1
|
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.
Collapse
|
2
|
Costa-Mattioli M, Walter P. The integrated stress response: From mechanism to disease. Science 2020; 368:368/6489/eaat5314. [PMID: 32327570 DOI: 10.1126/science.aat5314] [Citation(s) in RCA: 643] [Impact Index Per Article: 160.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Protein quality control is essential for the proper function of cells and the organisms that they make up. The resulting loss of proteostasis, the processes by which the health of the cell's proteins is monitored and maintained at homeostasis, is associated with a wide range of age-related human diseases. Here, we highlight how the integrated stress response (ISR), a central signaling network that responds to proteostasis defects by tuning protein synthesis rates, impedes the formation of long-term memory. In addition, we address how dysregulated ISR signaling contributes to the pathogenesis of complex diseases, including cognitive disorders, neurodegeneration, cancer, diabetes, and metabolic disorders. The development of tools through which the ISR can be modulated promises to uncover new avenues to diminish pathologies resulting from it for clinical benefit.
Collapse
Affiliation(s)
- Mauro Costa-Mattioli
- Department of Neuroscience, Memory and Brain Research Center, Baylor College of Medicine, Houston, TX, USA.
| | - Peter Walter
- Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA.
| |
Collapse
|
3
|
Baindara P. Host-directed therapies to combat tuberculosis and associated non-communicable diseases. Microb Pathog 2019; 130:156-168. [PMID: 30876870 DOI: 10.1016/j.micpath.2019.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 12/22/2022]
Abstract
Mycobacterium tuberculosis (Mtb) has coevolved with a human host to evade and exploit the immune system in multiple ways. Mtb is an enormously successful human pathogen that can remain undetected in hosts for decades without causing clinical disease. While tuberculosis (TB) represents a perfect prototype of host-pathogen interaction, it remains a major challenge to develop new therapies to combat mycobacterial infections. Additionally, recent studies emphasize on comorbidity of TB with different non-communicable diseases (NCDs), highlighting the impact of demographic and lifestyle changes on the global burden of TB. In the recent past, host-directed therapies have emerged as a novel and promising approach to treating TB. Drugs modulating host responses are likely to avoid the development of bacterial resistance which is a major public health concern for TB treatment. Interestingly, many of these drugs also form treatment strategies for non-communicable diseases. In general, technological advances along with novel host-directed therapies may open an exciting and promising research area, which can eventually deliver effective TB treatment as well as curtail the emergent synergy with NCDs.
Collapse
Affiliation(s)
- Piyush Baindara
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, USA.
| |
Collapse
|
4
|
Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
Collapse
Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
| |
Collapse
|
5
|
Dougan G, Dowson C, Overington J. Meeting the discovery challenge of drug-resistant infections: progress and focusing resources. Drug Discov Today 2018; 24:452-461. [PMID: 30476550 DOI: 10.1016/j.drudis.2018.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/12/2018] [Accepted: 11/20/2018] [Indexed: 01/10/2023]
Abstract
Following multiple warnings from governments and health organisations, there has been renewed investment, led by the public sector, in the discovery of novel antimicrobials to meet the challenge of rising levels of drug-resistant infection, particularly in the case of resistance to antibiotics. Initiatives have also been announced to support and enable the antibiotic discovery process. In January 2018, the Medicines Discovery Catapult, UK, hosted a symposium: Next Generation Antibiotics Discovery, to consider the latest initiatives and any remaining challenges to inform and guide the international research community and better focus resources to yield a novel class of antibiotic.
Collapse
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, UK; The Department of Medicine, University of Cambridge, UK.
| | | | - John Overington
- Medicine Discovery Catapult, Mereside, Alderly Park, Alderly Edge, Cheshire, UK
| | | |
Collapse
|
6
|
Chu J, Pelletier J. Therapeutic Opportunities in Eukaryotic Translation. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a032995. [PMID: 29440069 DOI: 10.1101/cshperspect.a032995] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ability to block biological processes with selective small molecules provides advantages distinct from most other experimental approaches. These include rapid time to onset, swift reversibility, ability to probe activities in manners that cannot be accessed by genetic means, and the potential to be further developed as therapeutic agents. Small molecule inhibitors can also be used to alter expression and activity without affecting the stoichiometry of interacting partners. These tenets have been especially evident in the field of translation. Small molecule inhibitors were instrumental in enabling investigators to capture short-lived complexes and characterize specific steps of protein synthesis. In addition, several drugs that are the mainstay of modern antimicrobial drug therapy are potent inhibitors of prokaryotic translation. Currently, there is much interest in targeting eukaryotic translation as decades of research have revealed that deregulated protein synthesis in cancer cells represents a targetable vulnerability. In addition to being potential therapeutics, small molecules that manipulate translation have also been shown to influence cognitive processes such as memory. In this review, we focus on small molecule modulators that target the eukaryotic translation initiation apparatus and provide an update on their potential application to the treatment of disease.
