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Zayas-Santiago A, Malpica-Nieves CJ, Ríos DS, Díaz-García A, Vázquez PN, Santiago JM, Rivera-Aponte DE, Veh RW, Méndez-González M, Eaton M, Skatchkov SN. Spermidine Synthase Localization in Retinal Layers: Early Age Changes. Int J Mol Sci 2024; 25:6458. [PMID: 38928162 PMCID: PMC11204015 DOI: 10.3390/ijms25126458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/06/2024] [Accepted: 06/08/2024] [Indexed: 06/28/2024] Open
Abstract
Polyamine (PA) spermidine (SPD) plays a crucial role in aging. Since SPD accumulates in glial cells, particularly in Müller retinal cells (MCs), the expression of the SPD-synthesizing enzyme spermidine synthase (SpdS) in Müller glia and age-dependent SpdS activity are not known. We used immunocytochemistry, Western blot (WB), and image analysis on rat retinae at postnatal days 3, 21, and 120. The anti-glutamine synthetase (GS) antibody was used to identify glial cells. In the neonatal retina (postnatal day 3 (P3)), SpdS was expressed in almost all progenitor cells in the neuroblast. However, by day 21 (P21), the SpdS label was pronouncedly expressed in multiple neurons, while GS labels were observed only in radial Müller glial cells. During early cell adulthood, at postnatal day 120 (P120), SpdS was observed solely in ganglion cells and a few other neurons. Western blot and semi-quantitative analyses of SpdS labeling showed a dramatic decrease in SpdS at P21 and P120 compared to P3. In conclusion, the redistribution of SpdS with aging indicates that SPD is first synthesized in all progenitor cells and then later in neurons, but not in glia. However, MCs take up and accumulate SPD, regardless of the age-associated decrease in SPD synthesis in neurons.
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Affiliation(s)
- Astrid Zayas-Santiago
- Department of Pathology and Laboratory Medicine, Universidad Central del Caribe, Bayamón, PR 00956, USA;
| | | | - David S. Ríos
- College of Science and Health Professions, Universidad Central de Bayamón, Bayamón, PR 00960, USA;
| | - Amanda Díaz-García
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA; (A.D.-G.); (D.E.R.-A.); (M.E.)
| | - Paola N. Vázquez
- Department of Natural Sciences, University of Puerto Rico-Carolina, Carolina, PR 00984, USA; (P.N.V.); (J.M.S.)
| | - José M. Santiago
- Department of Natural Sciences, University of Puerto Rico-Carolina, Carolina, PR 00984, USA; (P.N.V.); (J.M.S.)
| | - David E. Rivera-Aponte
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA; (A.D.-G.); (D.E.R.-A.); (M.E.)
| | - Rüdiger W. Veh
- Charité–Universitätsmedizin Berlin, Institut für Zell- und Neurobiologie, Centrum 2, Charitéplatz 1, D-10117 Berlin, Germany;
| | | | - Misty Eaton
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA; (A.D.-G.); (D.E.R.-A.); (M.E.)
| | - Serguei N. Skatchkov
- Department of Biochemistry, Universidad Central del Caribe, Bayamón, PR 00956, USA; (A.D.-G.); (D.E.R.-A.); (M.E.)
- Department of Physiology, Universidad Central del Caribe, Bayamón, PR 00956, USA
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Ojomoko LO, Kryukova EV, Egorova NS, Salikhov AI, Epifanova LA, Denisova DA, Khomutov AR, Sukhov DA, Vassilevski AA, Khomutov MA, Tsetlin VI, Shelukhina IV. Inhibition of nicotinic acetylcholine receptors by oligoarginine peptides and polyamine-related compounds. Front Pharmacol 2023; 14:1327603. [PMID: 38169863 PMCID: PMC10758494 DOI: 10.3389/fphar.2023.1327603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/30/2023] [Indexed: 01/05/2024] Open
Abstract
Oligoarginine peptides, known mostly for their cell-penetrating properties, are also inhibitors of the nicotinic acetylcholine receptors (nAChRs). Since octa-arginine (R8) inhibits α9α10 nAChR and suppresses neuropathic pain, we checked if other polycationic compounds containing amino and/or guanidino groups could be effective and tested the activity of the disulfide-fixed "cyclo"R8, a series of biogenic polyamines (putrescine, spermidine, and spermine), C-methylated spermine analogs, agmatine and its analogs, as well as acylpolyamine argiotoxin-636 from spider venom. Their inhibitory potency on muscle-type, α7 and α9α10 nAChRs was determined using radioligand analysis, electrophysiology, and calcium imaging. "Cyclo"R8 showed similar activity to that of R8 against α9α10 nAChR (IC50 ≈ 60 nM). Biogenic polyamines as well as agmatine and its analogs displayed low activity on muscle-type Torpedo californica, as well as α7 and α9α10 nAChRs, which increased with chain length, the most active being spermine and its C-methylated derivatives having IC50 of about 30 μM against muscle-type T. californica nAChR. Argiotoxin-636, which contains a polyamine backbone and terminal guanidino group, also weakly inhibited T. californica nAChR (IC50 ≈ 15 μM), but it revealed high potency against rat α9α10 nAChR (IC50 ≈ 200 nM). We conclude that oligoarginines and similar polycationic compounds effectively inhibiting α9α10 nAChR may serve as a basis for the development of analgesics to reduce neuropathic pain.
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Affiliation(s)
- Lucy O. Ojomoko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Elena V. Kryukova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Natalya S. Egorova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Arthur I. Salikhov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Lyubov A. Epifanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Daria A. Denisova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alex R. Khomutov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Dmitry A. Sukhov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexander A. Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
- Moscow Institute of Physics and Technology (State University), Moscow, Russia
| | - Maxim A. Khomutov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Victor I. Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Irina V. Shelukhina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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