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McGee SL, Hargreaves M. Exercise Performance and Health: Role of GLUT4 ‡. Free Radic Biol Med 2024:S0891-5849(24)00647-6. [PMID: 39243828 DOI: 10.1016/j.freeradbiomed.2024.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 08/20/2024] [Accepted: 09/01/2024] [Indexed: 09/09/2024]
Abstract
The glucose transporter GLUT4 is integral for optimal skeletal muscle performance during exercise, as well as for metabolic health. Physiological regulation of GLUT4 translocation during exercise and increased GLUT4 expression following exercise involves multiple, redundant signalling pathways. These include effects of reactive oxygen species (ROS). ROS contribute to GLUT4 translocation that increases skeletal muscle glucose uptake during exercise and stimulate signalling pathways that increase GLUT4 expression. Conversely, ROS can also inhibit GLUT4 translocation and expression in metabolic disease states. The opposing roles of ROS in GLUT4 regulation are ultimately linked to the metabolic state of skeletal muscle and the intricate mechanisms involved give insights into pathways critical for exercise performance and implicated in metabolic health and disease.
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Affiliation(s)
- Sean L McGee
- Institute for Mental and Physical Health and Clinical Translation (IMPACT), School of Medicine, Deakin University, Waurn Ponds, 3217, Australia.
| | - Mark Hargreaves
- Department of Anatomy & Physiology, University of Melbourne, 3010, Australia
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2
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Gupta I, Gaykalova DA. Unveiling the role of PIK3R1 in cancer: A comprehensive review of regulatory signaling and therapeutic implications. Semin Cancer Biol 2024; 106-107:58-86. [PMID: 39197810 DOI: 10.1016/j.semcancer.2024.08.004] [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: 05/07/2024] [Revised: 07/11/2024] [Accepted: 08/20/2024] [Indexed: 09/01/2024]
Abstract
Phosphoinositide 3-kinase (PI3K) is responsible for phosphorylating phosphoinositides to generate secondary signaling molecules crucial for regulating various cellular processes, including cell growth, survival, and metabolism. The PI3K is a heterodimeric enzyme complex comprising of a catalytic subunit (p110α, p110β, or p110δ) and a regulatory subunit (p85). The binding of the regulatory subunit, p85, with the catalytic subunit, p110, forms an integral component of the PI3K enzyme. PIK3R1 (phosphoinositide-3-kinase regulatory subunit 1) belongs to class IA of the PI3K family. PIK3R1 exhibits structural complexity due to alternative splicing, giving rise to distinct isoforms, prominently p85α and p55α. While the primary p85α isoform comprises multiple domains, including Src homology 3 (SH3) domains, a Breakpoint Cluster Region Homology (BH) domain, and Src homology 2 (SH2) domains (iSH2 and nSH2), the shorter isoform, p55α, lacks certain domains present in p85α. In this review, we will highlight the intricate regulatory mechanisms governing PI3K signaling along with the impact of PIK3R1 alterations on cellular processes. We will further delve into the clinical significance of PIK3R1 mutations in various cancer types and their implications for prognosis and treatment outcomes. Additionally, we will discuss the evolving landscape of targeted therapies aimed at modulating PI3K-associated pathways. Overall, this review will provide insights into the dynamic interplay of PIK3R1 in cancer, fostering advancements in precision medicine and the development of targeted interventions.
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Affiliation(s)
- Ishita Gupta
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Otorhinolaryngology-Head and Neck Surgery, Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Medical Center, Baltimore, MD, USA
| | - Daria A Gaykalova
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Otorhinolaryngology-Head and Neck Surgery, Marlene & Stewart Greenebaum Comprehensive Cancer Center, University of Maryland Medical Center, Baltimore, MD, USA; Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, USA.
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Trinh VH, Nguyen Huu T, Sah DK, Choi JM, Yoon HJ, Park SC, Jung YS, Lee SR. Redox Regulation of PTEN by Reactive Oxygen Species: Its Role in Physiological Processes. Antioxidants (Basel) 2024; 13:199. [PMID: 38397797 PMCID: PMC10886030 DOI: 10.3390/antiox13020199] [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: 01/03/2024] [Revised: 01/25/2024] [Accepted: 01/27/2024] [Indexed: 02/25/2024] Open
Abstract
Phosphatase and tensin homolog (PTEN) is a tumor suppressor due to its ability to regulate cell survival, growth, and proliferation by downregulating the PI3K/AKT signaling pathway. In addition, PTEN plays an essential role in other physiological events associated with cell growth demands, such as ischemia-reperfusion, nerve injury, and immune responsiveness. Therefore, recently, PTEN inhibition has emerged as a potential therapeutic intervention in these situations. Increasing evidence demonstrates that reactive oxygen species (ROS), especially hydrogen peroxide (H2O2), are produced and required for the signaling in many important cellular processes under such physiological conditions. ROS have been shown to oxidize PTEN at the cysteine residue of its active site, consequently inhibiting its function. Herein, we provide an overview of studies that highlight the role of the oxidative inhibition of PTEN in physiological processes.
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Affiliation(s)
- Vu Hoang Trinh
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
- Department of Oncology, Department of Medical Sciences, Pham Ngoc Thach University of Medicine, Ho Chi Minh City 700000, Vietnam
| | - Thang Nguyen Huu
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
| | - Dhiraj Kumar Sah
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
| | - Jin Myung Choi
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
| | - Hyun Joong Yoon
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
| | - Sang Chul Park
- The Future Life & Society Research Center, Advanced Institute of Aging Science, Chonnam National University, Gwangju 61469, Republic of Korea;
| | - Yu Seok Jung
- Chonnam National University Medical School, Gwangju 501190, Republic of Korea;
| | - Seung-Rock Lee
- Department of Biochemistry, Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju 501190, Republic of Korea; (V.H.T.); (T.N.H.); (D.K.S.); (J.M.C.); (H.J.Y.)
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Patel H, Mishra R, Wier A, Mokhtarpour N, Merino EJ, Garrett JT. RIDR-PI-103, ROS-activated prodrug PI3K inhibitor inhibits cell growth and impairs the PI3K/Akt pathway in BRAF and MEK inhibitor-resistant BRAF-mutant melanoma cells. Anticancer Drugs 2023; 34:519-531. [PMID: 36847042 PMCID: PMC9997637 DOI: 10.1097/cad.0000000000001500] [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: 09/07/2022] [Revised: 12/06/2022] [Indexed: 03/01/2023]
Abstract
Reactive oxygen species (ROS) levels are elevated after acquisition of resistance to v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors including dabrafenib and MEK inhibitors such as trametinib in BRAF-mutant melanoma. To circumvent toxicity to PI-103 (a pan PI3K inhibitor), we utilized a novel ROS-induced drug release (RIDR)-PI-103, with a self-cyclizing moiety linked to PI-103. Under high ROS conditions, RIDR-PI-103 releases PI-103, which inhibits conversion of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to phosphatidylinositol 3,4,5-triphosphate (PIP 3 ). Previous findings demonstrate that trametinib and dabrafenib-resistant (TDR) cells maintain p-Akt levels compared to parental counterparts and have significantly higher ROS. This is a rationale to explore the efficacy RIDR-PI-103 in TDR cells. We tested the effect of RIDR-PI-103 on melanocytes and TDR cells. RIDR-PI-103 exhibited less toxicity compared to PI-103 at 5 µM in melanocytes. RIDR-PI-103 significantly inhibited TDR cell proliferation at 5 and 10 µM. Twenty-four hour treatment with RIDR-PI-103 inhibited p-Akt, p-S6 (Ser240/244) and p-S6 (Ser235/236). We assessed the mechanism of activation of RIDR-PI-103, using glutathione or t-butyl hydrogen peroxide (TBHP) on the TDR cells in the presence or absence of RIDR-PI-103. Addition of the ROS scavenger glutathione to RIDR-PI-103 significantly rescued the cell proliferation in TDR cell lines while addition of the ROS inducer TBHP and RIDR-PI-103 inhibited cell proliferation in WM115 and WM983B TDR cell lines. Examining the efficacy of RIDR-PI-103 on BRAF and MEK inhibitor-resistant cells will expand possible treatment options and open avenues for the development of new ROS-based treatment therapies for BRAF-mutant melanoma patients.
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Affiliation(s)
- Hima Patel
- UT Southwestern Medical Center, Harold C. Simmons Cancer Center, Dallas
| | - Rosalin Mishra
- Department of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio
| | - Adam Wier
- Department of Chemistry, Hillsdale College, Hillsdale, Michigan
| | | | - Edward J. Merino
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio, USA
| | - Joan T. Garrett
- Department of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio
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Thomas HJ, Ang T, Morrison DJ, Keske MA, Parker L. Acute exercise and high-glucose ingestion elicit dynamic and individualized responses in systemic markers of redox homeostasis. Front Immunol 2023; 14:1127088. [PMID: 37063903 PMCID: PMC10102861 DOI: 10.3389/fimmu.2023.1127088] [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: 12/19/2022] [Accepted: 03/14/2023] [Indexed: 03/31/2023] Open
Abstract
BackgroundBiomarkers of oxidation-reduction (redox) homeostasis are commonly measured in human blood to assess whether certain stimuli (e.g., high-glucose ingestion or acute exercise) lead to a state of oxidative distress (detrimental to health) or oxidative eustress (beneficial to health). Emerging research indicates that redox responses are likely to be highly individualized, yet few studies report individual responses. Furthermore, the effects of complex redox stimuli (e.g., high-glucose-ingestion after exercise) on redox homeostasis remains unclear. We investigated the effect of acute exercise (oxidative eustress), high-glucose ingestion (oxidative distress), and high-glucose ingestion after exercise (both oxidative eu/distress), on commonly measured redox biomarkers in serum/plasma.MethodsIn a randomized crossover fashion, eight healthy men (age: 28 ± 4 years; BMI: 24.5 ± 1.5 kg/m2 [mean ± SD]) completed two separate testing conditions; 1) consumption of a high-glucose mixed-nutrient meal (45% carbohydrate [1.1 g glucose.kg-1], 20% protein, and 35% fat) at rest (control trial), and 2) consumption of the same meal 3 h and 24 h after 1 h of moderate-intensity cycling exercise (exercise trial). Plasma and serum were analyzed for an array of commonly studied redox biomarkers.ResultsOxidative stress and antioxidant defense markers (hydrogen peroxide, 8-isoprostanes, catalase, superoxide dismutase, and nitrate levels) increased immediately after exercise (p < 0.05), whereas nitric oxide activity and thiobarbituric acid reactive substances (TBARS) remained similar to baseline (p > 0.118). Nitric oxide activity and nitrate levels decreased at 3 h post-exercise compared to pre-exercise baseline levels. Depending on when the high-glucose mixed nutrient meal was ingested and the postprandial timepoint investigated, oxidative stress and antioxidant defense biomarkers either increased (hydrogen peroxide, TBARS, and superoxide dismutase), decreased (hydrogen peroxide, 8-isoprostanes, superoxide dismutase, nitric oxide activity, nitrate, and nitrite), or remained similar to pre-meal baseline levels (hydrogen peroxide, 8-isoprostanes, TBARS, catalase, superoxide dismutase and nitrite). Redox responses exhibited large inter-individual variability in the magnitude and/or direction of responses.ConclusionFindings highlight the necessity to interpret redox biomarkers in the context of the individual, biomarker measured, and stimuli observed. Individual redox responsiveness may be of physiological relevance and should be explored as a potential means to inform personalized redox intervention.
