1
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Wang S, Sun S. Translation dysregulation in neurodegenerative diseases: a focus on ALS. Mol Neurodegener 2023; 18:58. [PMID: 37626421 PMCID: PMC10464328 DOI: 10.1186/s13024-023-00642-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
RNA translation is tightly controlled in eukaryotic cells to regulate gene expression and maintain proteome homeostasis. RNA binding proteins, translation factors, and cell signaling pathways all modulate the translation process. Defective translation is involved in multiple neurological diseases including amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder and poses a major public health challenge worldwide. Over the past few years, tremendous advances have been made in the understanding of the genetics and pathogenesis of ALS. Dysfunction of RNA metabolisms, including RNA translation, has been closely associated with ALS. Here, we first introduce the general mechanisms of translational regulation under physiological and stress conditions and review well-known examples of translation defects in neurodegenerative diseases. We then focus on ALS-linked genes and discuss the recent progress on how translation is affected by various mutant genes and the repeat expansion-mediated non-canonical translation in ALS.
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Affiliation(s)
- Shaopeng Wang
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shuying Sun
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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2
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Sarkar P, Raju SV, Velayutham M, Guru A, Pasupuleti M, Al Olayan EM, Boushra AF, Juliet A, Arockiaraj J. A synthetic antioxidant molecule, GP13 derived from cysteine desulfurase of spirulina, Arthrospira platensis exhibited anti-diabetic activity on L6 rat skeletal muscle cells through GLUT-4 pathway. JOURNAL OF KING SAUD UNIVERSITY - SCIENCE 2023; 35:102450. [DOI: 10.1016/j.jksus.2022.102450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2023]
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3
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Rangwala AM, Mingione VR, Georghiou G, Seeliger MA. Kinases on Double Duty: A Review of UniProtKB Annotated Bifunctionality within the Kinome. Biomolecules 2022; 12:biom12050685. [PMID: 35625613 PMCID: PMC9138534 DOI: 10.3390/biom12050685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 01/27/2023] Open
Abstract
Phosphorylation facilitates the regulation of all fundamental biological processes, which has triggered extensive research of protein kinases and their roles in human health and disease. In addition to their phosphotransferase activity, certain kinases have evolved to adopt additional catalytic functions, while others have completely lost all catalytic activity. We searched the Universal Protein Resource Knowledgebase (UniProtKB) database for bifunctional protein kinases and focused on kinases that are critical for bacterial and human cellular homeostasis. These kinases engage in diverse functional roles, ranging from environmental sensing and metabolic regulation to immune-host defense and cell cycle control. Herein, we describe their dual catalytic activities and how they contribute to disease pathogenesis.
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4
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Li J, Zhu M, Qu H, Yang H, Li Q, Liu L, Jin L, Wu Y. The double-stranded RNA-dependent protein kinase inhibitor alleviates endoplasmic reticulum stress and alleviates sepsis-induced renal injury. J Toxicol Sci 2021; 46:445-451. [PMID: 34602529 DOI: 10.2131/jts.46.445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The double-stranded RNA-dependent protein kinase (PKR) is involved in inflammatory cytokine expression and disease pathogenesis in many conditions. The aim of this study was to explore the role of PKR in sepsis-induced renal tissue injury. Six-week-old C57BL/6J mice received PKR inhibitor (imoxin) and Endoplasmic reticulum (ER) inducer (tunicamycin) 2 hr prior to induction of inflammation via cecal ligation and puncture (CLP). Renal tissues were collected 24 hr after the CLP treatment and protein expression were assessed. The expression of creatinine (Cre) and blood urea nitrogen (BUN) in serum and inflammation factor in tissues was detected by ELISA, and the apoptosis of renal tissue was detected by TUNEL staining. PKR inhibitors reduce the expression of sepsis-induced ER stress in renal tissue, as well as the pathological changes and renal impairment in renal tissue. PKR inhibitors reduce the expression of sepsis-induced inflammatory response and sepsis-induced apoptosis in renal tissue by ER stress. In conclusion, PKR inhibitor alleviates ER stress and alleviates sepsis-induced renal injury.
