Browsing by Subject "CDNF"

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  • Hella, Emilia (Helsingfors universitet, 2015)
    This review focuses on neurotrophic factors, especially CDNF, and Amyotropic lateral sclerosis (ALS). This review finds out which neurotrophic factors have been studied in clinical trials of ALS and what kind of results have been got. Neurotrophic factors are important for development and function of neurons because they prevent apoptosis of neurons. They also play role in differentiation, development and migration of neurons. It is also known that many of the neurotrophic factors have protective and restorative properties. ALS is a rare neurodegenerative disease which causes the destruction of motor neurons and leads to death in three years. The disease degenerate the upper and lower motor neurons. Symptoms are muscle weakness, muscle atrophy, cramps and problems with swallowing. At the moment there is no cure for ALS so it is important to study neurotrophic factors that could prevent the progression of the disease and perhaps to protect or repair destroyed motor neurons. This is why it is important to study potential of CDNF in ALS. The experimental part consists of three different parts. The purpose of the first part study was to determine the distribution of CDNF after intraventricular delivery at different time points. CDNF was labeled with 125I (125I-CDNF). The distribution was determined by gammacounter and autoradiography. To determine the stability of the injected 125-I CDNF we performed SDS-PAGE. The second part studied the diffusion volume of CDNF after intraventricular injection with seven wild type mice. After stereotaxic surgery CDNF-immunohistochemistry staining from coronal sections was done. The last experimental part studied the effect of single intracerebral injection of CDNF on motivation, locomotor activity, anxiety and depression with male and female mice. Light-dark box, open field, rotarod, forced swim test (FST), elevated plus maze and fear conditioning were carried out with male mice. After behavioural tests mice were sacrified for HPLC-analysis. Light-dark box and IntelliCage were carried out with female mice before c-fos staining. Gammacounter and autoradiography shows that 125I-CDNF distributes widely after intracerebroventricular injection. It spread throughout to the brain and also all the way to the spinal cord after one and three hours from injection. After 24 hours 125I-CDNF was cleared so the CDNF signal was very weak. SDS-PAGE showed the stability of radioactive CDNF. CDNF increased locomotor activity and decreased anxiety in male mice. But a statistically significant difference appeared in forced swim test and fear conditioning test. HPLC-analysis supported these results partly. CDNF also increased motivation of female mice in IntelliCage experiment. C-fos staining was observed in CDNF group and PBS group so quantitative analysis should be done from these sections so that reliable conclusions could be done. However, because CDNF distributed to spinal cord and it showed some effect on locomotor activity, motivation and depression it might be potential for ALS disease.
  • Viljakainen, Tuulikki (Helsingfors universitet, 2019)
    Parkinson’s disease is a progressive neurodegenerative disease, in which dopamine neurons are dying in the nigrostriatal dopaminergic pathway. This causes motor symptoms such as slowness of movement, tremor, and rigidity. In addition, various non-motor symptoms appear. All currently used medicines are symptomatic, and there are no disease modifying treatment available for Parkinson’s disease. Several neurotrophic factors have shown promise in animal models of Parkinson’s disease. One of those is cerebral dopamine neurotrophic factor (CDNF) which has been studied in different animal models, including rodents and non-human primates. CDNF is a secreted protein but it is also localized in endoplasmic reticulum (ER). CDNF has two domains, N-terminal and C-terminal, which may have distinct functions. CDNF can be retained in the ER by the ER retention sequence at the end of the C-terminal domain. The C-terminal domain also has an evolutionarily conserved disulfide bridge which is crucial for the biological activity of CDNF. The exact mechanism of CDNF is still unknown. However, it has been shown that CDNF affects the unfolded protein response (UPR) in the presence of ER stress. Neurotrophic factors do not penetrate blood-brain barrier (BBB), for this reason, they need to be injected directly to the brain. Penetration of the BBB is also a problem in the treatment of many other diseases. Various methods for enhancing the BBB penetration of drugs have been studied. For example, permeability of the BBB can be temporarily increased by focused ultrasound combined with microbubbles. Another possibility is the use of a carrier molecule, which can be transported through BBB via specific transport mechanisms. Furthermore, molecule modification offers many applications to achieve enhanced BBB penetration. In view of peripheral administration, a next generation variant of CDNF (ngCDNF) has been developed. The efficacy of this novel variant after intrastriatal injection is equal to that of CDNF in a 6-hydroxydopamine (6-OHDA) rat model of Parkinson’s disease. Systemic administration could also enable treatment of non-motor symptoms of Parkinson’s disease. The aim of this experiment was to study the effects of subcutaneously injected ngCDNF on rotation behaviour, and nigrostriatal TH-positive cells in rats with 6-OHDA lesions. 6-OHDA was injected unilaterally to three different sites in the striatum. Two weeks later, the lesion size was estimated, via amphetamine- induced rotation test. ngCDNF, at two dose levels, was injected twice weekly for three weeks. Amphetamine-induced rotation test was assessed every other week, until week 12. At the end, optical density of tyrosine hydroxylase (TH) was measured from sections of the striatum, and TH positive cells in the substantia nigra were counted. In addition, the effect of ngCDNF on anxiety and depression like behaviour, learning, and locomotor activity were studied at three different levels in naïve mice. Behaviour was analyzed by open field test, forced swim test, and fear conditioning test. The ngCDNF did not seem to have clear effect on rats’ behaviour or TH positive cells and fibers compared to the control group, but positive tendency was found in the group with lower dose. The reduced efficacy of ngCDNF,via subcutaneous administration, is likely due to rapid metabolism and insufficient entry of the active form to the brain. In naïve mice, ngCDNF did not reduce anxiety-like behaviour and did not affect locomotor activity after subcutaneous injections. This result supports previous findings, which suggest that the effects of CDNF are specific to the toxin treated cells and CDNF has no effect in naïve animals.
