1
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Atta-Ur-Rahman. Protein Folding and Molecular Basis of Memory: Molecular Vibrations and Quantum Entanglement as Basis of Consciousness. Curr Med Chem 2024; 31:258-265. [PMID: 37424348 DOI: 10.2174/0929867331666230707123345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 06/28/2023] [Accepted: 06/28/2023] [Indexed: 07/11/2023]
Affiliation(s)
- Atta-Ur-Rahman
- Kings College, University of Cambridge, Cambridge CB2 1st, United Kingdom
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan
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2
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Kheirabadi NR, Chiolerio A, Szaciłowski K, Adamatzky A. Neuromorphic Liquids, Colloids, and Gels: A Review. Chemphyschem 2023; 24:e202200390. [PMID: 36002385 PMCID: PMC10092099 DOI: 10.1002/cphc.202200390] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/23/2022] [Indexed: 01/07/2023]
Abstract
Advances in flexible electronic devices and robotic software require that sensors and controllers be virtually devoid of traditional electronic components, be deformable and stretch-resistant. Liquid electronic devices that mimic biological synapses would make an ideal core component for flexible liquid circuits. This is due to their unbeatable features such as flexibility, reconfiguration, fault tolerance. To mimic synaptic functions in fluids we need to imitate dynamics and complexity similar to those that occurring in living systems. Mimicking ionic movements are considered as the simplest platform for implementation of neuromorphic in material computing systems. We overview a series of experimental laboratory prototypes where neuromorphic systems are implemented in liquids, colloids and gels.
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Affiliation(s)
| | - Alessandro Chiolerio
- Unconventional Computing Laboratory, UWE, Bristol, UK.,Center for Bioinspired Soft Robotics, Istituto Italiano di Tecnologia, Genova, Italy
| | - Konrad Szaciłowski
- Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Krakow, Poland
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3
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Arnold AM, Bradley AM, Taylor KL, Kennedy ZC, Omberg KM. The Promise of Emergent Nanobiotechnologies for In Vivo Applications and Implications for Safety and Security. Health Secur 2022; 20:408-423. [PMID: 36286588 PMCID: PMC9595614 DOI: 10.1089/hs.2022.0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Nanotechnology, the multidisciplinary field based on the exploitation of the unique physicochemical properties of nanoparticles (NPs) and nanoscale materials, has opened a new realm of possibilities for biological research and biomedical applications. The development and deployment of mRNA-NP vaccines for COVID-19, for example, may revolutionize vaccines and therapeutics. However, regulatory and ethical frameworks that protect the health and safety of the global community and environment are lagging, particularly for nanotechnology geared toward biological applications (ie, bionanotechnology). In this article, while not comprehensive, we attempt to illustrate the breadth and promise of bionanotechnology developments, and how they may present future safety and security challenges. Specifically, we address current advancements to streamline the development of engineered NPs for in vivo applications and provide discussion on nano–bio interactions, NP in vivo delivery, nanoenhancement of human performance, nanomedicine, and the impacts of NPs on human health and the environment.