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Affiliation(s)
- Jinghui Li
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Ming Zhu
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Hai Qu
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Heying Yang
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Qiuyu Li
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Lu Liu
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Lu Jin
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
| | - Yujuan Wu
- Intensive Care Unit, Kunming Medical University Affiliated Yan'an Hospital, China
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5
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High fructose and streptozotocin induced diabetic impairments are mitigated by Indirubin-3-hydrazone via downregulation of PKR pathway in Wistar rats. Sci Rep 2021; 11:12924. [PMID: 34155273 PMCID: PMC8217483 DOI: 10.1038/s41598-021-92345-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/09/2021] [Indexed: 12/03/2022] Open
Abstract
Metabolic disorders are becoming more common in young population due to increased consumption of carbohydrate rich diet, lack of physical activity and stress. Fructose is used as a sweetener in many carbonated beverages and is a known inducer of oxidative stress and hypertension. Up-regulation of the double-stranded RNA-dependent protein kinase (PKR) causes impairment in insulin signaling pathway and metabolic dysfunctions in type 2 diabetes mellitus. In the present study we investigated the role of PKR and associated pathways in high fructose (HF) and streptozotocin (STZ) induced diabetes and whether indirubin-3-hydrazone (IHZ), a novel PKR inhibitor can reverse the HF and STZ induced diabetic impairments in Wistar rats. Diabetes was induced by feeding rats 20% high fructose in drinking water for 6 weeks and by giving a single dose of STZ (35 mg/kg., i.p) at the end of week 5. Glucose and lipid levels were measured by using assay kits. Expression of PKR and its downstream genes were determined by immunohistochemistry, qRT-PCR and western blotting techniques. Histo-pathological studies were performed using H&E staining. Fibrosis was detected in insulin sensitive tissues and organs using Sirius red and Masson’s trichrome staining and apoptosis by TUNEL assay. HF and STZ induced hyperglycemia, fibrosis, oxidative stress, and inflammation in liver, pancreas, skeletal muscle and adipose tissue are mediated via PKR pathway and its downstream effectors, and these effects were attenuated by PKR inhibitor IHZ. Thus, inhibition of PKR can protect insulin sensitive organs and tissues from HF induced diabetic impairments via the inhibition of c-Jun N-terminal kinase (JNK) pathway.
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6
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Eo H, Valentine RJ. Imoxin inhibits tunicamycin-induced endoplasmic reticulum stress and restores insulin signaling in C2C12 myotubes. Am J Physiol Cell Physiol 2021; 321:C221-C229. [PMID: 34077277 DOI: 10.1152/ajpcell.00544.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Prolonged endoplasmic reticulum (ER) stress can mediate inflammatory myopathies and insulin signaling pathways. The double-stranded RNA (dsRNA)-activated protein kinase R (PKR) has been implicated in skeletal muscle dysfunction. However, pathological roles of PKR in ER stress in muscle are not fully understood. The current study aimed to investigate the effect of imoxin (IMX), a selective PKR inhibitor, on tunicamycin (TN)-induced promotion of ER stress and suppression of insulin signaling in C2C12 myotubes. Cells were pretreated with 5 µM IMX for 1 h and exposed to 0.5 µg/mL TN for 23 h. A subset of cells was stimulated with 100 nM insulin for the last 15 min. mRNA expression and protein levels involved in ER stress were measured by RT-PCR and Western blotting, respectively. TN significantly augmented PKR phosphorylation by 231%, which was prevented by IMX. In addition, IMX reduced mRNA and protein levels of ER stress-related markers, including CCAAT-enhancer-binding protein homologous protein (CHOP, mRNA: 95% decrease; protein: 98% decrease), activating transcription factor 4 (ATF4, mRNA: 69% decrease; protein: 99% decrease), cleavage of ATF6, and spliced X-box-binding protein 1 (XBP-1s, mRNA: 88% decrease; protein: 79% decrease), which were induced by TN. Furthermore, IMX ameliorated TN-induced suppression of phospho-insulin receptor β (317% increase) and Akt phosphorylation (by 36% at Ser473 and 30% at Thr308) in myotubes, while augmenting insulin-stimulated AS160 phosphorylation and glucose uptake (by ∼30%). These findings suggest that IMX may protect against TN-induced skeletal muscle ER stress and insulin resistance, which are potentially mediated by PKR.
