1
|
Martinez-Campesino L, Kocsy K, Cañedo J, Johnston JM, Moss CE, Johnston SA, Hamby S, Goodall AH, Redgrave J, Francis SE, Kiss-Toth E, Wilson HL. Tribbles 3 deficiency promotes atherosclerotic fibrous cap thickening and macrophage-mediated extracellular matrix remodelling. Front Cardiovasc Med 2022; 9:948461. [PMID: 36158793 PMCID: PMC9505024 DOI: 10.3389/fcvm.2022.948461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/02/2022] [Indexed: 12/02/2022] Open
Abstract
Tribbles 3 (TRIB3) modulates lipid and glucose metabolism, macrophage lipid uptake, with a gain-of-function variant associated with increased cardiovascular risk. Here we set out to examine the role of this pseudokinase in atherosclerotic plaque development. Human endarterectomy atherosclerotic tissue specimens analysed by immunofluorescence showed upregulated TRIB3 in unstable plaques and an enrichment in unstable regions of stable plaques. Atherosclerosis was induced in full body Trib3KO and Trib3WT littermate mice by injecting mPCSK9 expressing adeno-associated virus and western diet feeding for 12 weeks. Trib3KO mice showed expanded visceral adipose depot while circulatory lipid levels remained unaltered compared to wildtype mice. Trib3KO mice aortae showed a reduced plaque development and improved plaque stability, with increased fibrous cap thickness and collagen content, which was accompanied by increased macrophage content. Analysis of both mouse and human macrophages with reduced TRIB3 expression showed elongated morphology, increased actin expression and altered regulation of genes involved in extracellular matrix remodelling. In summary, TRIB3 controls plaque development and may be atherogenic in vivo. Loss of TRIB3 increases fibrous cap thickness via altered metalloproteinase expression in macrophages, thus inhibiting collagen and elastic fibre degradation, suggesting a role for TRIB3 in the formation of unstable plaques.
Collapse
Affiliation(s)
- Laura Martinez-Campesino
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Klaudia Kocsy
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Jaime Cañedo
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Jessica M. Johnston
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Charlotte E. Moss
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Simon A. Johnston
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Stephen Hamby
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- National Institute for Healthcare Research, Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Alison H. Goodall
- Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom
- National Institute for Healthcare Research, Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, United Kingdom
| | - Jessica Redgrave
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Sheila E. Francis
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
| | - Endre Kiss-Toth
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
- Biological Research Centre of the Hungarian Academy of Sciences, Szeged, Hungary
| | - Heather L. Wilson
- Department of Infection, Immunity and Cardiovascular Disease, Medical School, University of Sheffield, Sheffield, United Kingdom
- *Correspondence: Heather L. Wilson,
| |
Collapse
|
2
|
Busato S, Ford HR, Abdelatty AM, Estill CT, Bionaz M. Peroxisome Proliferator-Activated Receptor Activation in Precision-Cut Bovine Liver Slices Reveals Novel Putative PPAR Targets in Periparturient Dairy Cows. Front Vet Sci 2022; 9:931264. [PMID: 35903133 PMCID: PMC9315222 DOI: 10.3389/fvets.2022.931264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/06/2022] [Indexed: 12/24/2022] Open
Abstract
Metabolic challenges experienced by dairy cows during the transition between pregnancy and lactation (also known as peripartum), are of considerable interest from a nutrigenomic perspective. The mobilization of large amounts of non-esterified fatty acids (NEFA) leads to an increase in NEFA uptake in the liver, the excess of which can cause hepatic accumulation of lipids and ultimately fatty liver. Interestingly, peripartum NEFA activate the Peroxisome Proliferator-activated Receptor (PPAR), a transcriptional regulator with known nutrigenomic properties. The study of PPAR activation in the liver of periparturient dairy cows is thus crucial; however, current in vitro models of the bovine liver are inadequate, and the isolation of primary hepatocytes is time consuming, resource intensive, and prone to errors, with the resulting cells losing characteristic phenotypical traits within hours. The objective of the current study was to evaluate the use of precision-cut liver slices (PCLS) from liver biopsies as a model for PPAR activation in periparturient dairy cows. Three primiparous Jersey cows were enrolled in the experiment, and PCLS from each were prepared prepartum (−8.0 ± 3.6 DIM) and postpartum (+7.7± 1.2 DIM) and treated independently with a variety of PPAR agonists and antagonists: the PPARα agonist WY-14643 and antagonist GW-6471; the PPARδ agonist GW-50156 and antagonist GSK-3787; and the PPARγ agonist rosiglitazone and antagonist GW-9662. Gene expression was assayed through RT-qPCR and RNAseq, and intracellular triacylglycerol (TAG) concentration was measured. PCLS obtained from postpartum cows and treated with a PPARγ agonist displayed upregulation of ACADVL and LIPC while those treated with PPARδ agonist had increased expression of LIPC, PPARD, and PDK4. In PCLS from prepartum cows, transcription of LIPC was increased by all PPAR agonists and NEFA. TAG concentration tended to be larger in tissue slices treated with PPARδ agonist compared to CTR. Use of PPAR isotype-specific antagonists in PCLS cultivated in autologous blood serum failed to decrease expression of PPAR targets, except for PDK4, which was confirmed to be a PPARδ target. Transcriptome sequencing revealed considerable differences in response to PPAR agonists at a false discovery rate-adjusted p-value of 0.2, with the most notable effects exerted by the PPARδ and PPARγ agonists. Differentially expressed genes were mainly related to pathways involved with lipid metabolism and the immune response. Among differentially expressed genes, a subset of 91 genes were identified as novel putative PPAR targets in the bovine liver, by cross-referencing our results with a publicly available dataset of predicted PPAR target genes, and supplementing our findings with prior literature. Our results provide important insights on the use of PCLS as a model for assaying PPAR activation in the periparturient dairy cow.
