Increasing the Specificity of Neurotrophic Factors

Total Page:16

File Type:pdf, Size:1020Kb

Increasing the Specificity of Neurotrophic Factors COMMENTARY Increasing the specificity of neurotrophic factors Moses V. Chao1 The Skirball Institute of Biomolecular Medicine, New York University, New York, NY 10016 eurotrophic factors are capable of accomplishing many tasks. In N addition to regulating neural cell survival and differentiation, they can influence changes in synaptic transmission and higher order behaviors, such as aggression, addiction, depression, learning, and memory. Because many tro- phic factors use receptor tyrosine kinases as a means for initiating signaling, a major question is how tyrosine phosphorylation events that lead to canonical MAP kinase, Akt, and phospholipase C-γ activities can account for so many diverse outcomes (1). The article in PNAS by Schalm et al. (2) on protocadherins and the glial-derived neu- rotrophic factor (GDNF) provides a unique insight into this question. GDNF is an important protein that was discovered in 1993 as a potent survival factor for midbrain dopaminergic neurons (3). It has been frequently touted as a treatment for Parkinson’s disease. GDNF Fig. 1. A link between GDNF and protocadherins. A multitude of different protocadherin proteins are also exerts trophic effects on sympathetic, expressed in the nervous system. Each transmembrane protocadherin possesses six extracellular cad- sensory, parasympathetic, and enteric neu- herin domains and a short cytoplasmic segment. In the mouse, there are 14 protocadherin-α genes, 22 rons. The effects of GDNF and the related protocadherin-β genes, and 22 protocadherin-γ genes, which undergo multiple splicing events (16, family members neurturin, artemin, and 17). The GDNF family of ligands (GDNF, neurturin, artemin, and persephin) bind to individual GDNF-α persephin are mediated by RET, a trans- receptors (GFR-α), which form a complex with the RET tyrosine kinase (5). The specific protocadherin membrane receptor tyrosine kinase. GDNF proteins α4andγb7 are phosphorylated by RET after GDNF treatment, which, in turn, stabilizes RET ligands do not bind directly to RET but and delays its degradation (2). require GPI-anchored coreceptors [called GDNF receptor-α1–4] to activate the RET teracting protein of protocadherin-α4. In- junctions (8) has been backed by the ap- receptor, which efficiently increases in- terestingly, the interaction of RET with pearance of fewer and weaker synapses tracellular ERK and PI3K activities and 2+ protocadherin-α4 is specific and involves in spinal cord neurons in mice carrying Ca levels (4, 5). Many biological func- the extracellular domains of each protein, γ tions are affected by these ligand-receptor a large deletion in the protocadherin- events, including proliferation and migra- which both share similar cadherin-like gene cluster (11). motifs (Fig. 1). Moreover, the absence of multiple tion of progenitor cells, axon guidance, and γ chemoattraction (5). GDNF is also involved How are protocadherins relevant to -protocadherins results in dramatic neu- RET? Protocadherin-α was originally rodegeneration of spinal cord motor neu- in synapse formation and neuronal excit- fi fi ability in possessing the ability to modulate identi ed as a brain-speci c protein that rons (12), reminiscent of what happens postsynaptic currents in dopaminergic neu- interacted with the Fyn nonreceptor tyro- when there is a lack of trophic support. rons (6). Recently, considerable interest has sine kinase (8). It quickly became apparent Hence, protocadherins display multiple centered on the roles of GDNF to regulate that the protocadherin gene family rep- roles in the nervous system. In this re- drugs of abuse, such as cocaine and mor- resented the largest subgroup of the cad- gard, RET signaling is responsible for the phine, negatively as well as alcohol addic- herin superfamily, consisting of three survival and function of many neuron α β γ tion (7). The breadth of actions of GDNF tandemly arrayed gene clusters: , , and populations. The phosphorylation of family members begs for more mechanistic (9, 10). As a transmembrane protein with protocadherins by GDNF is therefore an insights to account for the specificity and a short cytoplasmic domain, each proto- important observation that implies an extent of RET receptor signaling and its cadherin is distinguished