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Affiliation(s)
- Anne M. Arnold
- Anne M. Arnold, PhD, is a Materials Scientist, National Security Directorate, Pacific Northwest National Laboratory, Richland, WA
| | - Ashley M. Bradley
- Ashley M. Bradley is a Biomedical Scientist, National Security Directorate, Pacific Northwest National Laboratory, Richland, WA
| | - Karen L. Taylor
- Karen L. Taylor, MPH, is a Senior Technical Advisor, National Security Directorate, Pacific Northwest National Laboratory, Seattle, WA
| | - Zachary C. Kennedy
- Zachary C. Kennedy, PhD, is a Materials Scientist, National Security Directorate, Pacific Northwest National Laboratory, Richland, WA
| | - Kristin M. Omberg
- Kristin M. Omberg, PhD, is Group Leader, National Security Directorate, Pacific Northwest National Laboratory, Richland, WA.,Address correspondence to: Kristin M. Omberg, PhD, Group Leader, National Security Directorate, Pacific Northwest National Laboratory, P.O. Box 999, MSIN P7-50, Richland, WA 99354
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4
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Marx G, Gilon C. History of Chemical Notations from Alchemy to Psycho‐Chemistry. Isr J Chem 2022. [DOI: 10.1002/ijch.202100088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Chaim Gilon
- Institute of Chemistry Hebrew University Jerusalem 9675518 Israel
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5
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Sinani A, Vassi A, Tsotsokou G, Nikolakopoulou M, Kouvelas ED, Mitsacos A. Early life stress influences basal ganglia dopamine receptors and novel object recognition of adolescent and adult rats. IBRO Neurosci Rep 2022; 12:342-354. [PMID: 35572456 PMCID: PMC9092503 DOI: 10.1016/j.ibneur.2022.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 12/15/2022] Open
Abstract
Environmental stimuli in early life are recognized to affect brain development and behavior. Mother-pup interaction constitutes a determinant stimulus during this critical period. It is known that the dopaminergic system undergoes significant reorganization during adolescence and that dopamine receptors are involved in recognition memory. Based on the above, we examined the effects of brief and prolonged maternal separation during the neonatal period (15 or 180 min daily) on basal ganglia dopamine receptors and on the behavior in the novel object recognition task of adolescent and adult male rats. Using the NOR task, we observed that the discrimination index (DI) was decreased in rats with brief maternal separations independent of age. Using receptor autoradiography, we observed that brief maternal separation induced decreases in D1, D2 and D4 receptor binding levels in adult basal ganglia nuclei, while prolonged maternal separation induced increases in D1 receptor binding levels in caudate - putamen (CPu) of adolescent rats. With immunoblotting experiments, we found decreases in D1 and increases in D2 total protein levels in CPu of adult rats with prolonged maternal separations. Α positive correlation was observed between DI and D1 binding levels in CPu, internal globus pallidus and substantia nigra, and D2 binding levels in nucleus accumbens core in adult rats, using the Pearson correlation coefficient. Our results indicate that the long-lasting effects of neonatal mother-offspring separation on dopamine receptors depend on the duration of maternal separation and age and that this early life experience impairs recognition memory in adolescent and adult rats. Furthermore, the present results suggest that modulation of striatal dopamine receptors might underlie the reduced recognition memory of adult rats with brief neonatal maternal separations.
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Affiliation(s)
| | | | - Giota Tsotsokou
- Laboratory of Physiology, Faculty of Medicine, University of Patras, Patras, Greece
| | - Maria Nikolakopoulou
- Laboratory of Physiology, Faculty of Medicine, University of Patras, Patras, Greece
| | - Elias D. Kouvelas
- Laboratory of Physiology, Faculty of Medicine, University of Patras, Patras, Greece
| | - Ada Mitsacos
- Laboratory of Physiology, Faculty of Medicine, University of Patras, Patras, Greece
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6
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Atta-Ur-Rahman. Protein Folding and Molecular Basis of Memory. Curr Med Chem 2022; 29:4317-4319. [PMID: 35532256 DOI: 10.2174/0929867329666220508173020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/22/2022]
Affiliation(s)
- Atta-Ur-Rahman
- International Center for Chemical and Biological Sciences, H. E. J. Research Institute of Chemistry, Pakistan
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7
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Dukes MP, Rowe RK, Harvey T, Rangel W, Pedigo S. Nickel reduces calcium dependent dimerization in neural cadherin. Metallomics 2020; 11:475-482. [PMID: 30624456 DOI: 10.1039/c8mt00349a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cadherins are the transmembrane component in adherens junctions, structures that link the actin cytoskeletons in adjacent cells within solid tissues including neurological synapses, epithelium and endothelium. Cell-cell adhesion by cadherins requires the binding of calcium ions to specific sites in the extracellular region. Given the complexity of the cell adhesion microenvironment, we are investigating whether other divalent cations might affect calcium-dependent dimerization of neural (N) cadherin. The studies reported herein characterize the impact of binding physiological magnesium(ii) or neurotoxic nickel(ii) on calcium-dependent N-cadherin function. Physiological levels of magnesium have only a small effect on the calcium-binding affinity and calcium-induced dimerization of N-cadherin. However, a tenfold lower concentration of nickel decreases the apparent calcium-binding affinity and calcium-induced dimerization of N-cadherin. Competitive binding studies indicate that the apparent dissociation constants for nickel and magnesium are 0.2 mM and 2.5 mM, respectively. These Kd values are consistent with concentrations observed for a range of divalent cations in the extracellular space. Results from these studies indicate that calcium-induced dimerization by N-cadherin is attenuated by natural and non-physiological divalent cations in the extracellular microenvironment.
