Browsing by Subject "DOPAMINERGIC-NEURONS"

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  • Yu, Seong-Jin; Airavaara, Mikko; Wu, Kuo-Jen; Harvey, Brandon K.; Liu, H. S.; Yang, Yihong; Zacharek, Alex; Chen, Jieli; Wang, Yun (2017)
    The purpose of this study was to examine the neurorestorative effect of delayed 9 cis retinoic acid (9cRA) treatment for stroke. Adult male rats received a 90-min right distal middle cerebral artery occlusion (dMCAo). Animals were separated into two groups with similar infarction sizes, based on magnetic resonance imaging on day 2 after dMCAo. 9cRA or vehicle was given via an intranasal route daily starting from day 3. Stroke rats receiving 9cRA post-treatment showed an increase in brain 9cRA levels and greater recovery in motor function. 9cRA enhanced the proliferation of bromodeoxyuridine (+) cells in the subventricular zone (SVZ) and lesioned cortex in the stroke brain. Using subventricular neurosphere and matrigel cultures, we demonstrated that proliferation and migration of SVZ neuroprogenitor cells were enhanced by 9cRA. Our data support a delayed and non-invasive drug therapy for stroke. Intranasal 9cRA can facilitate the functional recovery and endogenous repair in the ischemic brain.
  • Lauter, Gilbert; Coschiera, Andrea; Yoshihara, Masahito; Sugiaman-Trapman, Debora; Ezer, Sini; Sethurathinam, Shalini; Katayama, Shintaro; Kere, Juha; Swoboda, Peter (2020)
    Many human cell types are ciliated, including neural progenitors and differentiated neurons. Ciliopathies are characterized by defective cilia and comprise various disease states, including brain phenotypes, where the underlying biological pathways are largely unknown. Our understanding of neuronal cilia is rudimentary, and an easy-to-maintain, ciliated human neuronal cell model is absent. The Lund human mesencephalic (LUHMES) cell line is a ciliated neuronal cell line derived from human fetal mesencephalon. LUHMES cells can easily be maintained and differentiated into mature, functional neurons within one week. They have a single primary cilium as proliferating progenitor cells and as postmitotic, differentiating neurons. These developmental stages are completely separable within one day of culture condition change. The sonic hedgehog (SHH) signaling pathway is active in differentiating LUHMES neurons. RNA-sequencing imecourse analyses reveal molecular pathways and gene-regulatory networks critical for ciliogenesis and axon outgrowth at the interface between progenitor cell proliferation, polarization and neuronal differentiation. Gene expression dynamics of cultured LUHMES neurons faithfully mimic the corresponding in vivo dynamics of human fetal midbrain. In LUHMES cells, neuronal cilia biology can be investigated from proliferation through differentiation to mature neurons.
  • 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.
  • Chen, Honglei; Wang, Keran; Scheperjans, Filip; Killinger, Bryan (2022)
    Idiopathic Parkinson's disease (PD) may take decades to develop, during which many risk or protective factors may come into play to initiate the pathogenesis or modify its progression to clinical PD. The lack of understanding of this prodromal phase of PD and the factors involved has been a major hurdle in the study of PD etiology and preventive strategies. Although still controversial, the Braak and dual-hit hypotheses that PD may start peripherally in the olfactory structures and/or the gut provides a theoretical platform to identify the triggers and modifiers of PD prodromal development and progression. This is particularly true for the search of environmental causes of PD as the olfactory structures and gut are the major human mucosal interfaces with the environment. In this review, we lay out our personal views about how the Braak and dual-hit hypotheses may help us search for the environmental triggers and modifiers for PD, summarize available experimental and epidemiological evidence, and discuss research gaps and strategies.
  • Lindström, Riitta; Lindholm, Päivi; Kallijärvi, Jukka; Palgi, Mari; Saarma, Mart; Heino, Tapio I. (2016)
    Disturbances in the homeostasis of endoplasmic reticulum (ER) referred to as ER stress is involved in a variety of human diseases. ER stress activates unfolded protein response (UPR), a cellular mechanism the purpose of which is to restore ER homeostasis. Previous studies show that Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) is an important novel component in the regulation of UPR. In vertebrates, MANF is upregulated by ER stress and protects cells against ER stress-induced cell death. Biochemical studies have revealed an interaction between mammalian MANF and GRP78, the major ER chaperone promoting protein folding. In this study we discovered that the upregulation of MANF expression in response to drug-induced ER stress is conserved between Drosophila and mammals. Additionally, by using a genetic in vivo approach we found genetic interactions between Drosophila Manf and genes encoding for Drosophila homologues of GRP78, PERK and XBP1, the key components of UPR. Our data suggest a role for Manf in the regulation of Drosophila UPR.