  • Peltola, Roosa (Helsingin yliopisto, 2020)
    Amyotrophic lateral sclerosis (ALS) is a rare fatal neurodegenerative disease in which both the upper and lower motor neurons degenerate. Pathological features of the disease include misfolded proteins and accumulations in the central nervous system. The molecular mechanisms of the disease include neuroinflammation, glutamate induced excitotoxicity, and endoplasmic reticulum stress (ER-stress). Numerous genetic defects have been identified in the background of ALS, the most common mutations are in the C9ORF72, SOD1, TDP43 and FUS genes. For each gene mutation, it is important to develop a reliable animal model of ALS for studying pathology and testing new therapies. The most common and most recently found gene mutation, the C9ORF72 repeat expansion mutation, does not yet have an established animal disesase model. The molecular mechanisms of the disease include neuroinflammation, glutamate induced excitotoxicity, and endoplasmic reticulum stress (ER- stress). There is no drug treatment to cure or slow ALS, so the need for new drug therapies that affect the course of the disease is significant. Cerebral dopamine neurotrophic factor (CDNF) protects and restores dopamine neurons and controls ER-stress in preclinical models of Parkinson’s disease. CDNF has also been shown to improve motor coordination as well as protect spinal cord neurons from cell destruction in ALS genetic SOD1- G93A mouse and TDP-43M337 animal models. The purpose of this master's thesis study was to characterize the changes related to neurodegeneration and neuroinflammation in the new C9ORF72-500 disease model and study ER stress of the SOD1-93A disease model and the effect of CDNF on ER stress in SOD1-model and on inflammation in C9-model. In the first sub-study, brain sections from C9ORF72 transgenic and wild-type mice at different time points were subjected to six different immunohistological stainings. The results were compared at each time point (30, 70 and 170) between the wild type and the transgenic group. In another sub-study, spinal cord sections from CDNF snd vehicle treated SOD1- G93A mice were subjected to immunofluorescence staining, after which the intensity of their ER stress marker, GRP78, was analyzed using a confocal microscope. GFAP stained brain sections from CDNF and vehicle treated C9ORF72 mice were analyzed using microscope and imaging analyses. The results of the first sub-study showed neuroinflammation at 24 weeks timepoint in the transgenic group compared to wild-type mice. Pathological features of C9-ALS, various protein accumulations, were observed only in the transgenic group, mainly at 24 weeks. No neuronal loss was observed in this study. The obtained results support the previously published research results and support the reliability of the studied disease model. In the second sub-study ER stress levels were higher in SOD1-mice compared to wild-type mice. Single intracerebroventrical CDNF injection reduced ER stress in SOD1-G93A transgenic mice almost to the same level as ER stress in wild-type mice. CDNF treatment also showed a tendency for reducing inflammation in hippocampus and motor cortex of C9ORF72 mice. The results confirm the pathological role of ER stress in ALS and show that CDNF reduces ER stress when administered as early in the disease as possible, when neuronal damage begins to occur but does not yet lead to neuronal destruction. CDNF appears to be a promising drug candidate for the treatment of ALS and should therefore be further investigated.
  • Valkonen, Konsta Valentin (Helsingin yliopisto, 2021)
    Amyotrophic lateral sclerosis (ALS) is the most common adult-onset motoneuron disease. ALS is characterized by a progressive loss of upper and lower motoneurons, resulting in muscle atrophy, paralysis and ultimately in death. Approximately 30,000 people die of ALS annually. There is no cure for ALS, and only two drugs - riluzole and edavarone - have been approved for the treatment of the disease. The complex pathology of ALS contributes to the lack of effective treatments. Several cellular pathologies have been suggested to contribute to the pathogenesis, including ER stress, disruption of calcium homeostasis, oxidative stress and excitotoxicity. Here we describe the cytoprotective effects of C-terminal fragments of the novel proteins with neurotrophic factor properties MANF (mesencephalic astrocyte-derived neurotrophic factor) and CDNF (cerebral dopamine neurotrophic factor) on a toxin model of ALS in vitro. Unlike the classical neurotrophic factors, MANF and CDNF are predominantly localized to the endoplasmic reticulum (ER) and have been shown to alleviate ER stress by keeping the unfolded protein response (UPR) transducers inactive. ER stress is a major component in many neurodegenerative diseases, including ALS, and is a promising therapeutic target for MANF and CDNF. However, the potential of these proteins in ALS treatment remains to be insufficiently described. We used differentiated motoneuron-like NSC-34 cells treated with a range of toxins, modelling different cellular pathologies linked to ALS. After the toxin addition, we treated the cells with MANF and CDNF variants and riluzole and measured the cell viability. The toxin panel consists of tunicamycin, ionomycin and staurosporine. Tunicamycin causes cell death by activating proapoptotic branches of the UPR. Ionomycin is an ionophore and depletes the ER of calcium, thus inducing both UPR-dependent and UPR-independent apoptosis. Less is known about the mechanisms of staurosporine, but it has been shown to induce caspase-3-dependent apoptosis, increase intracellular calcium levels and cause oxidative stress. We hypothesized that both MANF and CDNF variants protect the cells against UPR-dependent apoptosis but not against UPR-independent cell death. We show that MANF and CDNF variants protect the cells against apoptosis induced by tunicamycin, ionomycin and staurosporine. Interestingly, the protein variants mediated the highest protection against ionomycin-induced stress, and they exhibited mild protective effects against staurosporine as well. These findings suggest that MANF and CDNF variants might have a role in maintaining intracellular calcium homeostasis. However, it is possible that staurosporine induces ER stress as well, which would explain the protection conferred by the protein variant. We report that the CDNF variant mediates higher protection at lower concentrations compared to the MANF variant in every toxin assay, whereas the MANF variant mediates higher protection at the highest tested concentration compared to the CDNF variant. We also show that the CDNF variant-mediated protection against staurosporine-induced stress peaked at lower concentrations, and the highest concentration provided distinctively lower, yet significant effect. These data lead us to hypothesize that the protein variants may have a slightly different mode of action, and that they might provide an additive effect when administered simultaneously. We tested a combination of MANF and CDNF variants in cells treated with tunicamycin, ionomycin and staurosporine. However, the combination treatment did not increase the viability more than MANF and CDNF variants independently did. The results answered our questions as well as raised new ones. In the future, the putative calcium-regulating effects of the protein variants should be investigated. The UPR-modifying effects of the drug candidates and toxins need to be assessed by quantifying changes in the UPR marker mRNA and protein expression levels. If it is revealed that the variants have a different mode of action, the possible additive protective effects must be assessed. Finally, a wider toxin panel is needed to fully explore the potential of MANF and CDNF variants in ALS treatment. This study demonstrates the potential of MANF and CDNF variants in protecting motoneurons against several pathological pathways contributing to ALS pathology. However, the mechanisms of action of the variants need further investigation to fully understood their therapeutic potential.