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Affiliation(s)
- M P Dukes
- Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA.
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8
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Marx G, Gilon C. Quantum considerations of neural memory. ADVANCES IN QUANTUM CHEMISTRY 2020. [DOI: 10.1016/bs.aiq.2020.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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9
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Zborowski VA, Heck SO, Sari MHM, Bastos NK, Neto JSS, Nogueira CW. (p-ClPhSe) 2 modulates hippocampal BDNF/TrkB signaling and reverses memory impairment induced by diabetes in mice. Prog Neuropsychopharmacol Biol Psychiatry 2019; 94:109660. [PMID: 31152861 DOI: 10.1016/j.pnpbp.2019.109660] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 01/27/2023]
Abstract
Diabetes is a metabolic disease characterized by hyperglycemia because of insulin resistance and/or insufficient insulin release. The most common diabetic brain complications include cognitive decline and depression. The present study investigated whether the 4-4'-dichlorodiphenyl diselenide (p-ClPhSe)2 is effective against memory impairment induced by diabetes in mice and the role of hippocampal BDNF/TrkB signaling in this effect. Male adult Swiss mice received an injection of streptozotocin (STZ) (200 mg/kg, i.p.) to induce diabetes. The results revealed that STZ injection in mice resulted in resilience (glycemia <200 mg/dl) or diabetes (glycemia ≥200 mg/dl). The vehicle-control group received citrate buffer (5 ml/kg). The animals were subchronically treated with (p-ClPhSe)2 (1 or 5 mg/kg, i.g.) for 7 days. Mice performed a battery of well-validated behavior tests designated to evaluate memory, object recognition (ORT), object location (OLT), and Morris water maze (MWM). The hippocampal protein contents of the BDNF/TrkB pathway were determined in the samples of experimental groups. Fluoro Jade C (FJC) was used for staining degenerating neurons. The STZ administration resulted in memory impairment that was demonstrated in the mouse ORT, OLT, and MWM tests. The molecular findings indicate an increase in hippocampal protein levels of proBDNF and TrKB but a decrease in those of mBDNF and pCREB in diabetic mice. The number of FJC-positive cells was increased in the hippocampus of diabetic mice. (p-ClPhSe)2 at the dose of 5 mg/kg modulated the hippocampal BDNF/TrkB pathway, reduced FJC-positive cells and reversed memory impairment induced by STZ in mice. These findings demonstrate the effectiveness of (p-ClPhSe)2 against memory impairment caused by diabetes in mice. (p-ClPhSe)2 modulated the hippocampal BDNF/TrkB signaling pathway in diabetic mice.
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Affiliation(s)
- Vanessa A Zborowski
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil
| | - Suélen O Heck
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil
| | - Marcel H M Sari
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil
| | - Nícolas K Bastos
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil
| | - José S S Neto
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil
| | - Cristina W Nogueira
- Laboratory of Synthesis, Reactivity, Pharmacological and Toxicological Evaluation of Organochalcogen Compounds, Department of Biochemistry and Molecular Biology, Center of Natural and Exact Sciences, Federal University of Santa Maria, Santa Maria - RS 97105-900, Brazil.
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10
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Kuzma S. Energy-information coupling during integrative cognitive processes. J Theor Biol 2019; 469:180-186. [PMID: 30849423 DOI: 10.1016/j.jtbi.2019.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 02/19/2019] [Accepted: 03/04/2019] [Indexed: 11/17/2022]
Abstract
The physical conception of energy is a natural and general approach to describe functional interactions in the brain at different levels starting from studies of molecular interactions up to the integrative studies of cognitive neuroimaging. In this article, we describe the representation of the brain as a fluctuating energy field, which adaptively reflects the environment. Within this neuroenergetic conception, we indicate a physically solid approach to the problem of the link between brain function and information processing - transmission and integration of information between neuroglial populations is coupled with the corresponding energy increase used for information encoding. We develop the integrative neuroenergetic model of face recognition, in which the input to the model tries to modify the fluctuations of activity according to the free-energy minimization principle corresponding to metabolic efficiency. Once the spatial path of integration in neural activity is known, the processed information can be decoded by spatial differentiation. Energy-based feedback with activity rescaling does not influence the possibility of decoding the information. The model provides further evidence that the conception of energy facilitates at both the computational and conceptual levels the understanding of brain function and its relation to cognition.