by six ectodo- overlap in their respective functions. ability to change synaptic plasticity. main cadherin-like repeats of 100 amino How do protocadherins and RET affect A unique set of mechanisms has now acids. Because there are nearly 70 proto- each other? One clue comes from the been provided by the finding that trans- cadherin genes that undergo a multitude finding that RET receptor levels are ex- membrane protocadherin molecules are of splicing events, a huge number of dif- quisitely sensitive to proteasomal degrada- associated with the RET receptor. Schalm ferent protocadherin proteins can be gen- tion (13, 14). Like many growth factors, et al. (2) report that GDNF causes the erated. For this reason, there has been phosphorylation of specific protocadherin enormous interest by neuroscientists in the proteins in sympathetic and motor neu- past decade in the potential roles of pro- Author contributions: M.V.C. wrote the paper. rons, two responsive populations. These tocadherins as synaptic recognition pro- The author declares no conflict of interest. interactions were uncovered by this group teins. The significance of the localization See companion article on page 13894. with the identification of RET as an in- of protocadherin proteins at synaptic 1E-mail: [email protected]. www.pnas.org/cgi/doi/10.1073/pnas.1008518107 PNAS | August 3, 2010 | vol. 107 | no. 31 | 13565–13566 Downloaded by guest on September 26, 2021 GDNF binding results in rapid ubiquitina- loss of GDNF-RET signaling or a deficit such as discoidin domain receptor 2 and Src tion of its receptor on lysine residues. There in retrograde transport can lead to neu- family members (2). are additional layers of regulation, be- rodegeneration (14). The responsiveness Protocadherins are found in combina- cause two isoforms of RET that contain of RET receptors is therefore dependent torial expression patterns frequently asso- different lengths of cytoplasmic tails, Ret51 on receptor trafficking and turnover. ciated with synapses, and they have been and Ret9, differ in their response to Phosphorylation of protocadherins after strongly implicated as cell recognition and GDNF. Also, there is cell type specificity. GDNF treatment ensures that RET is not adhesion molecules. It is likely that their In sympathetic neurons, Ret51 is degraded immediately inactivated through degrada- effects will have an impact on the kinetics faster in sympathetic neurons than in sen- tion. The current results suggest that the and strength of signaling of other synaptic sory neurons. However, when the levels of GDNF-RET receptor exists in a large molecules. In addition to mediating neu- protocadherin-α4 are increased in sympa- complex with protocadherin proteins, ronal survival and synaptic development, thetic neurons, the levels of phosphorylated which contribute to RET receptor stability protocadherin-α members have been im- Ret51 are increased. Conversely, lowering and signaling. The existence of an array of plicated in memory and learning (15). the levels of protocadherins brings about different protocadherins and different RET Hence, the association of GDNF with a decrease in the levels of responsive RET isoforms likely generates a diversity of re- the protocadherin family of proteins may receptors (2). Hence, one way in which ceptor complexes with different compo- indeed foreshadow further insights into protocadherins exert an effect on RET is nents, thus simultaneously increasing the molecular basis of neurodegenerative to stabilize the activated receptor and the diversity and specificity of trophic factor diseases and psychiatric disorders. prevent degradation. signaling. Indeed, Schalm et al. (2) report The association of protocadherins with there are other signaling proteins that ACKNOWLEDGMENTS. The figure was composed RET has a number of implications. A de- are associated with protocadherins, includ- by Kenneth Teng, and work on neurotrophic factors in the laboratory of M.V.C. has been lay in degradation of the RET receptor ing leukocyte antigen-related receptor ty- previously supported by National Institutes of allows neurons to survive for a longer pe- rosine phosphatase and protein tyrosine Health Grants NS21072, HD23315, AG25970, riod of time in the presence of GDNF. A phosphatase-α as well as tyrosine kinases, MH086651, and MH090638. 