  • Pakarinen, Emmi; Lindholm, Paivi; Saarma, Mart; Lindahl, Maria (2022)
    Cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) display cytoprotective effects in animal models of neurodegenerative diseases. These endoplasmic reticulum (ER)-resident proteins belong to the same protein family and function as ER stress regulators. The relationship between CDNF and MANF function, as well as their capability for functional compensation, is unknown. We aimed to investigate these questions by generating mice lacking both CDNF and MANF. Results showed that CDNF-deficient Manf(-/-) mice presented the same phenotypes of growth defect and diabetes as Manf(-/-) mice. In the muscle, CDNF deficiency resulted in increased activation of unfolded protein response (UPR), which was aggravated when MANF was ablated. In the brain, the combined loss of CDNF and MANF did not exacerbate UPR activation caused by the loss of MANF alone. Consequently, CDNF and MANF deficiency in the brain did not cause degeneration of dopamine neurons. In conclusion, CDNF and MANF present functional redundancy in the muscle, but not in the other tissues examined here. Thus, they regulate the UPR in a tissue-specific manner.
  • Huttunen, Henri J.; Saarma, Mart (2019)
    Neurotrophic factors (NTF) are a subgroup of growth factors that promote survival and differentiation of neurons. Due to their neuroprotective and neurorestorative properties, their therapeutic potential has been tested in various neurodegenerative diseases. Bioavailability of NTFs in the target tissue remains a major challenge for NTF-based therapies. Various intracerebral delivery approaches, both protein and gene transfer-based, have been tested with varying outcomes. Three growth factors, glial cell-line derived neurotrophic factor (GDNF), neurturin (NRTN) and platelet-derived growth factor (PDGF-BB) have been tested in clinical trials in Parkinson?s Disease (PD) during the past 20 years. A new protein can now be added to this list, as cerebral dopamine neurotrophic factor (CDNF) has recently entered clinical trials. Despite their misleading names, CDNF, together with its closest relative mesencephalic astrocyte-derived neurotrophic factor (MANF), form a novel family of unconventional NTF that are both structurally and mechanistically distinct from other growth factors. CDNF and MANF are localized mainly to the lumen of endoplasmic reticulum (ER) and their primary function appears to be modulation of the unfolded protein response (UPR) pathway. Prolonged ER stress, via the UPR signaling pathways, contributes to the pathogenesis in a number of chronic degenerative diseases, and is an important target for therapeutic modulation. Intraputamenally administered recombinant human CDNF has shown robust neurorestorative effects in a number of small and large animal models of PD, and had a good safety profile in preclinical toxicology studies. Intermittent monthly bilateral intraputamenal infusions of CDNF are currently being tested in a randomized placebo-controlled phase I?II clinical study in moderately advanced PD patients. Here, we review the history of growth factor-based clinical trials in PD, and discuss how CDNF differs from the previously tested growth factors.