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Affiliation(s)
- Strelnikov Kuzma
- UMR 5549, Faculté de Médecine Purpan, Centre National de la Recherche Scientifique, Toulouse, France; Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier, Toulouse, France; Service d'Oto-Rhino-Laryngologie et Oto-Neurologie, Hopital Purpan Toulouse, France.
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11
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Swain S, Gupta RK, Ratnayake K, Priyanka PD, Singh R, Jana S, Mitra K, Karunarathne A, Giri L. Confocal Imaging and k-Means Clustering of GABA B and mGluR Mediated Modulation of Ca 2+ Spiking in Hippocampal Neurons. ACS Chem Neurosci 2018; 9:3094-3107. [PMID: 30044088 DOI: 10.1021/acschemneuro.8b00297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Imaging cytosolic calcium in neurons is emerging as a new tool in neurological disease diagnosis, drug screening, and toxicity testing. Ca2+ oscillation signatures show a significant variation depending on GPCR targeting agonists. Quantification of Ca2+ spike trains in ligand induced Ca2+ oscillations remains challenging due to their inherent heterogeneity in primary culture. Moreover, there is no framework available for identification of optimal number of clusters and distance metric to cluster Ca2+ spike trains. Using quantitative confocal imaging and clustering analysis, we show the characterization of Ca2+ spiking in GPCR targeting drug-treated primary culture of hippocampal neurons. A systematic framework for selection of the clustering method instead of an intuition-based method was used to optimize the cluster number and distance metric. The results discern neurons with diverse Ca2+ response patterns, including higher amplitude fast spiking and lower spiking responses, and their relative percentage in a neuron population in absence and presence of GPCR-targeted drugs. The proposed framework was employed to show that the clustering pattern of Ca2+ spiking can be controlled using GABAB and mGluR targeting drugs. This approach can be used for unbiased measurement of neural activity and identification of spiking population with varying amplitude and frequencies, providing a platform for high-content drug screening.
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Affiliation(s)
- Sarpras Swain
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Rishikesh Kumar Gupta
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Pantula Devi Priyanka
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Ranjana Singh
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Soumya Jana
- Department of Electrical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Kishalay Mitra
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Lopamudra Giri
- Department of Chemical Engineering, Indian Institute of Technology, Hyderabad 502285, India
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12
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Cacha LA, Ali J, Rizvi ZH, Yupapin PP, Poznanski RR. Nonsynaptic plasticity model of long-term memory engrams. J Integr Neurosci 2018; 16:493-509. [PMID: 28891529 DOI: 10.3233/jin-170038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Using steady-state electrical properties of non-ohmic dendrite based on cable theory, we derive electrotonic potentials that do not change over time and are localized in space. We hypothesize that clusters of such stationary, local and permanent pulses are the electrical signatures of enduring memories which are imprinted through nonsynaptic plasticity, encoded through epigenetic mechanisms, and decoded through electrotonic processing. We further hypothesize how retrieval of an engram is made possible by integration of these permanently imprinted standing pulses in a neural circuit through neurotransmission in the extracellular space as part of conscious recall that acts as a guiding template in the reconsolidation of long-term memories through novelty characterized by uncertainty that arises when new fragments of memories reinstate an engram by way of nonsynaptic plasticity that permits its destabilization. Collectively, these findings seem to reinforce this hypothesis that electrotonic processing in non-ohmic dendrites yield insights into permanent electrical signatures that could reflect upon enduring memories as fragments of long-term memory engrams.