Collapse
Affiliation(s)
- Sebastiano Busato
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR, United States
| | - Hunter R. Ford
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR, United States
| | - Alzahraa M. Abdelatty
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt
| | - Charles T. Estill
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR, United States
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
| | - Massimo Bionaz
- Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR, United States
- *Correspondence: Massimo Bionaz
| |
Collapse
|
3
|
Erol SA, Anuk AT, Tanaçan A, Semiz H, Keskin HL, Neşelioğlu S, Erel Ö, Moraloğlu Tekin Ö, Şahin D. An evaluation of maternal serum dynamic thiol-disulfide homeostasis and ischemia modified albumin changes in pregnant women with COVID-19. Turk J Obstet Gynecol 2022; 19:21-27. [PMID: 35343216 PMCID: PMC8966320 DOI: 10.4274/tjod.galenos.2022.72929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Objective: It is thought that oxidative stress, free radicals, reactive oxygen species and reactive nitrogen species affect the pathophysiology of coronavirus disease-2019 (COVID-19). This study aimed to evaluate the oxidative status in pregnant patients with COVID-19 infection according to the changes seen in the levels of maternal serum thiol-disulfide and ischemia-modified albumin (IMA). Materials and Methods: A study group was formed of 40 pregnant women with confirmed COVID-19 infection (study group) and a control group of 40 healthy pregnant women with no risk factors determined. In this prospective, case-controlled study, analyses were made of the maternal serum native thiol, total thiol, disulfide, IMA, and disulfide/native thiol concentrations. Results: The maternal serum native thiol and total thiol concentrations in the study group were determined to be statistically significantly lower (p=0.007 and p=0.006, respectively), and the disulfide/native thiol ratio was higher but not to a level of statistical significance (p=0.473). There was no difference between the two groups regarding IMA levels (p=0.731). Conclusion: The thiol-disulfide balance was seen to shift in the oxidant direction in pregnancies with COVID-19, which might support the view that ischemic processes play a role in the etiopathogenesis of this novel disease.
Collapse
|
4
|
Lee SK, Park CY, Kim J, Kim D, Choe H, Kim JH, Hong JP, Lee YJ, Heo Y, Park HS, Jang YJ. TRIB3 Is Highly Expressed in the Adipose Tissue of Obese Patients and Is Associated With Insulin Resistance. J Clin Endocrinol Metab 2022; 107:e1057-e1073. [PMID: 34718616 DOI: 10.1210/clinem/dgab780] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT The upregulation of TRIB3 (Tribbles homolog 3), a stress-inducible gene encoding a pseudokinase, has been implicated in the development of insulin resistance in the skeletal muscle and liver of patients with obesity and type 2 diabetes. However, there is little information regarding TRIB3 expression in human adipose tissue. OBJECTIVE To investigate whether TRIB3 expression is dysregulated in human adipose tissue in the context of obesity and type 2 diabetes and whether TRIB3 expression in adipose tissues is associated with insulin resistance. METHODS We measured metabolic parameters and TRIB3 expression in abdominal subcutaneous and visceral adipose tissue in obese (with or without type 2 diabetes) and normal-weight women. Regulation of TRIB3 expression was studied in human adipocytes. RESULTS TRIB3 expression in both fat depots was higher in patients with obesity and/or type 2 diabetes; in addition, the expression level was significantly associated with insulin resistance. Incubating adipocytes under conditions mimicking the microenvironment of obese adipose tissue, including increased endoplasmic reticulum (ER) stress, induced TRIB3 expression. In human adipocytes, the overexpression of TRIB3 impaired insulin-stimulated protein kinase B (AKT) phosphorylation and caused dysregulation of the transcription of genes encoding bioactive molecules released from adipocytes, such as proinflammatory cytokines, adiponectin, and leptin. Pioglitazone, an insulin-sensitizing agent, reduced both these effects of TRIB3 and the ER stressor-induced expression of TRB3. CONCLUSION Our data indicate that TRIB3 expression in adipose tissue is enhanced in patients with obesity and suggest that increased TRIB3 dysregulates adipocyte function, which may contribute to the development of insulin resistance.
Collapse
Affiliation(s)
- Seul Ki Lee
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Brexogen Research Center, Brexogen Inc., Seoul, Korea
| | - Chan Yoon Park
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Department of Food Science and Nutrition, The University of Suwon, Hwaseong, Korea
| | - Jimin Kim
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Brexogen Research Center, Brexogen Inc., Seoul, Korea
| | - Donguk Kim
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Han Choe
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jong-Hyeok Kim
- Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Seoul, Korea
| | - Joon Pio Hong
- Department of Plastic Surgery, University of Ulsan College of Medicine, Seoul, Korea
| | - Yeon Ji Lee
- Department of Family Medicine, Inha University School of Medicine, Incheon, Korea
| | - Yoonseok Heo
- Department of General Surgery, Inha University School of Medicine, Incheon, Korea
| | - Hye Soon Park
- Department of Family Medicine, University of Ulsan College of Medicine, Seoul, Korea
| | - Yeon Jin Jang
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
| |
Collapse
|
5
|
Karam CS, Williams BL, Morozova I, Yuan Q, Panarsky R, Zhang Y, Hodgkinson CA, Goldman D, Kalachikov S, Javitch JA. Functional Genomic Analysis of Amphetamine Sensitivity in Drosophila. Front Psychiatry 2022; 13:831597. [PMID: 35250674 PMCID: PMC8894854 DOI: 10.3389/fpsyt.2022.831597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 01/24/2022] [Indexed: 11/14/2022] Open
Abstract
Abuse of psychostimulants, including amphetamines (AMPHs), is a major public health problem with profound psychiatric, medical, and psychosocial complications. The actions of these drugs at the dopamine transporter (DAT) play a critical role in their therapeutic efficacy as well as their liability for abuse and dependence. To date, however, the mechanisms that mediate these actions are not well-understood, and therapeutic interventions for AMPH abuse have been limited. Drug exposure can induce broad changes in gene expression that can contribute to neuroplasticity and effect long-lasting changes in neuronal function. Identifying genes and gene pathways perturbed by drug exposure is essential to our understanding of the molecular basis of drug addiction. In this study, we used Drosophila as a model to examine AMPH-induced transcriptional changes that are DAT-dependent, as those would be the most relevant to the stimulatory effects of the drug. Using this approach, we found genes involved in the control of mRNA translation to be significantly upregulated in response to AMPH in a DAT-dependent manner. To further prioritize genes for validation, we explored functional convergence between these genes and genes we identified in a genome-wide association study of AMPH sensitivity using the Drosophila Genetic Reference Panel. We validated a number of these genes by showing that they act specifically in dopamine neurons to mediate the behavioral effects of AMPH. Taken together, our data establish Drosophila as a powerful model that enables the integration of behavioral, genomic and transcriptomic data, followed by rapid gene validation, to investigate the molecular underpinnings of psychostimulant action.