  • Palgi, Mari; Greco, Dario; Lindström, Riitta; Auvinen, Petri; Heino, Tapio I. (2012)
  • Evsyukov, Valentin; Domanskyi, Andrii; Bierhoff, Holger; Gispert, Suzana; Mustafa, Rasem; Schlaudraff, Falk; Liss, Birgit; Parlato, Rosanna (2017)
    Genetic mutations underlying neurodegenerative disorders impair ribosomal DNA (rDNA) transcription suggesting that nucleolar dysfunction could be a novel pathomechanism in polyglutamine diseases and in certain forms of amyotrophic lateral sclerosis/frontotemporal dementia. Here, we investigated nucleolar activity in pre-symptomatic digenic models of Parkinson's disease (PD) that model the multifactorial aetiology of this disease. To this end, we analysed a novel mouse model mildly overexpressing mutant human alpha-synuclein (hA53T-SNCA) in a PTEN-induced kinase 1 (PINK1/ PARK6) knockout background and mutant mice lacking both DJ-1 (also known as PARK7) and PINK1. We showed that overexpressed hA53T-SNCA localizes to the nucleolus. Moreover, these mutants show a progressive reduction of rDNA transcription linked to a reduced mouse lifespan. By contrast, rDNA transcription is preserved in DJ-1/PINK1 double knockout (DKO) mice. mRNA levels of the nucleolar transcription initiation factor 1A (TIF-IA, also known as RRN3) decrease in the substantia nigra of individuals with PD. Because loss of TIF-IA, as a tool to mimic nucleolar stress, increases oxidative stress and because DJ-1 and PINK1 mutations result in higher vulnerability to oxidative stress, we further explored the synergism between these PD-associated genes and impaired nucleolar function. By the conditional ablation of TIF-IA, we blocked ribosomal RNA (rRNA) synthesis in adult dopaminergic neurons in a DJ-1/PINK1 DKO background. However, the early phenotype of these triple knockout mice was similar to those mice exclusively lacking TIF-IA. These data sustain a model in which loss of DJ-1 and PINK1 does not impair nucleolar activity in a pre-symptomatic stage. This is the first study to analyse nucleolar function in digenic PD models. We can conclude that, at least in these models, the nucleolus is not as severely disrupted as previously shown in DA neurons from PD patients and neurotoxin-based PD mouse models. The results also show that the early increase in rDNA transcription and nucleolar integrity may represent specific homeostatic responses in these digenic pre-symptomatic PD models.
  • Mahato, Arun Kumar; Sidorova, Yulia A. (2020)
    Rearranged during transfection (RET), in complex with glial cell line-derived (GDNF) family receptor alpha (GFR alpha), is the canonical signaling receptor for GDNF family ligands (GFLs) expressed in both central and peripheral parts of the nervous system and also in non-neuronal tissues. RET-dependent signaling elicited by GFLs has an important role in the development, maintenance and survival of dopamine and sensory neurons. Both Parkinson's disease and neuropathic pain are devastating disorders without an available cure, and at the moment are only treated symptomatically. GFLs have been studied extensively in animal models of Parkinson's disease and neuropathic pain with remarkable outcomes. However, clinical trials with recombinant or viral vector-encoded GFL proteins have produced inconclusive results. GFL proteins are not drug-like; they have poor pharmacokinetic properties and activate multiple receptors. Targeting RET and/or GFR alpha with small molecules may resolve the problems associated with using GFLs as drugs and can result in the development of therapeutics for disease-modifying treatments against Parkinson's disease and neuropathic pain.