1. Chao MV (1992) Growth factor signaling: Where is the 6. Bourque MJ, Trudeau LE (2000) GDNF enhances the 13. Pierchala BA, Milbrandt J, Johnson EM Jr. (2006) Glial specificity? Cell 68:995–997. synaptic efficacy of dopaminergic neurons in culture. cell line-derived neurotrophic factor-dependent re- 2. Schalm SS, Ballif BA, Buchanan SM, Phillips GR, Eur J Neurosci 12:3172–3180. cruitment of Ret into lipid rafts enhances signaling — Maniatis T (2010) Phosphorylation of protocadherin 7. Carnicella S, Ron D (2009) GDNF A potential target to by partitioning Ret from proteasome-dependent deg- treat addiction. Pharmacol Ther 122:9–18. proteins by the receptor tyrosine kinase Ret. Proc Natl radation. J Neurosci 26:2777–2787. 8. Kohmura N, et al. (1998) Diversity revealed by a novel Acad Sci USA 107:13894–13899. 14. Tsui CC, Pierchala BA (2010) The differential axonal family of cadherins expressed in neurons at a synaptic 3. Lin LF, Doherty DH, Lile JD,
Recommended publications
  • Differential Effects of Th1, Monocyte/Macrophage and Th2
    Wayne State University Wayne State University Associated BioMed Central Scholarship 2007 Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for glial and neural-related molecules in central nervous system mixed glial cell cultures: neurotrophins, growth factors and structural proteins Robert P. Lisak Wayne State University School of Medicine, [email protected] Joyce A. Benjamins Wayne State University School of Medicine, [email protected] Beverly Bealmear Wayne State University School of Medicine, [email protected] Liljana Nedelkoska Wayne State University School of Medicine, [email protected] Bin Yao Applied Genomics Technology Center, Wayne State University, [email protected] Recommended Citation Lisak et al. Journal of Neuroinflammation 2007, 4:30 doi:10.1186/1742-2094-4-30 Available at: http://digitalcommons.wayne.edu/biomedcentral/155 This Article is brought to you for free and open access by DigitalCommons@WayneState. It has been accepted for inclusion in Wayne State University Associated BioMed Central Scholarship by an authorized administrator of DigitalCommons@WayneState. See next page for additional authors Authors Robert P. Lisak, Joyce A. Benjamins, Beverly Bealmear, Liljana Nedelkoska, Bin Yao, Susan Land, and Diane Studzinski This article is available at DigitalCommons@WayneState: http://digitalcommons.wayne.edu/biomedcentral/155 Journal of Neuroinflammation BioMed Central Research Open Access Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures
    [Show full text]
  • Intravitreal Co-Administration of GDNF and CNTF Confers Synergistic and Long-Lasting Protection Against Injury-Induced Cell Death of Retinal † Ganglion Cells in Mice
    cells Article Intravitreal Co-Administration of GDNF and CNTF Confers Synergistic and Long-Lasting Protection against Injury-Induced Cell Death of Retinal y Ganglion Cells in Mice 1, 1, 1 2 2 Simon Dulz z , Mahmoud Bassal z, Kai Flachsbarth , Kristoffer Riecken , Boris Fehse , Stefanie Schlichting 1, Susanne Bartsch 1 and Udo Bartsch 1,* 1 Department of Ophthalmology, Experimental Ophthalmology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; [email protected] (S.D.); [email protected] (M.B.); kaifl[email protected] (K.F.); [email protected] (S.S.); [email protected] (S.B.) 2 Research Department Cell and Gene Therapy, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; [email protected] (K.R.); [email protected] (B.F.) * Correspondence: [email protected]; Tel.: +49-40-7410-55945 A first draft of this manuscript is part of the unpublished doctoral thesis of Mahmoud Bassal. y Shared first authorship. z Received: 9 August 2020; Accepted: 9 September 2020; Published: 11 September 2020 Abstract: We have recently demonstrated that neural stem cell-based intravitreal co-administration of glial cell line-derived neurotrophic factor (GDNF) and ciliary neurotrophic factor (CNTF) confers profound protection to injured retinal ganglion cells (RGCs) in a mouse optic nerve crush model, resulting in the survival of ~38% RGCs two months after the nerve lesion. Here, we analyzed whether this neuroprotective effect is long-lasting and studied the impact of the pronounced RGC rescue on axonal regeneration. To this aim, we co-injected a GDNF- and a CNTF-overexpressing neural stem cell line into the vitreous cavity of adult mice one day after an optic nerve crush and determined the number of surviving RGCs 4, 6 and 8 months after the lesion.
