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Ni Y, Wang Z, Zhuge F, Zhou K, Zheng L, Hu X, Wang S, Fu O, Fu Z. Hydrolyzed Chicken Meat Extract and Its Bioactive Cyclopeptides Protect Neural Function by Attenuating Inflammation and Apoptosis via PI3K/AKT and AMPK Pathways. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:16708-16725. [PMID: 39016108 DOI: 10.1021/acs.jafc.4c02063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Cognitive decline is inevitable with age, and due to the lack of well-established pharmacotherapies for neurodegenerative disorders, dietary supplements have become important alternatives to ameliorate brain deterioration. Hydrolyzed chicken meat extract (HCE) and its bioactive components were previously found to improve neuroinflammation and cognitive decline by regulating microglia polarization. However, the effects and mechanisms of these bioactives on neurons remain unclear. Here, the most potent bioactive component on neural function in HCE was screened out, and the detailed mechanism was clarified through in vivo and in vitro experiments. We found that HCE, cyclo(Val-Pro), cyclo(Phe-Phe), cyclo(His-Pro), cyclo(Leu-Lys), and arginine exerted stronger anti-inflammatory and antioxidant effects among the 12 bioactives in amyloid β (Aβ)-treated HT-22 cells. Further transcriptome sequencing and polymerase chain reaction (PCR) array analysis showed that these bioactives participated in different signaling pathways, and cyclo(Val-Pro) was identified as the most potent cyclic dipeptide. In addition, the antiapoptotic and neuroprotective effect of cyclo(Val-Pro) was partly regulated by the activation of PI3K/AKT and AMPK pathways, and the inhibition of these pathways abolished the effect of cyclo(Val-Pro). Moreover, cyclo(Val-Pro) enhanced cognitive function and neurogenesis and alleviated neuroinflammation and oxidative stress in middle-aged mice, with an effect similar to HCE. Hippocampal transcriptome analysis further revealed that HCE and cyclo(Val-Pro) significantly enriched the neuroactive ligand-receptor interaction pathway, verified by enhanced neurotransmitter levels and upregulated neurotransmitter receptor-related gene expression. Therefore, the mechanism of cyclo(Val-Pro) on neural function might be associated with PI3K/AKT and AMPK pathway-mediated antiapoptotic effect and neurogenesis and the activation of the neurotransmitter-receptor pathway.
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Affiliation(s)
- Yinhua Ni
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Zhaorong Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Fen Zhuge
- Institute of Translational Medicine, The Affiliated Hospital of Hangzhou Normal University, Hangzhou 310015, China
| | - Kexin Zhou
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Liujie Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Xinyang Hu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Sisi Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Ou Fu
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310032, China
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Bhargavan B, Chhunchha B, Kubo E, Singh DP. DNA methylation as an epigenetic mechanism in the regulation of LEDGF expression and biological response in aging and oxidative stress. Cell Death Discov 2024; 10:296. [PMID: 38909054 PMCID: PMC11193803 DOI: 10.1038/s41420-024-02076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/15/2024] [Accepted: 06/18/2024] [Indexed: 06/24/2024] Open
Abstract
The physiological quantum of stress-inducible transcriptional protein, Lens Epithelium-Derived Growth Factor (LEDGF), is vital for the maintenance of cellular physiology. Erratic epigenetic reprogramming in response to oxidative stress or with advancing age is found to be a major cause in the gene silencing, leading to pathobiologies. Using aging human (h) eye lens/lens epithelial cells (LECs) coupled with redox-active Peroxiredoxin 6 (Prdx6)-deficient (Prdx6-/-) mLECs as model systems, herein, we showed that in aging/oxidative stress, the human LEDGF gene was regulated by unique methylation patterns of CGs nucleotides within and around the Sp1 binding site(s) of CpG island of the LEDGF promoter (-170 to -27nts). The process caused the repression of LEDGF and its target, Hsp27, resulting in reactive oxygen species (ROS) amplification and cellular insults. This phenomenon was opposed to the unmethylated promoter in LECs. Clinically, we observed that the loss of LEDGF in the Prdx6-/- mLECs or aging lenses/LECs, correlating with increased expression of DNMT1, DNMT3a, and DNMT3b along with the methyl CpG binding protein 2 (MeCP2). Upon oxidative stress, the expression of these molecules was increased with the dramatic reduction in LEDGF expression. While demethylating agent, 5-Aza deoxycytidine (5-AzaC) transposed the aberrant methylation status, and revived LEDGF and Hsp27 expression. Mechanistically, the chloramphenicol acetyltransferase (CAT) reporter gene driven by the LEDGF promoter (-170/ + 35) and ChIP assays uncovered that 5-AzaC acted on GC/Sp1 sites to release LEDGF transcription. The data argued, for the first time, that de novo methylation of CGs around and within Sp1 sites of the CpG island directly disrupted Sp1 activity, which ensued in LEDGF repression and its biological functions. The findings should improve our understanding of cellular insults-associated with aberrant DNMTs-mediated LEDGF's activity, and can offer strategies for therapeutic intervention to halt aging/oxidative stress-induced abnormalities.