  • Panula, Pertti (2020)
    Alcohol use disorder is associated with several mental, physical, and social problems. Its treatment is difficult and often requires a combination of pharmacological and behavioural therapy. The brain histaminergic system, one of the wake-active systems that controls whole-brain activity, operates through three neuronal GPCRs. The histamine H-3 receptor (Hrh3), which is expressed in many brain areas involved in alcohol drinking and alcohol reward, can be targeted with a number of drugs developed initially for cognitive disorders and/or disorders related to sleep, wakefulness, and alertness. In all rodent alcohol drinking models tested so far, H-3 receptor antagonists have reduced alcohol drinking and alcohol-induced place preference and cue-induced alcohol reinstatement. Several H-3 receptor antagonists tested and found to be safe for humans could be subjected to clinical tests to treat alcohol use disorder. Preference should be given to short-acting drugs to avoid the sleep problems associated with the wake-maintaining effects of the drugs. Linked Articles This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc
  • Lindstrom, Riitta; Lindholm, Paivi; Palgi, Mari; Saarma, Mart; Heino, Tapio I. (2017)
    Background: Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) and Cerebral Dopamine Neurotrophic Factor (CDNF) form an evolutionarily conserved family of neurotrophic factors. Orthologues for MANF/CDNF are the only neurotrophic factors as yet identified in invertebrates with conserved amino acid sequence. Previous studies indicate that mammalian MANF and CDNF support and protect brain dopaminergic system in non-cell-autonomous manner. However, MANF has also been shown to function intracellularly in the endoplasmic reticulum. To date, the knowledge on the interacting partners of MANF/CDNF and signaling pathways they activate is rudimentary. Here, we have employed the Drosophila genetics to screen for potential interaction partners of Drosophila Manf (DmManf) in vivo. Results: We first show that DmManf plays a role in the development of Drosophila wing. We exploited this function by using Drosophila UAS-RNAi lines and discovered novel genetic interactions of DmManf with genes known to function in the mitochondria. We also found evidence of an interaction between DmManf and the Drosophila homologue encoding Ku70, the closest structural homologue of SAP domain of mammalian MANF. Conclusions: In addition to the previously known functions of MANF/CDNF protein family, DmManf also interacts with mitochondria-related genes. Our data supports the functional importance of these evolutionarily significant proteins and provides new insights for the future studies.
  • Galli, Emilia; Harkonen, Taina; Sainio, Markus; Ustav, Mart; Toots, Urve; Urtti, Arto; Yliperttula, Marjo; Lindahl, Maria; Knip, Mikael; Saarma, Mart; Lindholm, Paivi (2016)
    Mesencephalic astrocyte-derived neurotrophic factor (MANF) was recently shown to be essential for the survival and proliferation of pancreatic beta-cells in mice, where deletion of MANF resulted in diabetes. The current study aimed at determining whether the concentration of circulating MANF is associated with the clinical manifestation of human type 1 diabetes (T1D). MANF expression in T1D or MANF levels in serum have not been previously studied. We developed an enzyme-linked immunosorbent assay (ELISA) for MANF and measured serum MANF concentrations from 186 newly diagnosed children and adolescents and 20 adults with longer-term T1D alongside with age-matched controls. In healthy controls the mean serum MANF concentration was 7.0 ng/ml. High MANF concentrations were found in children 1-9 years of age close to the diagnosis of T1D. The increased MANF concentrations were not associated with diabetes-predictive autoantibodies and autoantibodies against MANF were extremely rare. Patients with conspicuously high MANF serum concentrations had lower C-peptide levels compared to patients with moderate MANF concentrations. Our data indicate that increased MANF concentrations in serum are associated with the clinical manifestation of T1D in children, but the exact mechanism behind the increase remains elusive.
  • Lindahl, Maria; Danilova, Tatiana; Palm, Erik; Lindholm, Paivi; Voikar, Vootele; Hakonen, Elina; Ustinov, Jarkko; Andressoo, Jaan-Olle; Harvey, Brandon K.; Otonkoski, Timo; Rossi, Jari; Saarma, Mart (2014)
    All forms of diabetes mellitus (DM) are characterized by the loss of functional pancreatic β cell mass, leading to insufficient insulin secretion. Thus, identification of novel approaches to protect and restore β cells is essential for the development of DM therapies. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER)-stress-inducible protein, but its physiological role in mammals has remained obscure. We generated MANF-deficient mice that strikingly develop severe diabetes due to progressive postnatal reduction of β cell mass, caused by decreased proliferation and increased apoptosis. Additionally, we show that lack of MANF in vivo in mouse leads to chronic unfolded protein response (UPR) activation in pancreatic islets. Importantly, MANF protein enhanced β cell proliferation in vitro and overexpression of MANF in the pancreas of diabetic mice enhanced β cell regeneration. We demonstrate that MANF specifically promotes β cell proliferation and survival, thereby constituting a therapeutic candidate for β cell protection and regeneration.