Collapse
Affiliation(s)
- Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada.,Department of Oncology, McGill University, Montreal, Quebec H3G 1Y6, Canada.,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3G 1Y6, Canada
| |
Collapse
|
7
|
López-Morató M, Brook JD, Wojciechowska M. Small Molecules Which Improve Pathogenesis of Myotonic Dystrophy Type 1. Front Neurol 2018; 9:349. [PMID: 29867749 PMCID: PMC5968088 DOI: 10.3389/fneur.2018.00349] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/30/2018] [Indexed: 12/30/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults for which there is currently no treatment. The pathogenesis of this autosomal dominant disorder is associated with the expansion of CTG repeats in the 3'-UTR of the DMPK gene. DMPK transcripts with expanded CUG repeats (CUGexpDMPK) are retained in the nucleus forming multiple discrete foci, and their presence triggers a cascade of toxic events. Thus far, most research emphasis has been on interactions of CUGexpDMPK with the muscleblind-like (MBNL) family of splicing factors. These proteins are sequestered by the expanded CUG repeats of DMPK RNA leading to their functional depletion. As a consequence, abnormalities in many pathways of RNA metabolism, including alternative splicing, are detected in DM1. To date, in vitro and in vivo efforts to develop therapeutic strategies for DM1 have mostly been focused on targeting CUGexpDMPK via reducing their expression and/or preventing interactions with MBNL1. Antisense oligonucleotides targeted to the CUG repeats in the DMPK transcripts are of particular interest due to their potential capacity to discriminate between mutant and normal transcripts. However, a growing number of reports describe alternative strategies using small molecule chemicals acting independently of a direct interaction with CUGexpDMPK. In this review, we summarize current knowledge about these chemicals and we describe the beneficial effects they caused in different DM1 experimental models. We also present potential mechanisms of action of these compounds and pathways they affect which could be considered for future therapeutic interventions in DM1.
Collapse
Affiliation(s)
- Marta López-Morató
- Queen’s Medical Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - John David Brook
- Queen’s Medical Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Marzena Wojciechowska
- Queen’s Medical Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- Polish Academy of Sciences, Department of Molecular Genetics, Institute of Bioorganic Chemistry, Poznan, Poland
| |
Collapse
|
8
|
Mundhra S, Bryk R, Hawryluk N, Zhang T, Jiang X, Nathan CF. Evidence for dispensability of protein kinase R in host control of tuberculosis. Eur J Immunol 2018; 48:612-620. [PMID: 29436711 DOI: 10.1002/eji.201747180] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 06/13/2017] [Accepted: 02/06/2018] [Indexed: 11/09/2022]
Abstract
Genetic deficiency of protein kinase R (PKR) in mice was reported to enhance macrophage activation in vitro in response to interferon-γ (IFNγ) and to reduce the burden of Mycobacterium tuberculosis (Mtb) in vivo (Wu et al. PloS One. 2012 7:e30512). Consistent with this, treatment of wild-type (WT) macrophages in vitro with a novel PKR inhibitor (Bryk et al., Bioorg. Med. Chem. Lett. 2011 21:4108-4114) also enhanced IFN-γ-dependent macrophage activation (Wu et al. PloS One. 2012 7:e30512). Here we show that co-treatment with IFN-γ and a new PKR inhibitor identified herein to be highly but not completely selective likewise induced macrophages to produce more reactive nitrogen intermediates (RNI) and tumor necrosis factor alpha (TNF-α) and less interleukin 10 (IL-10) than seen with IFN-γ alone. Unexpectedly, however, this new PKR inhibitor had a comparable effect on PKR-deficient macrophages. Retrospective investigation revealed that the PKR-deficient mice in (Wu et al. PloS One. 2012 7:e30512) had not been backcrossed. On comparing genetically matched PKR-deficient and WT mice, we saw no impact of PKR deficiency on macrophage activation in vitro or during the course of Mtb infection in vivo. In addition, although 129S1/SvImJ macrophage responses to IFN-γ were greater than those of C57BL/6J macrophages, PKR was not required to mediate the IFN-γ-dependent production of IL-10, RNI or TNF-α in either strain. Together the data cast doubt on PKR as a potential therapeutic target for tuberculosis.