  • Silmu, Veera (Helsingin yliopisto, 2021)
    Parkinsonin tauti on hitaasti etenevä hermorappeumasairaus, jossa mustatumakkeen dopamiinihermosolut tuhoutuvat. Taudille on tyypillistä dopamiinihermosoluissa esiintyvät Lewyn kappaleet, jotka koostuvat pääasiassa väärin laskostuneesta ja kasautuneesta alfasynukleiiniproteiinista. Myös neuroinflammaation uskotaan olevan osa Parkinsonin taudin patofysiologiaa. Nykyiset lääkkeet vaikuttavat ainoastaan taudin oireisiin, joten tarve uusille lääkkeille on suuri. Pilottikokeen tarkoituksena oli selvittää aiheuttaako adenoassosioidun virus- (AAV) vektorin alfasynukleiinin ja alfasynukleiinifibrillien yhdistelmämalli rotilla liikehäiriöitä ja tyrosiinihydroksylaasi- (TH) positiivisten dopamiinihermosolujen tuhoutumista mustatumakkeessa ja hermopäätteiden tuhoutumista aivojuoviossa sekä saadaanko mallilla aikaan neuroinflammatorinen vaste. Varsinaisen pitkän kokeen tarkoituksena oli selvittää aivojen dopamiinihermokasvutekijän (CDNF) mahdollinen neurorestoratiivinen vaikutus tässä mallissa. Alfasynukleiinin kasautumispatologian tasoa ja CDNF:n neurorestoratiivista vaikutusta selvitettiin käyttäytymiskokeilla sekä mustatumakkeen ja aivojuovion TH-vasta-ainevärjäyksillä. Yhdistelmämallista aiheutuvaa neuroinflammatorista vastetta selvitettiin ionisoidun kalsiumia sitovan adapterimolekyylin 1 (Iba1) ja gliaalisen fibrillaarisen happaman proteiinin (GFAP) vasta-ainevärjäyksillä. Pilottikokeen sylinterikokeessa yhdistelmämalli ei indusoinut liikehäiriötä, mutta pitkän kokeen askel- ja sylinterikokeessa mallin osoitettiin aiheuttavan unilateraalille leesiolle tyypillinen liikehäiriö. Pilottikokeen ja pitkän kokeen TH-vasta-ainevärjäyksissä mallin osoitettiin aiheuttavan TH-positiivisten dopamiinihermosolujen tuhoutumista mustatumakkeessa ja hermopäätteiden tuhoutumista aivojuoviossa. Nämä tulokset osoittavat, että yhdistelmämallilla saadaan aikaan alfasynukleiinin kasautumispatologiaa. Pilottikokeessa osoitettiin myös, että yhdistelmämallilla saadaan aikaan neuroinflammatorinen vaste, mikä osoittaa, että malli soveltuu hyvin uusien lääkkeiden vaikutuksen tutkimiseen Parkinsonin tautiin liittyvässä neuroinflammaatiossa. Pitkän kokeen sylinterikokeessa AAV-CDNF:llä ei ollut vaikutusta mallista aiheutuvaan liikehäiriöön. Sen sijaan askeltestissä kämmenen suunnan mittauksessa AAV-CDNF korjasi liikehäiriötä. AAV-CDNF ei kuitenkaan suojannut TH-positiivisia hermosoluja mustatumakkeessa tai hermopäätteitä aivojuoviossa, minkä perusteella johtopäätöstä CDNF:n neurorestoratiivisesta vaikutuksesta ei voida tehdä.
  • Tallberg, Thomas (Helsingfors universitet, 2017)
    Transactive DNA Response Element Binding Protein 43 (TDP-43) is a RNA binding protein participating in gene expression on a transcriptional level. It is localized in the cell nucleus. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting upper and lower motor neurons. In most ALS patients TDP-43 becomes localized into the cytoplasm of neurons and glia cells. The TDP-43 rat ALS model provide insight in ALS disease progression and molecular mechanisms. This animal model has been characterized previously in the literature. Cerebral Dopamine Growth Factor (CDNF) is a neuroprotective and restorative protein in rat animal model of Parkinson's disease. CDNF may have an impact on disease progression in ALS. One of the goals in this work was to recharacterize the TDP-43 rat ALS model and to try repeat published data. The other aim of this work was to treat TDP-43 rats with intraventricular chronic infusion of CDNF, and to compare symptom progression with TDP-43 rats treated with phosphate buffered saline. Behavioral assays were done trice a week and when rats reached endpoint, spinal cords were removed. Motor neuron counting and detection of stress granule formation were investigated in spinal cords with immunohistochemistry. Also, the volume of CDNF diffusion in rat brain after chronic intraventricular CDNF infusion was investigated with immunohistochemistry. In the characterization part, symptom progression was repeated in a similar manner as it has been reported previously. CDNF treatment could not stop the symptom progression nor slow down the progression of symptoms in TDP-43 rats. Motor neuron counting revealed a heavy loss of motor neurons in the lumbal part of the spinal cord in both treatment groups. Diffusion of CDNF was very poor in the rat brain. Higher doses of CDNF and proper administration depth in the brain or route of administration should be reconsidered in the future.
  • Montonen, Ella (Helsingfors universitet, 2015)
    Endoplasmic reticulum stress (ER-stress) is the result of accumulation of unfolded and misfolded proteins in the ER. The unfolded proteins activate the unfolded protein response (UPR), which seeks to reduce the protein load in the ER and reduces ER-stress. When ER-stress is prolonged, the UPR will activate apoptosis. Amyotrophic lateral sclerosis (ALS) is a rare, progressive neurodegenerative disease that affects lower and higher motorneurons. The cause of ALS is unknown but ER-stress is known to play a role in the disease progression. CDNF is a new neurotrophic factor, which is known to play a role in protein folding in the ER. CDNF is neuroprotective and neurorestorative in animal models of Parkinson's disease. Thus, CDNF is a potential new drug candidate for treating ALS. The aim of this work was to examine the effect of CDNF on disease state and life span in transgenic SOD1(G93A)-mice. CDNF or PBS was injected into the mouse's ventricle in stereotaxic surgery when the mice were about 90 days old. Clinical status and motor coordination was monitored twice a week throughout the study. The mice were dissected when they reached the end point that was set for the study. Deepfrozen gastrocnemius muscles were stained with antibodies, to examine the integrity of the neuromuscular junctions (NMJ). Quantitative PCR (qPCR) was executed on deepfrozen spinal cord and motor cortex samples to measure the expression of ER-stress genes. The results showed that CDNF improves motor coordination and delays disease progression in SOD1 female mice. The NMJs were notably more damaged in SOD1 mice than in wild type mice, but CDNF did not have any significant effect on NMJ integrity. ER-stress could be observed in the spinal cord and motor cortex of SOD1 mice and CDNF decreased ER-stress in the motor cortex. CDNF did not decrease ER-stress in the spinal cord where the expression of apoptosis related genes was increased. Thus, CDNF is a potential new drug candidate for treating ALS and it should be studied further.