    [Show full text]
  • GDNF, Neurturin, and Artemin Activate and Sensitize Bone Afferent Neurons and Contribute to Inflammatory Bone Pain
    The Journal of Neuroscience, May 23, 2018 • 38(21):4899–4911 • 4899 Neurobiology of Disease GDNF, Neurturin, and Artemin Activate and Sensitize Bone Afferent Neurons and Contribute to Inflammatory Bone Pain X Sara Nencini, XMitchell Ringuet, Dong-Hyun Kim, Claire Greenhill, and XJason J. Ivanusic Department of Anatomy and Neuroscience, University of Melbourne, Parkville 3010, Victoria, Australia Pain associated with skeletal pathology or disease is a significant clinical problem, but the mechanisms that generate and/or maintain it remain poorly understood. In this study, we explored roles for GDNF, neurturin, and artemin signaling in bone pain using male Sprague Dawley rats. We have shown that inflammatory bone pain involves activation and sensitization of peptidergic, NGF-sensitive neurons via artemin/GDNF family receptor ␣-3 (GFR␣3) signaling pathways, and that sequestering artemin might be useful to prevent inflammatory bone pain derived from activation of NGF-sensitive bone afferent neurons. In addition, we have shown that inflammatory bone pain also involves activation and sensitization of nonpeptidergic neurons via GDNF/GFR␣1 and neurturin/GFR␣2 signaling pathways, and that sequestration of neurturin, but not GDNF, might be useful to treat inflammatory bone pain derived from activation of nonpeptidergic bone afferent neurons. Our findings suggest that GDNF family ligand signaling pathways are involved in the pathogenesis of bone pain and could be targets for pharmacological manipulations to treat it. Key words: artemin; bone pain; GDNF; neurturin; pain; skeletal pain Significance Statement Painassociatedwithskeletalpathology,includingbonecancer,bonemarrowedemasyndromes,osteomyelitis,osteoarthritis,and fractures causes a major burden (both in terms of quality of life and cost) on individuals and health care systems worldwide.
    [Show full text]
  • Developing Therapeutically More Efficient Neurturin Variants For
    Neurobiology of Disease 96 (2016) 335–345 Contents lists available at ScienceDirect Neurobiology of Disease journal homepage: www.elsevier.com/locate/ynbdi Developing therapeutically more efficient Neurturin variants for treatment of Parkinson's disease Pia Runeberg-Roos a,⁎, Elisa Piccinini a,1,Anna-MaijaPenttinena,1, Kert Mätlik a, Hanna Heikkinen a, Satu Kuure a,2, Maxim M. Bespalov a,3, Johan Peränen a,4,EnriqueGarea-Rodríguezb,5, Eberhard Fuchs c, Mikko Airavaara a, Nisse Kalkkinen a, Richard Penn d,6, Mart Saarma a a Institute of Biotechnology, University of Helsinki, PB 56 (Viikinkaari 5D), FIN-00014, Finland b Department of Neuroanatomy, Institute for Anatomy and Cell Biology, University of Freiburg, Freiburg, Germany c German Primate Center, Göttingen, Germany d CNS Therapeutics Inc., 332 Minnesota Street, Ste W1750, St. Paul, MN 55101, USA article info abstract Article history: In Parkinson's disease midbrain dopaminergic neurons degenerate and die. Oral medications and deep brain Received 26 May 2016 stimulation can relieve the initial symptoms, but the disease continues to progress. Growth factors that might Revised 4 July 2016 support the survival, enhance the activity, or even regenerate degenerating dopamine neurons have been tried Accepted 13 July 2016 with mixed results in patients. As growth factors do not pass the blood-brain barrier, they have to be delivered Available online 15 July 2016 intracranially. Therefore their efficient diffusion in brain tissue is of crucial importance. To improve the diffusion of the growth factor neurturin (NRTN), we modified its capacity to attach to heparan sulfates in the extracellular Keywords: NRTN matrix. We present four new, biologically fully active variants with reduced heparin binding.