Collapse
Affiliation(s)
- Shashirekha Mundhra
- Immunology and Microbial Pathogenesis Program, Weill Graduate School of Medical Sciences of Cornell University, New York City, NY, USA
| | - Ruslana Bryk
- Department of Microbiology & Immunology, Weill Cornell Medicine, New York City, NY, USA
| | | | - Tuo Zhang
- Genomics Resources Core Facility, Weill Cornell Medicine, New York City, NY, USA
| | - Xiuju Jiang
- Department of Microbiology & Immunology, Weill Cornell Medicine, New York City, NY, USA
| | - Carl F Nathan
- Immunology and Microbial Pathogenesis Program, Weill Graduate School of Medical Sciences of Cornell University, New York City, NY, USA.,Department of Microbiology & Immunology, Weill Cornell Medicine, New York City, NY, USA
| |
Collapse
|
9
|
Burwick N, Aktas BH. The eIF2-alpha kinase HRI: a potential target beyond the red blood cell. Expert Opin Ther Targets 2017; 21:1171-1177. [PMID: 29063813 DOI: 10.1080/14728222.2017.1397133] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The eIF2α kinase heme-regulated inhibitor (HRI) is one of four well-described kinases that phosphorylate eIF2α in response to various cell stressors, resulting in reduced ternary complex formation and attenuation of mRNA translation. Although HRI is well known for its role as a heme sensor in erythroid progenitors, pharmacologic activation of HRI has been demonstrated to have anti-cancer activity across a wide range of tumor sub-types. Here, the potential of HRI activators as novel cancer therapeutics is explored. Areas covered: We provide an introduction to eIF2 signaling pathways in general, and specifically review data on the eIF2α kinase HRI in erythroid and non-erythroid cells. We review aspects of targeting eIF2 signaling in cancer and highlight promising data using HRI activators against tumor cells. Expert opinion: Pharmacologic activation of HRI inhibits tumor growth as a single agent without appreciable toxicity in vivo. The ability of HRI activators to provide direct and sustained eIF2α phosphorylation without inducing oxidative stress or broad eIF2α kinase activation may be especially advantageous for tolerability. Combination therapy with established therapeutics may further augment anti-cancer activity to overcome disease resistance.
Collapse
Affiliation(s)
- Nicholas Burwick
- a Division of hematology , VA Puget Sound Health Care System , Seattle , WA , USA.,b Division of Hematology , University of Washington School of Medicine , Seattle WA , USA
| | - Bertal H Aktas
- c Department of Medicine , Brigham and Women's Hospital and Harvard Medical School , Boston , MA , USA
| |
Collapse
|
10
|
Barage S, Kulkarni A, Pal JK, Joshi M. Unravelling the structural interactions between PKR kinase domain and its small molecule inhibitors using computational approaches. J Mol Graph Model 2017. [PMID: 28628858 DOI: 10.1016/j.jmgm.2017.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The RNA-dependent protein kinase (PKR), an eIF2α kinase plays an important role in anti-viral response, apoptosis and cell survival. It is also implicated to play a role in several cancers, metabolic and neurodegenerative disorders. A few ATP competitive inhibitors of the PKR have been reported in the literature with promising results in vitro and in vivo. The aim of this study was to unravel the structural interactions between these inhibitors and the PKR kinase domain using molecular simulations and docking. Our study reveals that the reported inhibitors bind in the adenine pocket and form hydrogen bonds with the hinge region and vdW interactions with non-polar residues in the binding site. The most potent inhibitor has several favorable interactions with the binding site and induces the P-loop to fold inward, creating a significant hydrophobic enclosure for itself. The computed binding free energies of these inhibitors are in accord with experimental data (IC50). Strategies to design potent and selective PKR inhibitors are discussed to overcome the reported promiscuity.