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Affiliation(s)
- Hannah J. Thomas
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Teddy Ang
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Dale J. Morrison
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
- Department of Medicine, University of Melbourne, Melbourne, VIC, Australia
| | - Michelle A. Keske
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Lewan Parker
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
- *Correspondence: Lewan Parker,
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Nguyen Huu T, Park J, Zhang Y, Duong Thanh H, Park I, Choi JM, Yoon HJ, Park SC, Woo HA, Lee SR. The Role of Oxidative Inactivation of Phosphatase PTEN and TCPTP in Fatty Liver Disease. Antioxidants (Basel) 2023; 12:antiox12010120. [PMID: 36670982 PMCID: PMC9854873 DOI: 10.3390/antiox12010120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/05/2023] Open
Abstract
Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are becoming increasingly prevalent worldwide. Despite the different etiologies, their spectra and histological feature are similar, from simple steatosis to more advanced stages such as steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Studies including peroxiredoxin knockout models revealed that oxidative stress is crucial in these diseases, which present as consequences of redox imbalance. Protein tyrosine phosphatases (PTPs) are a superfamily of enzymes that are major targets of reactive oxygen species (ROS) because of an oxidation-susceptible nucleophilic cysteine in their active site. Herein, we review the oxidative inactivation of two tumor suppressor PTPs, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and T-cell protein tyrosine phosphatase (TCPTP), and their contribution to the pathogenicity of ALD and NAFLD, respectively. This review might provide a better understanding of the pathogenic mechanisms of these diseases and help develop new therapeutic strategies to treat fatty liver disease.
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Affiliation(s)
- Thang Nguyen Huu
- Department of Biochemistry, Department of Biomedical Sciences, Research Center for Aging and Geriatrics, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
- BioMedical Sciences Graduate Program (BMSGP), Chonnam National University Medical School, Hwasun 58 128, Republic of Korea
| | - Jiyoung Park
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Ying Zhang
- Department of Cell Biology, School of Medicine, Jiangsu University, Zhenjiang 212013, China
| | - Hien Duong Thanh
- BioMedical Sciences Graduate Program (BMSGP), Chonnam National University Medical School, Hwasun 58 128, Republic of Korea
- Department of Anatomy, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Iha Park
- Department of Biochemistry, Department of Biomedical Sciences, Research Center for Aging and Geriatrics, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Jin Myung Choi
- Department of Biochemistry, Department of Biomedical Sciences, Research Center for Aging and Geriatrics, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Hyun Joong Yoon
- Department of Biochemistry, Department of Biomedical Sciences, Research Center for Aging and Geriatrics, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
| | - Sang Chul Park
- The Future Life and Society Research Center, Advanced Institute of Aging Science, Chonnam National University, Gwangju 61469, Republic of Korea
| | - Hyun Ae Woo
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Seung-Rock Lee
- Department of Biochemistry, Department of Biomedical Sciences, Research Center for Aging and Geriatrics, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 61469, Republic of Korea
- Correspondence: ; Tel.: +82-61-379-2775; Fax: +82-61-379-2782
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Mason SA, Parker L, van der Pligt P, Wadley GD. Vitamin C supplementation for diabetes management: A comprehensive narrative review. Free Radic Biol Med 2023; 194:255-283. [PMID: 36526243 DOI: 10.1016/j.freeradbiomed.2022.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022]
Abstract
Growing evidence suggests that vitamin C supplementation may be an effective adjunct therapy in the management of people with diabetes. This paper critically reviews the current evidence on effects of vitamin C supplementation and its potential mechanisms in diabetes management. Evidence from meta-analyses of randomized controlled trials (RCTs) show favourable effects of vitamin C on glycaemic control and blood pressure that may be clinically meaningful, and mixed effects on blood lipids and endothelial function. However, evidence is mostly of low evidence certainty. Emerging evidence is promising for effects of vitamin C supplementation on some diabetes complications, particularly diabetic foot ulcers. However, there is a notable lack of robust and well-designed studies exploring effects of vitamin C as a single compound supplement on diabetes prevention and patient-important outcomes (i.e. prevention and amelioration of diabetes complications). RCTs are also required to investigate potential preventative or ameliorative effects of vitamin C on gestational diabetes outcomes. Oral vitamin C doses of 500-1000 mg per day are potentially effective, safe, and affordable for many individuals with diabetes. However, personalisation of supplementation regimens that consider factors such as vitamin C status, disease status, current glycaemic control, vitamin C intake, redox status, and genotype is important to optimize vitamin C's therapeutic effects safely. Finally, given a high prevalence of vitamin C deficiency in patients with complications, it is recommended that plasma vitamin C concentration be measured and monitored in the clinic setting.
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Affiliation(s)
- Shaun A Mason
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia.
| | - Lewan Parker
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Paige van der Pligt
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia; Department of Nutrition and Dietetics, Western Health, Footscray, Australia
| | - Glenn D Wadley
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
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Methacrylic Acid-Based Regenerative Biomaterials: Explorations into the MAAgic. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2022. [DOI: 10.1007/s40883-022-00263-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mehan S, Bhalla S, Siddiqui EM, Sharma N, Shandilya A, Khan A. Potential Roles of Glucagon-Like Peptide-1 and Its Analogues in Dementia Targeting Impaired Insulin Secretion and Neurodegeneration. Degener Neurol Neuromuscul Dis 2022; 12:31-59. [PMID: 35300067 PMCID: PMC8921673 DOI: 10.2147/dnnd.s247153] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/16/2022] [Indexed: 12/20/2022] Open
Abstract
Dementia is a chronic, irreversible condition marked by memory loss, cognitive decline, and mental instability. It is clinically related to various progressive neurological diseases, including Parkinson’s disease, Alzheimer’s disease, and Huntington’s. The primary cause of neurological disorders is insulin desensitization, demyelination, oxidative stress, and neuroinflammation accompanied by various aberrant proteins such as amyloid-β deposits, Lewy bodies accumulation, tau formation leading to neurofibrillary tangles. Impaired insulin signaling is directly associated with amyloid-β and α-synuclein deposition, as well as specific signaling cascades involved in neurodegenerative diseases. Insulin dysfunction may initiate various intracellular signaling cascades, including phosphoinositide 3-kinase (PI3K), c-Jun N-terminal kinases (JNK), and mitogen-activated protein kinase (MAPK). Neuronal death, inflammation, neuronal excitation, mitochondrial malfunction, and protein deposition are all influenced by insulin. Recent research has focused on GLP-1 receptor agonists as a potential therapeutic target. They increase glucose-dependent insulin secretion and are beneficial in neurodegenerative diseases by reducing oxidative stress and cytokine production. They reduce the deposition of abnormal proteins by crossing the blood-brain barrier. The purpose of this article is to discuss the role of insulin dysfunction in the pathogenesis of neurological diseases, specifically dementia. Additionally, we reviewed the therapeutic target (GLP-1) and its receptor activators as a possible treatment of dementia.
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Affiliation(s)
- Sidharth Mehan
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
- Correspondence: Sidharth Mehan, Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, 142001, Punjab, India, Tel +91 8059889909; +91 9461322911, Email ;
| | - Sonalika Bhalla
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Ehraz Mehmood Siddiqui
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Nidhi Sharma
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Ambika Shandilya
- Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India
| | - Andleeb Khan
- Department of Pharmacology & Toxicology, College of Pharmacy, Jazan University, Jazan, Kingdom of Saudi Arabia
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Christmann A, Gries M, Scholz P, Stahr PL, Law JKY, Schulte S, Martin M, Lilischkis R, Ingebrandt S, Keck CM, Schäfer KH. The antioxidant Rutin counteracts the pathological impact of α-synuclein on the enteric nervous system in vitro. Biol Chem 2021; 403:103-122. [PMID: 34582634 DOI: 10.1515/hsz-2021-0259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 09/15/2021] [Indexed: 11/15/2022]
Abstract
Motoric disturbances in Parkinson's disease (PD) derive from the loss of dopaminergic neurons in the substantia nigra. Intestinal dysfunctions often appear long before manifestation of neuronal symptoms, suggesting a strong correlation between gut and brain in PD. Oxidative stress is a key player in neurodegeneration causing neuronal cell death. Using natural antioxidative flavonoids like Rutin, might provide intervening strategies to improve PD pathogenesis. To explore the potential effects of micro (mRutin) compared to nano Rutin (nRutin) upon the brain and the gut during PD, its neuroprotective effects were assessed using an in vitro PD model. Our results demonstrated that Rutin inhibited the neurotoxicity induced by A53T α-synuclein (Syn) administration by decreasing oxidized lipids and increasing cell viability in both, mesencephalic and enteric cells. For enteric cells, neurite outgrowth, number of synaptic vesicles, and tyrosine hydroxylase positive cells were significantly reduced when treated with Syn. This could be reversed by the addition of Rutin. nRutin revealed a more pronounced result in all experiments. In conclusion, our study shows that Rutin, especially the nanocrystals, are promising natural compounds to protect neurons from cell death and oxidative stress during PD. Early intake of Rutin may provide a realizable option to prevent or slow PD pathogenesis.
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Affiliation(s)
- Anne Christmann
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Manuela Gries
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Patrik Scholz
- Formulation Development, BAYER AG, R&D, D-51373Leverkusen, Germany
| | - Pascal L Stahr
- Department of Pharmaceutics and Biopharmaceutics, Philipps-Universität Marburg, D-35037Marburg, Germany
| | - Jessica Ka Yan Law
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Steven Schulte
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Monika Martin
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Rainer Lilischkis
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany
| | - Sven Ingebrandt
- Institute of Materials in Electrical Engineering, RWTH Aachen University, D-52074Aachen, Germany
| | - Cornelia M Keck
- Department of Pharmaceutics and Biopharmaceutics, Philipps-Universität Marburg, D-35037Marburg, Germany
| | - Karl-Herbert Schäfer
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, Working Group Enteric Nervous System, D-66482Zweibrücken, Germany.,Department of Pediatric Surgery, Medical Faculty Mannheim, University of Heidelberg, D-68167Mannheim, Germany
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Khan AQ, Rashid K, AlAmodi AA, Agha MV, Akhtar S, Hakeem I, Raza SS, Uddin S. Reactive oxygen species (ROS) in cancer pathogenesis and therapy: An update on the role of ROS in anticancer action of benzophenanthridine alkaloids. Biomed Pharmacother 2021; 143:112142. [PMID: 34536761 DOI: 10.1016/j.biopha.2021.112142] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/13/2021] [Accepted: 08/31/2021] [Indexed: 12/12/2022] Open
Abstract
Reactive oxygen species play crucial role in biological homeostasis and pathogenesis of human diseases including cancer. In this line, now it has become evident that ROS level/concentration is a major factor in the growth, progression and stemness of cancer cells. Moreover, cancer cells maintain a delicate balance between ROS and antioxidants to promote pathogenesis and clinical challenges via targeting a battery of signaling pathways converging to cancer hallmarks. Recent findings also entail the therapeutic importance of ROS for the better clinical outcomes in cancer patients as they induce apoptosis and autophagy. Moreover, poor clinical outcomes associated with cancer therapies are the major challenge and use of natural products have been vital in attenuation of these challenges due to their multitargeting potential with less adverse effects. In fact, most available drugs are derived from natural resources, either directly or indirectly and available evidence show the clinical importance of natural products in the management of various diseases, including cancer. ROS play a critical role in the anticancer actions of natural products, particularly phytochemicals. Benzophenanthridine alkaloids of the benzyl isoquinoline family of alkaloids, such as sanguinarine, possess several pharmacological properties and are thus being studied for the treatment of different human diseases, including cancer. In this article, we review recent findings, on how benzophenanthridine alkaloid-induced ROS play a critical role in the attenuation of pathological changes and stemness features associated with human cancers. In addition, we highlight the role of ROS in benzophenanthridine alkaloid-mediated activation of the signaling pathway associated with cancer cell apoptosis and autophagy.
