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Conventional protein kinase C isoforms mediate neuroprotection induced by phorbol ester and estrogen
Author(s) -
Cordey Myriam,
Pike Christian J.
Publication year - 2006
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.2005.03545.x
Subject(s) - neuroprotection , protein kinase c , gene isoform , estrogen , phorbol , microbiology and biotechnology , activator (genetics) , biology , signal transduction , isozyme , estrogen receptor , pharmacology , chemistry , biochemistry , endocrinology , enzyme , receptor , gene , genetics , cancer , breast cancer
Rapid signal transduction pathways play a prominent role in mediating neuroprotective actions of estrogen in the CNS. We have previously shown that estrogen‐induced neuroprotection of primary cerebrocortical neurons from β‐amyloid peptide (Aβ) toxicity depends on activation of protein kinase C (PKC). PKC activation with phorbol‐12‐myristate‐13‐acetate (PMA) also provides neuroprotection in this paradigm. Because the PKC family includes several isoforms that have opposing roles in regulating cell survival, we sought to identify which PKC isoforms contribute to neuroprotection induced by PMA and estrogen. We detected protein expression of multiple PKC isoforms in primary neuron cultures, including conventional (α, βI, βII), novel (δ, ε, θ) and atypical (ζ, ι/λ) PKC. Using a panel of isoform‐specific peptide inhibitors and activators, we find that novel and atypical PKC isoforms do not participate in the mechanism of either PMA or estrogen neuroprotection. In contrast, a selective peptide activator of conventional PKC isoforms provides dose‐dependent neuroprotection against Aβ toxicity. In addition, peptide inhibitors of conventional, βI, or βII PKC isoforms significantly reduce protection afforded by PMA or 17β‐estradiol. Taken together, these data provide evidence that conventional PKC isoforms mediate phorbol ester and estrogen neuroprotection of cultured neurons challenged by Aβ toxicity.