Browsing by Subject "KYP-2047"

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  • Pätsi, Henri T.; Kilpeläinen, Tommi P.; Auno, Samuli; Dillemuth, Pyry M. J.; Arja, Khaled; Lahtela-Kakkonen, Maija K.; Myöhänen, Timo T.; Wallen, Erik A. A. (2021)
    Different five-membered nitrogen-containing heteroaromatics in the position of the typical electrophilic group in prolyl oligopeptidase (PREP) inhibitors were investigated and compared to tetrazole. The 2-imidazoles were highly potent inhibitors of the proteolytic activity. The binding mode for the basic imidazole was studied by molecular docking as it was expected to differ from the acidic tetrazole. A new putative noncovalent binding mode with an interaction to His680 was found for the 2-imidazoles. Inhibition of the proteolytic activity did not correlate with the modulating effect on protein-protein-interaction-derived functions of PREP (i.e., dimerization of alpha-synuclein and autophagy). Among the highly potent PREP inhibiting 2-imidazoles, only one was also a potent modulator of PREP-catalyzed alpha-synuclein dimerization, indicating that the linker length on the opposite side of the molecule from the five-membered heteroaromatic is critical for the disconnected structure-activity relationships.
  • Huovila, Tiina (Helsingfors universitet, 2017)
    Autophagy is a pathway for cells to degrade intracellular components that are no longer needed or are detrimental for the cells. It is essential for cell homeostasis and survival and has been related to various diseases and pathophysiology. Autophagy is a complex process and there are still several unclear und unknown aspects to it. Regulation of autophagy is essential to prevent unwanted and escess activation, and several pathways and molecules, both stimulatory and inhibitory, are included. Different signaling pathways are sensitive to a variety of environmental clues. Two main autophagy pathways are mTOR-dependent pathway and mTOR-independent pathway. Induction of autophagy in the latter pathway is dependent on the interaction of Bcl-2 and Beclin 1. Prolyl oligopeptidase (PREP) is a peptidase enzyme that has several substrates. PREP-inhibition by KYP-2047 can reduce aggregation of α-synuclein in two ways: by increasing rate of autophagy and by decreasing dimerization. The aim of this study was to find out how PREP affects the interaction between Bcl-2 and Beclin 1 and how this affects autophagy. Based on previous studies, PREP-inhibition seems to increase the amount of Beclin 1 and to affect the phosphorylation of Bcl-2 and Beclin 1, leading to dissociation of the complex. Hypothesis was to see differences in colocalization of Bcl-2 and Beclin 1 in cells treated with different PREP-modifications and for PREP-inhibition to decrease the colocalization. Human embryonic kidney cells 293 (HEK-293) and hPREP knockout cell line created from them by using CRISPR/Cas9-silencing were used in the experiments. Two experiments were performed on regular HEK-cells: inhibitor experiment with KYP-2047 (1 or 10 µM) and overexpression experiment (transfection with either active or inactive hPREP plasmid). After immunofluorescence staining, cells were analysed with confocal microscope and colocation analysis of Bcl-2 and Beclin 1 was performed. The intensity of Beclin 1 in the nuclei was stronger than in other parts of the cell in all samples, which could indicate a stronger activity of its nuclear tasks compared to autophagy. However, the antibody used for immunofluorescence has most likely caused this staining pattern. Based on previous knowledge, it was expected to see differences in colocalization of Bcl-2 and Beclin 1 in cells treated with different PREP-modifications. However, there were no significant differences in colocalization of Beclin 1 and Bcl-2 in any of the experiments but it was nearly 100 percent in all treatments. Since rate of autophagy in cells was not detected, it is impossible to determine, if there were changes in autophagy that were not reflected as changes in colocalization of these two proteins. It is possible that even a small change in colocalization can affect the rate of autophagy or there might be subpopulations where the interaction is interrupted and these changes are so small that they are not detectable with the methods used in this experiment. Both Bcl-2 and Beclin 1 also have functions not related to autophagy, which could be one reason behind the results gained in this study.
