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Murphy K, Llewellyn K, Wakser S, Pontasch J, Samanich N, Flemer M, Hensley K, Kim DS, Park J. Mini-GAGR, an intranasally applied polysaccharide, activates the neuronal Nrf2-mediated antioxidant defense system. J Biol Chem 2018; 293:18242-18269. [PMID: 30282635 PMCID: PMC6254342 DOI: 10.1074/jbc.ra117.001245] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 09/12/2018] [Indexed: 12/24/2022] Open
Abstract
Oxidative stress triggers and exacerbates neurodegeneration in Alzheimer's disease (AD). Various antioxidants reduce oxidative stress, but these agents have little efficacy due to poor blood-brain barrier (BBB) permeability. Additionally, single-modal antioxidants are easily overwhelmed by global oxidative stress. Activating nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) and its downstream antioxidant system are considered very effective for reducing global oxidative stress. Thus far, only a few BBB-permeable agents activate the Nrf2-dependent antioxidant system. Here, we discovered a BBB-bypassing Nrf2-activating polysaccharide that may attenuate AD pathogenesis. Mini-GAGR, a 0.7-kDa cleavage product of low-acyl gellan gum, increased the levels and activities of Nrf2-dependent antioxidant enzymes, decreased reactive oxygen species (ROS) under oxidative stress in mouse cortical neurons, and robustly protected mitochondria from oxidative insults. Moreover, mini-GAGR increased the nuclear localization and transcriptional activity of Nrf2 similarly to known Nrf2 activators. Mechanistically, mini-GAGR increased the dissociation of Nrf2 from its inhibitor, Kelch-like ECH-associated protein 1 (Keap1), and induced phosphorylation and nuclear translocation of Nrf2 in a protein kinase C (PKC)- and fibroblast growth factor receptor (FGFR1)-dependent manner. Finally, 20-day intranasal treatment of 3xTg-AD mice with 100 nmol of mini-GAGR increased nuclear p-Nrf2 and growth-associated protein 43 (GAP43) levels in hippocampal neurons, reduced p-tau and β-amyloid (Aβ) peptide-stained neurons, and improved memory. The BBB-bypassing Nrf2-activating polysaccharide reported here may be effective in reducing oxidative stress and neurodegeneration in AD.
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Affiliation(s)
| | | | | | | | | | | | - Kenneth Hensley
- Pathology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio 43614 and
| | - Dong-Shik Kim
- the Department of Chemical Engineering, College of Engineering, University of Toledo, Toledo, Ohio 43607
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Zhang E, Chu F, Xu L, Liang H, Song S, Ji A. Use of fluorescein isothiocyanate isomer I to study the mechanism of intestinal absorption of fucoidan sulfate in vivo
and in vitro. Biopharm Drug Dispos 2018; 39:298-307. [DOI: 10.1002/bdd.2137] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 12/20/2022]
Affiliation(s)
- E Zhang
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
| | - Fulong Chu
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
- Food and Drug Administration of Beijing Haidian District; Beijing China
| | - Lixu Xu
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
| | - Hao Liang
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
| | - Shuliang Song
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
| | - Aiguo Ji
- Marine College; Shandong University; Weihai China
- Weihai International Biotechnology Research and Development Centre; Shandong University; Weihai China
- School of Pharmaceutical Sciences; Shandong University; Jinan China
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Makani V, Jang YG, Christopher K, Judy W, Eckstein J, Hensley K, Chiaia N, Kim DS, Park J. BBB-Permeable, Neuroprotective, and Neurotrophic Polysaccharide, Midi-GAGR. PLoS One 2016; 11:e0149715. [PMID: 26939023 PMCID: PMC4777489 DOI: 10.1371/journal.pone.0149715] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 02/04/2016] [Indexed: 12/19/2022] Open
Abstract
An enormous amount of efforts have been poured to find an effective therapeutic agent for the treatment of neurodegenerative diseases including Alzheimer’s disease (AD). Among those, neurotrophic peptides that regenerate neuronal structures and increase neuron survival show a promise in slowing neurodegeneration. However, the short plasma half-life and poor blood-brain-barrier (BBB)-permeability of neurotrophic peptides limit their in vivo efficacy. Thus, an alternative neurotrophic agent that has longer plasma half-life and better BBB-permeability has been sought for. Based on the recent findings of neuroprotective polysaccharides, we searched for a BBB-permeable neuroprotective polysaccharide among natural polysaccharides that are approved for human use. Then, we discovered midi-GAGR, a BBB-permeable, long plasma half-life, strong neuroprotective and neurotrophic polysaccharide. Midi-GAGR is a 4.7kD cleavage product of low acyl gellan gum that is approved by FDA for human use. Midi-GAGR protected rodent cortical neurons not only from the pathological concentrations of co-/post-treated free reactive radicals and Aβ42 peptide but also from activated microglial cells. Moreover, midi-GAGR showed a good neurotrophic effect; it enhanced neurite outgrowth and increased phosphorylated cAMP-responsive element binding protein (pCREB) in the nuclei of primary cortical neurons. Furthermore, intra-nasally administered midi-GAGR penetrated the BBB and exerted its neurotrophic effect inside the brain for 24 h after one-time administration. Midi-GAGR appears to activate fibroblast growth factor receptor 1 (FGFR1) and its downstream neurotrophic signaling pathway for neuroprotection and CREB activation. Additionally, 14-day intranasal administration of midi-GAGR not only increased neuronal activity markers but also decreased hyperphosphorylated tau, a precursor of neurofibrillary tangle, in the brains of the AD mouse model, 3xTg-AD. Taken together, midi-GAGR with good BBB-permeability, long plasma half-life, and strong neuroprotective and neurotrophic effects has a great therapeutic potential for the treatment of neurodegenerative diseases, especially AD.
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Affiliation(s)
- Vishruti Makani
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Yong-gil Jang
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Kevin Christopher
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Wesley Judy
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Jacob Eckstein
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Kenneth Hensley
- Department of Pathology, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Nicolas Chiaia
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Dong-Shik Kim
- Department of Chemical Engineering, College of Engineering, University of Toledo, Toledo, Ohio, United States of America
| | - Joshua Park
- Department of Neurosciences, College of Medicine and Life Sciences, University of Toledo, Toledo, Ohio, United States of America
- * E-mail:
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