Collapse
Affiliation(s)
- Caline S Karam
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States
| | - Brenna L Williams
- Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States
| | - Irina Morozova
- Center for Genome Technology and Biomolecular Engineering, Columbia University, New York, NY, United States.,Department of Chemical Engineering, Columbia University, New York, NY, United States
| | - Qiaoping Yuan
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Rony Panarsky
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Yuchao Zhang
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States
| | - Colin A Hodgkinson
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - David Goldman
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Sergey Kalachikov
- Center for Genome Technology and Biomolecular Engineering, Columbia University, New York, NY, United States.,Department of Chemical Engineering, Columbia University, New York, NY, United States
| | - Jonathan A Javitch
- Department of Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, United States.,Department of Molecular Pharmacology and Therapeutics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY, United States
| |
Collapse
|
6
|
Saltykova IV, Elahi A, Pitale PM, Gorbatyuk OS, Athar M, Gorbatyuk MS. Tribbles homolog 3-mediated targeting the AKT/mTOR axis in mice with retinal degeneration. Cell Death Dis 2021; 12:664. [PMID: 34215725 PMCID: PMC8253859 DOI: 10.1038/s41419-021-03944-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 05/28/2021] [Accepted: 06/15/2021] [Indexed: 02/07/2023]
Abstract
Various retinal degenerative disorders manifest in alterations of the AKT/mTOR axis. Despite this, consensus on the therapeutic targeting of mTOR in degenerating retinas has not yet been achieved. Therefore, we investigated the role of AKT/mTOR signaling in rd16 retinas, in which we restored the AKT/mTOR axis by genetic ablation of pseudokinase TRB3, known to inhibit phosphorylation of AKT and mTOR. First, we found that TRB3 ablation resulted in preservation of photoreceptor function in degenerating retinas. Then, we learned that the mTOR downstream cellular pathways involved in the homeostasis of photoreceptors were also reprogrammed in rd16 TRB3-/- retinas. Thus, the level of inactivated translational repressor p-4E-BP1 was significantly increased in these mice along with the restoration of translational rate. Moreover, in rd16 mice manifesting decline in p-mTOR at P15, we found elevated expression of Beclin-1 and ATG5 autophagy genes. Thus, these mice showed impaired autophagy flux measured as an increase in LC3 conversion and p62 accumulation. In addition, the RFP-EGFP-LC3 transgene expression in rd16 retinas resulted in statistically fewer numbers of red puncta in photoreceptors, suggesting impaired late autophagic vacuoles. In contrast, TRIB3 ablation in these mice resulted in improved autophagy flux. The restoration of translation rate and the boost in autophagosome formation occurred concomitantly with an increase in total Ub and rhodopsin protein levels and the elevation of E3 ligase Parkin1. We propose that TRB3 may retard retinal degeneration and be a promising therapeutic target to treat various retinal degenerative disorders.
Collapse
Affiliation(s)
- Irina V Saltykova
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Asif Elahi
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Priyam M Pitale
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Oleg S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mohammad Athar
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Marina S Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
7
|
Vega RB, Brouwers B, Parsons SA, Stephens NA, Pino MF, Hodges A, Yi F, Yu G, Pratley RE, Smith SR, Sparks LM. An improvement in skeletal muscle mitochondrial capacity with short-term aerobic training is associated with changes in Tribbles 1 expression. Physiol Rep 2021; 8:e14416. [PMID: 32562350 PMCID: PMC7305239 DOI: 10.14814/phy2.14416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 03/17/2020] [Accepted: 03/17/2020] [Indexed: 12/18/2022] Open
Abstract
Exercise training and physical activity are known to be associated with high mitochondrial content and oxidative capacity in skeletal muscle. Metabolic diseases including obesity and insulin resistance are associated with low mitochondrial capacity in skeletal muscle. Certain transcriptional factors such as PGC-1α are known to mediate the exercise response; however, the precise molecular mechanisms involved in the adaptation to exercise are not completely understood. We performed multiple measurements of mitochondrial capacity both in vivo and ex vivo in lean or overweight individuals before and after an 18-day aerobic exercise training regimen. These results were compared to lean, active individuals. Aerobic training in these individuals resulted in a marked increase in mitochondrial oxidative respiratory capacity without an appreciable increase in mitochondrial content. These adaptations were associated with robust transcriptome changes. This work also identifies the Tribbles pseudokinase 1, TRIB1, as a potential mediator of the exercise response in human skeletal muscle.
Collapse
Affiliation(s)
- Rick B Vega
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Bram Brouwers
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | | | | | - Maria F Pino
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Andrew Hodges
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Fanchao Yi
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Gongxin Yu
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | | | - Steven R Smith
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| | - Lauren M Sparks
- Translational Research Institute, AdventHealth, Orlando, FL, USA
| |
Collapse
|
8
|
Chen S, Sbuh N, Veedu RN. Antisense Oligonucleotides as Potential Therapeutics for Type 2 Diabetes. Nucleic Acid Ther 2020; 31:39-57. [PMID: 33026966 DOI: 10.1089/nat.2020.0891] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) is a chronic metabolic disorder characterized by persistent hyperglycemia resulting from inefficient signaling and insufficient production of insulin. Conventional management of T2D has largely relied on small molecule-based oral hypoglycemic medicines, which do not halt the progression of the disease due to limited efficacy and induce adverse effects as well. To this end, antisense oligonucleotide has attracted immense attention in developing antidiabetic agents because of their ability to downregulate the expression of disease-causing genes at the RNA and protein level. To date, seven antisense agents have been approved by the United States Food and Drug Administration for therapies of a variety of human maladies, including genetic disorders. Herein, we provide a comprehensive review of antisense molecules developed for suppressing the causative genes believed to be responsible for insulin resistance and hyperglycemia toward preventing and treating T2D.