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Affiliation(s)
- L A Cacha
- Laser Centre, Ibnu Sina ISIR, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
| | - J Ali
- Laser Centre, Ibnu Sina ISIR, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia.,Faculty of Science, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
| | - Z H Rizvi
- Laser Centre, Ibnu Sina ISIR, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
| | - P P Yupapin
- Faculty of Electrical & Electronics Engineering, Ton Duc Thang University, Ho Chi Minh City, District 7, Vietnam
| | - R R Poznanski
- Faculty of Biosciences & Medical Engineering, Universiti Teknologi Malaysia, Johor Bahru 81310, Malaysia
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13
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Marx G, Gilon C. The Molecular Basis of Neural Memory. Part 7:
Neural Intelligence (NI) versus Artificial Intelligence (AI). AIMS MEDICAL SCIENCE 2017. [DOI: 10.3934/medsci.2017.3.241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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14
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Magrì A, Tabbì G, Giuffrida A, Pappalardo G, Satriano C, Naletova I, Nicoletti VG, Attanasio F. Influence of the N-terminus acetylation of Semax, a synthetic analog of ACTH(4-10), on copper(II) and zinc(II) coordination and biological properties. J Inorg Biochem 2016; 164:59-69. [PMID: 27586814 DOI: 10.1016/j.jinorgbio.2016.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 08/23/2016] [Accepted: 08/25/2016] [Indexed: 10/21/2022]
Abstract
Semax is a heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) that encompasses the sequence 4-7 of N-terminal domain of the adrenocorticotropic hormone and a C-terminal Pro-Gly-Pro tripeptide. N-terminal amino group acetylation (Ac-Semax) modulates the chemical and biological properties of parental peptide, modifying the ability of Semax to form complex species with Cu(II) ion. At physiological pH, the main complex species formed by Ac-Semax, [CuLH-2]2-, consists in a distorted CuN3O chromophore with a weak apical interaction of the methionine sulphur. Such a complex differs from the Cu(II)-Semax complex system, which exhibits a CuN4 chromophore. The reduced ligand field affects the [CuLH-2]2- formal redox potential, which is more positive than that of Cu(II)-Semax corresponding species. In the amino-free form, the resulting complex species is redox-stable and unreactive against ascorbic acid, unlike the acetylated form. Semax acetylation did not protect from Cu(II) induced toxicity on a SH-SY5Y neuroblastoma cell line, thus demonstrating the crucial role played by the free NH2 terminus in the cell protection. Since several brain diseases are associated either to Cu(II) or Zn(II) dyshomeostasis, here we characterized also the complex species formed by Zn(II) with Semax and Ac-Semax. Both peptides were able to form Zn(II) complex species with comparable strength. Confocal microscopy imaging confirmed that peptide group acetylation does not affect the Zn(II) influx in neuroblastoma cells. Moreover, a punctuate distribution of Zn(II) within the cells suggests a preferred subcellular localization that might explain the zinc toxic effect. A future perspective can be the use of Ac-Semax as ionophore in antibody drug conjugates to produce a dysmetallostasis in tumor cells.
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Affiliation(s)
- Antonio Magrì
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche (CNR), Via P. Gaifami 18, 95126 Catania, Italy
| | - Giovanni Tabbì
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche (CNR), Via P. Gaifami 18, 95126 Catania, Italy.
| | - Alessandro Giuffrida
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche (CNR), Via P. Gaifami 18, 95126 Catania, Italy
| | - Giuseppe Pappalardo
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche (CNR), Via P. Gaifami 18, 95126 Catania, Italy
| | - Cristina Satriano
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Irina Naletova
- Dipartimento di Scienze Biomediche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy; Consorzio Interuniversitario C.I.R.C.S.M.B., Via C. Ulpiani 27, 70125 Bari, Italy
| | - Vincenzo G Nicoletti
- Dipartimento di Scienze Biomediche, Università degli Studi di Catania, Viale A. Doria 6, 95125 Catania, Italy
| | - Francesco Attanasio
- Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche (CNR), Via P. Gaifami 18, 95126 Catania, Italy.