  • Almeida, Sérgio (Helsingfors universitet, 2016)
    Cerebral dopamine neurotrophic factor (CDNF) and mesencephalic astrocyte-derived neurotrophic factor (MANF) form a novel neurotrophic factor family due to their unique structure and different mode of action when compared to classical neurotrophic factors. CDNF and MANF have shown to protect dopaminergic neurons in Parkinson's disease animal models and therefore they are considered potential therapy agents. However, their target molecules, i.e., putative receptor(s) and signalling pathways are still unknown. 78 kDa glucose-regulated protein (GRP78) member of the heat shock protein (HSP) family is a major chaperone that under Endoplasmic Reticulum (ER) stress conditions is up-regulated and prevents protein aggregation as well as facilitates degradation of misfolded proteins. It locates mainly in the ER but location can change in different conditions. In cancer research, GRP78 has been found highly expressed on the surface of cancer cells where it regulates critical oncogenic signalling pathways. For example, it was recently shown that Par-4 (Prostate apoptosis response-4) induces apoptosis via activation of caspase-3 by binding to GRP78, expressed at the surface of cancer cells. GRP78 has been shown capable of relocating extracellularly also in neurons. Especially, it was recently shown that accumulating extracellular α-synuclein induces an increase in surface-exposed GRP78 in cultured neurons. α-synuclein interacts with cell surface GRP78 and activates a signalling cascade affecting the morphology and dynamics of actin cytoskeleton. Our group has recent, yet unpublished data suggesting that CDNF and MANF interact with GRP78 protein. The emerging role for GRP78 also in the neurodegeneration requests further investigation on its possible interaction with CDNF and MANF and on the biological meaning of that interaction. In order to test whether CDNF and MANF would interact with cell surface GRP78 and possibly compete with par-4 for the binding and in this way prevent apoptosis, we built a plasmid that would guide the expression and extracellular localization of GRP78 in the transfected cells. We transfected HEK293 cells with this plasmid and incubated them for 24h with two concentrations of par-4. We could see a trend of increasing apoptosis in PAR-4 –treated cells, but this was not enhanced in the cells expressing GRP78 extracellularly, as we had hypothesised. Thus we did not continue further with testing CDNF and MANF on this setting. Transfected HEK293 cells were incubated with alkaline phosphatase tagged MANF or CDNF (AP-MANF or AP-CDNF) and using the alkaline phosphatase substrate pNitrophenylphosphate (pNPP), we were able to study the binding between GRP78 and CDNF and MANF. Even though we could not prove the cell surface GRP78 interaction with MANF with this method, we show a high affinity binding between cell surface GRP78 and CDNF when transfected cells are incubated with different concentrations of AP-CDNF.
  • Zaki, Urfa (Helsingin yliopisto, 2019)
    Cerebral dopamine neurotrophic factor (CDNF) belongs to the the family of neurotrophic factors that are evolutionary conserved, having a unique structure, with two domains: C-terminal domain and the N-terminal domain, and a cysteine bridge. It is known to be involved in the repair of the dopaminergic neurons when studied in the animal models of PD, which shows their different mode of action as compared to other neurotrophic factors, highlighting their therapeutic potential. Analysis of the crystal structure shows that CDNF and MANF consist of two domains: the saposin-like N-terminal domain with five α-helices stabilized by three disulphide bridges, and presumably unstructured C-terminal domain with a disulphide bridge. Characteristic feature of saposin-like proteins is their ability to interact with membranes or lipids. The lipid interaction may be crucial for the activity of CDNF and MANF proteins. In the first part of this project, the binding of CDNF was tested with several oxidized lipids, using two methods; Co-sedementation assay and lipid fluorescence assay;with two different types of probes. According to the results, CDNF seemed to show binding with POVPC. The second part of the project involved testing the binding and internalization of CDNF to mouse myoblast cells in the presence of oxidized lipid; POVPC. It was observed that CDNF seemed to show binding to the cell surface of the mouse myoblast cells (C2C12) and is also observed to be internalized to the cells as well. However, as these are the preliminary results, so we need to further test the binding between the protein and other lipids and devise more precise protocols for the testing the internalization to the cells.
  • Galli, Emilia; Lindholm, Päivi; Kontturi, Leena-Stiina; Saarma, Mart; Urtti, Arto; Yliperttula, Marjo (2019)
    Cerebral Dopamine Neurotrophic Factor (CDNF) shows beneficial effects in rodent models of Parkinson?s and Alzheimer?s disease. The brain is a challenging target for protein therapy due to its exclusive blood?brain barrier. Hence, the therapeutic protein should be delivered directly to the brain parenchyma. Implantation of encapsulated mammalian cells that constantly secrete CDNF is a potential approach for targeted and long-term protein delivery to the brain. In this study, we generated several CDNF-secreting cell clones derived from human retinal pigment epithelial cell line ARPE-19, and studied CDNF secretion from the clones maintained as monolayers and in polymeric microcapsules. The secretion of wild type (wt) CDNF transgene was low and the majority of the produced protein remained intracellular, locating mainly to the endoplasmic reticulum (ER). The secretion of wtCDNF decreased to even lower levels when the clones were in a non-dividing state, as in the microcapsules. Both codon optimization and deletion of the putative ER-retrieval signal (four last amino acids: KTEL) improved CDNF secretion. More importantly, the secretion of KTEL-deleted CDNF remained constant in the non-dividing clones. Thus, cells expressing KTEL-deleted CDNF, in contrast to wtCDNF, can be considered for cell encapsulation applications if the KTEL-deleted CDNF is proven to be biologically active in vivo.
