Sirtuins are a family of signaling proteins involved in metabolic regulation. They are ancient in animal evolution and appear to possess a highly conserved structure throughout all kingdoms of life. Chemically, sirtuins are a class of proteins that possess either mono-ADP-ribosyltransferase or deacylase activity, including deacetylase, desuccinylase, demalonylase, demyristoylase and depalmitoylase activity. The name Sir2 comes from the yeast gene 'silent mating-type information regulation 2', the gene responsible for cellular regulation in yeast.
Pyroptosis is a highly inflammatory form of lytic programmed cell death that occurs most frequently upon infection with intracellular pathogens and is likely to form part of the antimicrobial response. This process promotes the rapid clearance of various bacterial, viral, fungal and protozoan infections by removing intracellular replication niches and enhancing the host's defensive responses. Pyroptosis can take place in immune cells and is also reported to occur in keratinocytes and some epithelial cells.
Histone deacetylase inhibitors are chemical compounds that inhibit histone deacetylases.
Nicotinamide phosphoribosyltransferase, formerly known as pre-B-cell colony-enhancing factor 1 (PBEF1) or visfatin for its extracellular form (eNAMPT), is an enzyme that in humans is encoded by the NAMPT gene. The intracellular form of this protein (iNAMPT) is the rate-limiting enzyme in the nicotinamide adenine dinucleotide (NAD+) salvage pathway that converts nicotinamide to nicotinamide mononucleotide (NMN) which is responsible for most of the NAD+ formation in mammals. iNAMPT can also catalyze the synthesis of NMN from phosphoribosyl pyrophosphate (PRPP) when ATP is present. eNAMPT has been reported to be a cytokine (PBEF) that activates TLR4, that promotes B cell maturation, and that inhibits neutrophil apoptosis.
Sirtuin 1, also known as NAD-dependent deacetylase sirtuin-1, is a protein that in humans is encoded by the SIRT1 gene.
NAD-dependent deacetylase sirtuin 2 is an enzyme that in humans is encoded by the SIRT2 gene. SIRT2 is an NAD+ -dependent deacetylase. Studies of this protein have often been divergent, highlighting the dependence of pleiotropic effects of SIRT2 on cellular context. The natural polyphenol resveratrol is known to exert opposite actions on neural cells according to their normal or cancerous status. Similar to other sirtuin family members, SIRT2 displays a ubiquitous distribution. SIRT2 is expressed in a wide range of tissues and organs and has been detected particularly in metabolically relevant tissues, including the brain, muscle, liver, testes, pancreas, kidney, and adipose tissue of mice. Of note, SIRT2 expression is much higher in the brain than all other organs studied, particularly in the cortex, striatum, hippocampus, and spinal cord.
NAD-dependent deacetylase sirtuin 7 is an enzyme that in humans is encoded by the SIRT7 gene. SIRT7 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein.
Sirtuin 6 is a stress responsive protein deacetylase and mono-ADP ribosyltransferase enzyme encoded by the SIRT6 gene. In laboratory research, SIRT6 appears to function in multiple molecular pathways related to aging, including DNA repair, telomere maintenance, glycolysis and inflammation. SIRT6 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein.
Tesaglitazar is a dual peroxisome proliferator-activated receptor agonist with affinity to PPARα and PPARγ, proposed for the management of type 2 diabetes.
Fibroblast growth factor 21 is a liver-secreted peptide hormone that in humans is encoded by the FGF21 gene. Together with FGF19 and FGF23, this protein is a member of the endocrine subgroup within the fibroblast growth factor (FGF) family. FGF21 is a potent, extracellularly acting metabolic regulator, whose action was discovered through in vitro phenotypic screening and diet manipulation studies in rodents., unlike canonical growth-stimulating FGFs known to stimulate mitosis, differentiation and angiogenesis in their target tissues, FGF21 exerts its action by activating FGF21 receptors located in the cell membrane of target cells. Each FGF21 receptor is composed of a transmembrane FGF receptor protein, and its complexing co-receptor β-Klotho. Loss of β-Klotho abolishes all effects of FGF21 in vitro and in vivo. In addition to its action as a hormone, FGF21 may be able to act in an autocrine fashion, or possibly also in a paracrine manner in the pancreas.
SRT-1720 is an experimental drug that was studied by Sirtris Pharmaceuticals intended as a small-molecule activator of the sirtuin subtype SIRT1. The compound has been studied in animals, but safety and efficacy in humans have not been established.
Sirtuin 4, also known as SIRT4, is a mitochondrial protein which in humans is encoded by the SIRT4 gene. SIRT4 is member of the mammalian sirtuin family of proteins, which are homologs to the yeast Sir2 protein. SIRT4 exhibits NAD+-dependent deacetylase activity.
Sirtris Pharmaceuticals, Inc. was a biotechnology company based in Cambridge, MA that developed therapies for type 2 diabetes, cancer, and other diseases. Conceived in 2004 by Harvard University biologist David Sinclair and serial entrepreneur Andrew Perlman, and founded that year by Sinclair and Perlman, along with Christoph Westphal, Richard Aldrich, Richard Pops, and Paul Schimmel, the company was focused on developing Sinclair's research into activators of sirtuins, work that began in the laboratory of Leonard P. Guarente where Sinclair worked as a post-doc before starting his own lab.
Fisetin (7,3′,4′-flavon-3-ol) is a plant flavonol from the flavonoid group of polyphenols. It can be found in many plants, where it serves as a yellow/ochre colouring agent. It is also found in many fruits and vegetables, such as strawberries, apples, persimmons, onions and cucumbers. Its chemical formula was first described by Austrian chemist Josef Herzig in 1891.
Sirtuin-activating compounds (STAC) are chemical compounds having an effect on sirtuins, a group of enzymes that use NAD+ to remove acetyl groups from proteins. They are caloric restriction mimetic compounds that may be helpful in treating various aging-related diseases.
SRT-2183 is a drug in development by Sirtris Pharmaceuticals intended as a small-molecule activator of the sirtuin subtype SIRT1. It has similar activity in animal studies to another SIRT1 activator SRT-1720, but is closer in potency to resveratrol. In animal studies it was found to improve insulin sensitivity and lower plasma glucose levels in fat, muscle and liver tissue, and increased mitochondrial and metabolic function. However, the claim that SRT-2183 is a SIRT1 activator has been questioned and further defended.
SRT-1460 is a drug in development by Sirtris Pharmaceuticals intended as a small-molecule activator of the sirtuin subtype SIRT1. It has similar activity in animal studies to the known SIRT1 activator resveratrol, but is closer in potency to SRT-1720. In animal studies it was found to improve insulin sensitivity and lower plasma glucose levels in fat, muscle and liver tissue, and increased mitochondrial and metabolic function. However, the claim that SRT1460 is a SIRT1 activator has been questioned and further defended.
A senolytic is among a class of small molecules under basic research to determine if they can selectively induce death of senescent cells and improve health in humans. A goal of this research is to discover or develop agents to delay, prevent, alleviate, or reverse age-related diseases. A related concept is "senostatic", which means to suppress senescence.
SRT-3025 is an experimental drug that was studied by Sirtris Pharmaceuticals as a small-molecule activator of the sirtuin subtype SIRT1. It has been investigated as a potential treatment for osteoporosis, and anemia.
STAC-9 is an experimental drug that was developed by GlaxoSmithKline as a small-molecule activator of the sirtuin subtype SIRT1, with potential applications in the treatment of diabetes.