Collapse
Affiliation(s)
- Sagar Barage
- Bioinformatics Centre, S. P. Pune University, Pune 411007, India
| | | | - Jayanta K Pal
- Department of Biotechnology, S. P. Pune University, Pune 411007, India; Dr. D.Y. Patil Biotechnology & Bioinformatics Institute, Dr. D.Y. Patil Vidyapeeth, Tathawade, Pune 411033, India
| | - Manali Joshi
- Bioinformatics Centre, S. P. Pune University, Pune 411007, India.
| |
Collapse
|
11
|
Design and synthesis of novel protein kinase R (PKR) inhibitors. Mol Divers 2016; 20:805-819. [PMID: 27480630 DOI: 10.1007/s11030-016-9689-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 07/11/2016] [Indexed: 12/13/2022]
Abstract
Protein kinase RNA-activated (PKR) plays an important role in a broad range of intracellular regulatory mechanisms and in the pathophysiology of many human diseases, including microbial and viral infections, cancer, diabetes and neurodegenerative disorders. Recently, several potent PKR inhibitors have been synthesized. However, the enzyme's multifunctional character and a multitude of PKR downstream targets have prevented the successful transformation of such inhibitors into effective drugs. Thus, the need for additional PKR inhibitors remains. With the help of computer-aided drug-discovery tools, we designed and synthesized potential PKR inhibitors. Indeed, two compounds were found to inhibit recombinant PKR in pharmacologically relevant concentrations. One compound, 6-amino-3-methyl-2-oxo-N-phenyl-2,3-dihydro-1H-benzo[d]imidazole-1-carboxamide, also showed anti-apoptotic properties. The novel molecules diversify the existing pool of PKR inhibitors and provide a basis for the future development of compounds based on PKR signal transduction mechanism.
Collapse
|
12
|
Abstract
Host-directed therapies are a relatively new and promising approach to treatment of tuberculosis. Modulation of specific host immune pathways, including those that impact inflammation and immunopathology, can limit mycobacterial infection and pathology, both in cell culture and in animal models. This review explores a range of host pathways and drugs, some already approved for clinical use that have the potential to provide new adjunctive therapies for tuberculosis. Drugs targeting host processes may largely avoid the development of bacterial antibiotic resistance, a major public health concern for tuberculosis. However, these drugs may also have generally increased risk for side effects on the host. Understanding the specific mechanisms by which these drugs act and the relationship of these mechanisms to Mycobacterium tuberculosis pathogenesis will be critical in selecting appropriate host-directed therapy. Overall, these host-directed compounds provide a novel strategy for antituberculosis therapy.
Collapse
Affiliation(s)
- David M Tobin
- Department of Molecular Genetics and Microbiology, Center for Microbial Pathogenesis, Center for AIDS Research, Duke University School of Medicine, Durham, North Carolina 27710
| |
Collapse
|
13
|
Abstract
Treatment of tuberculosis (TB) remains challenging, with lengthy treatment durations and complex drug regimens that are toxic and difficult to administer. Similar to the vast majority of antibiotics, drugs for Mycobacterium tuberculosis are directed against microbial targets. Although more effective drugs that target the bacterium may lead to faster cure of patients, it is possible that a biological limit will be reached that can be overcome only by adopting a fundamentally new treatment approach. TB regimens might be improved by including agents that target host pathways. Recent work on host-pathogen interactions, host immunity, and host-directed interventions suggests that supplementing anti-TB therapy with host modulators may lead to shorter treatment times, a reduction in lung damage caused by the disease, and a lower risk of relapse or reinfection. We undertook this review to identify molecular pathways of the host that may be amenable to modulation by small molecules for the treatment of TB. Although several approaches to augmenting standard TB treatment have been proposed, only a few have been explored in detail or advanced to preclinical and clinical studies. Our review focuses on molecular targets and inhibitory small molecules that function within the macrophage or other myeloid cells, on host inflammatory pathways, or at the level of TB-induced lung pathology.
Collapse
|
14
|
Wojciechowska M, Taylor K, Sobczak K, Napierala M, Krzyzosiak WJ. Small molecule kinase inhibitors alleviate different molecular features of myotonic dystrophy type 1. RNA Biol 2014; 11:742-54. [PMID: 24824895 PMCID: PMC4156505 DOI: 10.4161/rna.28799] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Expandable (CTG)n repeats in the 3′ UTR of the DMPK gene are a cause of myotonic dystrophy type 1 (DM1), which leads to a toxic RNA gain-of-function disease. Mutant RNAs with expanded CUG repeats are retained in the nucleus and aggregate in discrete inclusions. These foci sequester splicing factors of the MBNL family and trigger upregulation of the CUGBP family of proteins resulting in the mis-splicing of their target transcripts. To date, many efforts to develop novel therapeutic strategies have been focused on disrupting the toxic nuclear foci and correcting aberrant alternative splicing via targeting mutant CUG repeats RNA; however, no effective treatment for DM1 is currently available. Herein, we present results of culturing of human DM1 myoblasts and fibroblasts with two small-molecule ATP-binding site-specific kinase inhibitors, C16 and C51, which resulted in the alleviation of the dominant-negative effects of CUG repeat expansion. Reversal of the DM1 molecular phenotype includes a reduction of the size and number of foci containing expanded CUG repeat transcripts, decreased steady-state levels of CUGBP1 protein, and consequent improvement of the aberrant alternative splicing of several pre-mRNAs misregulated in DM1.