    [Show full text]
  • Glial Cell Line-Derived Neurotrophic Factor Family Members Sensitize Nociceptors in Vitro and Produce Thermal Hyperalgesia in Vivo
    8588 • The Journal of Neuroscience, August 16, 2006 • 26(33):8588–8599 Cellular/Molecular Glial Cell Line-Derived Neurotrophic Factor Family Members Sensitize Nociceptors In Vitro and Produce Thermal Hyperalgesia In Vivo Sacha A. Malin,1 Derek C. Molliver,1 H. Richard Koerber,2 Pamela Cornuet,1 Rebecca Frye,1 Kathryn M. Albers,1,2 and Brian M. Davis1,2 Departments of 1Medicine and 2Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261 Nerve growth factor (NGF) has been implicated as an effector of inflammatory pain because it sensitizes primary afferents to noxious thermal, mechanical, and chemical [e.g., capsaicin, a transient receptor potential vanilloid receptor 1 (TRPV1) agonist] stimuli and because NGF levels increase during inflammation. Here, we report the ability of glial cell line-derived neurotrophic factor (GDNF) family members artemin, neurturin and GDNF to potentiate TRPV1 signaling and to induce behavioral hyperalgesia. Analysis of capsaicin- evoked Ca 2ϩ transients in dissociated mouse dorsal root ganglion (DRG) neurons revealed that a 7 min exposure to GDNF, neurturin, or artemin potentiated TRPV1 function at doses 10–100 times lower than NGF. Moreover, GDNF family members induced capsaicin responses in a subset of neurons that were previously insensitive to capsaicin. Using reverse transcriptase-PCR, we found that artemin mRNA was profoundly upregulated in response to inflammation induced by hindpaw injection of complete Freund’s adjuvant (CFA): arteminexpressionincreased10-fold1dafterCFAinjection,whereasNGFexpressiondoubledbyday7.Noincreasewasseeninneurturin or GDNF. A corresponding increase in mRNA for the artemin coreceptor GFR␣3 (for GDNF family receptor ␣) was seen in DRG, and GFR␣3 immunoreactivity was widely colocalized with TRPV1 in epidermal afferents.
    [Show full text]
  • Neurotrophic Factors and Receptors in the Immature and Adult Spinal Cord After Mechanical Injury Or Kainic Acid
    The Journal of Neuroscience, May 15, 2001, 21(10):3457–3475 Neurotrophic Factors and Receptors in the Immature and Adult Spinal Cord after Mechanical Injury or Kainic Acid Johan Widenfalk, Karin Lundstro¨ mer, Marie Jubran, Stefan Brene´ , and Lars Olson Department of Neuroscience, Karolinska Institute, S-171 77 Stockholm, Sweden Delivery of neurotrophic factors to the injured spinal cord has mRNA increased in astrocytes of degenerating white matter. been shown to stimulate neuronal survival and regeneration. The relatively limited upregulation of neurotrophic factors in the This indicates that a lack of sufficient trophic support is one spinal cord contrasted with the response of affected nerve factor contributing to the absence of spontaneous regeneration roots, in which marked increases of NGF and GDNF mRNA in the mammalian spinal cord. Regulation of the expression of levels were observed in Schwann cells. The difference between neurotrophic factors and receptors after spinal cord injury has the ability of the PNS and CNS to provide trophic support not been studied in detail. We investigated levels of mRNA- correlates with their different abilities to regenerate. Kainic acid encoding neurotrophins, glial cell line-derived neurotrophic fac- delivery led to only weak upregulations of BDNF and CNTF tor (GDNF) family members and related receptors, ciliary neu- mRNA. Compared with several brain regions, the overall re- rotrophic factor (CNTF), and c-fos in normal and injured spinal sponse of the spinal cord tissue to kainic acid was weak. The cord. Injuries in adult rats included weight-drop, transection, relative sparseness of upregulations of endogenous neurotro- and excitotoxic kainic acid delivery; in newborn rats, partial phic factors after injury strengthens the hypothesis that lack of transection was performed.
