation, vasodilation, and pyroptosis, an inflammatory programmed cell death. Inflammasome signaling contributes to the onset of a number of diseases, including atherosclerosis, type II diabetes, Alzheimer’s disease, and autoimmune disorders.