The Results of IGF-1 on TNF-?-Handled DRG Neurons by Modulating ATF3 and GAP-43 Expression through PI3K/Akt/S6K Signaling Pathway.
Neurochem Res. 2017 Could;42(5):1403-1421
Authors: Zhang L, Yue Y, Ouyang M, Liu H, Li Z
Upregulation of the pro-inflammatory cytokine tumor necrosis issue ? (TNF-?) is concerned within the growth and development of quite a few neurological issues. Latest studies have challenged the idea that TNF-? reveals solely deleterious results of pro-inflammatory destruction, and have raised the attention that it might play a helpful position in neuronal progress and performance specifically circumstances, which prompts us to additional examine the position of this cytokine. Insulin-like progress factor-1 (IGF-1) is a cytokine possessing highly effective neuroprotective results in selling neuronal survival, neuronal differentiation, neurite elongation, and neurite regeneration. The affiliation of IGF-1 with TNF-? and the organic results, produced by interplay of IGF-1 and TNF-?, on neuronal outgrowth standing of major sensory neurons are nonetheless to be clarified. Within the current research, utilizing an in vitro mannequin of major cultured rat dorsal root ganglion (DRG) neurons, we demonstrated that TNF-? problem at totally different concentrations elicited numerous organic results. Larger focus of TNF-? (10 ng/mL) dampened neurite outgrowth, induced activating transcription issue Three (ATF3) expression, decreased growth-associated protein 43 (GAP-43) expression, and promoted GAP-43 and ATF3 coexpression, which could possibly be reversed by IGF-1 remedy; whereas decrease focus of TNF-? (1 ng/mL) promoted neurite sprouting, decreased ATF3 expression, elevated GAP-43 expression, and inhibited GAP-43 and ATF3 coexpression, which could possibly be potentiated by IGF-1 complement. Furthermore, IGF-1 administration restored the activation of Akt and p70 S6 kinase (S6K) suppressed by greater focus of TNF-? (10 ng/mL) problem. In distinction, decrease focus of TNF-? (1 ng/mL) had no vital impact on Akt or S6K activation, and IGF-1 administration activated these two kinases. The results of IGF-1 had been abrogated by phosphatidylinositol Three-kinase (PI3K) inhibitor LY294002. These knowledge indicate that IGF-1 counteracts the poisonous impact of upper focus of TNF-?, whereas potentiates the growth-promoting impact of decrease focus of TNF-?, with the node for TNF-? and IGF-1 interplay being the PI3K/Akt/S6K signaling pathway. This research is useful for interpretation of the affiliation of IGF-1 with TNF-? and the neurobiological results elicited by interplay of IGF-1 and TNF-? in neurological issues.
PMID: 28210955 [PubMed – indexed for MEDLINE]