    [Show full text]
  • Artemin Is Oncogenic for Human Mammary Carcinoma Cells
    Oncogene (2009) 28, 2034–2045 & 2009 Macmillan Publishers Limited All rights reserved 0950-9232/09 $32.00 www.nature.com/onc ORIGINAL ARTICLE Artemin is oncogenic for human mammary carcinoma cells J Kang1, JK Perry1, V Pandey1, GC Fielder1, B Mei2,3, PX Qian2,ZSWu4, T Zhu2, DX Liu1 and PE Lobie1,5 1The Liggins Institute, University of Auckland, Auckland, New Zealand; 2Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, PR China; 3Institute of Basic Medicine, Anhui Medical University, Hefei, Anhui, PR China; 4Department of Pathology, Anhui Medical University, Hefei, Anhui, PR China and 5Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand We report that artemin, a member of the glial cell line- All GFLs are potent neurotrophic factors (Airaksinen and derived neurotrophic factor family of ligands, is oncogenic Saarma, 2002). GDNF was identified as a trophic factor for human mammary carcinoma. Artemin is expressedin for midbrain dopaminergic neurons (Lin et al., 1993). It numerous human mammary carcinoma cell lines. Forced promotes survival of many types of neurons, including expression of artemin in mammary carcinoma cells results subpopulations of peripheral autonomic and sensory, as in increased anchorage-independent growth, increased well as central motor, dopamine and noradrenaline, colony formation in soft agar andin three-dimensional neurons (Airaksinen et al., 1999). GDNF, neurturin and Matrigel, andalso promotes a scatteredcell phenotype artemin all support the survival of peripheral sympathetic with enhancedmigration andinvasion. Moreover, forced and sensory neurons, as well as midbrain dopamine expression of artemin increases tumor size in xenograft neurons, whereas persephin supports central nervous models and leads to highly proliferative, poorly differ- system dopamine and motor neurons, but not peripheral entiatedandinvasive tumors.
    [Show full text]
  • Potential Ciliary Neurotrophic Factor Application in Dental Stem Cell Therapy Patrick Suezaki University of the Pacific
    University of the Pacific Scholarly Commons Dugoni School of Dentistry Faculty Articles Arthur A. Dugoni School of Dentistry 2-2017 Potential Ciliary Neurotrophic Factor Application in Dental Stem Cell Therapy Patrick Suezaki University of the Pacific Nan (Tori) Xiao University of the Pacific, [email protected] Follow this and additional works at: https://scholarlycommons.pacific.edu/dugoni-facarticles Part of the Dentistry Commons Recommended Citation Suezaki, P., & Xiao, N. (2017). Potential Ciliary Neurotrophic Factor Application in Dental Stem Cell Therapy. Journal of Dentistry and Oral Biology, 2(3), 1–2. https://scholarlycommons.pacific.edu/dugoni-facarticles/415 This Article is brought to you for free and open access by the Arthur A. Dugoni School of Dentistry at Scholarly Commons. It has been accepted for inclusion in Dugoni School of Dentistry Faculty Articles by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Mini Review Journal of Dentistry and Oral Biology Published: 08 Feb, 2017 Potential Ciliary Neurotrophic Factor Application in Dental Stem Cell Therapy Patrick Suezaki1 and Nan Xiao2* 1Doctor of Dental Surgery Program, Arthur A. Dugoni School of Dentistry University of the Pacific, USA 2Department of Biomedical Sciences, Arthur A. Dugoni School of Dentistry University of the Pacific, USA Abstract Neurotrophic factors have long been considered growth factors that promote survival and growth of various neuronal tissues. Recent studies showed that neurotrophic factors are also present in dental pulp and periodontal ligament. This paper reviews the literature about the ciliary neurotrophic factor (CNTF), a member of the neurotrophic factor family, and indicates the potential clinical application of CNTF in dental stem cell therapy.