Collapse
Affiliation(s)
- Suxiang Chen
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Australia.,Perron Institute for Neurological and Translational Science, Perth, Australia
| | - Nabayet Sbuh
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Australia.,Perron Institute for Neurological and Translational Science, Perth, Australia
| | - Rakesh N Veedu
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Perth, Australia.,Perron Institute for Neurological and Translational Science, Perth, Australia
| |
Collapse
|
9
|
Sun L, Liu YL, Ye F, Xie JW, Zeng JW, Qin L, Xue J, Wang YT, Guo KM, Ma MM, Tang YB, Li XY, Gao M. Free fatty acid-induced H 2O 2 activates TRPM2 to aggravate endothelial insulin resistance via Ca 2+-dependent PERK/ATF4/TRB3 cascade in obese mice. Free Radic Biol Med 2019; 143:288-299. [PMID: 31445205 DOI: 10.1016/j.freeradbiomed.2019.08.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 08/16/2019] [Accepted: 08/19/2019] [Indexed: 01/12/2023]
Abstract
Transient Receptor Potential Melastatin-2 (TRPM2) is a nonselective cation channel mediating Ca2+ influx in response to oxidative stress. Given that insulin resistance-related endothelial dysfunction in obesity attributes to fatty-acid-induced reactive oxygen species (ROS) overproduction, in this study, we addressed the possible role of TRPM2 in obesity-related endothelial insulin resistance and the underlying mechanisms. Whole-cell patch clamp technique, intracellular Ca2+ concentration measurement, western blot, vasorelaxation assay, and high-fat diet (HFD)-induced obese model were employed to assess the relationship between TRPM2 and endothelial insulin response. We found that both the expression and activity of TRPM2 were higher in endothelial cells of obese mice. Palmitate rose a cationic current in endothelial cells which was inhibited or enlarged by TRPM2 knockdown or overexpression. Silencing of TRPM2 remarkably improved insulin-induced endothelial Akt activation, nitric oxide synthase (eNOS) phosphorylation and nitric oxide (NO) production, while TRPM2 overexpression resulted in the opposite effects. Furthermore, TRPM2-mediated Ca2+ entry, CaMKII activation and the following activation of PERK/ATF4/TRB3 cascade were involved in the mechanism of obesity or palmitate-induced endothelial insulin resistance. Notably, in vivo study, knockdown of TRPM2 with adeno-associated virus harboring short-hairpin RNA (shRNA) against TRPM2 alleviated endothelial insulin resistance and ameliorated endothelium-dependent vasodilatation in obese mice. Thus, these results suggest that TRPM2-activated Ca2+ signaling is necessary to induce insulin resistance-related endothelial dysfunction in obesity. Downregulation or pharmacological inhibition of TRPM2 channels may lead to the development of effective drugs for treatment of endothelial dysfunction associated with oxidative stress state.
Collapse
Affiliation(s)
- Lu Sun
- Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China; Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230001, China
| | - Yan-Li Liu
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Fang Ye
- Department of Anesthesiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, China
| | - Jing-Wen Xie
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jia-Wei Zeng
- Department of Pharmacy, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China
| | - Li Qin
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Jing Xue
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Yi-Ting Wang
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China
| | - Kai-Min Guo
- Department of Obstetrics and Gynecology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, 510623, China
| | - Ming-Ming Ma
- Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Yong-Bo Tang
- Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Xiao-Yan Li
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
| | - Min Gao
- Department of Pharmacy, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China.
| |
Collapse
|
10
|
Gurzeler E, Aavik E, Laine A, Valkama T, Niskanen H, Huusko J, Kaikkonen MU, Ylä-Herttuala S. Therapeutic effects of rosuvastatin in hypercholesterolemic prediabetic mice in the absence of low density lipoprotein receptor. Biochim Biophys Acta Gen Subj 2018; 1863:481-490. [PMID: 30508567 DOI: 10.1016/j.bbagen.2018.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/27/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
Abstract
Statins are effective drugs used to prevent and treat cardiovascular diseases but their effects in the absence of low density lipoprotein receptor (LDLR) and on the risk of diabetes are not yet well characterized. The aim of this study was to clarify systemic and pleiotropic effects of rosuvastatin on cardiovascular and diabetic phenotypes. IGF-II/LDLR-/-ApoB100/100 hypercholesterolemic prediabetic mice were used to test the effects of rosuvastatin on plasma glucose, insulin, lipids, atherosclerosis and liver steatosis. To get a more comprehensive view about changes in gene expression RNA-sequencing was done from the liver. Rosuvastatin significantly reduced plasma cholesterol in hypercholesterolemic mice in the absence of LDLR but had no effects on atherosclerosis at aortic sinus level or in coronary arteries. Rosuvastatin also significantly reduced liver steatosis without any harmful effects on glucose or insulin metabolism. RNA-sequencing showed relatively specific effects of rosuvastatin on genes involved in cholesterol metabolism together with a significant anti-inflammatory gene expression profile in the liver. In addition, significant changes were found in the expression of Perilipin 4 and 5 which are involved in lipid droplet formation in the liver. For the first time it could be shown that Tribbles proteins are affected by rosuvastatin treatment in the hyperlipidemic mice. Rosuvastatin had several positive effects on hypercholesterolemic mice showing early signs of diabetes, many of which are unrelated to cholesterol and lipoprotein metabolism. These results increase our understanding about the systemic and pleiotropic effects of rosuvastatin in the absence of LDLR expression.
Collapse
Affiliation(s)
- Erika Gurzeler
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Einari Aavik
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Anssi Laine
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Teemu Valkama
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Henri Niskanen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Jenni Huusko
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Minna U Kaikkonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland
| | - Seppo Ylä-Herttuala
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210 Kuopio, Finland; Gene Therapy Unit, Kuopio University Hospital, Kuopio, 70211 Kuopio, Finland; Heart Center, Kuopio University Hospital, 70211 Kuopio, Finland.
| |
Collapse
|
11
|
Mondal D, Mathur A, Chandra PK. Tripping on TRIB3 at the junction of health, metabolic dysfunction and cancer. Biochimie 2016; 124:34-52. [DOI: 10.1016/j.biochi.2016.02.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 02/04/2016] [Indexed: 12/16/2022]
|
12
|
Abstract
Inflammation is part of the physiological innate immune response to invading pathogens and tissue injury. However, unresolved inflammation leads to human disease. The tribbles (TRIB) family of pseudokinase proteins has been shown to modulate key inflammatory signalling pathways, including the MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase) networks. This review summarizes our current knowledge on TRIBs in the context of inflammation, both at the level of molecular mechanisms and in disease development.
