Octadecaneuropeptide (ODN) Induces N2a Cells Differentiation through a PKA/PLC/PKC/MEK/ERK-Dependent Pathway: Incidence on Peroxisome, Mitochondria, and Lipid Profiles.

Abstract

Neurodegenerative diseases are characterized by oxidative stress, mitochondrial damage, and death of neuronal cells. To counteract such damage and to favor neurogenesis, neurotrophic factors could be used as therapeutic agents. Octadecaneuropeptide (ODN), produced by astrocytes, is a potent neuroprotective agent. In N2a cells, we studied the ability of ODN to promote neuronal differentiation. This parameter was evaluated by phase contrast microscopy, staining with crystal violet, cresyl blue, and Sulforhodamine 101. The effect of ODN on cell viability and mitochondrial activity was determined with fluorescein diacetate and DiOC6(3), respectively. The impact of ODN on the topography of mitochondria and peroxisomes, two tightly connected organelles involved in nerve cell functions and lipid metabolism, was evaluated by transmission electron microscopy and fluorescence microscopy: detection of mitochondria with MitoTracker Red, and peroxisome with an antibody directed against the ABCD3 peroxisomal transporter. The profiles in fatty acids, cholesterol, and cholesterol precursors were determined by gas chromatography, in some cases coupled with mass spectrometry. Treatment of N2a cells with ODN (10-14 M, 48 h) induces neurite outgrowth. ODN-induced neuronal differentiation was associated with modification of topographical distribution of mitochondria and peroxisomes throughout the neurites and did not affect cell viability and mitochondrial activity. The inhibition of ODN-induced N2a differentiation with H89, U73122, chelerythrine and U0126 supports the activation of a PKA/PLC/PKC/MEK/ERK-dependent signaling pathway. Although there is no difference in fatty acid profile between control and ODN-treated cells, the level of cholesterol and some of its precursors (lanosterol, desmosterol, lathosterol) was increased in ODN-treated cells. The ability of ODN to induce neuronal differentiation without cytotoxicity reinforces the interest for this neuropeptide with neurotrophic properties to overcome nerve cell damage in major neurodegenerative diseases.

• Authors: Amira Namsi, Thomas Nury, Amira S Khan, Jérôme Leprince, David Vaudry, Claudio Caccia, Valerio Leoni, Atanas G Atanasov, Marie-Christine Tonon, Olfa Masmoudi-Kouki, Gérard Lizard
• Journal: Molecules (Basel, Switzerland) (Molecules) Vol. 24 Issue 18 (Sep 11 2019) ISSN: 1420-3049 [Electronic] Switzerland
• PMID: 31514417 (Publication Type: Journal Article)

Chemical References

• Diazepam Binding Inhibitor
• Lipids
• Neuropeptides
• Peptide Fragments
• Rhodamines
• diazepam binding inhibitor (33-50)
• Cyclic AMP-Dependent Protein Kinases
• Protein Kinase C
• Type C Phospholipases
• sulforhodamine 101

Topics

• Animals
• Cell Differentiation (drug effects)
• Cell Line, Tumor
• Cell Survival (drug effects)
• Cyclic AMP-Dependent Protein Kinases (metabolism)
• Diazepam Binding Inhibitor (pharmacology)
• Lipids (chemistry)
• MAP Kinase Signaling System (drug effects)
• Mice
• Mitochondria (drug effects, metabolism, ultrastructure)
• Neuropeptides (pharmacology)
• Peptide Fragments (pharmacology)
• Peroxisomes (drug effects, metabolism, ultrastructure)
• Protein Kinase C (metabolism)
• Rhodamines (chemistry, metabolism)
• Signal Transduction (drug effects)
• Type C Phospholipases (metabolism)