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Affiliation(s)
- Hyeyoon Eo
- Department of Kinesiology, Iowa State University, Ames, Iowa.,Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, Iowa
| | - Rudy J Valentine
- Department of Kinesiology, Iowa State University, Ames, Iowa.,Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, Iowa
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Guru A, Issac PK, Saraswathi NT, Seshadri VD, Gabr GA, Arockiaraj J. Deteriorating insulin resistance due to WL15 peptide from cysteine and glycine-rich protein 2 in high glucose-induced rat skeletal muscle L6 cells. Cell Biol Int 2021; 45:1698-1709. [PMID: 33818831 DOI: 10.1002/cbin.11608] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/17/2021] [Accepted: 04/01/2021] [Indexed: 12/19/2022]
Abstract
This study investigates the antioxidant and antidiabetic activity of the WL15 peptide derived from Channa striatus on regulating the antioxidant property in the rat skeletal muscle cell line (L6) and enhancing glucose uptake via glucose metabolism. Increased oxidative stress plays a major role in the development of diabetes and its complications. Strategies are needed to mitigate the oxidative stress that can reduce these pathogenic processes. Our results showed that with treatment with WL15 peptide, the reactive oxygen species significantly decreased in L6 myotubes in a dose-dependent manner, and increased antioxidant enzymes help to prevent the formation of lipid peroxidation in L6 myotubes. The cytotoxicity of WL15 is evaluated in the L6 cells and found to be non-cytotoxic at the tested concentration. Also, for the analysis of glucose uptake activity in L6 cells, the 2-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl]amino)-2-deoxy- d -glucose assay was performed in the presence of wortmannin and genistein inhibitors. WL15 demonstrated antidiabetic activities through a dose-dependent increase in glucose uptake (64%) and glycogen storage (7.8 mM). The optimal concentration for the maximum activity was found to be 50 µM. In addition, studies of gene expression in L6 myotubes demonstrated upregulation of antioxidant genes and genes involved in the pathway of insulin signaling. In cell-based assays, WL15 peptide decreased intracellular reactive oxygen species levels and demonstrated insulin mimic activity by enhancing the primary genes involved in the insulin signaling pathway by increased glucose uptake indicating that glucose transporter type 4 (GLUT4) is regulated from the intracellular pool to the plasma membrane.
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Affiliation(s)
- Ajay Guru
- SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India.,Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
| | - Praveen Kumar Issac
- SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
| | - N T Saraswathi
- Molecular Biophysics Lab, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, Tamil Nadu, India
| | - Vidya Devanathadesikan Seshadri
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam bin Abdul Aziz University, Al Kharj, Saudi Arabia
| | - Gamal A Gabr
- Department of Pharmacology and Toxicology, College of Pharmacy, Prince Sattam bin Abdul Aziz University, Al Kharj, Saudi Arabia
| | - Jesu Arockiaraj
- SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India.,Department of Biotechnology, Faculty of Science and Humanities, SRM Institute of Science and Technology, Kattankulathur, Chennai, Tamil Nadu, India
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Eo H, Reed CH, Valentine RJ. Imoxin prevents dexamethasone-induced promotion of muscle-specific E3 ubiquitin ligases and stimulates anabolic signaling in C2C12 myotubes. Biomed Pharmacother 2020; 128:110238. [PMID: 32450522 DOI: 10.1016/j.biopha.2020.110238] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 04/30/2020] [Accepted: 05/03/2020] [Indexed: 12/26/2022] Open
Abstract
Muscle atrophy is the loss of skeletal muscle mass during several pathological conditions such as long-term fasting, aging, cancer, diabetes, sepsis and immune disorders. Glucocorticoids are known to trigger skeletal muscle atrophy. Dexamethasone (DEX), a synthetic glucocorticoid, induces skeletal muscle atrophy by suppression of protein synthesis and promotion of protein degradation. The double-stranded RNA (dsRNA)-activated protein kinase R (PKR) plays a significant role in mediating lipopolysaccharide-induced inflammation. However, pathological roles of PKR in muscle atrophy are not fully understood. The current study aimed to investigate the effect of imoxin, a PKR inhibitor, on DEX-induced muscle atrophy in C2C12 myotubes. Myotubes were incubated with imoxin at different concentrations with or without 5 μM DEX for 24 h. In the current study, imoxin treatment significantly reduced protein levels of MuRF1 and MAFbx induced by DEX by 88 ± 2% and MAFbx by 99 ± 0%, respectively. Moreover, 5 μM imoxin treatment reduced protein ubiquitination by 42 ± 4% and protein content of nuclear FoxO3α (77 ± 4%) in presence of DEX. Furthermore, 5 μM imoxin treatment stimulated Akt phosphorylation (195 ± 5%), mTOR phosphorylation (171 ± 21 %) and p70S6K1 phosphorylation (314 ± 31 %) under DEX-treated condition even though DEX treatment did not suppressed Akt/mTOR/p70S6K1 axis. These findings suggest that imoxin may protect against DEX-induced skeletal muscle atrophy by alleviating muscle specific E3 ubiquitin ligases and imoxin alone may promote protein synthesis via Akt/mTOR/S6K1 axis in muscle cells.