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15
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Tabbì G, Magrì A, Giuffrida A, Lanza V, Pappalardo G, Naletova I, Nicoletti VG, Attanasio F, Rizzarelli E. Semax, an ACTH4-10 peptide analog with high affinity for copper(II) ion and protective ability against metal induced cell toxicity. J Inorg Biochem 2015; 142:39-46. [DOI: 10.1016/j.jinorgbio.2014.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/05/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
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16
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Jungles JM, Dukes MP, Vunnam N, Pedigo S. Impact of pH on the structure and function of neural cadherin. Biochemistry 2014; 53:7436-44. [PMID: 25365402 DOI: 10.1021/bi5010798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neural (N-) cadherin is a transmembrane protein within adherens junctions that mediates cell-cell adhesion. It has 5 modular extracellular domains (EC1-EC5) that bind 3 calcium ions between each of the modules. Calcium binding is required for dimerization. N-Cadherin is involved in diverse processes including tissue morphogenesis, excitatory synapse formation and dynamics, and metastasis of cancer. During neurotransmission and tumorigenesis, fluctuations in extracellular pH occur, causing tissue acidosis with associated physiological consequences. Studies reported here aim to determine the effect of pH on the dimerization properties of a truncated construct of N-cadherin containing EC1-EC2. Since N-cadherin is an anionic protein, we hypothesized that acidification of solution would cause an increase in stability of the apo protein, a decrease in the calcium-binding affinity, and a concomitant decrease in the formation of adhesive dimer. The stability of the apo monomer was increased and the calcium-binding affinity was decreased at reduced pH, consistent with our hypothesis. Surprisingly, analytical SEC studies showed an increase in calcium-induced dimerization as solution pH decreased from 7.4 to 5.0. Salt-dependent dimerization studies indicated that electrostatic repulsion attenuates dimerization affinity. These results point to a possible electrostatic mechanism for moderating dimerization affinity of the Type I cadherin family. Extrapolating these results to cell adhesion in vivo leads to the assertion that decreased pH promotes adhesion by N-cadherin, thereby stabilizing synaptic junctions.
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Affiliation(s)
- Jared M Jungles
- Department of Chemistry and Biochemistry, University of Mississippi , University, Mississippi 38677, United States
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17
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Evolutionary implications of metal binding features in different species' prion protein: an inorganic point of view. Biomolecules 2014; 4:546-65. [PMID: 24970230 PMCID: PMC4101497 DOI: 10.3390/biom4020546] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/29/2014] [Accepted: 05/06/2014] [Indexed: 12/21/2022] Open
Abstract
Prion disorders are a group of fatal neurodegenerative conditions of mammals. The key molecular event in the pathogenesis of such diseases is the conformational conversion of prion protein, PrPC, into a misfolded form rich in β-sheet structure, PrPSc, but the detailed mechanistic aspects of prion protein conversion remain enigmatic. There is uncertainty on the precise physiological function of PrPC in healthy individuals. Several evidences support the notion of its role in copper homeostasis. PrPC binds Cu2+ mainly through a domain composed by four to five repeats of eight amino acids. In addition to mammals, PrP homologues have also been identified in birds, reptiles, amphibians and fish. The globular domain of protein is retained in the different species, suggesting that the protein carries out an essential common function. However, the comparison of amino acid sequences indicates that prion protein has evolved differently in each vertebrate class. The primary sequences are strongly conserved in each group, but these exhibit a low similarity with those of mammals. The N-terminal domain of different prions shows tandem amino acid repeats with an increasing amount of histidine residues going from amphibians to mammals. The difference in the sequence affects the number of copper binding sites, the affinity and the coordination environment of metal ions, suggesting that the involvement of prion in metal homeostasis may be a specific characteristic of mammalian prion protein. In this review, we describe the similarities and the differences in the metal binding of different species' prion protein, as revealed by studies carried out on the entire protein and related peptide fragments.
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Marx G, Gilon C. The molecular basis of memory. Part 3: tagging with "emotive" neurotransmitters. Front Aging Neurosci 2014; 6:58. [PMID: 24778616 PMCID: PMC3985027 DOI: 10.3389/fnagi.2014.00058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 03/17/2014] [Indexed: 12/02/2022] Open
Abstract
Many neurons of all animals that exhibit memory (snails, worms, flies, vertebrae) present arborized shapes with many varicosities and boutons. These neurons, release neurotransmitters and contain ionotropic receptors that produce and sense electrical signals (ephaptic transmission). The extended shapes maximize neural contact with the surrounding neutrix [defined as: neural extracellular matrix (nECM) + diffusible (neurometals and neurotransmitters)] as well as with other neurons. We propose a tripartite mechanism of animal memory based on the dynamic interactions of splayed neurons with the "neutrix." Their interactions form cognitive units of information (cuinfo), metal-centered complexes within the nECM around the neuron. Emotive content is provided by NTs, which embody molecular links between physiologic (body) responses and psychic feelings. We propose that neurotransmitters form mixed complexes with cuinfo used for tagging emotive memory. Thus, NTs provide encoding option not available to a Turing, binary-based, device. The neurons employ combinatorially diverse options, with >10 NMs and >90 NTs for encoding ("flavoring") cuinfo with emotive tags. The neural network efficiently encodes, decodes and consolidates related (entangled) sets of cuinfo into a coherent pattern, the basis for emotionally imbued memory, critical for determining a behavioral choice aimed at survival. The tripartite mechanism with tagging of NTs permits of a causal connection between physiology and psychology.