Collapse
|
13
|
Rigo F, Seth PP, Bennett CF. Antisense oligonucleotide-based therapies for diseases caused by pre-mRNA processing defects. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:303-52. [PMID: 25201110 DOI: 10.1007/978-1-4939-1221-6_9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Before a messenger RNA (mRNA) is translated into a protein in the cytoplasm, its pre-mRNA precursor is extensively processed through capping, splicing and polyadenylation in the nucleus. Defects in the processing of pre-mRNAs due to mutations in RNA sequences often cause disease. Traditional small molecules or protein-based therapeutics are not well suited for correcting processing defects by targeting RNA. However, antisense oligonucleotides (ASOs) designed to bind RNA by Watson-Crick base pairing can target most RNA transcripts and have emerged as the ideal therapeutic agents for diseases that are caused by pre-mRNA processing defects. Here we review the diverse ASO-based mechanisms that can be exploited to modulate the expression of RNA. We also discuss how advancements in medicinal chemistry and a deeper understanding of the pharmacokinetic and toxicological properties of ASOs have enabled their use as therapeutic agents. We end by describing how ASOs have been used successfully to treat various pre-mRNA processing diseases in animal models.
Collapse
Affiliation(s)
- Frank Rigo
- Isis Pharmaceuticals, 2855 Gazelle Court, Carlsbad, CA, USA,
| | | | | |
Collapse
|
14
|
Das R, Sebo Z, Pence L, Dobens LL. Drosophila tribbles antagonizes insulin signaling-mediated growth and metabolism via interactions with Akt kinase. PLoS One 2014; 9:e109530. [PMID: 25329475 PMCID: PMC4198113 DOI: 10.1371/journal.pone.0109530] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 09/09/2014] [Indexed: 12/30/2022] Open
Abstract
Drosophila Tribbles (Trbl) is the founding member of the Trib family of kinase-like docking proteins that modulate cell signaling during proliferation, migration and growth. In a wing misexpression screen for Trbl interacting proteins, we identified the Ser/Thr protein kinase Akt1. Given the central role of Akt1 in insulin signaling, we tested the function of Trbl in larval fat body, a tissue where rapid increases in size are exquisitely sensitive to insulin/insulin-like growth factor levels. Consistent with a role in antagonizing insulin-mediated growth, trbl RNAi knockdown in the fat body increased cell size, advanced the timing of pupation and increased levels of circulating triglyceride. Complementarily, overexpression of Trbl reduced fat body cell size, decreased overall larval size, delayed maturation and lowered levels of triglycerides, while circulating glucose levels increased. The conserved Trbl kinase domain is required for function in vivo and for interaction with Akt in a yeast two-hybrid assay. Consistent with direct regulation of Akt, overexpression of Trbl in the fat body decreased levels of activated Akt (pSer505-Akt) while misexpression of trbl RNAi increased phospho-Akt levels, and neither treatment affected total Akt levels. Trbl misexpression effectively suppressed Akt-mediated wing and muscle cell size increases and reduced phosphorylation of the Akt target FoxO (pSer256-FoxO). Taken together, these data show that Drosophila Trbl has a conserved role to bind Akt and block Akt-mediated insulin signaling, and implicate Trib proteins as novel sites of signaling pathway integration that link nutrient availability with cell growth and proliferation.
Collapse
Affiliation(s)
- Rahul Das
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Zachary Sebo
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Laramie Pence
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
| | - Leonard L. Dobens
- Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, Missouri, United States of America
- * E-mail:
| |
Collapse
|
15
|
Modes-of-Action Related to Repeated Dose Toxicity: Tissue-Specific Biological Roles of PPAR γ Ligand-Dependent Dysregulation in Nonalcoholic Fatty Liver Disease. PPAR Res 2014; 2014:432647. [PMID: 24772164 PMCID: PMC3977565 DOI: 10.1155/2014/432647] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/13/2014] [Accepted: 01/24/2014] [Indexed: 12/17/2022] Open
Abstract
Comprehensive understanding of the precise mode of action/adverse outcome pathway (MoA/AOP) of chemicals becomes a key step towards superseding the current repeated dose toxicity testing methodology with new generation predictive toxicology tools. The description and characterization of the toxicological MoA leading to non-alcoholic fatty liver disease (NAFLD) are of specific interest, due to its increasing incidence in the modern society. Growing evidence stresses on the PPAR γ ligand-dependent dysregulation as a key molecular initiating event (MIE) for this adverse effect. The aim of this work was to analyze and systematize the numerous scientific data about the steatogenic role of PPAR γ . Over 300 papers were ranked according to preliminary defined criteria and used as reliable and significant sources of data about the PPAR γ -dependent prosteatotic MoA. A detailed analysis was performed regarding proteins which PPAR γ -mediated expression changes had been confirmed to be prosteatotic by most experimental evidence. Two probable toxicological MoAs from PPAR γ ligand binding to NAFLD were described according to the Organisation for Economic Cooperation and Development (OECD) concepts: (i) PPAR γ activation in hepatocytes and (ii) PPAR γ inhibition in adipocytes. The possible events at different levels of biological organization starting from the MIE to the organ response and the connections between them were described in details.
Collapse
|
16
|
Ozcan L, Cristina de Souza J, Harari AA, Backs J, Olson EN, Tabas I. Activation of calcium/calmodulin-dependent protein kinase II in obesity mediates suppression of hepatic insulin signaling. Cell Metab 2013; 18:803-15. [PMID: 24268736 PMCID: PMC3863383 DOI: 10.1016/j.cmet.2013.10.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/07/2013] [Accepted: 10/11/2013] [Indexed: 01/12/2023]
Abstract
A hallmark of obesity is selective suppression of hepatic insulin signaling ("insulin resistance"), but critical gaps remain in our understanding of the molecular mechanisms. We now report a major role for hepatic CaMKII, a calcium-responsive kinase that is activated in obesity. Genetic targeting of hepatic CaMKII, its downstream mediator p38, or the p38 substrate and stabilizer MK2 enhances insulin-induced p-Akt in palmitate-treated hepatocytes and obese mouse liver, leading to metabolic improvement. The mechanism of improvement begins with induction of ATF6 and the ATF6 target p58(IPK), a chaperone that suppresses the PERK-p-eIF2α-ATF4 branch of the UPR. The result is a decrease in the ATF4 target TRB3, an inhibitor of insulin-induced p-Akt, leading to enhanced activation of Akt and its downstream metabolic mediators. These findings increase our understanding of the molecular mechanisms linking obesity to selective insulin resistance and suggest new therapeutic targets for type 2 diabetes and metabolic syndrome.