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Affiliation(s)
- Hyeyoon Eo
- Department of Kinesiology, Iowa State University, Ames, Iowa, United States; Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, Iowa, United States
| | - Carter H Reed
- Department of Kinesiology, Iowa State University, Ames, Iowa, United States; Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, Iowa, United States; Department of Food Science and Human Nutrition, Ames, Iowa, United States
| | - Rudy J Valentine
- Department of Kinesiology, Iowa State University, Ames, Iowa, United States; Interdepartmental Graduate Program in Nutritional Sciences, Iowa State University, Ames, Iowa, United States.
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Yalçin A, Şarkici G, Kolaç UK. PKR inhibitors suppress endoplasmic reticulum stress and subdue glucolipotoxicity-mediated impairment of insulin secretion in pancreatic beta cells. ACTA ACUST UNITED AC 2020; 44:93-102. [PMID: 32256145 PMCID: PMC7129068 DOI: 10.3906/biy-1909-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes mellitus is characterized by insulin resistance and hypersecretion of insulin from the pancreas to compensate for decreased insulin sensitivity in the peripheral tissues. In later stages of the disease insulin-secreting beta cell degeneration commences and patients require insulin replacement therapy in order to accomplish proper regulation of their blood glucose. Endoplasmic reticulum (ER) stress in the beta cells is one of the factors contributing to this detrimental effect. Protein kinase R (PKR) is a cellular stress kinase activated by ER stress and contributing to degeneration of pancreatic islets. In order to determine whether inhibition of PKR activation by specific small molecule inhibitors of PKR ameliorates pancreatic insulin secretion capacity, we treated beta cells with two imidazole/oxindole-derived inhibitors of PKR kinase, imoxin (C16) and 2-aminopurine (2-AP), in the presence of ER stress. Our results demonstrate that PKR inhibition suppresses tunicamycin-mediated ER stress without altering the insulin production capacity of the cells. Palmitic acid-mediated suppression of insulin secretion, however, was subdued significantly by PKR inhibitor treatment through an ER stress-related mechanism. We suggest that PKR inhibitor treatment may be used to increase the insulin secretion capacity of the pancreas in later stages of diabetes.
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Affiliation(s)
- Abdullah Yalçin
- Department of Medical Biology, Faculty of Medicine, Adnan Menderes University AYDIN TURKEY
| | - Gülçin Şarkici
- Department of Medical Biology, Faculty of Medicine, Adnan Menderes University AYDIN TURKEY
| | - Umut Kerem Kolaç
- Department of Medical Biology, Faculty of Medicine, Adnan Menderes University AYDIN TURKEY
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10
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Silva-Vignato B, Coutinho LL, Poleti MD, Cesar ASM, Moncau CT, Regitano LCA, Balieiro JCC. Gene co-expression networks associated with carcass traits reveal new pathways for muscle and fat deposition in Nelore cattle. BMC Genomics 2019; 20:32. [PMID: 30630417 PMCID: PMC6329100 DOI: 10.1186/s12864-018-5345-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/30/2018] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Positively correlated with carcass weight and animal growth, the ribeye area (REA) and the backfat thickness (BFT) are economic important carcass traits, which impact directly on producer's payment. The selection of these traits has not been satisfactory since they are expressed later in the animal's life and multigene regulated. So, next-generation technologies have been applied in this area to improve animal's selection and better understand the molecular mechanisms involved in the development of these traits. Correlation network analysis, performed by tools like WGCNA (Weighted Correlation Network Analysis), has been used to explore gene-gene interactions and gene-phenotype correlations. Thus, this study aimed to identify putative candidate genes and metabolic pathways that regulate REA and BFT by constructing a gene co-expression network using WGCNA and RNA sequencing data, to better understand genetic and molecular variations behind these complex traits in Nelore cattle. RESULTS The gene co-expression network analysis, using WGCNA, were built using RNA-sequencing data normalized by transcript per million (TPM) from 43 Nelore steers. Forty-six gene clusters were constructed, between them, three were positively correlated (p-value< 0.1) to the BFT (Green Yellow, Ivory, and Light Yellow modules) and, one cluster was negatively correlated (p-value< 0.1) with REA (Salmon module). The enrichment analysis performed by DAVID and WebGestalt (FDR 5%) identified eight Gene Ontology (GO) terms and three KEGG pathways in the Green Yellow module, mostly associated with immune response and inflammatory mechanisms. The enrichment of the Salmon module demonstrated 19 GO terms and 21 KEGG pathways, related to muscle energy metabolism, lipid metabolism, muscle degradation, and oxidative stress diseases. The Ivory and Light yellow modules have not shown significant results in the enrichment analysis. CONCLUSION With this study, we verified that inflammation and immune response pathways modulate the BFT trait. Energy and lipid metabolism pathways, highlighting fatty acid metabolism, were the central pathways associated with REA. Some genes, as RSAD2, EIF2AK2, ACAT1, and ACSL1 were considered as putative candidate related to these traits. Altogether these results allow us to a better comprehension of the molecular mechanisms that lead to muscle and fat deposition in bovine.