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Affiliation(s)
| | - Chaim Gilon
- Department of Organic Chemistry, Institute of Chemistry, Hebrew UniversityJerusalem, Israel
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Travaglia A, La Mendola D, Magrì A, Pietropaolo A, Nicoletti VG, Grasso G, Malgieri G, Fattorusso R, Isernia C, Rizzarelli E. Zinc(II) interactions with brain-derived neurotrophic factor N-terminal peptide fragments: inorganic features and biological perspectives. Inorg Chem 2013; 52:11075-83. [PMID: 24070197 DOI: 10.1021/ic401318t] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin essential for neuronal differentiation, growth, and survival; it is involved in memory formation and higher cognitive functions. The N-terminal domain of BDNF is crucial for the binding selectivity and activation of its specific TrkB receptor. Zn(2+) ion binding may influence BDNF activity. Zn(2+) complexes with the peptide fragment BDNF(1-12) encompassing the sequence 1-12 of the N-terminal domain of BDNF were studied by means of potentiometry, electrospray mass spectrometry, NMR, and density functional theory (DFT) approaches. The predominant Zn(2+) complex species, at physiological pH, is [ZnL] in which the metal ion is bound to an amino, an imidazole, and two water molecules (NH2, N(Im), and 2O(water)) in a tetrahedral environment. DFT-based geometry optimization of the zinc coordination environment showed a hydrogen bond between the carboxylate and a water molecule bound to zinc in [ZnL]. The coordination features of the acetylated form [AcBDNF(1-12)] and of a single mutated peptide [BDNF(1-12)D3N] were also characterized, highlighting the role of the imidazole side chain as the first anchoring site and ruling out the direct involvement of the aspartate residue in the metal binding. Zn(2+) addition to the cell culture medium induces an increase in the proliferative activity of the BDNF(1-12) peptide and of the whole protein on the SHSY5Y neuroblastoma cell line. The effect of Zn(2+) is opposite to that previously observed for Cu(2+) addition, which determines a decrease in the proliferative activity for both peptide and protein, suggesting that these metals might discriminate and modulate differently the activity of BDNF.
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Affiliation(s)
- Alessio Travaglia
- Center for Neural Science, New York University , 4 Washington Place, New York, New York 10003, United States
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Marx G, Gilon C. The molecular basis of memory. Part 2: chemistry of the tripartite mechanism. ACS Chem Neurosci 2013; 4:983-93. [PMID: 23419130 DOI: 10.1021/cn300237r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
We propose a tripartite mechanism to describe the processing of cognitive information (cog-info), comprising the (1) neuron, (2) surrounding neural extracellular matrix (nECM), and (3) numerous "trace" metals distributed therein. The neuron is encased in a polyanionic nECM lattice doped with metals (>10), wherein it processes (computes) and stores cog-info. Each [nECM:metal] complex is the molecular correlate of a cognitive unit of information (cuinfo), similar to a computer "bit". These are induced/sensed by the neuron via surface iontophoretic and electroelastic (piezoelectric) sensors. The generic cuinfo are used by neurons to biochemically encode and store cog-info in a rapid, energy efficient, but computationally expansive manner. Here, we describe chemical reactions involved in various processes that underline the tripartite mechanism. In addition, we present novel iconographic representations of various types of cuinfo resulting from"tagging" and cross-linking reactions, essential for the indexing cuinfo for organized retrieval and storage of memory.
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Affiliation(s)
| | - Chaim Gilon
- Institute of Chemistry, Hebrew University, Jerusalem, Israel
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