TY - JOUR
T1 - Induction of nerve growth factor by phorbol 12-myristate 13-acetate is dependent upon the mitogen activated protein kinase pathway
AU - Davis, Justin B.
AU - Calvert, Valerie
AU - Roberts, Steven
AU - Bracero, Sabrina
AU - Petricoin, Emanuel
AU - Couch, Robin
N1 - Publisher Copyright:
© 2018
PY - 2018/5
Y1 - 2018/5
N2 - Several small molecules have been identified that induce glial cells to synthesize and secrete nerve growth factor (NGF), a critical neurotrophin that supports neuronal growth and survival, and as such show promise in the development of drugs for the chemoprevention of Alzheimer's disease. To map the signal transduction cascade leading to NGF synthesis and secretion, cultured human glial cells were stimulated by phorbol 12-myristate 13-acetate (PMA), an agonist of Protein Kinase C. Changes in intracellular protein phosphorylation states were evaluated by reverse phase protein microarrays (RPPA), selectively screening over 130 protein endpoints. Of these, 55 proteins showed statistically significant changes in phosphorylation state due to cellular exposure to PMA. A critical signal transduction pathway was identified, and subsequent validation by ELISA and qPCR revealed that the signaling proteins Raf, MEK, ERK, and the signal transduction factor CREB are all essential to the upregulation of NGF gene expression by PMA. Additionally, members of the RSK family of kinases appear to be involved in glial secretion (exocytosis) of the NGF protein. Furthermore, through RPPA, the effects of PMA on apoptosis signaling events and cell proliferation were differentiated from the pathway to NGF upregulation. Overall, this study reveals potential protein targets for the rational design of Alzheimer's therapeutics.
AB - Several small molecules have been identified that induce glial cells to synthesize and secrete nerve growth factor (NGF), a critical neurotrophin that supports neuronal growth and survival, and as such show promise in the development of drugs for the chemoprevention of Alzheimer's disease. To map the signal transduction cascade leading to NGF synthesis and secretion, cultured human glial cells were stimulated by phorbol 12-myristate 13-acetate (PMA), an agonist of Protein Kinase C. Changes in intracellular protein phosphorylation states were evaluated by reverse phase protein microarrays (RPPA), selectively screening over 130 protein endpoints. Of these, 55 proteins showed statistically significant changes in phosphorylation state due to cellular exposure to PMA. A critical signal transduction pathway was identified, and subsequent validation by ELISA and qPCR revealed that the signaling proteins Raf, MEK, ERK, and the signal transduction factor CREB are all essential to the upregulation of NGF gene expression by PMA. Additionally, members of the RSK family of kinases appear to be involved in glial secretion (exocytosis) of the NGF protein. Furthermore, through RPPA, the effects of PMA on apoptosis signaling events and cell proliferation were differentiated from the pathway to NGF upregulation. Overall, this study reveals potential protein targets for the rational design of Alzheimer's therapeutics.
KW - Biochemistry
KW - Cell biology
KW - Molecular biology
KW - Neuroscience
UR - http://www.scopus.com/inward/record.url?scp=85047082182&partnerID=8YFLogxK
U2 - 10.1016/j.heliyon.2018.e00617
DO - 10.1016/j.heliyon.2018.e00617
M3 - Article
AN - SCOPUS:85047082182
SN - 2405-8440
VL - 4
JO - Heliyon
JF - Heliyon
IS - 5
M1 - e00617
ER -