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Affiliation(s)
- Bárbara Silva-Vignato
- College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, SP, 13418-900, Brazil.
| | - Luiz L Coutinho
- College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | - Mirele D Poleti
- College of Animal Science and Food Engineering, University of São Paulo, Pirassununga, SP, 13635-900, Brazil
| | - Aline S M Cesar
- College of Agriculture "Luiz de Queiroz", University of São Paulo, Piracicaba, SP, 13418-900, Brazil
| | | | | | - Júlio C C Balieiro
- College of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga, SP, 13635-900, Brazil
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Gal-Ben-Ari S, Barrera I, Ehrlich M, Rosenblum K. PKR: A Kinase to Remember. Front Mol Neurosci 2019; 11:480. [PMID: 30686999 PMCID: PMC6333748 DOI: 10.3389/fnmol.2018.00480] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
Aging is a major risk factor for many diseases including metabolic syndrome, cancer, inflammation, and neurodegeneration. Identifying mechanistic common denominators underlying the impact of aging is essential for our fundamental understanding of age-related diseases and the possibility to propose new ways to fight them. One can define aging biochemically as prolonged metabolic stress, the innate cellular and molecular programs responding to it, and the new stable or unstable state of equilibrium between the two. A candidate to play a role in the process is protein kinase R (PKR), first identified as a cellular protector against viral infection and today known as a major regulator of central cellular processes including mRNA translation, transcriptional control, regulation of apoptosis, and cell proliferation. Prolonged imbalance in PKR activation is both affected by biochemical and metabolic parameters and affects them in turn to create a feedforward loop. Here, we portray the central role of PKR in transferring metabolic information and regulating cellular function with a focus on cancer, inflammation, and brain function. Later, we integrate information from open data sources and discuss current knowledge and gaps in the literature about the signaling cascades upstream and downstream of PKR in different cell types and function. Finally, we summarize current major points and biological means to manipulate PKR expression and/or activation and propose PKR as a therapeutic target to shift age/metabolic-dependent undesired steady states.