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Affiliation(s)
- Abdul Q Khan
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Khalid Rashid
- Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai, China
| | | | - Maha Victor Agha
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Sabah Akhtar
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Ishrat Hakeem
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar
| | - Syed Shadab Raza
- Department of Stem Cell Biology and Regenerative Medicine, Era University, Lucknow, India
| | - Shahab Uddin
- Translational Research Institute, Academic Health System, Hamad Medical Corporation, Doha, Qatar; Dermatology Institute, Academic Health System, Hamad Medical Corporation, Doha 3050, Qatar; Department of Dermatology and Venereology, Rumailah Hospital, Hamad Medical Corporation, Doha 3050, Qatar; Laboratory Animal Research Center, Qatar University, Doha 2713, Qatar.
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12
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McKeegan K, Mason SA, Trewin AJ, Keske MA, Wadley GD, Della Gatta PA, Nikolaidis MG, Parker L. Reactive oxygen species in exercise and insulin resistance: Working towards personalized antioxidant treatment. Redox Biol 2021; 44:102005. [PMID: 34049222 PMCID: PMC8167146 DOI: 10.1016/j.redox.2021.102005] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/25/2021] [Accepted: 05/06/2021] [Indexed: 12/11/2022] Open
Abstract
Reactive oxygen species (ROS) are well known for their role in insulin resistance and the development of cardiometabolic disease including type 2 diabetes mellitus (T2D). Conversely, evidence supports the notion that ROS are a necessary component for glucose cell transport and adaptation to physiological stress including exercise and muscle contraction. Although genetic rodent models and cell culture studies indicate antioxidant treatment to be an effective strategy for targeting ROS to promote health, human findings are largely inconsistent. In this review we discuss human research that has investigated antioxidant treatment and glycemic control in the context of health (healthy individuals and during exercise) and disease (insulin resistance and T2D). We have identified key factors that are likely to influence the effectiveness of antioxidant treatment: 1) the context of treatment including whether oxidative distress or eustress is present (e.g., hyperglycemia/lipidaemia or during exercise and muscle contraction); 2) whether specific endogenous antioxidant deficiencies are identified (redox screening); 3) whether antioxidant treatment is specifically designed to target and restore identified deficiencies (antioxidant specificity); 4) and the bioavailability and bioactivity of the antioxidant which are influenced by treatment dose, duration, and method of administration. The majority of human research has failed to account for these factors, limiting their ability to robustly test the effectiveness of antioxidants for health promotion and disease prevention. We propose that a modern "redox screening" and "personalized antioxidant treatment" approach is required to robustly explore redox regulation of human physiology and to elicit more effective antioxidant treatment in humans.
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Affiliation(s)
- Kathryn McKeegan
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Shaun A Mason
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Adam J Trewin
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Michelle A Keske
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Glenn D Wadley
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Paul A Della Gatta
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Michalis G Nikolaidis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Lewan Parker
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia.
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13
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Pleiotropic and Potentially Beneficial Effects of Reactive Oxygen Species on the Intracellular Signaling Pathways in Endothelial Cells. Antioxidants (Basel) 2021; 10:antiox10060904. [PMID: 34205032 PMCID: PMC8229098 DOI: 10.3390/antiox10060904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 02/06/2023] Open
Abstract
Endothelial cells (ECs) are exposed to molecular dioxygen and its derivative reactive oxygen species (ROS). ROS are now well established as important signaling messengers. Excessive production of ROS, however, results in oxidative stress, a significant contributor to the development of numerous diseases. Here, we analyze the experimental data and theoretical concepts concerning positive pro-survival effects of ROS on signaling pathways in endothelial cells (ECs). Our analysis of the available experimental data suggests possible positive roles of ROS in induction of pro-survival pathways, downstream of the Gi-protein-coupled receptors, which mimics insulin signaling and prevention or improvement of the endothelial dysfunction. It is, however, doubtful, whether ROS can contribute to the stabilization of the endothelial barrier.
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Redox regulation of the insulin signalling pathway. Redox Biol 2021; 42:101964. [PMID: 33893069 PMCID: PMC8113030 DOI: 10.1016/j.redox.2021.101964] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/19/2021] [Accepted: 03/29/2021] [Indexed: 12/11/2022] Open
Abstract
The peptide hormone insulin is a key regulator of energy metabolism, proliferation and survival. Binding of insulin to its receptor activates the PI3K/AKT signalling pathway, which mediates fundamental cellular responses. Oxidants, in particular H2O2, have been recognised as insulin-mimetics. Treatment of cells with insulin leads to increased intracellular H2O2 levels affecting the activity of downstream signalling components, thereby amplifying insulin-mediated signal transduction. Specific molecular targets of insulin-stimulated H2O2 include phosphatases and kinases, whose activity can be altered via redox modifications of critical cysteine residues. Over the past decades, several of these redox-sensitive cysteines have been identified and their impact on insulin signalling evaluated. The aim of this review is to summarise the current knowledge on the redox regulation of the insulin signalling pathway.
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Gong L, Zou Z, Liu L, Guo S, Xing D. Photobiomodulation therapy ameliorates hyperglycemia and insulin resistance by activating cytochrome c oxidase-mediated protein kinase B in muscle. Aging (Albany NY) 2021; 13:10015-10033. [PMID: 33795530 PMCID: PMC8064177 DOI: 10.18632/aging.202760] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 11/25/2020] [Indexed: 12/27/2022]
Abstract
Ameliorating hyperglycemia and insulin resistance are major therapeutic strategies for type 2 diabetes. Previous studies have indicated that photobiomodulation therapy (PBMT) attenuates metabolic abnormalities in insulin-resistant adipose cells and tissues. However, it remains unclear whether PBMT ameliorates glucose metabolism in skeletal muscle in type 2 diabetes models. Here we showed that PBMT reduced blood glucose and insulin resistance, and reversed metabolic abnormalities in skeletal muscle in two diabetic mouse models. PBMT accelerated adenosine triphosphate (ATP) and reactive oxygen species (ROS) generation by elevating cytochrome c oxidase (CcO) activity. ROS-induced activation of phosphatase and tensin homolog (PTEN)/ protein kinase B (AKT) signaling after PBMT promoted glucose transporter GLUT4 translocation and glycogen synthase (GS) activation, accelerating glucose uptake and glycogen synthesis in skeletal muscle. CcO subunit III deficiency, ROS elimination, and AKT inhibition suppressed the PBMT effects of glucose metabolism in skeletal muscle. This study indicated amelioration of glucose metabolism after PBMT in diabetic mouse models and revealed the metabolic regulatory effects and mechanisms of PBMT on skeletal muscle.
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Affiliation(s)
- Longlong Gong
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China.,College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Zhengzhi Zou
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China.,College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Lei Liu
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
| | - Shuang Guo
- College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Da Xing
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China.,College of Biophotonics, South China Normal University, Guangzhou 510631, China
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16
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FOXO activity adaptation safeguards the hematopoietic stem cell compartment in hyperglycemia. Blood Adv 2020; 4:5512-5526. [PMID: 33166407 DOI: 10.1182/bloodadvances.2020001826] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 10/05/2020] [Indexed: 12/17/2022] Open
Abstract
Hematopoietic stem cell (HSC) activity is tightly controlled to ensure the integrity of the hematopoietic system during the organism's lifetime. How the HSC compartment maintains its long-term fitness in conditions of chronic stresses associated with systemic metabolic disorders is poorly understood. In this study, we show that obesity functionally affects the long-term function of the most immature engrafting HSC subpopulation. We link this altered regenerative activity to the oxidative stress and the aberrant constitutive activation of the AKT signaling pathway that characterized the obese environment. In contrast, we found minor disruptions of the HSC function in obese mice at steady state, suggesting that active mechanisms could protect the HSC compartment from its disturbed environment. Consistent with this idea, we found that FOXO proteins in HSCs isolated from obese mice become insensitive to their normal upstream regulators such as AKT, even during intense oxidative stress. We established that hyperglycemia, a key condition associated with obesity, is directly responsible for the alteration of the AKT-FOXO axis in HSCs and their abnormal oxidative stress response. As a consequence, we observed that HSCs isolated from a hyperglycemic environment display enhanced resistance to oxidative stress and DNA damage. Altogether, these results indicate that chronic metabolic stresses associated with obesity and/or hyperglycemia affect the wiring of the HSCs and modify their oxidative stress response. These data suggest that the uncoupling of FOXO from its environmental regulators could be a key adaptive strategy that promotes the survival of the HSC compartment in obesity.
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Gong L, Zou Z, Huang L, Guo S, Xing D. Photobiomodulation therapy decreases free fatty acid generation and release in adipocytes to ameliorate insulin resistance in type 2 diabetes. Cell Signal 2020; 67:109491. [DOI: 10.1016/j.cellsig.2019.109491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/02/2019] [Accepted: 12/02/2019] [Indexed: 12/17/2022]
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Quan Y, Hua S, Li W, Zhan M, Li Y, Lu L. Resveratrol bidirectionally regulates insulin effects in skeletal muscle through alternation of intracellular redox homeostasis. Life Sci 2019; 242:117188. [PMID: 31863772 DOI: 10.1016/j.lfs.2019.117188] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 12/18/2022]
Abstract
AIMS Reactive oxygen species (ROS) bidirectionally regulate insulin sensitivity in skeletal muscle. Insulin-induced ROS generation elevates insulin-regulated metabolic effects; however, chronic oxidative stress causes severe insulin resistance in skeletal muscle. Resveratrol (RV), as a natural antioxidant, eliminates intracellular ROS. It's unclear that whether it has different roles in insulin signaling pathway in skeletal muscle. MAIN METHODS C57BL/6J mice and C2C12 myotubes were used to assess metabolic regulation effects of RV. Protein activation was detected using Immunofluorescence and Western Blot analysis. ROS were analyzed using confocal microscope and flow cytometry sorting (FACS). Intracellular reducing molecules were detected using an enzymatic method. Glucose uptake was measured using a fluorescent deoxyglucose analog (2-NBDG). KEY FINDINGS We found that RV attenuated insulin-stimulated AKT phosphorylation via elimination of insulin-induced ROS generation in skeletal muscle, suggesting that RV decreased activation of the insulin-induced AKT signaling. In skeletal muscle of insulin resistance, RV reduced oxidative stress, restored intracellular glutathione (GSH) level, and enhanced insulin-induced AKT activation and glucose absorption. These results suggested that RV ameliorated insulin resistance by change of redox levels in skeletal muscle. SIGNIFICANCE This study revealed bidirectional regulation effects of RV on insulin-stimulated metabolism in skeletal muscle through alternation of intracellular redox homeostasis, which might provide a guidance role for treatment of metabolic diseases.