  • Jokinen, Birgitta (Helsingfors universitet, 2010)
    Angiogenesis may be regarded as one of the most important phenomena involved in basic physiology as well as in numerous pathological conditions. Angiogenesis is a multistep process involving the balance of pro- and con-angiogenic factors. Several studies have suggested that angiogenesis is regulated in vitro and in vivo by peptides thymosin ȕ4 (Tȕ4) and tetrapeptide Ac-SDKP (N-acetyl-seryl-aspartyl-lysyl-proline). There are also studies supporting the view that Ac-SDKP, a peptide fragment is released from the proline-containing C-terminus of Tȕ4 (43-mer) by hydrolyzing prolyl oligopeptidase (POP). POP is a widely existing serine protease cleaving oligopeptides of no longer than 30 amino acids. Thus, Tȕ4 should first be cleaved into a shorter peptide by some other, yet unknown peptidase. POP has been mostly studied in memory and learning disorders as well as in neurodegenerative diseases. The true physiological character of POP is still unresolved. In this Master's thesis, the associations of the factors involved in angiogenesis are reviewed in the literature part as well as the character, presence and function of the angiogenic molecules 7ȕ4, Ac-SDKP and POP. In the experimental part attempts were made to find whether POP and Tȕ4 increase Ac-SDKP formation and capillary tube network and consequently, whether the POP activity, tetrapeptide and capillary formation could be inhibited by the proline-spesific POP inhibitor KYP-2047. The study had two phases. The first phase included POP activity and Ac-SDKP measurements(time period 0-180 min) with Wistar rat kidney homogenates. Study groups were 0,1 and 0,5 µM KYP-2047 (+2 µM Tȕ4), 1:20 (0.625 µM) human recombinant POP (+ 2 µM Tȕ4), 2 µM 7ȕ4 (pos. control) and raw homogenate (neg. control). The second phase involved the study of capillary formation (time period 0-180 min) with primary endothelial HUVECs on a 48-well plate seeded with 50 000 cells/well on an extracellular membrane mimicking MatrigelTM Matrix dissolved in DMEM. Study groups treated with fetal bovine serum and antibiotics were 5 and 10 µM KYP-2047 (+4 µM Tȕ4), 1:20 (0.625 µM) human recombinant POP (+4 µM Tȕ4)4 µM Tȕ4 (pos. control) and DMEM (neg. control). The wells were cultured and capillary formation photographed with a light microscope using a digital camera. All experiments were repeated four times, and each study group in wells was measured in triplicate. Enclosed capillaries were counted manually and statistical tests were performed. 7ȕ4 along with POP participated in the formation of AC-SDKP in the kidney homogenates. Cultures of primary endothelial cells on Matrigel resulted in clear capillary formation in Tȕ4 and POP groups. KYP-2047 had a strong POP-inhibitory activity on antiangiogenesis throughout the study resulting. Obviously, underlying mechanisms of angiogenesis and the function of the interaction between POP, Tȕ4 and Ac-SDKP in capillary formation require further studies.
  • Myöhänen, Timo T.; Norrbacka, Susanna; Savolainen, Mari H. (2017)
    Lewy bodies, the histopathological hallmarks of Parkinson's disease (PD), contain insoluble and aggregated alpha-synuclein (aSyn) and many other proteins, proposing a role for failure in protein degradation system in the PD pathogenesis. Proteasomal dysfunction has indeed been linked to PD and aSyn oligomers have been shown to inhibit proteasomes and autophagy. Our recent studies have shown that inhibitors of prolyl oligopeptidase (PREP) can prevent the aggregation and enhance the clearance of accumulated aSyn, and therefore, we wanted to study if PREP inhibition can overcome the aSyn aggregation and toxicity induced by lactacystin, a proteasomal inhibitor. The cells overexpressing human A30P or A53T mutated aSyn were incubated with lactacystin and a PREP inhibitor, KYP-2047, for 48 h. Theafter, the cells were fractioned, and the effects of lactacystin with/without 1 mu M KYP-2047 on aSyn aggregation and ubiquitin accumulation, cell viability and on autophagic markers (p62, Beclin1 and LC3BII) were studied. We found that KYP-2047 attenuated lactacystin-induced cell death in mutant aSyn overexpressing cells but not in non-overexpressing control cells. KYP-2047 reduced significantly SDS-insoluble high-molecular-weight aSyn oligomers that were in line with the cell viability results. In addition, significant reduction in protein accumulation marker, p62, was seen in SDS fraction while LC3BII, a marker for autophagosome formation, was increased, indicating to enhanced autophagy. Our results further streghten the possibilities for PREP inhibitors as a potential drug therapy against synucleinopathies and other protein aggregating diseases. (C) 2016 Elsevier Ireland Ltd. All rights reserved.