  • Korpelainen, Anna (Helsingfors universitet, 2019)
    Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease in which both upper and lower motor neurons degenerate gradually. The disease leads to a total paralysis of almost all skeletal muscles and to death within 3-5 years after onset. At the moment there are two disease modifying medicines available, riluzole and edaravone. Neither is able to cure the disease or even to stop or remarkably slow down its progression. Endoplasmic reticulum (ER) stress has been proposed as one of the pathophysiological mechanisms underlying ALS. During ER stress misfolded of unfolded proteins accumulate in ER lumen. As a defense mechanism, the cell launches unfolded protein response (UPR). UPR response aims to reduce the protein load in ER and restore cell’s normal functions. If the damage is already beyond repair, UPR signal cascades lead to programmed cell death. Neurotrophic factors (NTFs) regulate the growth of nervous tissue and participate in repairing processed. Many of the known NTFs have first seemed promising in the preclinical models of ALS but however failed in clinical trials. Cerebral dopamine neurotrophic factor (CDNF) differs drastically both in structure and function from conventional NTFs. CDNF has seen to relieve ER stress and improve motor behavior in the animal models of Parkinsons’s disease. Recently CDNF entered clinical trials in Parkinson’s patients. Since ER stress is believed to be present not only in ALS but also in Parkinson’s disease and other neurodegenerative diseases, it might have an effect in treating ALS patients. SOD1-G93A is a well-established animal model of ALS in which the animals show typical motor impairments comparable to human disease. In this study we used a novel mouse line obtained from crossing traditional SOD1-G93A model and CDNF knock out models. The study aimed to evaluate the effect of endogenic CDNF loss in survival, onset of symptoms, motor behavioral and spinal motor neuron degeneration in the new line. ER-stress and autophagy marker levels were studied with quantitative polymerase chain reaction (CNDF) and western blotting techniques. Spinal motor neuron loss was examined by anti-choline acetyltransferase antibody (ChAT) stainings. SOD1-G93A CDNF knock out animals were observed to have more severe motor impairments in the early stages of the disease compared to the traditional SOD1-G93A mice. In addition, the degeneration of spinal motor neurons appeared to be more severe in the new line. There were no statistically significant differences in ER stress between the genotypes although a trend of increased ER stress was observed. Endogenous CDNF loss had no effect on the healthy animals. The results suggest that CNDF is a potential treatment for ALS and it might have only little side effect since it does not seen to affect healthy tissue. In medical usage, CDNF might be most effective when administered immediately after disease onset. However, this might be difficult because of the challenges in ALS diagnosis.
  • Huotarinen, Antti; Penttinen, Anna-Maija; Bäck, Susanne; Voutilainen, Merja H.; Julku, Ulrika; Piepponen, T. Petteri; Männistö, Pekka T.; Saarma, Mart; Tuominen, Raimo; Laakso, Aki; Airavaara, Mikko (2018)
    Several neurotrophic factors ( NTF) are shown to be neuroprotective and neurorestorative in pre-clinical animal models for Parkinson's disease ( PD), particularly in models where striatal dopamine neuron innervation partially exists. The results of clinical trials on late-stage patients have been modest. Subthalamic deep brain stimulation ( STN DBS) is a proven treatment for a selected group of advanced PD patients. The cerebral dopamine neurotrophic factor ( CDNF) is a promising therapeutic protein, but its effects in animal models of late-stage PD have remained under-researched. The interactions of NTF and STN DBS treatments have not been studied before. We found that a nigral CDNF protein alone had only a marginal effect on the behavioral deficits in a late-stage hemiparkinsonian rat model ( 6-OHDA MFB). However, CDNF improved the effect of acute STN DBS on front limb use asymmetry at 2 and 3 weeks after CDNF injection. STN lesion-modeling chronic stimulation-had an additive effect in reducing front limb use in the cylinder test and apomorphine-induced rotation. The combination of CDNF and acute STN DBS had a favorable effect on striatal tyrosine hydroxylase. This study presents a novel additive beneficial effect of NTF and STN DBS, which might be explained by the interaction of DBS-induced endogenous NTFs and exogenously injected CDNF. SNpc can be reached via similar trajectories used in clinical STN DBS, and this interaction is an important area for future studies. (C) 2018 The Authors. Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/).
  • Sket, Tina (Helsingin yliopisto, 2020)
    Endoplasmic reticulum (ER) stress is caused by the accumulation of unfolded proteins in the ER, which leads to the activation of unfolded protein response (UPR) through three transmembrane protein sensors located in the ER membrane. The sensors correspond to three branches of the UPR, namely protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1 (IRE1) branches. Upon ER stress, IRE1 dimerizes and oligomerizes, and its endonuclease domain is activated. It specifically targets X-box-binding protein 1 (XBP1) mRNA, from which a 26 nt intron is spliced. This allows a complete translation of spliced XBP1 mRNA into a functional protein that acts as a transcription factor. Together with the other pathways, the UPR leads to a decrease in the protein folding load by causing a reduction in the general level of protein translation, and by inducing the expression of protein folding machinery. However, if the UPR is activated continuously for a long time, the apoptotic pathway will be triggered, and the cell will die. ER stress and UPR are associated with various disorders, such as some types of cancer, diabetes, chronic inflammatory syndromes, and particularly neurodegeneration. For example, in Parkinson’s disease, it was suggested that prolonged ER stress induces the extensive apoptosis of dopaminergic neurons in substantia nigra pars compacta region of the midbrain. This hinders the normal functioning of the nigrostriatal pathway, and hence results in the progressive development of Parkinson’s motor symptoms. In order to study the regulation or IRE1 branch of the UPR, and to identify the ER-stress-modulating compounds, a