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Affiliation(s)
- Yingyao Quan
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China
| | - Shengni Hua
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China
| | - Wei Li
- Department of General Surgery, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affilated with Jinan University, Zhuhai, Guangdong 519000, PR China
| | - Meixiao Zhan
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China
| | - Yong Li
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China
| | - Ligong Lu
- Zhuhai Interventional Medical Center, Zhuhai Precision Medical Center, Zhuhai People's Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, Guangdong 519000, PR China.
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19
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Changes of the stability and bioactivity of quercetin and myricetin in BGC-823 cells in response to heat treatment and Fe2+/Cu2+ addition. JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2019. [DOI: 10.1007/s11694-019-00250-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Agbo E, Liu D, Li M, Saahene RO, Chen L, Zhao L, Wang Y, Tian G. Modulation of PTEN by hexarelin attenuates coronary artery ligation-induced heart failure in rats. Turk J Med Sci 2019; 49:945-958. [PMID: 31091855 PMCID: PMC7018219 DOI: 10.3906/sag-1812-49] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background/aim Hexarelin is a synthetic growth hormone-releasing peptide that exerts cardioprotective effects. However, its cardioprotective effect against heart failure (HF) is yet to be explained. This study investigated the therapeutic role of hexarelin and the mechanisms underlying its cardioprotective effects against coronary artery ligation (CAL)-induced HF in rats. Materials and methods Rats with four weeks of permanent CAL, induced myocardial infarction, and HF were randomly separated into four groups: the control group (Ctrl), sham group (Sham), hexarelin treatment group (HF + Hx), and heart failure group (HF). The rats were treated with subcutaneous injection of hexarelin (100 µg/kg) in the treatment group or saline in the other groups twice a day for 30 days. Left ventricular (LV) function, oxidative stress, apoptosis, molecular analyses, and cardiac structural and pathological changes in rats were assessed. Results The treatment of HF rats with hexarelin significantly induced the upregulation of phosphatase and tensin homologue (PTEN) expression and inhibited the phosphorylation of protein kinase B (Akt) and mammalian target of rapamycin (mTOR) to significantly improve LV function, ameliorate myocardial remodeling, and reduce oxidative stress. Conclusion These findings indicate that hexarelin attenuates CAL-induced HF in rats by ameliorating myocardial remodeling, LV dysfunction, and oxidative stress via the upmodulation of PTEN signaling and downregulation of the Akt/mTOR signaling pathway.
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Affiliation(s)
- Elvis Agbo
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Donhai Liu
- College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Meixiu Li
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Roland Osei Saahene
- Department of Immunology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Liqiang Chen
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Lunpeng Zhao
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Yiquan Wang
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
| | - Guozhong Tian
- Department of Human Anatomy, Histology, and Embryology, College of Basic Medicine, Jiamusi University, Jiamusi, P.R. China
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Zhou J, Li X. Association of PTEN expression with liver function and inflammatory changes in patients with liver cancer after chemotherapy. Oncol Lett 2018; 16:6633-6637. [PMID: 30405802 PMCID: PMC6202462 DOI: 10.3892/ol.2018.9458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/07/2018] [Indexed: 01/12/2023] Open
Abstract
This study investigated the effects of phosphatase and tensin homolog deleted on chromosome ten (PTEN) expression on liver function classification, serum tumor markers and liver function of patients with liver cancer. A total of 63 patients with primary liver cancer treated in Xiangya Hospital (Changsha, China) were retrospectively analyzed. The difference in the PTEN expression levels in normal liver cells and liver cancer cells was compared via immunohistochemistry. According to the expression level of PTEN in the patient's pathological report, patients were divided into PTEN-positive and PTEN-negative groups. The expression level of each tumor marker in serum of patients was observed, and the association of PTEN expression level with the serum tumor markers was analyzed. Moreover, the changes in liver function and inflammatory factors before and after chemotherapy were compared. Finally, the relationship between the PTEN expression level and Child-Pugh grading of the liver function was detected. Compared with that in normal liver cells, the positive expression rate of PTEN protein in liver cancer cells was significantly decreased (P<0.05). No significant difference was found in the expression levels of serum tumor markers, except α-fetoprotein (AFP) in liver cancer patients between PTEN-positive and PTEN-negative group, indicating that PTEN expression has no significant effects on serum tumor markers. The levels of albumin (ALB), alkaline phosphatase (ALP) and prothrombin activity (PTA) were decreased significantly after chemotherapy compared with those before chemotherapy (P<0.05). Besides, the levels of inflammatory factors were remarkably reduced after chemotherapy. PTEN expression was negatively associated with liver function grading, and the higher the PTEN expression, the lower the liver function grading was. The low expression of PTEN has a certain association with the occurrence and grading of liver cancer. PTEN gene has guiding significance in predicting the occurrence, development and prognosis of liver cancer.
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Affiliation(s)
- Jixiang Zhou
- Department of Hepatobiliary Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Xiaoli Li
- Department of Hepatobiliary Surgery, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
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Glennon-Alty L, Hackett AP, Chapman EA, Wright HL. Neutrophils and redox stress in the pathogenesis of autoimmune disease. Free Radic Biol Med 2018; 125:25-35. [PMID: 29605448 DOI: 10.1016/j.freeradbiomed.2018.03.049] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/22/2018] [Accepted: 03/28/2018] [Indexed: 12/18/2022]
Abstract
Polymorphonuclear leukocytes, or neutrophils, are specialist phagocytic cells of the innate immune system. Their primary role is host defence against micro-organisms, which they kill via phagocytosis, followed by release of reactive oxygen species (ROS) and proteolytic enzymes within the phagosome. ROS are generated via the action of the NADPH oxidase (also known as NOX2), in a process termed the 'Respiratory Burst'. This process consumes large amounts of oxygen, which is converted into the highly-reactive superoxide radical O2- and H2O2. Subsequent activation of myeloperoxidase (MPO) generates secondary oxidants and chloroamines that are highly microbiocidal in nature, which together with proteases such as elastase and gelatinase provide a toxic intra-phagosomal environment able to kill a broad range of micro-organisms. However, under certain circumstances such as during an auto-immune response, neutrophils can be triggered to release ROS and proteases extracellularly causing damage to host tissues, modification of host proteins, lipids and DNA and dysregulation of oxidative homeostasis. This review describes the range of ROS species produced by human neutrophils with a focus on the implications of neutrophil redox products in autoimmune inflammation.
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Affiliation(s)
- Laurence Glennon-Alty
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, L7 8TX Liverpool, UK; Liverpool Health Partners, University of Liverpool, Liverpool, UK
| | - Angela P Hackett
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, L7 8TX Liverpool, UK
| | - Elinor A Chapman
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, L7 8TX Liverpool, UK
| | - Helen L Wright
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, 6 West Derby Street, L7 8TX Liverpool, UK.
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Ma M, Quan Y, Li Y, He X, Xiao J, Zhan M, Zhao W, Xin Y, Lu L, Luo L. Bidirectional modulation of insulin action by reactive oxygen species in 3T3‑L1 adipocytes. Mol Med Rep 2018; 18:807-814. [PMID: 29767231 PMCID: PMC6059710 DOI: 10.3892/mmr.2018.9016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 05/04/2018] [Indexed: 01/20/2023] Open
Abstract
Reactive oxygen species (ROS) serve an important role in glucose‑lipid metabolic regulation. In the present study, the results demonstrated that there was bidirectional regulation of insulin action in 3T3‑L1 adipocytes treated with ROS. Transient and acute ROS exposure improved insulin‑induced metabolic effects in 3T3‑L1 adipocytes. Hydrogen peroxide (H2O2), as a stable and diffusible ROS, diffused into adipocytes and altered intracellular redox homeostasis, resulting in oxidation and inactivation of phosphatase and tensin homologue deleted on chromosome 10 (PTEN). Inactivation of PTEN enhanced the activation of insulin‑induced protein kinase B (AKT), leading to increased glucose transporter 4 (GLUT4) redistribution and glucose uptake in 3T3‑L1 adipocytes. However, chronic ROS treatment induced insulin resistance in 3T3‑L1 adipocytes. It was also revealed that insulin‑induced AKT activation, GLUT4 translocation to cell membrane and glucose uptake were significantly inhibited in chronic ROS‑treated 3T3‑L1 adipocytes. Taken together, the present study provided further demonstration that transient ROS treatment improved insulin sensitivity; however, chronic ROS exposure induced insulin resistance in 3T3‑L1 adipocytes.
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Affiliation(s)
- Mingfeng Ma
- Department of Cardiology, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People's Hospital), Zhuhai, Guangdong 519000, P.R. China
| | - Yingyao Quan
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Yong Li
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Xu He
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Jing Xiao
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Meixiao Zhan
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Wei Zhao
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Yongjie Xin
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Ligong Lu
- Center of Intervention Radiology, Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Zhuhai, Guangdong 519000, P.R. China
| | - Liangping Luo
- Department of Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, P.R. China
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Kim JH, Park SJ, Chae U, Seong J, Lee HS, Lee SR, Lee S, Lee DS. Peroxiredoxin 2 mediates insulin sensitivity of skeletal muscles through regulation of protein tyrosine phosphatase oxidation. Int J Biochem Cell Biol 2018; 99:80-90. [PMID: 29605633 DOI: 10.1016/j.biocel.2018.03.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/07/2018] [Accepted: 03/27/2018] [Indexed: 01/14/2023]
Abstract
Insulin signaling is essential for regulating glucose homeostasis. Numerous studies have demonstrated that reactive oxygen species (ROS) affect insulin signaling, and low ROS levels can act as a signal to regulate cellular function. Peroxiredoxins (Prxs) are highly abundant and widely expressed antioxidant enzymes. However, it is unclear whether antioxidant enzymes, such as Prx2, mediate insulin signaling. The aim of our study was to investigate the influence of Prx2 deficiency on insulin signaling. Our western blot results showed that Prx2 deficiency enhanced insulin signaling and increased oxidation of protein tyrosine phosphatase 1B (PTP1B) and phosphatase and tensin homologue (PTEN) in mouse embryonic fibroblasts (MEFs) treated with insulin. In addition, we assessed ROS levels with a Cytosol-HyPer H2O2 sensor. As a result, increased ROS levels and Akt activation were decreased by N-acetyl-cysteine (Nac), which acted as an antioxidant in Prx2-deficient MEFs. Body weight measurements and glucose tolerance test (GTT) revealed significant body weight reduction and increase in glucose clearance in Prx2-/- mice fed a high-fat diet. Interestingly, glucose transporter type 4 (GLUT4) was significantly higher in Prx2-/- mice than in wild-type mice according to western blotting results. Western blotting also revealed that Akt phosphorylation was higher in Prx2-/- MEFs and muscle tissue than in wild-type. Together, our findings indicate that increased ROS due to Prx2 deficiency promotes insulin sensitivity and glucose clearance in skeletal muscles by increasing protein tyrosine phosphatase (PTPs) oxidation. These results provide novel insights into the fundamental mechanisms of insulin signaling induced by Prx2 deficiency and suggest that ROS-based therapeutic strategies can be used to suppress insulin resistance.