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Affiliation(s)
- Shunit Gal-Ben-Ari
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Iliana Barrera
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Marcelo Ehrlich
- Laboratory of Intracellular Trafficking and Signaling, School of Molecular Cell Biology & Biotechnology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Kobi Rosenblum
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Center for Gene Manipulation in the Brain, University of Haifa, Haifa, Israel
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Platania CBM, Leggio GM, Drago F, Salomone S, Bucolo C. Computational systems biology approach to identify novel pharmacological targets for diabetic retinopathy. Biochem Pharmacol 2018; 158:13-26. [DOI: 10.1016/j.bcp.2018.09.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/13/2018] [Indexed: 12/11/2022]
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13
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Mangali S, Bhat A, Udumula MP, Dhar I, Sriram D, Dhar A. Inhibition of protein kinase R protects against palmitic acid-induced inflammation, oxidative stress, and apoptosis through the JNK/NF-kB/NLRP3 pathway in cultured H9C2 cardiomyocytes. J Cell Biochem 2018; 120:3651-3663. [PMID: 30259999 DOI: 10.1002/jcb.27643] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 08/14/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE Double-stranded RNA-dependent protein kinase (PKR) is a critical regulator of apoptosis, oxidative stress, and inflammation under hyperlipidemic and insulin resistance conditions. Saturated free fatty acids, such as palmitic acid (PA), are known inducers of apoptosis in numerous cell types. However, the underlying molecular mechanism is not fully understood. The aim of the present study was to examine the effect of PA on cultured rat H9C2 cardiac myocytes cells and to investigate the PKR mediated harmful effects of PA in vitro in cultured cardiomyocytes. EXPERIMENTAL APPROACH PKR expression was determined by immunofluorescence and immunoblotting. Oxidative stress and apoptosis were determined by flow cytometry and assay kits. The expression of different gene markers of apoptosis, oxidative stress, and inflammation were measured by Western blot analysis and reverse transcription polymerase chain reaction. KEY RESULTS PKR expression, reactive oxygen species levels as well as apoptosis were increased in PA-treated cultured H9C2 cardiomyocytes. The harmful effects of PA were attenuated by a selective PKR inhibitor, C16. Moreover, we observed that upregulation of c-Jun N-terminal kinase (JNK), nuclear factor-kB (NF-kB) and NACHT, LRR and PYD domains-containing protein 3 (NLRP3) pathways is associated with increased expression of interleukin 6 and tumor necrosis factor-α in PA-treated cardiomyocytes and attenuation by a selective PKR inhibitor. CONCLUSION AND IMPLICATIONS Our study reports, for the first time, that PKR-mediated harmful effects of PA in cultured cardiomyocytes via activation of JNK, NF-kB, and NLRP3 pathways. Inhibition of PKR is one of the possible mechanistic approaches to inhibit inflammation, oxidative stress, and apoptosis in lipotoxicity-induced cardiomyocyte damage.
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Affiliation(s)
- Sureshbabu Mangali
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad, Telangana, India
| | - Audesh Bhat
- Department of Molecular Biology, Central University of Jammu, Jammu and Kashmir, India
| | - Mary Priyanka Udumula
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad, Telangana, India
| | - Indu Dhar
- Department of Clinical Sciences, University of Bergen, Bergen, Norway
| | - Dharmarajan Sriram
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad, Telangana, India
| | - Arti Dhar
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad, Telangana, India
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14
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Udumula MP, Bhat A, Mangali S, Kalra J, Dhar I, Sriram D, Dhar A. Pharmacological evaluation of novel PKR inhibitor indirubin-3-hydrazone in-vitro in cardiac myocytes and in-vivo in wistar rats. Life Sci 2018; 209:85-96. [PMID: 30076923 DOI: 10.1016/j.lfs.2018.07.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 07/18/2018] [Accepted: 07/30/2018] [Indexed: 02/06/2023]
Abstract
AIMS Double stranded protein kinase R cellular response is associated with various stress signals such as nutrients, endoplasmic stress, cytokines and mechanical stress. Increased PKR activity has been observed under diabetic and cardiovascular disease conditions. Most of the currently available PKR inhibitors are non-specific and have other effects as well. Thus, the aim of the present study was to examine the effect of novel PKR inhibitor indirubin-3-hydrazone (IHZ) in cultured rat H9C2 cardiomyocytes and wistar rats. MATERIALS AND METHODS PKR expression was determined by Q-PCR, immunofluorescence and immunoblotting. The expression of different gene markers for apoptosis was measured by RT-PCR. Apoptosis and oxidative stress were determined by flow cytometry. KEY FINDINGS High glucose (HG) treated H9C2 cardiomyocytes and high fructose (HF) treated wistar rats developed a significant increase in PKR expression. A significant increase in apoptosis and generation of reactive oxygen species was also observed in HG treated H9C2 cells and HF treated rats. Reduced vacuole formation and prominent nuclei were also observed in high glucose treated cells. Cardiac hypertrophy and increased fibrosis were observed in HF treated rats. All these effects of HG and HF were attenuated by novel PKR inhibitor, indirubin-3-hydrazone. SIGNIFICANCE Our results indicate IHZ as an effective inhibitor of PKR in vitro and in-vivo, thus it may prove very useful in blocking the multiple harmful effects of PKR.