    [Show full text]
  • Revisiting the Role of Neurotrophic Factors in Inflammation
    cells Review Revisiting the Role of Neurotrophic Factors in Inflammation Lucas Morel, Olivia Domingues, Jacques Zimmer and Tatiana Michel * Department of Infection and Immunity, Luxembourg Institute of Health, 29 rue Henri Koch, L-4354 Esch-sur Alzette, Luxembourg; [email protected] (L.M.); [email protected] (O.D.); [email protected] (J.Z.) * Correspondence: [email protected]; Tel.: +352-26970-264 Received: 6 March 2020; Accepted: 31 March 2020; Published: 2 April 2020 Abstract: The neurotrophic factors are well known for their implication in the growth and the survival of the central, sensory, enteric and parasympathetic nervous systems. Due to these properties, neurturin (NRTN) and Glial cell-derived neurotrophic factor (GDNF), which belong to the GDNF family ligands (GFLs), have been assessed in clinical trials as a treatment for neurodegenerative diseases like Parkinson’s disease. In addition, studies in favor of a functional role for GFLs outside the nervous system are accumulating. Thus, GFLs are present in several peripheral tissues, including digestive, respiratory, hematopoietic and urogenital systems, heart, blood, muscles and skin. More precisely, recent data have highlighted that different types of immune and epithelial cells (macrophages, T cells, such as, for example, mucosal-associated invariant T (MAIT) cells, innate lymphoid cells (ILC) 3, dendritic cells, mast cells, monocytes, bronchial epithelial cells, keratinocytes) have the capacity to release GFLs and express their receptors, leading to the participation in the repair of epithelial barrier damage after inflammation. Some of these mechanisms pass on to ILCs to produce cytokines (such as IL-22) that can impact gut microbiota.
    [Show full text]
  • High-Efficiency Expression and Secretion of Human FGF21 In
    Li et al. Microb Cell Fact (2019) 18:17 https://doi.org/10.1186/s12934-019-1066-4 Microbial Cell Factories RESEARCH Open Access High-efciency expression and secretion of human FGF21 in Bacillus subtilis by intercalation of a mini-cistron cassette and combinatorial optimization of cell regulatory components Dandan Li1,2†, Gang Fu2,3†, Ran Tu2, Zhaoxia Jin1* and Dawei Zhang2,3* Abstract Background: Recombinant human Fibroblast growth factor 21 (rhFGF21) is an endocrine hormone that has pro- found efects on treatment of metabolic diseases. However, rhFGF21 is prone to form inclusion body when expressed in bacteria, which results in, the downstream process of purifcation of bioactive rhFGF21 is time-consuming and labor intensive. The aim of this work is to explore a new method for improving the soluble expression and secretion level of rhFGF21 in B. subtilis. Results: A codon optimized rhFGF21 gene was expressed under the control of a strong inducible promoter P malA in B. subtilis. A mini-cistron cassette (from gsiB) was located upstream of rhFGF21 in expression vector (pMATEFc5), which could reduce the locally stabilized mRNA secondary structure of transcripts and enhance the efciency of transla- tion initiation. Then various chaperones were further overexpressed to improve the expression efciency of rhFGF21. Results showed that overexpression of the chaperone DnaK contributed to the increase of solubility of rhFGF21. Moreover, an extracellular proteases defcient strain B. subtilis Kno6cf was used to accumulate the secreted rhFGF21 solidly. In addition, eleven signal peptides from B. subtilis were evaluated and the SP dacB appeared the highest secre- tion yield of rhFGF21 in B.