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Affiliation(s)
- Jung-Hak Kim
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; Division of Endocrinology, Internal Medicine, University of California, Davis, CA, 95616, USA
| | - Sun-Ji Park
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea; Renal Division, School of Medicine, Washington University in St. Louis, MO, 63130, USA
| | - Unbin Chae
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Joongbae Seong
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Hyun-Shik Lee
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Sang-Rae Lee
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Chungcheongbuk-do, 34141, Republic of Korea
| | - Seunghoon Lee
- Animal Biotechnology Division, National Institute of Animal Science, Jeollabuk-do, 55365, Republic of Korea
| | - Dong-Seok Lee
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea.
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Abstract
Parkinson’s disease (PD) is a chronic and progressive neurodegeneration of dopamine neurons in the substantia nigra. The reason for the death of these neurons is unclear; however, studies have demonstrated the potential involvement of mitochondria, endoplasmic reticulum, α-synuclein or dopamine levels in contributing to cellular oxidative stress as well as PD symptoms. Even though those papers had separately described the individual roles of each element leading to neurodegeneration, recent publications suggest that neurodegeneration is the product of various cellular interactions. This review discusses the role of oxidative stress in mediating separate pathological events that together, ultimately result in cell death in PD. Understanding the multi-faceted relationships between these events, with oxidative stress as a common denominator underlying these processes, is needed for developing better therapeutic strategies.
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Yanagisawa S, Baker JR, Vuppusetty C, Fenwick P, Donnelly LE, Ito K, Barnes PJ. Decreased phosphatase PTEN amplifies PI3K signaling and enhances proinflammatory cytokine release in COPD. Am J Physiol Lung Cell Mol Physiol 2017; 313:L230-L239. [PMID: 28522564 PMCID: PMC5582930 DOI: 10.1152/ajplung.00382.2016] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 12/31/2022] Open
Abstract
The phosphatidylinositol 3-kinase (PI3K) pathway is activated in chronic obstructive pulmonary disease (COPD), but the regulatory mechanisms for this pathway are yet to be elucidated. The aim of this study was to determine the expression and role of phosphatase and tensin homolog deleted from chromosome 10 (PTEN), a negative regulator of the PI3K pathway, in COPD. PTEN protein expression was measured in the peripheral lung of COPD patients compared with smoking and nonsmoking controls. The direct influence of cigarette smoke extract (CSE) on PTEN expression was assessed using primary lung epithelial cells and a cell line (BEAS-2B) in the presence or absence of l-buthionine-sulfoximine (BSO) to deplete intracellular glutathione. The impact of PTEN knockdown by RNA interference on cytokine production was also examined. In peripheral lung, PTEN protein was significantly decreased in patients with COPD compared with the subjects without COPD (P < 0.001) and positively correlated with the severity of airflow obstruction (forced expiratory volume in 1-s percent predicted; r = 0.50; P = 0.0012). Conversely, phosphorylated Akt, as a marker of PI3K activation, showed a negative correlation with PTEN protein levels (r = -0.41; P = 0.0042). In both primary bronchial epithelial cells and BEAS-2B cells, CSE decreased PTEN protein, which was reversed by N-acetyl cysteine treatment. PTEN knockdown potentiated Akt phosphorylation and enhanced production of proinflammatory cytokines, such as IL-6, CXCL8, CCL2, and CCL5. In conclusion, oxidative stress reduces PTEN protein levels, which may result in increased PI3K signaling and amplification of inflammation in COPD.
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Affiliation(s)
- Satoru Yanagisawa
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Jonathan R Baker
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Chaitanya Vuppusetty
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter Fenwick
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Louise E Donnelly
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Kazuhiro Ito
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Peter J Barnes
- Airway Disease Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
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Redox Regulation of the Tumor Suppressor PTEN by Hydrogen Peroxide and Tert-Butyl Hydroperoxide. Int J Mol Sci 2017; 18:ijms18050982. [PMID: 28489026 PMCID: PMC5454895 DOI: 10.3390/ijms18050982] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/21/2017] [Accepted: 04/25/2017] [Indexed: 12/25/2022] Open
Abstract
Organic peroxides and hydroperoxides are skin tumor promoters. Free radical derivatives from these compounds are presumed to be the prominent mediators of tumor promotion. However, the molecular targets of these species are unknown. Phosphatase and tensin homologs deleted on chromosome 10 (PTEN) are tumor suppressors that play important roles in cell growth, proliferation, and cell survival by negative regulation of phosphoinositol-3-kinase/protein kinase B signaling. PTEN is reversibly oxidized in various cells by exogenous and endogenous hydrogen peroxide. Oxidized PTEN is converted back to the reduced form by cellular reducing agents, predominantly by the thioredoxin (Trx) system. Here, the role of tert-butyl hydroperoxide (t-BHP) in redox regulation of PTEN was analyzed by using cell-based and in vitro assays. Exposure to t-BHP led to oxidation of recombinant PTEN. In contrast to H2O2, PTEN oxidation by t-BHP was irreversible in HeLa cells. However, oxidized PTEN was reduced by exogenous Trx system. Taken together, these results indicate that t-BHP induces PTEN oxidation and inhibits Trx system, which results in irreversible PTEN oxidation in HeLa cells. Collectively, these results suggest a novel mechanism of t-BHP in the promotion of tumorigenesis.
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The effect of exercise-intensity on skeletal muscle stress kinase and insulin protein signaling. PLoS One 2017; 12:e0171613. [PMID: 28182793 PMCID: PMC5300197 DOI: 10.1371/journal.pone.0171613] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/23/2017] [Indexed: 12/30/2022] Open
Abstract
Background Stress and mitogen activated protein kinase (SAPK) signaling play an important role in glucose homeostasis and the physiological adaptation to exercise. However, the effects of acute high-intensity interval exercise (HIIE) and sprint interval exercise (SIE) on activation of these signaling pathways are unclear. Methods Eight young and recreationally active adults performed a single cycling session of HIIE (5 x 4 minutes at 75% Wmax), SIE (4 x 30 second Wingate sprints), and continuous moderate-intensity exercise work-matched to HIIE (CMIE; 30 minutes at 50% of Wmax), separated by a minimum of 1 week. Skeletal muscle SAPK and insulin protein signaling were measured immediately, and 3 hours after exercise. Results SIE elicited greater skeletal muscle NF-κB p65 phosphorylation immediately after exercise (SIE: ~40%; HIIE: ~4%; CMIE; ~13%; p < 0.05) compared to HIIE and CMIE. AS160Ser588 phosphorylation decreased immediately after HIIE (~-27%; p < 0.05), and decreased to the greatest extent immediately after SIE (~-60%; p < 0.05). Skeletal muscle JNK (~42%; p < 0.05) and p38 MAPK (~171%; p < 0.05) phosphorylation increased, and skeletal muscle AktSer473 phosphorylation (~-32%; p < 0.05) decreased, to a similar extent immediately after all exercise protocols. AS160Ser588 phosphorylation was similar to baseline three hours after SIE (~-12%; p > 0.05), remained lower 3 hours after HIIE (~-34%; p < 0.05), and decreased 3 hours after CMIE (~-33%; p < 0.05). Conclusion Despite consisting of less total work than CMIE and HIIE, SIE proved to be an effective stimulus for the activation of stress protein kinase signaling pathways linked to exercise-mediated adaptation of skeletal muscle. Furthermore, post-exercise AS160Ser588 phosphorylation decreased in an exercise-intensity and post-exercise time-course dependent manner.
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Parker L, Shaw CS, Stepto NK, Levinger I. Exercise and Glycemic Control: Focus on Redox Homeostasis and Redox-Sensitive Protein Signaling. Front Endocrinol (Lausanne) 2017; 8:87. [PMID: 28529499 PMCID: PMC5418238 DOI: 10.3389/fendo.2017.00087] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/04/2017] [Indexed: 12/16/2022] Open
Abstract
Physical inactivity, excess energy consumption, and obesity are associated with elevated systemic oxidative stress and the sustained activation of redox-sensitive stress-activated protein kinase (SAPK) and mitogen-activated protein kinase signaling pathways. Sustained SAPK activation leads to aberrant insulin signaling, impaired glycemic control, and the development and progression of cardiometabolic disease. Paradoxically, acute exercise transiently increases oxidative stress and SAPK signaling, yet postexercise glycemic control and skeletal muscle function are enhanced. Furthermore, regular exercise leads to the upregulation of antioxidant defense, which likely assists in the mitigation of chronic oxidative stress-associated disease. In this review, we explore the complex spatiotemporal interplay between exercise, oxidative stress, and glycemic control, and highlight exercise-induced reactive oxygen species and redox-sensitive protein signaling as important regulators of glucose homeostasis.
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Affiliation(s)
- Lewan Parker
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
- *Correspondence: Lewan Parker, ,
| | - Christopher S. Shaw
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - Nigel K. Stepto
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
- Monash Centre for Health Research and Implementation, School of Public Health and Preventative Medicine, Monash University, Clayton, VIC, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University and Western Health, St. Albans, VIC, Australia
| | - Itamar Levinger
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, VIC, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University and Western Health, St. Albans, VIC, Australia
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Merry TL, Tran M, Dodd GT, Mangiafico SP, Wiede F, Kaur S, McLean CL, Andrikopoulos S, Tiganis T. Hepatocyte glutathione peroxidase-1 deficiency improves hepatic glucose metabolism and decreases steatohepatitis in mice. Diabetologia 2016; 59:2632-2644. [PMID: 27628106 DOI: 10.1007/s00125-016-4084-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/05/2016] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS In obesity oxidative stress is thought to contribute to the development of insulin resistance, non-alcoholic fatty liver disease and the progression to non-alcoholic steatohepatitis. Our aim was to examine the precise contributions of hepatocyte-derived H2O2 to liver pathophysiology. METHODS Glutathione peroxidase (GPX) 1 is an antioxidant enzyme that is abundant in the liver and converts H2O2 to water. We generated Gpx1 lox/lox mice to conditionally delete Gpx1 in hepatocytes (Alb-Cre;Gpx1 lox/lox) and characterised mice fed chow, high-fat or choline-deficient amino-acid-defined (CDAA) diets. RESULTS Chow-fed Alb-Cre;Gpx1 lox/lox mice did not exhibit any alterations in body composition or energy expenditure, but had improved insulin sensitivity and reduced fasting blood glucose. This was accompanied by decreased gluconeogenic and increased glycolytic gene expression as well as increased hepatic glycogen. Hepatic insulin receptor Y1163/Y1163 phosphorylation and Akt Ser-473 phosphorylation were increased in fasted chow-fed Alb-Cre;Gpx1 lox/lox mice, associated with increased H2O2 production and insulin signalling in isolated hepatocytes. The enhanced insulin signalling was accompanied by the increased oxidation of hepatic protein tyrosine phosphatases previously implicated in the attenuation of insulin signalling. High-fat-fed Alb-Cre;Gpx1 lox/lox mice did not exhibit alterations in weight gain or hepatosteatosis, but exhibited decreased hepatic inflammation, decreased gluconeogenic gene expression and increased insulin signalling in the liver. Alb-Cre;Gpx1 lox/lox mice fed a CDAA diet that promotes non-alcoholic steatohepatitis exhibited decreased hepatic lymphocytic infiltrates, inflammation and liver fibrosis. CONCLUSIONS/INTERPRETATION Increased hepatocyte-derived H2O2 enhances hepatic insulin signalling, improves glucose control and protects mice from the development of non-alcoholic steatohepatitis.