human luciferase reporter cell line (XBP1-NLuc) was created in this work. The reporter was expressed when IRE1 splicing was activated, since the XBP1 intron fragment was fused to the Nano luciferase gene. The expression of the reporter was observed with luciferase assay at several time points during treatments. The treatments were done with ER stress inducers thapsigargin and tunicamycin, and with IRE1 inhibitors KIRA6 and 4μ8c, or the combination of those. Quantitative PCR (qPCR) was used to validate the expression of the reporter and to monitor the expression of the other branches of the UPR. Additionally, the oligomerization of IRE1 was observed with IRE1-GFP cell line that was treated identically to the XBP1-NLuc cell line, fixed, stained for nuclei, and imaged with fluorescent microscopy. After imaging, the IRE1-GFP clusters were analysed and quantified with CellProfiller and CellAnalyst softwares. Both cell lines were used to test the effect of neurotrophic factors CDNF, MANF, and MANF mutant isomers on the UPR with and without tunicamycin treatment. Collectively, the experiments confirmed that XBP1-NLuc cell line was created successfully and that it accurately reports IRE1 splicing activity. As expected, ER stress treatment increased the reporter expression, while IRE1 inhibitors decreased the expression of the reporter. qPCR revealed that the other observed UPR markers were activated as well upon thapsigargin treatment, however, they were not decreased with the treatment with IRE1 specific inhibitors. In line with XBP1-NLuc cell line, the IRE1-GFP cell line demonstrated an increased oligomerization of IRE1 upon ER stress induction. The KIRA6 inhibitor of IRE1, which prevents IRE1 oligomerization, decreased the formation of IRE1-GFP clusters. Additionally, the IRE1-endonuclease-activity inhibitor 4μ8c induced the formation of IRE1-GFP clusters. Curiously, the distribution of the intensity of IRE1-GFP clusters was bimodal and could point to two manners of IRE1 clustering and/or activation. Together, the experiments done with cells transfected with CDNF, MANF or MANF mutants, suggested that the tested neurotrophic factors decreased IRE1 oligomerization and its activation. However, there were substantial problems in the quantification of viable cells, which should be considered in the interpretation of these results. No significant difference among the tested neurotrophic factors was observed. In conclusion, the XBP1-NLuc reporter cell line provided a reliable reporter of IRE1 endonuclease activity, whose expression is increased during the ER stress. Together with IRE1-GFP cell line, it revealed the amount of IRE1 oligomerization and activation under various treatments and at different time points relative to treatments. Due to the effectiveness and accuracy, the XBP1-NLuc cell line can be further used in studying the regulation and activation of IRE1, as well as for the identification of ER-stress modulating molecules, which can be used for development of novel treatments for ER stress associated diseases, such as Parkinson’s disease.
  • Saukkonen, Anni (Helsingfors universitet, 2015)
    Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease affecting motor neurons. It finally leads to the malfunction of the respiratory muscles and death after 1-3 years of diagnosis. Sporadic cases of ALS cover 90-95% of all patients and familial 5-10% respectively. The onset of the disease is usually between age of 40 and 60 and the worldwide incidence is considered to be 1-2/100000. Currently discovered cerebral dopamine neurotrophic factor, CDNF, has showed neuroprotective effects on Parkinson's disease model. What is more, it is known that CDNF is expressed in the muscles of mice and one of its' main functions is to protect cells from ER-stress, one of the pathological mechanisms in ALS. Hence, it is rational to study the effects of CDNF in ALS mouse model. Treatment options are needed, since there is only one approved treatment for ALS, anti-glutaminergic rilutzole. The aim of this study was to find out whether CDNF shows neuroprotective effects in SOD1-mice e.g. by measuring the changes in motor function with different behavioral tests. More over, the distribution of CDNF after intrathecal ventricle injection was studied using immunohistochemical and radioactive labeling methods. The hypothesis was that CDNF is distributed through the cerebrospinal fluid into the spinal cord and muscles in the limbs and shows neuroprotective effects in this SOD1 mouse model.
  • Walkowicz, Lucyna; Kijak, Ewelina; Krzeptowski, Wojciech; Gorska-Andrzejak, Jolanta; Stratoulias, Vassilis; Woznicka, Olga; Chwastek, Elzbieta; Heino, Tapio I.; Pyza, Elzbieta M. (2017)
    In Drosophila melanogaster, mesencephalic astrocyte-derived neurotrophic factor(DmMANF) is an evolutionarily conserved ortholog of mammalian MANF and cerebral dopamine neurotrophic factor (CDNF), which have been shown to promote the survival of dopaminergic neurons in the brain. We observed especially high levels of DmMANF in the visual system of Drosophil a, particularly in the first optic neuropil (lamina). In the lamina, DmMANF was found in glial cells (surface and epithelial glia), photoreceptors and interneurons. Interestingly, silencing of DmMANF in all neurons or specifically in photoreceptors or L2 interneurons had no impact on the structure of the visual system. However, downregulation of DmMANF in glial cells induced degeneration of the lamina. Remarkably, this degeneration in the form of holes and/or tightly packed membranes was observed only in the lamina epithelial glial cells. Those membranes seem to originate from the endoplasmic reticulum, which forms autophagosome membranes. Moreover, capitate projections, the epithelial glia invaginations into photoreceptor terminals that are involved in recycling of the photoreceptor neurotransmitter histamine, were less numerous after DmMANF silencing either in neurons or glial cells. The distribution of the alpha subunit of Na+/K+-ATPase protein in the lamina cell membranes was also changed. At the behavioral level, silencing of DmMANF either in neurons or glial cells affected the daily activity/sleep pattern, and flies showed less activity during the day but higher activity during the night than did controls. In the case of silencing in glia, the lifespan of flies was also shortened. The obtained results showed that DmMANF regulates many functions in the brain, particularly those dependent on glial cells.