  • Julku, Ulrika H.; Panhelainen, Anne E.; Tiilikainen, Saija E.; Svarcbahs, Reinis; Tammimäki, Anne E.; Piepponen, T. Petteri; Savolainen, Mari H.; Myöhänen, Timo T. (2018)
    Alpha-synuclein is the main component of Lewy bodies, a histopathological finding of Parkinson's disease. Prolyl oligopeptidase (PREP) is a serine protease that binds to alpha-synuclein and accelerates its aggregation in vitro. PREP enzyme inhibitors have been shown to block the alpha-synuclein aggregation process in vitro and in cellular models, and also to enhance the clearance of alpha-synuclein aggregates in transgenic mouse models. Moreover, PREP inhibitors have induced alterations in dopamine and metabolite levels, and dopamine transporter immunoreactivity in the nigrostriatal tissue. In this study, we characterized the role of PREP in the nigrostriatal dopaminergic and GABAergic systems of wild-type C57Bl/6 and PREP knockout mice, and the effects of PREP overexpression on these systems. Extracellular concentrations of dopamine and protein levels of phosphorylated dopamine transporter were increased and dopamine reuptake was decreased in the striatum of PREP knockout mice, suggesting increased internalization of dopamine transporter from the presynaptic membrane. Furthermore, PREP overexpression increased the level of dopamine transporters in the nigrostriatal tissue but decreased phosphorylated dopamine transporters in the striatum in wild-type mice. Our results suggest that PREP regulates the function of dopamine transporter, possibly by controlling the phosphorylation and transport of dopamine transporter into the striatum or synaptic membrane.
  • Kilpelainen, Tommi P.; Tyni, Jonna K.; Lahtela-Kakkonen, Maija K.; Eteläinen, Tony S.; Myöhänen, Timo T.; Wallen, Erik A. A. (2019)
    4-Phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines were studied as prolyl oligopeptidase inhibitors. The compounds were more potent than expected from the assumption that the tetrazole would also here be a bioisostere of the carboxylic acid group and the corresponding carboxylic acids are at their best only weak inhibitors. The aminoacyl groups L-prolyl and L-alanyl gave potent inhibitors with IC50 values of 12 and 129 nM, respectively. This was in line with typical prolyl oligopeptidase inhibitors; however, we did observe a difference with N-methyl-L-alanyl, which gave potent inhibitors in typical prolyl oligopeptidase inhibitors but not in our novel compound series. Furthermore, all studied 4-phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines decreased alpha-synuclein dimerization at the concentration of 10 mu M, also when they were only weak inhibitors of the proteolytic activity of the enzyme with an IC50 value of 205 mu M. Molecular docking studies revealed that the compounds are likely to bind differently to the enzyme compared to typical prolyl oligopeptidase inhibitors represented in this study by 4-phenylbutanoyl-aminoacyl-2(S)-cyanopyrrolidines.
  • Kilpeläinen, Tommi P.; Hellinen, Laura; Vrijdag, Johannes; Yan, Xu; Svarcbahs, Reinis; Vellonen, Kati-Sisko; Lambeir, Anne-Marie; Huttunen, Henri; Urtti, Arto; Wallen, Erik A. A.; Myohanen, Timo T. (2020)
    Previous studies have shown that prolyl oligopeptidase (PREP) negatively regulates autophagy and increases the aggregation of alpha-synuclein (alpha Syn), linking it to the pathophysiology of Parkinson's disease. Our earlier results have revealed that the potent small molecular PREP inhibitor KYP-2047 is able to increase autophagy and decrease dimerization of alpha Syn but other PREP inhibitors have not been systematically studied for these two protein-protein interaction mediated biological functions of PREP. In this study, we characterized these effects for 12 known PREP inhibitors with IC50-values ranging from 0.2 nM to 1010 nM. We used protein-fragment complementation assay (PCA) to assess alpha Syn dimerization and Western Blot of microtubule-associated protein light chain 3B II (LC3B-II) and a GFP-LC3-RFP expressing cell line to study autophagy. In addition, we tested selected compounds in a cell-free alpha Syn aggregation assay, native gel electrophoresis, and determined the compound concentration inside the cell by LC-MS. We found that inhibition of the proteolytic activity of PREP did not predict decreased alpha Syn dimerization or increased autophagy, and we also confirmed that this result did not simply reflect concentration differences of the compounds inside the cell. Thus, PREP ligands regulate the effect of PREP on autophagy and alpha Syn aggregation through a conformational stabilization of the enzyme that is not equivalent to inhibiting its proteolytic activity.