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Affiliation(s)
- Troy L Merry
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
- Faculty of Medical and Health Sciences, The University of Auckland, Aukland, New Zealand
| | - Melanie Tran
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Garron T Dodd
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Salvatore P Mangiafico
- Department of Medicine (Austin Hospital), The University of Melbourne, Melbourne, VIC, Australia
| | - Florian Wiede
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Supreet Kaur
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia
| | - Catriona L McLean
- Department of Anatomical Pathology, Alfred Hospital, Prahran, VIC, Australia
| | - Sofianos Andrikopoulos
- Department of Medicine (Austin Hospital), The University of Melbourne, Melbourne, VIC, Australia
| | - Tony Tiganis
- Metabolic Disease and Obesity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, 3800, Australia.
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Abstract
The phosphatase and tensin homolog gene PTEN is one of the most frequently mutated tumor suppressor genes in human cancer. Loss of PTEN function occurs in a variety of human cancers via its mutation, deletion, transcriptional silencing, or protein instability. PTEN deficiency in cancer has been associated with advanced disease, chemotherapy resistance, and poor survival. Impaired PTEN function, which antagonizes phosphoinositide 3-kinase (PI3K) signaling, causes the accumulation of phosphatidylinositol (3,4,5)-triphosphate and thereby the suppression of downstream components of the PI3K pathway, including the protein kinase B and mammalian target of rapamycin kinases. In addition to having lipid phosphorylation activity, PTEN has critical roles in the regulation of genomic instability, DNA repair, stem cell self-renewal, cellular senescence, and cell migration. Although PTEN deficiency in solid tumors has been studied extensively, rare studies have investigated PTEN alteration in lymphoid malignancies. However, genomic or epigenomic aberrations of PTEN and dysregulated signaling are likely critical in lymphoma pathogenesis and progression. This review provides updated summary on the role of PTEN deficiency in human cancers, specifically in lymphoid malignancies; the molecular mechanisms of PTEN regulation; and the distinct functions of nuclear PTEN. Therapeutic strategies for rescuing PTEN deficiency in human cancers are proposed.
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Affiliation(s)
- Xiaoxiao Wang
- Department of Hematopathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77230, USA.,Department of Medical Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Huiqiang Huang
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Ken H Young
- Department of Hematopathology, The University of Texas M. D. Anderson Cancer Center, Houston, TX 77230, USA.,The University of Texas Graduate School of Biomedical Science, Houston, TX 77230, USA
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Kim SH, Kim H, Ku HJ, Park JH, Cha H, Lee S, Lee JH, Park JW. Oxalomalate reduces expression and secretion of vascular endothelial growth factor in the retinal pigment epithelium and inhibits angiogenesis: Implications for age-related macular degeneration. Redox Biol 2016; 10:211-220. [PMID: 27810736 PMCID: PMC5094379 DOI: 10.1016/j.redox.2016.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/20/2016] [Accepted: 10/21/2016] [Indexed: 11/21/2022] Open
Abstract
Clinical and experimental observations indicate a critical role for vascular endothelial growth factor (VEGF), secreted by the retinal pigment epithelium (RPE), in pathological angiogenesis and the development of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). RPE-mediated VEGF expression, leading to angiogenesis, is a major signaling mechanism underlying ocular neovascular disease. Inhibiting this signaling pathway with a therapeutic molecule is a promising anti-angiogenic strategy to treat this disease with potentially fewer side effects. Oxalomalate (OMA) is a competitive inhibitor of NADP+-dependent isocitrate dehydrogenase (IDH), which plays an important role in cellular signaling pathways regulated by reactive oxygen species (ROS). Here, we have investigated the inhibitory effect of OMA on the expression of VEGF, and the associated underlying mechanism of action, using in vitro and in vivo RPE cell models of AMD. We found that OMA reduced the expression and secretion of VEGF in RPE cells, and consequently inhibited CNV formation. This function of OMA was linked to its capacity to activate the pVHL-mediated HIF-1α degradation in these cells, partly via a ROS-dependent ATM signaling axis, through inhibition of IDH enzymes. These findings reveal a novel role for OMA in inhibiting RPE-derived VEGF expression and angiogenesis, and suggest unique therapeutic strategies for treating pathological angiogenesis and AMD development. Oxalomalate reduces VEGF expression in RPE cells by promoting HIF-1α degradation. Oxalomalate activates pVHL-mediated HIF-1α degradation by regulation of ATM-Chk2-E2F1 axis. Inhibition of IDH enzymes by oxalomalate activates ROS-mediated ATM signaling axis. Oxalomalate inhibits CNV-related angiogenesis in in vivo mouse model of AMD.
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Affiliation(s)
- Sung Hwan Kim
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Hyunjin Kim
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Hyeong Jun Ku
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Jung Hyun Park
- Department of Food and Biotechnology, Korea University, Sejong, Republic of Korea
| | - Hanvit Cha
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Seoyoon Lee
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea
| | - Jin Hyup Lee
- Department of Food and Biotechnology, Korea University, Sejong, Republic of Korea; Institutes of Natural Sciences, Korea University, Sejong, Republic of Korea.
| | - Jeen-Woo Park
- School of Life Sciences and Biotechnology, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Republic of Korea.
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Ogino M, Ichimura M, Nakano N, Minami A, Kitagishi Y, Matsuda S. Roles of PTEN with DNA Repair in Parkinson's Disease. Int J Mol Sci 2016; 17:ijms17060954. [PMID: 27314344 PMCID: PMC4926487 DOI: 10.3390/ijms17060954] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 05/27/2016] [Accepted: 06/09/2016] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress is considered to play key roles in aging and pathogenesis of many neurodegenerative diseases such as Parkinson’s disease, which could bring DNA damage by cells. The DNA damage may lead to the cell apoptosis, which could contribute to the degeneration of neuronal tissues. Recent evidence suggests that PTEN (phosphatase and tensin homolog on chromosome 10) may be involved in the pathophysiology of the neurodegenerative disorders. Since PTEN expression appears to be one dominant determinant of the neuronal cell death, PTEN should be a potential molecular target of novel therapeutic strategies against Parkinson’s disease. In addition, defects in DNA damage response and DNA repair are often associated with modulation of hormone signaling pathways. Especially, many observations imply a role for estrogen in a regulation of the DNA repair action. In the present review, we have attempted to summarize the function of DNA repair molecules at a viewpoint of the PTEN signaling pathway and the hormone related functional modulation of cells, providing a broad interpretation on the molecular mechanisms for treatment of Parkinson’s disease. Particular attention will be paid to the mechanisms proposed to explain the health effects of food ingredients against Parkinson’s disease related to reduce oxidative stress for an efficient therapeutic intervention.
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Affiliation(s)
- Mako Ogino
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Mayuko Ichimura
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Noriko Nakano
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Akari Minami
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Yasuko Kitagishi
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
| | - Satoru Matsuda
- Department of Food Science and Nutrition, Nara Women's University, Kita-Uoya Nishimachi, Nara 630-8506, Japan.
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Pal R, Bajaj L, Sharma J, Palmieri M, Di Ronza A, Lotfi P, Chaudhury A, Neilson J, Sardiello M, Rodney GG. NADPH oxidase promotes Parkinsonian phenotypes by impairing autophagic flux in an mTORC1-independent fashion in a cellular model of Parkinson's disease. Sci Rep 2016; 6:22866. [PMID: 26960433 PMCID: PMC4785399 DOI: 10.1038/srep22866] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/22/2016] [Indexed: 02/06/2023] Open
Abstract
Oxidative stress and aberrant accumulation of misfolded proteins in the cytosol are key pathological features associated with Parkinson's disease (PD). NADPH oxidase (Nox2) is upregulated in the pathogenesis of PD; however, the underlying mechanism(s) of Nox2-mediated oxidative stress in PD pathogenesis are still unknown. Using a rotenone-inducible cellular model of PD, we observed that a short exposure to rotenone (0.5 μM) resulted in impaired autophagic flux through activation of a Nox2 dependent Src/PI3K/Akt axis, with a consequent disruption of a Beclin1-VPS34 interaction that was independent of mTORC1 activity. Sustained exposure to rotenone at a higher dose (10 μM) decreased mTORC1 activity; however, autophagic flux was still impaired due to dysregulation of lysosomal activity with subsequent induction of the apoptotic machinery. Cumulatively, our results highlight a complex pathogenic mechanism for PD where short- and long-term oxidative stress alters different signaling pathways, ultimately resulting in anomalous autophagic activity and disease phenotype. Inhibition of Nox2-dependent oxidative stress attenuated the impaired autophagy and cell death, highlighting the importance and therapeutic potential of these pathways for treating patients with PD.
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Affiliation(s)
- Rituraj Pal
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Lakshya Bajaj
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Jaiprakash Sharma
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Michela Palmieri
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Alberto Di Ronza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Parisa Lotfi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - Arindam Chaudhury
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Joel Neilson
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, United States
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Reactive oxygen species mediate insulin signal transduction in mouse hypothalamus. Neurosci Lett 2016; 619:1-7. [PMID: 26968348 DOI: 10.1016/j.neulet.2016.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 01/26/2023]
Abstract
In the hypothalamus, several reports have implied that ROS mediate physiological effects of insulin. In this study, we investigated the mechanisms of insulin-induced ROS production and the effect of ROS on insulin signal transduction in mouse hypothalamic organotypic cultures. Insulin increased intracellular ROS, which were suppressed by NADPH oxidase inhibitor. H2O2 increased phospho-insulin receptor β (p-IRβ) and phospho-Akt (p-Akt) levels. Insulin-induced increases in p-IRβ and p-Akt levels were attenuated by ROS scavenger or NADPH oxidase inhibitor. Our data suggest that insulin-induced phosphorylation of IRβ and Akt is mediated via ROS which are predominantly produced by NADPH oxidase in mouse hypothalamus.
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Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward. Atherosclerosis 2016; 247:225-82. [PMID: 26967715 DOI: 10.1016/j.atherosclerosis.2016.02.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 12/31/2015] [Accepted: 02/02/2016] [Indexed: 02/08/2023]
Abstract
The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.