  • Tseng, Kuan-Yin; Anttila, Jenni E.; Khodosevich, Konstantin; Tuominen, Raimo K.; Lindahl, Maria; Domanskyi, Andrii; Airavaara, Mikko (2018)
    Cerebral ischemia activates endogenous reparative processes, such as increased proliferation of neural stem cells (NSCs) in the subventricular zone (SVZ) and migration of neural progenitor cells (NPCs) toward the ischemic area. However, this reparative process is limited because most of the NPCs die shortly after injury or are unable to arrive at the infarct boundary. In this study, we demonstrate for the first time that endogenous mesencephalic astrocyte-derived neurotrophic factor (MANF) protects NSCs against oxygen-glucose-deprivation-induced injury and has a crucial role in regulating NPC migration. In NSC cultures, MANF protein administration did not affect growth of cells but triggered neuronal and glial differentiation, followed by activation of STAT3. In SVZ explants, MANF over expression facilitated cell migration and activated the STAT3 and ERK1/2 pathway. Using a rat model of cortical stroke, intracerebroventricular injections of MANF did not affect cell proliferation in the SVZ, but promoted migration of doublecortin (DCX)(+) cells toward the corpus callosum and infarct boundary on day 14 post-stroke. Long-term infusion of MANF into the per'-infarct zone increased the recruitment of DCX+ cells in the infarct area. In conclusion, our data demonstrate a neuroregenerative activity of MANF that facilitates differentiation and migration of NPCs, thereby increasing recruitment of neuroblasts in stroke cortex.
  • Raba, Mikk; Palgi, Jaan; Lehtivaara, Maria; Arumäe, Urmas (2016)
    Postnatal maturation of the neurons whose main phenotype and basic synaptic contacts are already established includes neuronal growth, refinement of synaptic contacts, final steps of differentiation, programmed cell death period (PCD) etc. In the sympathetic neurons, postnatal maturation includes permanent end of the PCD that occurs with the same time schedule in vivo and in vitro suggesting that the process could be genetically determined. Also many other changes in the neuronal maturation could be permanent and thus based on stable changes in the genome expression. However, postnatal maturation of the neurons is poorly studied. Here we compared the gene expression profiles of immature and mature sympathetic neurons using Affymetrix microarray assay. We found 1310 significantly up-regulated and 1151 significantly down-regulated genes in the mature neurons. Gene ontology analysis reveals up-regulation of genes related to neuronal differentiation, chromatin and epigenetic changes, extracellular factors and their receptors, and cell adhesion, whereas many down-regulated genes were related to metabolic and biosynthetic processes. We show that termination of PCD is not related to major changes in the expression of classical genes for apoptosis or cell survival. Our dataset is deposited to the ArrayExpress database and is a valuable source to select candidate genes in the studies of neuronal maturation. As an example, we studied the changes in the expression of selected genes Igf2bp3, CorolA, Zfp57, Dcx, and Apafl in the young and mature sympathetic ganglia by quantitative PCR and show that these were strongly downregulated in the mature ganglia.