    [Show full text]
  • NGF, BDNF, and NT-3 and Their Relevance for Treatment of Spinal Cord Injury
    International Journal of Molecular Sciences Review Targeting Neurotrophins to Specific Populations of Neurons: NGF, BDNF, and NT-3 and Their Relevance for Treatment of Spinal Cord Injury Kathleen M. Keefe *, Imran S. Sheikh * and George M. Smith Shriners Hospital’s Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, 6th Floor Medical Education & Research Building, 3500 N. Broad Street, Philadelphia, PA 19140-4106, USA; [email protected] * Correspondence: [email protected] (K.M.K.); [email protected] (I.S.S.); Tel.: +1-215-926-9330 (K.M.K. & I.S.S.) Academic Editors: Margaret Fahnestock and Keri Martinowich Received: 21 December 2016; Accepted: 24 February 2017; Published: 3 March 2017 Abstract: Neurotrophins are a family of proteins that regulate neuronal survival, synaptic function, and neurotransmitter release, and elicit the plasticity and growth of axons within the adult central and peripheral nervous system. Since the 1950s, these factors have been extensively studied in traumatic injury models. Here we review several members of the classical family of neurotrophins, the receptors they bind to, and their contribution to axonal regeneration and sprouting of sensory and motor pathways after spinal cord injury (SCI). We focus on nerve growth factor (NGF), brain derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3), and their effects on populations of neurons within diverse spinal tracts. Understanding the cellular targets of neurotrophins and the responsiveness of specific neuronal populations will allow for the most efficient treatment strategies in the injured spinal cord. Keywords: spinal cord injury; neurotrophic factors; nerve growth factor; brain-derived neurotrophic factor; neurotrophin-3; neuroprotection; plasticity; regeneration 1.
    [Show full text]
  • Neurturin-Mediated Ret Activation Is Required for Retinal Function
    The Journal of Neuroscience, April 16, 2008 • 28(16):4123–4135 • 4123 Development/Plasticity/Repair Neurturin-Mediated Ret Activation Is Required for Retinal Function Milam A. Brantley Jr,1 Sanjay Jain,2,3 Emily E. Barr,1 Eugene M. Johnson Jr,3,4,5 and Jeffrey Milbrandt3,5,6 1Department of Ophthalmology and Visual Sciences, 2Department of Medicine, Renal Division, 3Hope Center for Neurological Disorders, and Departments of 4Molecular Biology and Pharmacology, 5Neurology, and 6Pathology, Washington University School of Medicine, St. Louis, Missouri 63110 The glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) [GDNF, NRTN (neurturin), ARTN (artemin), and PSPN (persephin)] interact with GDNF family receptors (GFR␣s) and activate intracellular signaling through the Ret receptor tyrosine kinase. To characterize the role of Ret signaling in retinal activity, we examined Ret hypomorphic and Ret conditional mice using electroreti- nography. We found that aberrant Ret function resulted in markedly diminished scotopic and photopic responses. Using mice deficient in individual GFLs, we found that only NRTN deficiency led to reduced retinal activity. To determine the potential target cell type for NRTN, we examined the retinal expression of its coreceptors (GFR␣1 and GFR␣2) and Ret using mice expressing fluorescence reporter enhanced green fluorescent protein from their respective loci. We found robust GFR␣1 and Ret expression in horizontal, amacrine, and ganglion cells, whereas GFR␣2 expression was only detected in a subset of amacrine and ganglion cells. In contrast to previous studies, no expression of GFR␣1, GFR␣2, or Ret was detected in photoreceptors or Mu¨ller cells, suggesting that these cells are not directly affected by Ret.
    [Show full text]