Collapse
Affiliation(s)
- Lale Ozcan
- Department of Medicine, Columbia University, New York, NY 10032, USA.
| | | | | | | | | | | |
Collapse
|
17
|
Geng T, Hu W, Broadwater MH, Snider JM, Bielawski J, Russo SB, Schwacke JH, Ross J, Cowart LA. Fatty acids differentially regulate insulin resistance through endoplasm reticulum stress-mediated induction of tribbles homologue 3: a potential link between dietary fat composition and the pathophysiological outcomes of obesity. Diabetologia 2013; 56:2078-87. [PMID: 23820633 DOI: 10.1007/s00125-013-2973-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/31/2013] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Previous studies have shown that saturated fatty acids cause insulin resistance (IR) that is prevented by unsaturated fatty acids. Tribbles homologue 3 (TRIB3) is a putative endogenous inhibitor of insulin signalling, but its role in insulin signalling is controversial. This study aimed to determine whether fatty acids regulate IR via TRIB3. METHODS We treated HepG2 cells with saturated and unsaturated fatty acids and evaluated TRIB3 expression. We then tested whether regulation of TRIB3 occurred through endoplasmic reticulum (ER) stress, and whether modulating TRIB3 and ER stress marker genes was necessary and/or sufficient for regulation of insulin signalling. To test the in vivo significance of this mechanism, we fed mice obesogenic diets with different fatty acid profiles and assessed physiological variables of diabetes, ER stress markers and Trib3 expression in the liver. RESULTS Our data show that fatty acids differentially regulate IR through ER stress-mediated induction of TRIB3. Intriguingly, a standard and widely used obesogenic diet high in unsaturated fats failed to induce ER stress, TRIB3 or IR. However, an alternative obesogenic diet with lower unsaturated fat recapitulated the cell studies by causing ER stress, TRIB3 induction and IR. CONCLUSIONS/INTERPRETATION This study revealed a novel mechanism linking dietary fat composition to IR. Given the emerging roles for ER stress in non-alcoholic liver disease, we conclude that dietary fat composition rather than total amount may mediate hepatic pathology associated with obesity.
Collapse
Affiliation(s)
- T Geng
- Department of Biochemistry and Molecular Biology, the Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Bechmann LP, Vetter D, Ishida J, Hannivoort RA, Lang UE, Kocabayoglu P, Fiel MI, Muñoz U, Patman GL, Ge F, Yakar S, Li X, Agius L, Lee YM, Zhang W, Hui KY, Televantou D, Schwartz GJ, LeRoith D, Berk PD, Nagai R, Suzuki T, Reeves HL, Friedman SL. Post-transcriptional activation of PPAR alpha by KLF6 in hepatic steatosis. J Hepatol 2013; 58:1000-6. [PMID: 23353867 PMCID: PMC3631429 DOI: 10.1016/j.jhep.2013.01.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 01/06/2013] [Accepted: 01/08/2013] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Dysregulated glucose homeostasis and lipid accumulation characterize non-alcoholic fatty liver disease (NAFLD), but underlying mechanisms are obscure. We report here that Krüppel-like factor 6 (KLF6), a ubiquitous transcription factor that promotes adipocyte differentiation, also provokes the metabolic abnormalities of NAFLD by post-transcriptionally activating PPARα-signaling. METHODS Mice with either hepatocyte-specific depletion of KLF6 ('ΔHepKlf6') or global KLF6 heterozygosity (Klf6+/-) were fed a high fat diet (HFD) or chow for 8 or 16 weeks. Glucose and insulin tolerance tests were performed to assess insulin sensitivity. Overexpression and knockdown of KLF6 in cultured cells enabled the elucidation of underlying mechanisms. In liver samples from a cohort of 28 NAFLD patients, the expression of KLF6-related target genes was quantified. RESULTS Mice with global- or hepatocyte-depletion of KLF6 have reduced body fat content and improved glucose and insulin tolerance, and are protected from HFD-induced steatosis. In hepatocytes, KLF6 deficiency reduces PPARα-regulated genes (Trb3, Pepck) with diminished PPARα protein but no change in Pparα mRNA, which is explained by the discovery that KLF6 represses miRNA 10b, which leads to induction of PPARα. In NAFLD patients with advanced disease and inflammation, the expression of miRNA 10b is significantly downregulated, while PEPCK mRNA is upregulated; KLF6 mRNA expression also correlates with TRB3 as well as PEPCK gene expression. CONCLUSIONS KLF6 increases PPARα activity, whereas KLF6 loss leads to PPARα repression and attenuation of lipid and glucose abnormalities associated with a high fat diet. The findings establish KLF6 as a novel regulator of hepatic glucose and lipid metabolism in fatty liver.
