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: 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: Distinct microglial activation states have been identified using RNA-seq data from a vast array of neurological disease and aging models. These activation states have been categorized into modules corresponding to proliferation, neurodegeneration, interferon-relation, LPS-relation, and many others (1). Previous work identifying markers of specific brain cell types using RNA-seq has shown HS1 and ASC/TMS1 to be useful and specific tools to study microglia (2). HS1 is a protein kinase substrate that is expressed only in tissues and cells of hematopoietic origin (3) and ASC/TMS1 has been found to be a critical component of inflammatory signaling where it associates with and activates caspase-1 in response to pro-inflammatory signals (4).
Background: Vascular endothelial growth factor receptor 2 (VEGFR2, KDR, Flk-1) is a major receptor for VEGF-induced signaling in endothelial cells. Upon ligand binding, VEGFR2 undergoes autophosphorylation and becomes activated (1). Major autophosphorylation sites of VEGFR2 are located in the kinase insert domain (Tyr951/996) and in the tyrosine kinase catalytic domain (Tyr1054/1059) (2). Activation of the receptor leads to rapid recruitment of adaptor proteins, including Shc, GRB2, PI3 kinase, NCK, and the protein tyrosine phosphatases SHP-1 and SHP-2 (3). Phosphorylation at Tyr1212 provides a docking site for GRB2 binding and phospho-Tyr1175 binds the p85 subunit of PI3 kinase and PLCγ, as well as Shb (1,4,5). Signaling from VEGFR2 is necessary for the execution of VEGF-stimulated proliferation, chemotaxis and sprouting, as well as survival of cultured endothelial cells in vitro and angiogenesis in vivo (6-8).
Background: The innate immune system responds rapidly to pathogens by detecting conserved pathogen-associated molecular patterns (PAMPs) and damage/danger-associated molecular patterns (DAMPs) through pattern recognition receptors (PRRs). There are several families of PRRs. Toll-like receptors (TLRs) are transmembrane PRRs and signal through recruitment of adaptor proteins, including MyD88, which leads to recruitment and phosphorylation of IRAK1 and IRAK4, followed by activation of NF-κB and MAP kinases (1-3). Some TLRs also activate IRFs, which upregulate the type I interferon response. Activation of TLR3 and TLR4 results in phosphorylation and activation of IRF-3, while TLR7, TLR8, and TLR9 lead to activation of IRF-7 (2, 3). STING is a multi-pass ER transmembrane protein that is activated in response to intracellular DNA downstream of DNA-sensing cytoplasmic PRRs, such as DDX41, or by binding the second messenger cyclic-GMP-AMP (cGAMP) produced by cGAS (4-6). Following activation, STING translocates with TBK1 to perinuclear endosomes, leading to phosphorylation and activation of IRF-3 and NF-κB (7, 8). Following activation and translocation, STING gets phosphorylated by ULK1, resulting in STING inactivation and degradation (9). Inflammasomes are cytoplasmic multimeric protein complexes that assemble in response to PAMPs or DAMPs detected by AIM2 or members of the nod-like receptor (NLR) family, such as NLRP3 (10). Inflammasomes activate Caspase-1, which cleaves the IL-1β and IL-18 precursor proteins into the mature forms (10).