  • Singh, Abhishek (Helsingin yliopisto, 2019)
    Neurotrophic factors (NTFs) play an important role in regulating the survival, differentiation and maturation of developing neurons. Based on strong pre-clinical evidences, some of NTFs have been suggested to be efficient therapeutic agents for treatment of Parkinson’s disease (PD). PD is a neurodegenerative disorder characterized by loss of dopamine (DA) neurons from nigrostriatal pathway resulting in motor symptoms of the disease. A hallmark of the disease is the presence of Lewy bodies in the brain and they comprise majorly of aggregated alpha-synuclein (aSyn) protein. MANF, an unconventional NTF, was discovered over a decade ago and differs from traditional NTFs. Removal of MANF has been shown to trigger unfolded protein response in cells. Evidences indicate that increased endogenous level of aSyn may have a role in enhancing the process of aggregation of aSyn into Lewy body. Determining the initiation event of aSyn aggregation is an important step in Lewy body pathology and it is still under investigation. In the first part of this study, I aimed to elucidate if MANF knockout can trigger any change in endogenous level of aSyn. Transmission of Lewy bodies from cell to cell has been well studied by researchers and is suggested to spread across brain in a prion like fashion. CDNF has been neuroprotective and restorative for tyrosine hydroxylase (TH)-positive neurons in a toxin-based models of PD. However, presently exists no study which has evaluated the effects of CDNF on propagation of aSyn aggregates in vivo. In the second part of this study, I aimed at evaluating effects of long-term intrastriatal infusion of CDNF at two concentrations (1.5 μg/24h or 3 μg/24h) on propagation of endogenous phosphorylated aSyn inclusions in vivo. CRISPR/Cas9-mediated MANF knockout in SH-SY5Y cells did not yield any significant changes in the endogenous level of aSyn. Additionally, brain samples derived from MANF knockout mice yielded similar non-significant difference in level of aSyn compared to wild-type mice. MANF knockout primary DA neurons when inoculated either with only pre-formed fibrils (PFFs) or with a combination of PFFs and aSyn overexpression, showed no significant difference in the number of Lewy body like aggregates, suggesting no change in endogenous aSyn levels. Rats were injected with PFFs and then chronically infused with CDNF, 1 month and 2 months after PFFs at 2 different concentrations (1.5 μg/24h or 3 μg/24h). Immunohistochemical analysis of substantia nigra pars compacta (SNpc) derived from rats showed similar numbers of endogenous phosphorylated aSyn inclusions in animals treated chronically with either CDNF or PBS. In summary, only MANF knockout from cells or animals has no direct effect on endogenous level of aSyn. But external stressors may perhaps trigger upregulation of aSyn in MANF knockout cells. Furthermore, chronic infusion of CDNF either 1 month or 2 months after PFF injection doesn’t reduce the total number of phosphorylated aSyn inclusions in SNpc compared to control. Nevertheless, we need more data to corroborate this evidence.
  • Poyhonen, Suvi; Er, Safak; Domanskyi, Andrii; Airavaara, Mikko (2019)
    Astrocytes, oligodendrocytes, and microglia are abundant cell types found in the central nervous system and have been shown to play crucial roles in regulating both normal and disease states. An increasing amount of evidence points to the critical importance of glia in mediating neurodegeneration in Alzheimer's and Parkinson's diseases (AD, PD), and in ischemic stroke, where microglia are involved in initial tissue clearance, and astrocytes in the subsequent formation of a glial scar. The importance of these cells for neuronal survival has previously been studied in co-culture experiments and the search for neurotrophic factors (NTFs) initiated after finding that the addition of conditioned media from astrocyte cultures could support the survival of primary neurons in vitro. This led to the discovery of the potent dopamine neurotrophic factor, glial cell line-derived neurotrophic factor (GDNF). In this review, we focus on the relationship between glia and NTFs including neurotrophins, GDNF-family ligands, CNTF family, and CDNF/MANF-family proteins. We describe their expression in astrocytes, oligodendrocytes and their precursors (NG2-positive cells, OPCs), and microglia during development and in the adult brain. Furthermore, we review existing data on the glial phenotypes of NTF knockout mice and follow NTF expression patterns and their effects on glia in disease models such as AD, PD, stroke, and retinal degeneration.
  • Voutilainen, Merja H.; De Lorenzo, Francesca; Stepanova, Polina; Bäck, Susanne; Pulkkila, Päivi; Pörsti, Eeva; Saarma, Mart; Männistö, Pekka T.; Tuominen, Raimo K. (2017)
    Parkinson's disease (PD) is a neurodegenerative disorder associated with a progressive loss of dopaminergic (DAergic) neurons of the substantia nigra (SN) and the accumulation of intracellular inclusions containing alpha-synuclein. Current therapies do not stop the progression of the disease, and the efficacy of these treatments wanes over time. Neurotrophic factors (NTFs) are naturally occurring proteins promoting the survival and differentiation of neurons and the maintenance of neuronal contacts. CDNF (cerebral dopamine NTF) and GDNF (glial cell line-derived NTF) are able to protect DAergic neurons against toxin-induced degeneration in experimental models of PD. Here, we report an additive neurorestorative effect of coadministration of CDNF and GDNF in the unilateral 6-hydroxydopamine (6-OHDA) lesion model of PD in rats. NTFs were given into the striatum four weeks after unilateral intrastriatal injection of 6-OHDA (20 mu g). Amphetamine-induced (2.5 mg/kg, i.p.) rotational behavior was measured every two weeks. Number of tyrosine hydroxylase (TH)-positive cells from SN pars compacta (SNpc) and density of TH-positive fibers in the striatum were analyzed at 12 weeks after lesion. CDNF and GDNF alone restored the DAergic function, and one specific dose combination had an additive effect: CDNF (2.5 mu g) and GDNF (1 mu g) coadministration led to a stronger trophic effect relative to either of the single treatments alone. The additive effect may indicate different mechanism of action for the NTFs. Indeed, both NTFs activated the survival promoting PI3 kinase (PI3K)-Akt signaling pathway, but only CDNF decreased the expression level of tested endoplasmatic reticulum (ER) stress markers ATF6, glucose-regulated protein 78 (GRP78), and phosphorylation of eukaryotic initiation factor 2 alpha subunit (eIF2 alpha).