Collapse
Affiliation(s)
- Lars P. Bechmann
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
- Department of Gastroenterology and Hepatology; University Hospital Essen, Essen, Germany
| | - Diana Vetter
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| | - Junichi Ishida
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Rebekka A. Hannivoort
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
- Department of Gastroenterology and Hepatology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ursula E. Lang
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| | - Peri Kocabayoglu
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| | - M. Isabel Fiel
- Lillian and Henry M. Stratton-Hans Popper Department of Pathology; Mount Sinai School of Medicine; New York, NY
| | - Ursula Muñoz
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| | - Gillian L. Patman
- The Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Fengxia Ge
- Department of Medicine, Divisions of Digestive & Liver Disease, Columbia University Medical Center, Columbia University College of Physicians & Surgeons, New York, NY
| | - Shoshana Yakar
- Division of Endocrinology, Diabetes and Bone Diseases, Mount Sinai School of Medicine, New York, NY
| | - Xiaosong Li
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, NY
| | - Loranne Agius
- The Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, UK
| | - Young-Min Lee
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| | - Weijia Zhang
- Department of Medicine, Bioinformatics Laboratory, Mount Sinai School of Medicine; New York, NY
| | - Kei Yiu Hui
- The Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Despina Televantou
- The Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Gary J. Schwartz
- Department of Medicine, Division of Endocrinology, Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, NY
| | - Derek LeRoith
- Division of Endocrinology, Diabetes and Bone Diseases, Mount Sinai School of Medicine, New York, NY
| | - Paul D. Berk
- Department of Medicine, Divisions of Digestive & Liver Disease, Columbia University Medical Center, Columbia University College of Physicians & Surgeons, New York, NY
| | - Ryozo Nagai
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Toru Suzuki
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Department of Ubiquitous Preventive Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Helen L. Reeves
- The Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK
| | - Scott L. Friedman
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, NY
| |
Collapse
|
19
|
Zheng W, Feng X, Qiu L, Pan Z, Wang R, Lin S, Hou D, Jin L, Li Y. Identification of the antibiotic ionomycin as an unexpected peroxisome proliferator-activated receptor γ (PPARγ) ligand with a unique binding mode and effective glucose-lowering activity in a mouse model of diabetes. Diabetologia 2013. [PMID: 23178929 DOI: 10.1007/s00125-012-2777-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS Existing thiazolidinedione (TZD) drugs for diabetes have severe side effects. The aim of this study is to develop alternative peroxisome proliferator-activated receptor γ (PPARγ) ligands that retain the benefits in improving insulin resistance but with reduced side effects. METHODS We used AlphaScreen assay to screen for new PPARγ ligands from compound libraries. In vitro biochemical binding affinity assay and in vivo cell-based reporter assay were used to validate ionomycin as a partial ligand of PPARγ. A mouse model of diabetes was used to assess the effects of ionomycin in improving insulin sensitivity. Crystal structure of PPARγ complexed with ionomycin revealed the unique binding mode of ionomycin, which elucidated the molecular mechanisms allowing the discrimination of ionomycin from TZDs. RESULTS We found that the antibiotic ionomycin is a novel modulating ligand for PPARγ. Both the transactivation and binding activity of PPARγ by ionomycin can be blocked by PPARγ specific antagonist GW9662. Ionomycin interacts with the PPARγ ligand-binding domain in a unique binding mode with properties and epitopes distinct from those of TZD drugs. Ionomycin treatment effectively improved hyperglycaemia and insulin resistance, but had reduced side effects compared with TZDs in the mouse model of diabetes. In addition, ionomycin effectively blocked the phosphorylation of PPARγ at Ser273 by cyclin-dependent kinase 5 both in vitro and in vivo. CONCLUSIONS/INTERPRETATION Our studies suggest that ionomycin may represent a unique template for designing novel PPARγ ligands with advantages over current TZD drugs.
Collapse
Affiliation(s)
- W Zheng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Fujian, China
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Cunard R. Mammalian tribbles homologs at the crossroads of endoplasmic reticulum stress and Mammalian target of rapamycin pathways. SCIENTIFICA 2013; 2013:750871. [PMID: 24490110 PMCID: PMC3892554 DOI: 10.1155/2013/750871] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 11/20/2013] [Indexed: 05/03/2023]
Abstract
In 2000, investigators discovered Tribbles, a Drosophila protein that coordinates morphogenesis by inhibiting mitosis. Further work has delineated Xenopus (Xtrb2), Nematode (Nipi-3), and mammalian homologs of Drosophila tribbles, which include TRB1, TRB2, and TRB3. The sequences of tribbles homologs are highly conserved, and despite their protein kinase structure, to date they have not been shown to have kinase activity. TRB family members play a role in the differentiation of macrophages, lymphocytes, muscle cells, adipocytes, and osteoblasts. TRB isoforms also coordinate a number of critical cellular processes including glucose and lipid metabolism, inflammation, cellular stress, survival, apoptosis, and tumorigenesis. TRB family members modulate multiple complex signaling networks including mitogen activated protein kinase cascades, protein kinase B/AKT signaling, mammalian target of rapamycin, and inflammatory pathways. The following review will discuss metazoan homologs of Drosophila tribbles, their structure, expression patterns, and functions. In particular, we will focus on TRB3 function in the kidney in podocytes. This review will also discuss the key signaling pathways with which tribbles proteins interact and provide a rationale for developing novel therapeutics that exploit these interactions to provide better treatment options for both acute and chronic kidney disease.
Collapse
Affiliation(s)
- Robyn Cunard
- Research Service and Division of Nephrology-Hypertension, Veterans Affairs San Diego Healthcare System, Veterans Medical Research Foundation, Mail Code 151, 3350 La Jolla Village Drive, San Diego, CA 92161, USA
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- *Robyn Cunard:
| |
Collapse
|
21
|
Prudente S, Sesti G, Pandolfi A, Andreozzi F, Consoli A, Trischitta V. The mammalian tribbles homolog TRIB3, glucose homeostasis, and cardiovascular diseases. Endocr Rev 2012; 33:526-46. [PMID: 22577090 PMCID: PMC3410226 DOI: 10.1210/er.2011-1042] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Insulin signaling plays a physiological role in traditional insulin target tissues controlling glucose homeostasis as well as in pancreatic β-cells and in the endothelium. Insulin signaling abnormalities may, therefore, be pathogenic for insulin resistance, impaired insulin secretion, endothelial dysfunction, and eventually, type 2 diabetes mellitus (T2DM) and cardiovascular disease. Tribbles homolog 3 (TRIB3) is a 45-kDa pseudokinase binding to and inhibiting Akt, a key mediator of insulin signaling. Akt-mediated effects of TRIB3 in the liver, pancreatic β-cells, and skeletal muscle result in impaired glucose homeostasis. TRIB3 effects are also modulated by its direct interaction with other signaling molecules. In humans, TRIB3 overactivity, due to TRIB3 overexpression or to Q84R genetic polymorphism, with R84 being a gain-of-function variant, may be involved in shaping the risk of insulin resistance, T2DM, and cardiovascular disease. TRIB3 overexpression has been observed in the liver, adipose tissue, skeletal muscle, and pancreatic β-cells of individuals with insulin resistance and/or T2DM. The R84 variant has also proved to be associated with insulin resistance, T2DM, and cardiovascular disease. TRIB3 direct effects on the endothelium might also play a role in increasing the risk of atherosclerosis, as indicated by studies on human endothelial cells carrying the R84 variant that are dysfunctional in terms of Akt activation, NO production, and other proatherogenic changes. In conclusion, studies on TRIB3 have unraveled new molecular mechanisms underlying metabolic and cardiovascular abnormalities. Additional investigations are needed to verify whether such acquired knowledge will be relevant for improving care delivery to patients with metabolic and cardiovascular alterations.