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Tebay LE, Robertson H, Durant ST, Vitale SR, Penning TM, Dinkova-Kostova AT, Hayes JD. Mechanisms of activation of the transcription factor Nrf2 by redox stressors, nutrient cues, and energy status and the pathways through which it attenuates degenerative disease. Free Radic Biol Med 2015; 88:108-146. [PMID: 26122708 PMCID: PMC4659505 DOI: 10.1016/j.freeradbiomed.2015.06.021] [Citation(s) in RCA: 603] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 12/11/2022]
Abstract
UNLABELLED Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) regulates the basal and stress-inducible expression of a battery of genes encoding key components of the glutathione-based and thioredoxin-based antioxidant systems, as well as aldo-keto reductase, glutathione S-transferase, and NAD(P)H quinone oxidoreductase-1 drug-metabolizing isoenzymes along with multidrug-resistance-associated efflux pumps. It therefore plays a pivotal role in both intrinsic resistance and cellular adaptation to reactive oxygen species (ROS) and xenobiotics. Activation of Nrf2 can, however, serve as a double-edged sword because some of the genes it induces may contribute to chemical carcinogenesis by promoting futile redox cycling of polycyclic aromatic hydrocarbon metabolites or confer resistance to chemotherapeutic drugs by increasing the expression of efflux pumps, suggesting its cytoprotective effects will vary in a context-specific fashion. In addition to cytoprotection, Nrf2 also controls genes involved in intermediary metabolism, positively regulating those involved in NADPH generation, purine biosynthesis, and the β-oxidation of fatty acids, while suppressing those involved in lipogenesis and gluconeogenesis. Nrf2 is subject to regulation at multiple levels. Its ability to orchestrate adaptation to oxidants and electrophiles is due principally to stress-stimulated modification of thiols within one of its repressors, the Kelch-like ECH-associated protein 1 (Keap1), which is present in the cullin-3 RING ubiquitin ligase (CRL) complex CRLKeap1. Thus modification of Cys residues in Keap1 blocks CRLKeap1 activity, allowing newly translated Nrf2 to accumulate rapidly and induce its target genes. The ability of Keap1 to repress Nrf2 can be attenuated by p62/sequestosome-1 in a mechanistic target of rapamycin complex 1 (mTORC1)-dependent manner, thereby allowing refeeding after fasting to increase Nrf2-target gene expression. In parallel with repression by Keap1, Nrf2 is also repressed by β-transducin repeat-containing protein (β-TrCP), present in the Skp1-cullin-1-F-box protein (SCF) ubiquitin ligase complex SCFβ-TrCP. The ability of SCFβ-TrCP to suppress Nrf2 activity is itself enhanced by prior phosphorylation of the transcription factor by glycogen synthase kinase-3 (GSK-3) through formation of a DSGIS-containing phosphodegron. However, formation of the phosphodegron in Nrf2 by GSK-3 is inhibited by stimuli that activate protein kinase B (PKB)/Akt. In particular, PKB/Akt activity can be increased by phosphoinositide 3-kinase and mTORC2, thereby providing an explanation of why antioxidant-responsive element-driven genes are induced by growth factors and nutrients. Thus Nrf2 activity is tightly controlled via CRLKeap1 and SCFβ-TrCP by oxidative stress and energy-based signals, allowing it to mediate adaptive responses that restore redox homeostasis and modulate intermediary metabolism. Based on the fact that Nrf2 influences multiple biochemical pathways in both positive and negative ways, it is likely its dose-response curve, in terms of susceptibility to certain degenerative disease, is U-shaped. Specifically, too little Nrf2 activity will lead to loss of cytoprotection, diminished antioxidant capacity, and lowered β-oxidation of fatty acids, while conversely also exhibiting heightened sensitivity to ROS-based signaling that involves receptor tyrosine kinases and apoptosis signal-regulating kinase-1. By contrast, too much Nrf2 activity disturbs the homeostatic balance in favor of reduction, and so may have deleterious consequences including overproduction of reduced glutathione and NADPH, the blunting of ROS-based signal transduction, epithelial cell hyperplasia, and failure of certain cell types to differentiate correctly. We discuss the basis of a putative U-shaped Nrf2 dose-response curve in terms of potentially competing processes relevant to different stages of tumorigenesis.
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Affiliation(s)
- Lauren E Tebay
- Jacqui Wood Cancer Centre, Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Holly Robertson
- Jacqui Wood Cancer Centre, Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - Stephen T Durant
- AstraZeneca Oncology Innovative Medicines, Bioscience, 33F197 Mereside, Alderley Park, Cheshire SK10 4TG, UK
| | - Steven R Vitale
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-6160, USA
| | - Trevor M Penning
- Center of Excellence in Environmental Toxicology, Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104-6160, USA
| | - Albena T Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK
| | - John D Hayes
- Jacqui Wood Cancer Centre, Division of Cancer Research, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, UK.
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Cheng D, Zhang L, Yang G, Zhao L, Peng F, Tian Y, Xiao X, Chung RT, Gong G. Hepatitis C virus NS5A drives a PTEN-PI3K/Akt feedback loop to support cell survival. Liver Int 2015; 35:1682-91. [PMID: 25388655 DOI: 10.1111/liv.12733] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 11/06/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Decreased levels of phosphatase and tensin homologue (PTEN) are associated with hepatocellular carcinoma (HCC) pathogenesis and poor prognosis in hepatitis C virus (HCV)-infected HCC patients. The molecular processes governing the reduction in PTEN and outcome of PTEN dysfunction in hepatocytes are poorly understood. METHODS The levels of proteins and mRNA were assessed by real time PCR and immunoblot. PTEN promoter activity was measured by reporter assay. Signalling pathways were perturbed using siRNAs or pharmacological inhibitors. RESULTS Here, we report that HCV down-regulates PTEN expression at the transcriptional level by decreasing its promoter activity, mRNA transcription, and protein levels. We further identify NS5A protein as a key determinant of PTEN reduction among HCV proteins. NS5A-mediated down-regulation of PTEN occurs through a cooperation of reactive oxygen species (ROS)-dependent Nuclear Factor- kappa B (NF-κB) and ROS-independent phosphoinositol-3-kinase (PI3K) pathways. Moreover, NS5A protects cells against apoptosis. In addition, we found that down-regulation of PTEN relieves its inhibitory effect on PI3K-Akt pathway and triggers cumulative activation of Akt. This PTEN-PI3K/Akt feedback network mediates the suppression of cell apoptosis caused by NS5A. CONCLUSIONS These data demonstrate that HCV NS5A down-regulates PTEN expression through a cooperation of ROS-dependent and -independent pathways that subsequently drives a PTEN-PI3K/Akt feedback loop to support cell survival. Our findings provide new insights suggesting that NS5A contributes to HCV-related hepatocarcinogenesis.
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Affiliation(s)
- Du Cheng
- Department of Gastroenterology, Renmin Hospital, Wuhan University, Wuhan, China.,Liver Center, Gastrointestinal Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,Liver Diseases Center, Department of Infectious Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Leiliang Zhang
- Liver Center, Gastrointestinal Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Guangbo Yang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Lei Zhao
- Liver Center, Gastrointestinal Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Feng Peng
- Liver Diseases Center, Department of Infectious Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Yi Tian
- Liver Diseases Center, Department of Infectious Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xinqiang Xiao
- Liver Diseases Center, Department of Infectious Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Raymond T Chung
- Liver Center, Gastrointestinal Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Guozhong Gong
- Liver Diseases Center, Department of Infectious Diseases, The Second Xiangya Hospital, Central South University, Changsha, China
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Sottero B, Gargiulo S, Russo I, Barale C, Poli G, Cavalot F. Postprandial Dysmetabolism and Oxidative Stress in Type 2 Diabetes: Pathogenetic Mechanisms and Therapeutic Strategies. Med Res Rev 2015; 35:968-1031. [PMID: 25943420 DOI: 10.1002/med.21349] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Postprandial dysmetabolism in type 2 diabetes (T2D) is known to impact the progression and evolution of this complex disease process. However, the underlying pathogenetic mechanisms still require full elucidation to provide guidance for disease prevention and treatment. This review focuses on the marked redox changes and inflammatory stimuli provoked by the spike in blood glucose and lipids in T2D individuals after meals. All the causes of exacerbated postprandial oxidative stress in T2D were analyzed, also considering the consequence of enhanced inflammation on vascular damage. Based on this in-depth analysis, current strategies of prevention and pharmacologic management of T2D were critically reexamined with particular emphasis on their potential redox-related rationale.
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Affiliation(s)
- Barbara Sottero
- Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
| | - Simona Gargiulo
- Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
| | - Isabella Russo
- Internal Medicine and Metabolic Disease Unit, Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
| | - Cristina Barale
- Internal Medicine and Metabolic Disease Unit, Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
| | - Giuseppe Poli
- Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
| | - Franco Cavalot
- Internal Medicine and Metabolic Disease Unit, Department of Clinical and Biological Sciences, University of Turin, San Luigi Gonzaga Hospital, Orbassano, Turin, 10043, Italy
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Han SJ, Ahn Y, Park I, Zhang Y, Kim I, Kim HW, Ku CS, Chay KO, Yang SY, Ahn BW, Jang DI, Lee SR. Assay of the redox state of the tumor suppressor PTEN by mobility shift. Methods 2015; 77-78:58-62. [DOI: 10.1016/j.ymeth.2015.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/14/2015] [Accepted: 01/19/2015] [Indexed: 11/25/2022] Open
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Gupta RK, Patel AK, Shah N, Chaudhary AK, Jha UK, Yadav UC, Gupta PK, Pakuwal U. Oxidative stress and antioxidants in disease and cancer: a review. Asian Pac J Cancer Prev 2015; 15:4405-9. [PMID: 24969860 DOI: 10.7314/apjcp.2014.15.11.4405] [Citation(s) in RCA: 219] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Reactive oxygen species (ROS), highly reactive molecules, are produced by living organisms as a result of normal cellular metabolism and environmental factors, and can damage nucleic acids and proteins, thereby altering their functions. The human body has several mechanisms to counteract oxidative stress by producing antioxidants. A shift in the balance between oxidants and antioxidants in favor of oxidants is termed as "oxidative stress". Paradoxically, there is a large body of research demonstrating the general effect of oxidative stress on signaling pathways, less is known about the initial and direct regulation of signaling molecules by ROS, or what we term the "oxidative interface." This review focuses on the molecular mechanisms through which ROS directly interact with critical signaling molecules to initiate signaling in a broad variety of cellular processes, such as proliferation and survival (MAP kinases and PI3 kinase), ROS homeostasis, and antioxidant gene regulation (Ref-1 and Nrf-2). This review also deals with classification as well as mechanisms of formation of free radicals, examining their beneficial and deleterious effects on cellular activities and focusing on the potential role of antioxidants in preventing and repairing damage caused by oxidative stress. A discussion of the role of phytochemical antioxidants in oxidative stress, disease and the epigenome is included.
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Affiliation(s)
- Rakesh Kumar Gupta
- Department of Biochemistry, National Medical College, Birgunj, Nepal E-mail :
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Abstract
The importance of PTEN in cellular function is underscored by the frequency of its deregulation in cancer. PTEN tumor-suppressor activity depends largely on its lipid phosphatase activity, which opposes PI3K/AKT activation. As such, PTEN regulates many cellular processes, including proliferation, survival, energy metabolism, cellular architecture, and motility. More than a decade of research has expanded our knowledge about how PTEN is controlled at the transcriptional level as well as by numerous posttranscriptional modifications that regulate its enzymatic activity, protein stability, and cellular location. Although the role of PTEN in cancers has long been appreciated, it is also emerging as an important factor in other diseases, such as diabetes and autism spectrum disorders. Our understanding of PTEN function and regulation will hopefully translate into improved prognosis and treatment for patients suffering from these ailments.
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Affiliation(s)
- Carolyn A Worby
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721;
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Clark O, Park I, Di Florio A, Cichon AC, Rustin S, Jugov R, Maeshima R, Stoker AW. Oxovanadium-based inhibitors can drive redox-sensitive cytotoxicity in neuroblastoma cells and synergise strongly with buthionine sulfoximine. Cancer Lett 2014; 357:316-327. [PMID: 25444896 DOI: 10.1016/j.canlet.2014.11.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 11/17/2014] [Accepted: 11/18/2014] [Indexed: 12/30/2022]
Abstract
In a wide range of neuroblastoma-derived lines oxovanadium compounds such as bis(maltolato)oxovanadium(IV) (BMOV) are cytotoxic. This is not explained by oxidative stress or inhibition of ion channels. Genotoxicity is unlikely given that a p53 response is absent and p53-mutant lines are also sensitive. Cytotoxicity is inhibited by N-acetyl cysteine and glutathione ester, indicating that BMOV action is sensitive to cytoplasmic redox and thiol status. Significantly, combining BMOV with glutathione synthesis inhibition greatly enhances BMOV-induced cell death. This combination treatment triggers high AKT pathway activation, highlighting the potential functional importance of PTP inhibition by BMOV. AKT activation itself, however, is not required for cytotoxicity. Oxovanadium compounds may thus represent novel leads as p53-independent therapeutics for neuroblastoma.
