20.500.12556/RUL-173588 Vloga gama-enolaze pri razvoju in degeneraciji celic centralnega živčnega sistema The role of gamma-enolase in the development and degeneration of the central nervous system cells Celice centralnega živčnega sistema za svoj razvoj in delovanje potrebujejo natančno usklajene signale, pri čemer pomembno vlogo igrajo nevrotrofični dejavniki. Encim ?-enolaza, poleg svoje presnovne funkcije, deluje tudi kot nevrotrofični dejavnik, katerega aktivnost je uravnana s cisteinsko peptidazo katepsinom X. Namen doktorske disertacije je bil raziskati vlogo ?-enolaze in njenega uravnavanja v različnih celičnih tipih osrednjega živčevja ter preučiti njun pomen pri diferenciaciji, preživetju in vnetno pogojeni nevrodegeneraciji. Rezultati so pokazali, da se med diferenciacijo nevronov, posebej v holinergični podtip, poveča izražanje aktivne oblike ?-enolaze, kar je povezano s spodbujeno rastjo nevritov, zmanjšano proliferacijo in povečanjem izražanja zrelostnih označevalcev. Zaviranje katepsina X dodatno poveča delež aktivne oblike ?-enolaze in okrepi diferenciacijo. V celičnim modelih Alzheimerjeve in Parkinsonove bolezni smo potrdili, da patološki dejavniki, kot sta peptid amiloid-ß in 6-hidroksidopamin, povzročijo zmanjšanje ravni aktivne oblike ?-enolaze in s tem oslabljen nevrotrofični učinek, medtem ko tretiranje celic s peptidom, ki posnema delovanje ?-enolaze, ali zaviranje katepsina X, ki ohrani aktivno obliko encima, stabilizira citoskeletno strukturo in izboljša preživetje nevronov. V celicah glije smo pokazali, da zaviranje katepsina X poveča raven aktivne oblike ?-enolaze, kar izboljša njihovo preživetje in posredno varuje nevrone, saj v mikrogliji zmanjšuje vnetni odziv, medtem ko v oligodendrocitih aktivna oblika ?-enolaze spodbuja diferenciacijo v zrele, mielinizacijske celice. Tudi v in vivo modelu eksperimentalnega avtoimunskega encefalomielitisa smo potrdili povečano izražanje aktivne oblike ?-enolaze sočasno z izražanjem regeneracijskih označevalcev in povišano aktivnostjo katepsina X, kar kaže na njegovo vlogo pri uravnavanju ravnovesja med nevrodegeneracijo in regeneracijo. Disertacija opredeljuje vlogo ?-enolaze v različnih celicah centralnega živčnega sistema ter njeno povezavo z vnetnimi in degenerativnimi procesi, kar odpira možnosti za ciljno zdravljenje nevrodegeneracije. Obetavne terapevtske strategije pri tem predstavljajo zaviralci katepsina X in mimetični peptidi ?-enolaze. Cells of the central nervous system require highly regulated signaling pathways for development and function, with neurotrophic factors playing a key role in these processes. Enzyme γ-enolase, in addition to its glycolytic function, acts as a neurotrophic factor whose activity is regulated by the cysteine peptidase cathepsin X through C-terminal cleavage. The present doctoral thesis investigates the role of γ-enolase and its regulation in central nervous system cells, focusing on their relevance in neuronal differentiation, survival, and inflammation-induced neurodegeneration. Our findings demonstrate that during neuronal differentiation, particularly toward a cholinergic phenotype, levels of active γ-enolase increase in association with enhanced neurite extension, reduced cellular proliferation, and upregulated expression of neuronal maturation markers. Inhibition of cathepsin X further elevated γ-enolase active form and facilitated neuronal differentiation. In cellular models of Alzheimer’s and Parkinson’s diseases, pathological agents such as amyloid β-peptide and 6-hydroxydopamine reduced active form of γ-enolase levels, compromising its neurotrophic function. Conversely, treatment with a γ-enolase–derived peptide that mimics its neurotrophic activity, or with a cathepsin X inhibitor that preserves active γ-enolase, maintained cytoskeletal integrity and improved neuronal survival. In glial cells, cathepsin X inhibition increased the levels of active form of γ-enolase, enhancing cell viability and exerting neuroprotective effects. Specifically, it reduced inflammatory activation in microglia and promoted oligodendrocyte differentiation and myelination. Moreover, secreted γ-enolase from glial cells supported neuronal survival under inflammatory conditions. In an in vivo model of experimental autoimmune encephalomyelitis, expression of active γ-enolase increased at peak disease stages, together with regeneration markers and cathepsin X activity. These findings elucidate the role of γ-enolase across distinct cell types of central nervous system and highlight its involvement in inflammatory and degenerative mechanisms, thereby providing a basis for therapeutic approaches in neurodegeneration. Altogether, cathepsin X inhibitors and γ-enolase mimetic peptides emerge as promising strategies for neurodegenerative diseases. γ-enolaza katepsin X razvoj celic centralnega živčnega sistema diferenciacija celic nevrodegeneracija nevrovnetje terapevtski pristopi γ-enolase cathepsin X development of central nervous system cells cell differentiation neurodegeneration neuroinflammation therapeutic approaches true false false Slovenski jezik Angleški jezik Doktorsko delo/naloga 2025-09-19 07:15:09 2025-09-19 07:15:36 2026-08-21 06:54:37 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 2027-09-15 35897 7972.pdf 7972.pdf 1 898CD936448BC49782A7EE0240B0A544 1c58d641edac471034c62d3b3a049ec71ad9622f06947f58e3c7e78112495b6d 8a42b164-9517-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=218192 Fakulteta za farmacijo 0 0 0