Smoothened agonist (SAG) was one of the first small-molecule

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

s developed for the protein

Smoothened Smoothened is a protein that in humans is encoded by the ''SMO'' gene. Smoothened is a Class Frizzled (Class F) G protein-coupled receptor that is a component of the hedgehog signaling pathway and is conserved from flies to humans. It is the mole ...

, a key part of the

hedgehog signaling pathway The Hedgehog signaling pathway is a signaling pathway that transmits information to embryonic cells required for proper cell differentiation. Different parts of the embryo have different concentrations of hedgehog signaling proteins. The pathwa ...

, which is involved in brain development as well as having a number of other functions in the body. Smoothened agonist has been shown to aid proliferation and survival of developing

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

s, and prevent drug-induced brain injury. When injected into the

cerebellum The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...

of newborn mice with an induced Down syndrome-like condition, Smoothened agonist was able to stimulate normal cerebellum development, resulting in significant behavioural improvement once the mice had grown to adulthood. Smoothened Agonist was capable of inducing

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

production in both prostate and bone stromal cells that was significantly greater than even similarly treated

prostate cancer Prostate cancer is the neoplasm, uncontrolled growth of cells in the prostate, a gland in the male reproductive system below the bladder. Abnormal growth of the prostate tissue is usually detected through Screening (medicine), screening tests, ...

cells. The substance has been used as part of a chemical cocktail to turn old and senescent human cells back into young ones (as measured by transcriptomic age), without turning them all the way back into undifferentiated

stem cells In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...

References

{{Reflist Receptor agonists Down syndrome Chloroarenes