Collapse
Affiliation(s)
- Marzena Wojciechowska
- Department of Molecular Biomedicine; Institute of Bioorganic Chemistry; Polish Academy of Sciences; Noskowskiego; Poznan, Poland
| | - Katarzyna Taylor
- Department of Gene Expression; Institute of Molecular Biology and Biotechnology; Adam Mickiewicz University; Umultowska 89; Poznan, Poland
| | - Krzysztof Sobczak
- Department of Gene Expression; Institute of Molecular Biology and Biotechnology; Adam Mickiewicz University; Umultowska 89; Poznan, Poland
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics and UAB Stem Cell Institute; University of Alabama at Birmingham; Birmingham, AL USA
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine; Institute of Bioorganic Chemistry; Polish Academy of Sciences; Noskowskiego; Poznan, Poland
| |
Collapse
|
15
|
Joshi M, Kulkarni A, Pal JK. Small molecule modulators of eukaryotic initiation factor 2α kinases, the key regulators of protein synthesis. Biochimie 2013; 95:1980-90. [PMID: 23939221 DOI: 10.1016/j.biochi.2013.07.030] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/26/2013] [Indexed: 01/25/2023]
Abstract
Eukaryotic initiation factor 2 alpha kinases (eIF-2α kinases) are key mediators of stress response in cells. In mammalian cells, there are four eIF-2α kinases, namely HRI (Heme-Regulated Inhibitor), PKR (RNA-dependent Protein Kinase), PERK (PKR-like ER Kinase) and GCN2 (General Control Non-derepressible 2). These kinases get activated during diverse cytoplasmic stress conditions and phosphorylate the alpha-subunit of eIF2, leading to global protein synthesis inhibition. Therefore, eIF-2α kinases play a vital role in various cellular processes such as proliferation, differentiation, apoptosis and cell signaling. Deregulation of eIF-2α kinases and protein synthesis has been linked to numerous pathological conditions such as certain cancers, anemia and neurodegenerative disorders. Thus, modulation of these kinases by small molecules holds a great therapeutic promise. In this review we have compiled the available information on inhibitors and activators of these four eIF-2α kinases. The review concludes with a note on the selectivity issue of currently available modulators and future perspectives for the design of specific small molecule probes.
Collapse
Affiliation(s)
- Manali Joshi
- Bioinformatics Center, University of Pune, Pune - 411007, Maharashtra, India.
| | | | | |
Collapse
|
16
|
|
17
|
Wu K, Koo J, Jiang X, Chen R, Cohen SN, Nathan C. Improved control of tuberculosis and activation of macrophages in mice lacking protein kinase R. PLoS One 2012; 7:e30512. [PMID: 22359543 PMCID: PMC3281035 DOI: 10.1371/journal.pone.0030512] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 12/22/2011] [Indexed: 11/19/2022] Open
Abstract
Host factors that microbial pathogens exploit for their propagation are potential targets for therapeuic countermeasures. No host enzyme has been identified whose genetic absence benefits the intact mammalian host in vivo during infection with Mycobacterium tuberculosis (Mtb), the leading cause of death from bacterial infection. Here, we report that the dsRNA-dependent protein kinase (PKR) is such an enzyme. PKR-deficient mice contained fewer viable Mtb and showed less pulmonary pathology than wild type mice. We identified two potential mechanisms for the protective effect of PKR deficiency: increased apoptosis of macrophages in response to Mtb and enhanced activation of macrophages in response to IFN-gamma. The restraining effect of PKR on macrophage activation was explained by its mediation of a previously unrecognized ability of IFN-gamma to induce low levels of the macrophage deactivating factor interleukin 10 (IL10). These observations suggest that PKR inhibitors may prove useful as an adjunctive treatment for tuberculosis.
Collapse
Affiliation(s)
- Kangyun Wu
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Jovanka Koo
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Xiuju Jiang
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
| | - Ran Chen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, California, United States of America
| | - Stanley N. Cohen
- Department of Genetics, Stanford University School of Medicine, Palo Alto, California, United States of America
| | - Carl Nathan
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, United States of America
- * E-mail:
| |
Collapse
|