Project description:The biological activities of NGF and of its precursor proNGF are quite distinct, due to different receptor binding profiles, but nothing is known about how proNGF regulates gene expression. We performed experiments to address this question, by verifying whether a proNGF specific transcriptional signature, distinct from that of NGF, could be identified. To this aim, we studied gene expression regulation by proNGF and NGF in PC12 cells incubated for 1 and 4 hours with recombinant NGF and proNGF, in its wild-type or in a furin-cleavage resistant form. mRNA expression profiles were analyzed by whole genome microarrays at these early time points, in order to identify specific profiles of NGF and proNGF. Three-conditions experiment: PC12 cells were treated with NGF, wild type proNGF precursor (proNGF-WT), furin resistant mutated proNGF precursor (proNGF-KR) for 1 and 4 hours. Two biological replicates were performed for each condition. RNA was extracted after 1 hour and 4 hours of treatment for each treatment.
Project description:miRNA profiling of PC12 rat pheochromocytoma cells during NGF-induced differentiation and apoptosis of differentiated cells after 24h of NGF deprivation. miRNA expression in differentiating and deprivated cells was compared to untreated and terminally differentiated PC12 cells respectivelly.
Project description:miRNA profiling of PC12 rat pheochromocytoma cells during NGF-induced differentiation and apoptosis of differentiated cells after 24h of NGF deprivation. miRNA expression in differentiating and deprivated cells was compared to untreated and terminally differentiated PC12 cells respectivelly. Five-condition experiment, NGF-treated cells (1h, 3h, 6h, 24h, 240h) vs. untreated. One-condition experiment, NGF-deprivated vs. differentiated cells.
Project description:Expression profiling of PC12 cells stably transfected with GFP, GFP-SH2-Bb, or GFP-SH2-Bb(R555E), treated with or without NGF for 6h Keywords: response to NGF
Project description:The biological activities of NGF and of its precursor proNGF are quite distinct, due to different receptor binding profiles, but nothing is known about how proNGF regulates gene expression. We performed experiments to address this question, by verifying whether a proNGF specific transcriptional signature, distinct from that of NGF, could be identified. To this aim, we studied gene expression regulation by proNGF and NGF in PC12 cells incubated for 1 and 4 hours with recombinant NGF and proNGF, in its wild-type or in a furin-cleavage resistant form. mRNA expression profiles were analyzed by whole genome microarrays at these early time points, in order to identify specific profiles of NGF and proNGF.
Project description:Neuronal differentiation of PC12 cells in response to NGF is a prototypical model in which signal duration determines a biological response. Sustained ERK activity induced by NGF, as compared to transient activity induced by EGF, is critical to the differentiation of these cells. To characterize the transcriptional program activated preferentially by NGF, we compared global gene expression profiles between cells treated with NGF and EGF for 2-4 hrs, when sustained ERK signaling in response to NGF is most distinct from the transient signal elicited by EGF. This analysis identified 69 genes that were preferentially upregulated in response to NGF. PC12 cells that were starved in low serum media for 24 hrs were treated with NGF (50ng/mL) or EGF (25ng/mL) for 2 or 4 hrs, or left untreated. Total RNA for 3 independent biological replicates was extracted and subjected to Affymetrix Rat Gene 1.0ST Arrays. The 69 genes that were preferentially upregulated by NGF compared to EGF met the following criteria: NGF/No treatment log2> 1, FDR p value< 0.01 and NGF/EGF log2> 0.75, FDR p value< 0.01.
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that control protein expression through translational inhibition or mRNA degradation. MiRNAs have been implicated in diverse biological processes such as development, proliferation, apoptosis and differentiation. Upon treatment with nerve growth factor (NGF), rat pheochromocytoma PC12 cells elicit neurite outgrowth and differentiae into neuron-like cells. NGF plays a critical role not only in neuronal differentiation but also in protection against apoptosis. In an attempt to identify NGF-regulated miRNAs in PC12 cells, we performed miRNA microarray analysis using total RNAs harvested from cells treated with NGF. In response to NGF treatment, expression of 8 and 12 miRNAs were up- and down-regulated, respectively. Quantitative RT-PCR analysis confirmed increased expression of miR-221, miR-181a* and miR-326, and decreased expression of miR-143, miR-210 and miR-532-3p after NGF treatment, among which miR-221 was drastically up-regulated. Overexpression of miR-221 induced neurite outgrowth of PC12 cells in the absence of NGF treatment, and also enhanced neurite outgrowth caused by low-dose NGF. More importantly, knockdown of miR-221 by antagomir attenuated NGF-mediated neurite outgrowth. Finally, miR-221 decreased expression of Foxo3a and Apaf-1, both of which are involved in apoptosis in PC12 cells. Our results indicate that miR-221 plays a critical role for neuronal differentiation as well as protection against apoptosis in PC12 cells.