Collapse
Affiliation(s)
- Sabrina Prudente
- Instituto di Ricovero e Cura a Carattere Scientifico Casa Sollievo della Sofferenza, Mendel Laboratory, Italy
| | | | | | | | | | | |
Collapse
|
22
|
Achard CS, Laybutt DR. Lipid-induced endoplasmic reticulum stress in liver cells results in two distinct outcomes: adaptation with enhanced insulin signaling or insulin resistance. Endocrinology 2012; 153:2164-77. [PMID: 22374970 DOI: 10.1210/en.2011-1881] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Chronically elevated fatty acids contribute to insulin resistance through poorly defined mechanisms. Endoplasmic reticulum (ER) stress and the subsequent unfolded protein response (UPR) have been implicated in lipid-induced insulin resistance. However, the UPR is also a fundamental mechanism required for cell adaptation and survival. We aimed to distinguish the adaptive and deleterious effects of lipid-induced ER stress on hepatic insulin action. Exposure of human hepatoma HepG2 cells or mouse primary hepatocytes to the saturated fatty acid palmitate enhanced ER stress in a dose-dependent manner. Strikingly, exposure of HepG2 cells to prolonged mild ER stress activation induced by low levels of thapsigargin, tunicamycin, or palmitate augmented insulin-stimulated Akt phosphorylation. This chronic mild ER stress subsequently attenuated the acute stress response to high-level palmitate challenge. In contrast, exposure of HepG2 cells or hepatocytes to severe ER stress induced by high levels of palmitate was associated with reduced insulin-stimulated Akt phosphorylation and glycogen synthesis, as well as increased expression of glucose-6-phosphatase. Attenuation of ER stress using chemical chaperones (trimethylamine N-oxide or tauroursodeoxycholic acid) partially protected against the lipid-induced changes in insulin signaling. These findings in liver cells suggest that mild ER stress associated with chronic low-level palmitate exposure induces an adaptive UPR that enhances insulin signaling and protects against the effects of high-level palmitate. However, in the absence of chronic adaptation, severe ER stress induced by high-level palmitate exposure induces deleterious UPR signaling that contributes to insulin resistance and metabolic dysregulation.
Collapse
Affiliation(s)
- Caroline S Achard
- Diabetes and Obesity Research Program, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, New South Wales 2010, Australia
| | | |
Collapse
|
23
|
Abstract
PURPOSE OF REVIEW The success of high throughput sequencing programmes, including the Human Genome Project led to the 'identification' of a large number of novel genes of completely unknown function. Since then, many of these genes have been subject to functional studies focussed on uncovering their biological importance. Recent advances in genome-wide screening of DNA sequence variants as well as focussed genetic studies identified a number of candidate loci contributing to the development of complex diseases, including those affecting lipid homeostasis. An excellent example for the convergence of genetics and experimental biology is the tribbles gene family which was among those identified both in recent genetic studies and were implicated in dysregulation of lipid levels experimentally. Thus, there is a need now to take a step back and reconcile these findings accumulated over recent years. RECENT FINDINGS Allelic variants of tribbles proteins have been associated with the control of fatty acid synthesis and insulin resistance as well as regulating plasma triglyceride and HDL cholesterol levels. Several mechanisms of molecular action have been proposed for the tribbles mediated control of these processes, including the regulation of signalling events, protein turnover and transcription, sometimes with conflicting evidence emerging. SUMMARY This review attempts to synthesize knowledge obtained on the biology of the tribbles protein family in the context of lipid metabolism as well as discussing the recently emerging genetic evidence for the importance of these proteins in human disease.
Collapse
Affiliation(s)
- Adrienn Angyal
- Department of Cardiovascular Science, University of Sheffield, Sheffield, UK
| | | |
Collapse
|
24
|
Current World Literature. Curr Opin Nephrol Hypertens 2012; 21:106-18. [DOI: 10.1097/mnh.0b013e32834ee42b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
25
|
Zhao Y, Tan Y, Dai J, Wang B, Li B, Guo L, Cui J, Wang G, Li W, Cai L. Zinc deficiency exacerbates diabetic down-regulation of Akt expression and function in the testis: essential roles of PTEN, PTP1B and TRB3. J Nutr Biochem 2011; 23:1018-26. [PMID: 22000581 DOI: 10.1016/j.jnutbio.2011.05.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 05/04/2011] [Accepted: 05/20/2011] [Indexed: 12/29/2022]
Abstract
Since zinc (Zn) plays an important role in the spermatogenesis and Zn deficiency exacerbated diabetes-induced testicular apoptosis, the present study investigated the effect of Zn deficiency on diabetes-induced testicular Akt-mediated glucose metabolism changes and inflammation. Zn deficiency was induced by chronic treatment of normal and diabetic mice with the Zn chelator N,N,N',N', tetrakis (2-pyridylmethyl) ethylenediaminepentaethylene (TPEN). After diabetes onset induced by streptozotocin, both diabetic and age-matched control mice were given TPEN intraperitoneally for 4 months. Western blotting assay revealed that Akt-mediated glucose metabolism signaling was down-regulated in the diabetic testis and was further decreased in diabetic mice with Zn deficiency, reflected by reduced phosphorylation of both Akt and GSK-3β and increased phosphorylation of glycogen synthase along with a disarrangement of fatty acid metabolism (increased expression of PPAR-α and decreased adenosine-monophosphate-activated protein kinase phosphorylation). Testicular expressions of plasminogen activator inhibitor-1 and intracellular adhesion molecule-1 as inflammatory factors were increased in the TPEN or diabetes-alone group, but not additive in the group of diabetes with Zn deficiency. A mechanistic study showed that Akt negative regulators phosphatase and tensin homology deleted on chromosome 10 (PTEN), protein tyrosine phosphatases 1B and Tribbles 3 all increased in diabetic testis and further increased in the testis of diabetic mice with Zn deficiency. These studies suggest that Zn deficiency significantly exacerbated diabetic down-regulation of Akt expression and function, most likely by up-regulation of Akt negative regulators. Therefore, prevention of Zn deficiency for diabetic patients is important in order to avoid the exacerbation of diabetic inhibition of glucose metabolism in the testis.
Collapse
Affiliation(s)
- Yuguang Zhao
- The Cancer Center, the First Hospital of Jilin University, Changchun, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|