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Affiliation(s)
- Mary Priyanka Udumula
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet, Hyderabad, Andhra Pradesh 500078, India
| | - Audesh Bhat
- Department of Molecular Biology, Central University of Jammu, India
| | - Sureshbabu Mangali
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet, Hyderabad, Andhra Pradesh 500078, India
| | - Jaspreet Kalra
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet, Hyderabad, Andhra Pradesh 500078, India
| | - Indu Dhar
- Department of Clinical Sciences, University of Bergen, Norway
| | - Dharamrajan Sriram
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet, Hyderabad, Andhra Pradesh 500078, India
| | - Arti Dhar
- Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Hyderabad Campus, Jawahar Nagar, Shameerpet, Hyderabad, Andhra Pradesh 500078, India..
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Kalra J, Mangali SB, Bhat A, Dhar I, Udumula MP, Dhar A. Imoxin attenuates high fructose-induced oxidative stress and apoptosis in renal epithelial cells via downregulation of protein kinase R pathway. Fundam Clin Pharmacol 2018; 32:297-305. [DOI: 10.1111/fcp.12352] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/24/2018] [Accepted: 02/05/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Jaspreet Kalra
- Department of Pharmacy; Birla Institute of Technology and Sciences Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Hyderabad Andhra Pradesh 500078 India
| | - Suresh Babu Mangali
- Department of Pharmacy; Birla Institute of Technology and Sciences Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Hyderabad Andhra Pradesh 500078 India
| | - Audesh Bhat
- Department of Molecular Biology; Central University of Jammu; Jammu Jammu and Kashmir 181143 India
| | - Indu Dhar
- Department of Clinical Sciences; University of Bergen; Bergen 5007 Norway
| | - Mary Priyanka Udumula
- Department of Pharmacy; Birla Institute of Technology and Sciences Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Hyderabad Andhra Pradesh 500078 India
| | - Arti Dhar
- Department of Pharmacy; Birla Institute of Technology and Sciences Pilani; Hyderabad Campus, Jawahar Nagar, Shameerpet Hyderabad Andhra Pradesh 500078 India
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16
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Hugon J, Mouton-Liger F, Dumurgier J, Paquet C. PKR involvement in Alzheimer's disease. ALZHEIMERS RESEARCH & THERAPY 2017; 9:83. [PMID: 28982375 PMCID: PMC5629792 DOI: 10.1186/s13195-017-0308-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 09/08/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Brain lesions in Alzheimer's disease (AD) are characterized by Aβ accumulation, neurofibrillary tangles, and synaptic and neuronal vanishing. According to the amyloid cascade hypothesis, Aβ1-42 oligomers could trigger a neurotoxic cascade with kinase activation that leads to tau phosphorylation and neurodegeneration. Detrimental pathways that are associated with kinase activation could also be linked to the triggering of direct neuronal death, the production of free radicals, and neuroinflammation. RESULTS Among these kinases, PKR (eukaryotic initiation factor 2α kinase 2) is a pro-apoptotic enzyme that inhibits translation and that has been implicated in several molecular pathways that lead to AD brain lesions and disturbed memory formation. PKR accumulates in degenerating neurons and is activated by Aβ1-42 neurotoxicity. It might modulate Aβ synthesis through BACE 1 induction. PKR is increased in cerebrospinal fluid from patients with AD and mild cognitive impairment and can induce the activation of pro-inflammatory pathways leading to TNFα and IL1-β production. In addition, experimentally, PKR seems to down-regulate the molecular processes of memory consolidation. This review highlights the major findings linking PKR and abnormal brain metabolism associated with AD lesions. CONCLUSIONS Studying the detrimental role of PKR signaling in AD could pave the way for a neuroprotective strategy in which PKR inhibition could reduce neuronal demise and alleviate cognitive decline as well as the cumbersome burden of AD for patients.
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Affiliation(s)
- Jacques Hugon
- Center of Cognitive Neurology and Inserm U942 Lariboisière Hospital AP-HP University Paris Diderot, 75010, Paris, France. .,Center of Cognitive Neurology, Lariboisière FW Hospital, 200 rue du Faubourg Saint Denis, 75010, Paris, France.
| | | | - Julien Dumurgier
- Center of Cognitive Neurology and Inserm U942 Lariboisière Hospital AP-HP University Paris Diderot, 75010, Paris, France
| | - Claire Paquet
- Center of Cognitive Neurology and Inserm U942 Lariboisière Hospital AP-HP University Paris Diderot, 75010, Paris, France
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