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Affiliation(s)
- Owen Clark
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Inhye Park
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Alessia Di Florio
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Ann-Christin Cichon
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Sarah Rustin
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Roman Jugov
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Ruhina Maeshima
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Andrew W Stoker
- Cancer Section, Developmental Biology & Cancer Programme, UCL Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
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Yu W, He X, Ni Y, Ngeow J, Eng C. Cowden syndrome-associated germline SDHD variants alter PTEN nuclear translocation through SRC-induced PTEN oxidation. Hum Mol Genet 2014; 24:142-53. [PMID: 25149476 PMCID: PMC4262496 DOI: 10.1093/hmg/ddu425] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Germline mutations in the PTEN tumor-suppressor gene and germline variations in succinate dehydrogenase subunit D gene (SDHD-G12S, SDHD-H50R) are associated with a subset of Cowden syndrome and Cowden syndrome-like individuals (CS/CSL) and confer high risk of breast, thyroid and other cancers. However, very little is known about the underlying crosstalk between SDHD and PTEN in CS-associated thyroid cancer. Here, we show SDHD-G12S and SDHD-H50R lead to impaired PTEN function through alteration of its subcellular localization accompanied by resistance to apoptosis and induction of migration in both papillary and follicular thyroid carcinoma cell lines. Other studies have shown elevated proto-oncogene tyrosine kinase (SRC) activity in invasive thyroid cancer cells; so, we explore bosutinib, a specific inhibitor for SRC, to explore SRC as a mediator of SDH-PTEN crosstalk in this context. We show that SRC inhibition could rescue SDHD dysfunction-induced cellular phenotype and tumorigenesis only when wild-type PTEN is expressed, in thyroid cancer lines. Patient lymphoblast cells carrying either SDHD-G12S or SDHD-H50R also show increased nuclear PTEN and more oxidized PTEN after hydrogen peroxide treatment. Like in thyroid cells, bosutinib decreases oxidative PTEN in patient lymphoblast cells carrying SDHD variants, but not in patients carrying both SDHD variants and PTEN truncating mutations. In summary, our data suggest a novel mechanism whereby SDHD germline variants SDHD-G12S or SDHD-H50R induce thyroid tumorigenesis mediated by PTEN accumulation in the nucleus and may shed light on potential treatment with SRC inhibitors like bosutinib in PTEN-wild-type SDHD-variant/mutation positive CS/CSL patients and sporadic thyroid neoplasias.
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Affiliation(s)
- Wanfeng Yu
- Genomic Medicine Institute, Learner Research Institute
| | - Xin He
- Genomic Medicine Institute, Learner Research Institute
| | - Ying Ni
- Genomic Medicine Institute, Learner Research Institute CASE Comprehensive Cancer Center Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44116, USA and
| | - Joanne Ngeow
- Genomic Medicine Institute, Learner Research Institute Oncology Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore 169610, Singapore
| | - Charis Eng
- Genomic Medicine Institute, Learner Research Institute Taussig Cancer Institute Stanley Shalom Zielony Institute of Nursing Excellence, Cleveland Clinic, Cleveland, OH 44195, USA Department of Genetics and Genome Sciences CASE Comprehensive Cancer Center Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44116, USA and
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Schwertassek U, Haque A, Krishnan N, Greiner R, Weingarten L, Dick TP, Tonks NK. Reactivation of oxidized PTP1B and PTEN by thioredoxin 1. FEBS J 2014; 281:3545-58. [PMID: 24976139 DOI: 10.1111/febs.12898] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 06/02/2014] [Accepted: 06/26/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED The transient inactivation of protein phosphatases contributes to the efficiency and temporal control of kinase-dependent signal transduction. In particular, members of the protein tyrosine phosphatase family are known to undergo reversible oxidation of their active site cysteine. The thiol oxidation step requires activation of colocalized NADPH oxidases and is mediated by locally produced reactive oxygen species, in particular H2 O2 . How oxidized phosphatases are returned to the reduced active state is less well studied. Both major thiol reductive systems, the thioredoxin and the glutathione systems, have been implicated in the reactivation of phosphatases. Here, we show that the protein tyrosine phosphatase PTP1B and the dual-specificity phosphatase PTEN are preferentially reactivated by the thioredoxin system. We show that inducible depletion of thioredoxin 1(TRX1) slows PTEN reactivation in intact living cells. Finally, using a mechanism-based trapping approach, we demonstrate direct thiol disulphide exchange between the active sites of thioredoxin and either phosphatase. The application of thioredoxin trapping mutants represents a complementary approach to direct assays of PTP oxidation in elucidating the significance of redox regulation of PTP function in the control of cell signaling. STRUCTURED DIGITAL ABSTRACT TRX1 physically interacts with PTP1B by anti tag coimmunoprecipitation (1, 2).
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Martínez-Reyes I, Cuezva JM. The H+-ATP synthase: A gate to ROS-mediated cell death or cell survival. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1099-112. [DOI: 10.1016/j.bbabio.2014.03.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/03/2014] [Accepted: 03/19/2014] [Indexed: 12/13/2022]
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Mitochondrial ROS and involvement of Bcl-2 as a mitochondrial ROS regulator. Mitochondrion 2014; 19 Pt A:39-48. [PMID: 24954615 DOI: 10.1016/j.mito.2014.06.002] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 12/22/2022]
Abstract
Mitochondria are the major intracellular source of reactive oxygen species (ROS). While excessive mitochondrial ROS (mitoROS) production induces cell injury and death, there is accumulating evidence that non-toxic low levels of mitoROS could serve as important signaling molecules. Therefore, maintenance of mitoROS at physiological levels is crucial for cell homeostasis as well as for survival and proliferation. This review describes the various mechanisms that keep mitoROS in check, with particular focus on the role of the onco-protein Bcl-2 in redox regulation. In addition to its canonical anti-apoptotic activity, Bcl-2 has been implicated in mitoROS regulation by its effect on mitochondrial complex IV activity, facilitating the mitochondrial incorporation of GSH and interaction with the small GTPase-Rac1 at the mitochondria. We also discuss some of the plausible mechanism(s) which allows Bcl-2 to sense and respond to the fluctuations in mitoROS.
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48
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The PPARβ/δ agonist GW0742 modulates signaling pathways associated with cardiac myocyte growth via a non-genomic redox mechanism. Mol Cell Biochem 2014; 395:145-54. [PMID: 24939361 DOI: 10.1007/s11010-014-2120-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/02/2014] [Indexed: 12/28/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that belong to the nuclear hormone receptor superfamily and appear to have beneficial effects in the cardiovascular system. PPARβ/δ has been shown previously to exert an inhibitory effect on cardiac myocyte hypertrophy in vivo and in vitro although the exact mechanism is not fully clear yet. The principal signaling pathways that have been involved in triggering cardiac hypertrophic response are mitogen-activated protein kinases (MAPKs) and PI3K/Akt cascades. In this study, we sought to evaluate the potential effects evoked by PPARβ/δ activation on signaling pathways that are implicated in cardiac myocyte growth responses. The selective PPARβ/δ agonist GW0742 attenuated ERK1/2 and Akt phosphorylation that was stimulated by growth promoting agonists (phenylephrine, insulin or IGF-1). This effect was not reversed by the specific PPARβ/δ antagonist, GSK0660, but was inhibited by vanadate, a potent protein tyrosine phosphatase inhibitor. In addition, GW0742 prevented the oxidation and inactivation of PTEN supporting further the notion that its inhibitory action on the agonist-induced kinase phosphorylation is mediated by the modulation of phosphatase activity. Furthermore, GW0742 abolished the agonist-induced intracellular generation of reactive oxygen species, independently of PPARβ/δ activation. Our data reveals a new non-genomic mechanism of GW0742, which ameliorates the generation of reactive oxygen species and attenuates ERK1/2 and PI3K/Akt signaling, with implications in the regulation of cardiac hypertrophic response.
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Abstract
SIGNIFICANCE Functional stem cell decline has been postulated to result in loss of maintenance of tissue homeostasis leading to organismal decline and diseases of aging. RECENT ADVANCES Recent findings implicate redox metabolism in the control of stem cell pool and stem cell aging. Although reactive oxygen species (ROS) are better known for their damaging properties to DNA, proteins and lipids, recent findings suggest that ROS may also be an integral physiological mediator of cellular signaling in primary cells. CRITICAL ISSUES Here we review recent published work on major signaling pathways and transcription factors that are regulated by ROS and mediate ROS regulation of stem cell fate. We will specifically focus on how alterations in this regulation may be implicated in disease and particularly in diseases of stem cell aging. In general, based on the work described here we propose a model in which ROS function as stem cell rheostat. FUTURE DIRECTIONS Future work in elucidating how ROS control stem cell cycling, apoptotic machinery, and lineage determination should shed light on mechanisms whereby ROS may control stem cell aging.
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Affiliation(s)
- Raymond Liang
- 1 Department of Developmental & Regenerative Biology, Icahn School of Medicine at Mount Sinai , New York, New York
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DeBalsi KL, Wong KE, Koves TR, Slentz DH, Seiler SE, Wittmann AH, Ilkayeva OR, Stevens RD, Perry CGR, Lark DS, Hui ST, Szweda L, Neufer PD, Muoio DM. Targeted metabolomics connects thioredoxin-interacting protein (TXNIP) to mitochondrial fuel selection and regulation of specific oxidoreductase enzymes in skeletal muscle. J Biol Chem 2014; 289:8106-20. [PMID: 24482226 DOI: 10.1074/jbc.m113.511535] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thioredoxin-interacting protein (TXNIP) is an α-arrestin family member involved in redox sensing and metabolic control. Growing evidence links TXNIP to mitochondrial function, but the molecular nature of this relationship has remained poorly defined. Herein, we employed targeted metabolomics and comprehensive bioenergetic analyses to evaluate oxidative metabolism and respiratory kinetics in mouse models of total body (TKO) and skeletal muscle-specific (TXNIP(SKM-/-)) Txnip deficiency. Compared with littermate controls, both TKO and TXNIP(SKM-/-) mice had reduced exercise tolerance in association with muscle-specific impairments in substrate oxidation. Oxidative insufficiencies in TXNIP null muscles were not due to perturbations in mitochondrial mass, the electron transport chain, or emission of reactive oxygen species. Instead, metabolic profiling analyses led to the discovery that TXNIP deficiency causes marked deficits in enzymes required for catabolism of branched chain amino acids, ketones, and lactate, along with more modest reductions in enzymes of β-oxidation and the tricarboxylic acid cycle. The decrements in enzyme activity were accompanied by comparable deficits in protein abundance without changes in mRNA expression, implying dysregulation of protein synthesis or stability. Considering that TXNIP expression increases in response to starvation, diabetes, and exercise, these findings point to a novel role for TXNIP in coordinating mitochondrial fuel switching in response to nutrient availability.
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