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Affiliation(s)
- Biju Bhargavan
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Bhavana Chhunchha
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Ishikawa, 9200293, Japan
| | - Dhirendra P Singh
- Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, USA.
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Chhunchha B, Kumar R, Kubo E, Thakur P, Singh DP. Prdx6 Regulates Nlrp3 Inflammasome Activation-Driven Inflammatory Response in Lens Epithelial Cells. Int J Mol Sci 2023; 24:16276. [PMID: 38003466 PMCID: PMC10671722 DOI: 10.3390/ijms242216276] [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: 10/15/2023] [Revised: 11/06/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
The continuum of antioxidant response dysregulation in aging/oxidative stress-driven Nlrp3 inflammasome activation-mediated inflammatory response is associated with age-related diseases. Peroxiredoxin (Prdx) 6 is a key antioxidant that provides cytoprotection by regulating redox homeostasis. Herein, using lens epithelial cells (LECs) derived from the targeted inactivation of Prdx6 gene and aging lenses, we present molecular evidence that Prdx6-deficiency causes oxidative-driven Nlrp3 inflammasome activation, resulting in pyroptosis in aging/redox active cells wherein Prdx6 availability offsets the inflammatory process. We observed that Prdx6-/- and aging LECs harboring accumulated reactive oxygen species (ROS) showed augmented activation of Nlrp3 and bioactive inflammatory components, like Caspase-1, IL-1β, ASC and Gasdermin-D. Similar to lipopolysaccharide treatment, oxidative exposure led to further ROS amplification with increased activation of the Nlrp3 inflammasome pathway. Mechanistically, we found that oxidative stress enhanced Kruppel-like factor 9 (Klf9) expression in aging/Prdx6-/- mLECs, leading to a Klf9-dependent increase in Nlrp3 transcription, while the elimination of ROS by the delivery of Prdx6 or by silencing Klf9 prevented the inflammatory response. Altogether, our data identify the biological significance of Prdx6 as an intrinsic checkpoint for regulating the cellular health of aging or redox active LECs and provide opportunities to develop antioxidant-based therapeutic(s) to prevent oxidative/aging-related diseases linked to aberrant Nlrp3 inflammasome activation.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Rakesh Kumar
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kahoku 9200293, Ishikawa, Japan;
| | - Priyanka Thakur
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA; (R.K.); (P.T.)
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Thoreson WB, Chhunchha B. EAAT5 glutamate transporter rapidly binds glutamate with micromolar affinity in mouse rods. J Gen Physiol 2023; 155:e202313349. [PMID: 37477643 PMCID: PMC10359920 DOI: 10.1085/jgp.202313349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 04/17/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023] Open
Abstract
Light responses of rod photoreceptor cells in the retina are encoded by changes in synaptic glutamate release that is in turn shaped by reuptake involving EAAT5 plasma membrane glutamate transporters. Heterologously expressed EAAT5 activates too slowly upon glutamate binding to support significant uptake. We tested EAAT5 activation in mouse rods in vivo by stimulating glutamate transporter anion currents (IA(glu)) with UV flash photolysis of MNI-glutamate, varying flash intensity to vary glutamate levels. Responses to uncaging rose rapidly with time constants of 2-3 ms, similar to IA(glu) events arising from spontaneous release. Spontaneous release events and IA(glu) evoked by weak flashes also declined with similar time constants of 40-50 ms. Stronger flashes evoked responses that decayed more slowly. Time constants were twofold faster at 35°C, suggesting that they reflect transporter kinetics, not diffusion. Selective EAAT1 and EAAT2 inhibitors had no significant effect, suggesting IA(glu) in rods arises solely from EAAT5. We calibrated glutamate levels attained during flash photolysis by expressing a fluorescent glutamate sensor iGluSnFr in cultured epithelial cells. We compared fluorescence at different glutamate concentrations to fluorescence evoked by photolytic uncaging of MNI-glutamate. The relationship between flash intensity and glutamate yielded EC50 values for EAAT5 amplitude, decay time, and rise time of ∼10 μM. Micromolar affinity and rapid activation of EAAT5 in rods show it can rapidly bind synaptic glutamate. However, we also found that EAAT5 currents are saturated by the synchronous release of only a few vesicles, suggesting limited capacity and a role for glial uptake at higher release rates.
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Affiliation(s)
- Wallace B. Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, Omaha, NE, USA
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE, USA
| | - Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, Omaha, NE, USA
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Chhunchha B, Kubo E, Krueger RR, Singh DP. Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response. Antioxidants (Basel) 2023; 12:140. [PMID: 36671002 PMCID: PMC9854670 DOI: 10.3390/antiox12010140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kanazawa 9200293, Japan
| | - Ronald R. Krueger
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
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