Neuronal subtype-specific expression of γ-enolase : its role in neuronal differentiation

Horvat, Selena (author), Pečar Fonović, Urša (author), Zidar, Nace (author), Doljak, Bojan (author), Kos, Janko (author), Pišlar, Anja (author)

Neuronal differentiation into specific subtypes is crucial for nervous system development and function, guided by neurotrophic factors. γ-Enolase, a neuron-specific glycolytic enzyme, exhibits neurotrophic-like properties and supports neuronal differentiation; however, its role in specific neuronal subtypes remains unknown. Here, we investigate the role of γ-enolase in differentiation dopaminergic-, cholinergic-, and adrenergic-like neuronal cells. Our results demonstrate that γ-enolase expression is significantly upregulated in differentiated cells, with the highest expression observed in cholinergic-like neurons. Full-length γ-enolase, compared to its truncated form, promoted enhanced neurite outgrowth and increased β-tubulin, a cytoskeletal marker. Conversely, silencing endogenous γ-enolase significantly reduced neurite length, confirming its essential role in driving neuronal morphological maturation. Furthermore, a γ-enolase-derived peptide corresponding to the active C-terminus of γ-enolase significantly promoted neurite outgrowth and increased β-tubulin expression, particularly in cholinergic-like neuronal cells. Notably, γ-enolase activity is regulated by cathepsin X, a lysosomal peptidase that cleaves γ-enolase at its C-terminus, reducing its neurotrophic effects. Confocal microscopy revealed increased co-localization of γ-enolase and cathepsin X in differentiated neuronal cells, emphasizing their interaction in cholinergic-like neurons. Inhibiting cathepsin X preserved active γ-enolase, promoted neuronal differentiation, and altered cytoskeletal marker expression. These findings suggest an important role for γ-enolase in cholinergic-like neuronal cells and propose cathepsin X as a regulatory modulator of γ-enolase activity, suggesting novel therapeutic strategies for neuroregeneration.

• Language: English
• Keywords: cathepsin x regulation, enolase isoforms, neuronal specific subtype, neurotrophic activity, γ-enolase
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FFA - Faculty of Pharmacy
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 22 str.
• Numbering: Vol. 28, iss. 1, art. 4
• PID: 20.500.12556/RUL-181041
• UDC: 577.152.34
• ISSN on article: 1559-1174
• DOI: 10.1007/s12017-025-08902-9
• COBISS.SI-ID: 272309507
• Publication date in RUL: 23.03.2026

Record is a part of a journal

• Title: Neuromolecular medicine
• Shortened title: Neuromol. med.
• Publisher: Springer Nature
• ISSN: 1559-1174
• COBISS.SI-ID: 513713689

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: regulacija katepsina X, ozooblike enolaze, nevronsko specifični podtip, nevrotrofična aktivnost, γ-enolaza, katepsin X

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P4-0127
• Name: Farmacevtska biotehnologija: znanost za zdravje