  • Bondarenko, Olesja; Saarma, Mart (2021)
    Neurotrophic factors (NTFs) are small secreted proteins that support the development, maturation and survival of neurons. NTFs injected into the brain rescue and regenerate certain neuronal populations lost in neurodegenerative diseases, demonstrating the potential of NTFs to cure the diseases rather than simply alleviating the symptoms. NTFs (as the vast majority of molecules) do not pass through the blood-brain barrier (BBB) and therefore, are delivered directly into the brain of patients using costly and risky intracranial surgery. The delivery efficacy and poor diffusion of some NTFs inside the brain are considered the major problems behind their modest effects in clinical trials. Thus, there is a great need for NTFs to be delivered systemically thereby avoiding intracranial surgery. Nanoparticles (NPs), particles with the size dimensions of 1-100 nm, can be used to stabilize NTFs and facilitate their transport through the BBB. Several studies have shown that NTFs can be loaded into or attached onto NPs, administered systemically and transported to the brain. To improve the NP-mediated NTF delivery through the BBB, the surface of NPs can be functionalized with specific ligands such as transferrin, insulin, lactoferrin, apolipoproteins, antibodies or short peptides that will be recognized and internalized by the respective receptors on brain endothelial cells. In this review, we elaborate on the most suitable NTF delivery methods and envision "ideal" NTF for Parkinson's disease (PD) and clinical trial thereof. We shortly summarize clinical trials of four NTFs, glial cell line-derived neurotrophic factor (GDNF), neurturin (NRTN), platelet-derived growth factor (PDGF-BB), and cerebral dopamine neurotrophic factor (CDNF), that were tested in PD patients, focusing mainly on GDNF and CDNF. We summarize current possibilities of NP-mediated delivery of NTFs to the brain and discuss whether NPs have impact in improving the properties of NTFs and delivery across the BBB. Emerging delivery approaches and future directions of NTF-based nanomedicine are also discussed.
  • Albert, Katrina; Niskanen, Jonna; Kälvälä, Sara; Lehtonen, Šárka (2021)
    Induced pluripotent stem cells (iPSCs) are a self-renewable pool of cells derived from an organism’s somatic cells. These can then be programmed to other cell types, including neurons. Use of iPSCs in research has been two-fold as they have been used for human disease modelling as well as for the possibility to generate new therapies. Particularly in complex human diseases, such as neurodegenerative diseases, iPSCs can give advantages over traditional animal models in that they more accurately represent the human genome. Additionally, patient-derived cells can be modified using gene editing technology and further transplanted to the brain. Glial cells have recently become important avenues of research in the field of neurodegenerative diseases, for example, in Alzheimer’s disease and Parkinson’s disease. This review focuses on using glial cells (astrocytes, microglia, and oligodendrocytes) derived from human iPSCs in order to give a better understanding of how these cells contribute to neurodegenerative disease pathology. Using glia iPSCs in in vitro cell culture, cerebral organoids, and intracranial transplantation may give us future insight into both more accurate models and disease-modifying therapies.
  • Baronio, Diego; Chen, Yu-Chia; Decker, Amanda R.; Enckell, Louise; Fernandez-Lopez, Blanca; Semenova, Svetlana; Puttonen, Henri A. J.; Cornell, Robert A.; Panula, Pertti (2022)
    Aim We aimed at identifying potential roles of vesicular monoamine transporter 2, also known as Solute Carrier protein 18 A2 (SLC18A2) (hereafter, Vmat2), in brain monoamine regulation, their turnover, behaviour and brain development using a novel zebrafish model. Methods A zebrafish strain lacking functional Vmat2 was generated with the CRISPR/Cas9 system. Larval behaviour and heart rate were monitored. Monoamines and their metabolites were analysed with high-pressure liquid chromatography. Amine synthesising and degrading enzymes, and genes essential for brain development, were analysed with quantitative PCR, in situ hybridisation and immunocytochemistry. Results The 5-bp deletion in exon 3 caused an early frameshift and was lethal within 2 weeks post-fertilisation. Homozygous mutants (hereafter, mutants) displayed normal low locomotor activity during night-time but aberrant response to illumination changes. In mutants dopamine, noradrenaline, 5-hydroxytryptamine and histamine levels were reduced, whereas levels of dopamine and 5-hydroxytryptamine metabolites were increased, implying elevated monoamine turnover. Consistently, there were fewer histamine, 5-hydroxytryptamine and dopamine immunoreactive cells. Cellular dopamine immunostaining, in wild-type larvae more prominent in tyrosine hydroxylase 1 (Th1)-expressing than in Th2-expressing neurons, was absent in mutants. Despite reduced dopamine levels, mutants presented upregulated dopamine-synthesising enzymes. Further, in mutants the number of histidine decarboxylase-expressing neurons was increased, notch1a and pax2a were downregulated in brain proliferative zones. Conclusion Lack of Vmat2 increases monoamine turnover and upregulates genes encoding amine-synthesising enzymes, including histidine decarboxylase. Notch1a and pax2a, genes implicated in stem cell development, are downregulated in mutants. The zebrafish vmat2 mutant strain may be a useful model to study how monoamine transport affects brain development and function, and for use in drug screening.