1
|
Zhou WH, Luo Y, Li RX, Degrace P, Jourdan T, Qiao F, Chen LQ, Zhang ML, Du ZY. Inhibition of mitochondrial fatty acid β-oxidation activates mTORC1 pathway and protein synthesis via Gcn5-dependent acetylation of Raptor in zebrafish. J Biol Chem 2023; 299:105220. [PMID: 37660921 PMCID: PMC10540046 DOI: 10.1016/j.jbc.2023.105220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 09/05/2023] Open
Abstract
Pharmacological inhibition of mitochondrial fatty acid oxidation (FAO) has been clinically used to alleviate certain metabolic diseases by remodeling cellular metabolism. However, mitochondrial FAO inhibition also leads to mechanistic target of rapamycin complex 1 (mTORC1) activation-related protein synthesis and tissue hypertrophy, but the mechanism remains unclear. Here, by using a mitochondrial FAO inhibitor (mildronate or etomoxir) or knocking out carnitine palmitoyltransferase-1, we revealed that mitochondrial FAO inhibition activated the mTORC1 pathway through general control nondepressible 5-dependent Raptor acetylation. Mitochondrial FAO inhibition significantly promoted glucose catabolism and increased intracellular acetyl-CoA levels. In response to the increased intracellular acetyl-CoA, acetyltransferase general control nondepressible 5 activated mTORC1 by catalyzing Raptor acetylation through direct interaction. Further investigation also screened Raptor deacetylase histone deacetylase class II and identified histone deacetylase 7 as a potential regulator of Raptor. These results provide a possible mechanistic explanation for the mTORC1 activation after mitochondrial FAO inhibition and also bring light to reveal the roles of nutrient metabolic remodeling in regulating protein acetylation by affecting acetyl-CoA production.
Collapse
Affiliation(s)
- Wen-Hao Zhou
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Yuan Luo
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Rui-Xin Li
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Pascal Degrace
- Pathophysiology of Dyslipidemia Research Group, INSERM UMR1231 CTM (Center for Translational and Molecular Medicine) Ex-Lipids, Nutrition, Cancer, Université de Bourgogne Franche-Comté, Dijon, France
| | - Tony Jourdan
- Pathophysiology of Dyslipidemia Research Group, INSERM UMR1231 CTM (Center for Translational and Molecular Medicine) Ex-Lipids, Nutrition, Cancer, Université de Bourgogne Franche-Comté, Dijon, France
| | - Fang Qiao
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Li-Qiao Chen
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Mei-Ling Zhang
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China
| | - Zhen-Yu Du
- LANEH, School of Life Sciences, East China Normal University, Shanghai, P.R. China.
| |
Collapse
|
2
|
Management of Complex Pulmonary Vein Stenosis at Altitude Combining Comprehensive Percutaneous Interventional Treatment with Sirolimus, Pulmonary Hypertension Medications and Intraluminal Imaging with Optical Coherence Tomography. Pediatr Cardiol 2023; 44:1125-1134. [PMID: 36723625 DOI: 10.1007/s00246-023-03102-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/10/2023] [Indexed: 02/02/2023]
Abstract
BACKGROUND Pulmonary vein stenosis (PVS) is a growing problem for the pediatric congenital heart population. Sirolimus has previously been shown to improve survival and slow down the progression of in-stent stenosis in patients with PVS. We evaluated patients before and after initiation of sirolimus to evaluate its effects on re-intervention and vessel patency utilizing Optical Coherence Tomography (OCT). METHODS We performed a retrospective study, reviewing the charts of patients with PVS, who had been prescribed sirolimus between October 2020 and December 2021. OCT was performed in the pulmonary vein of interest as per our published protocol. Angiographic and OCT imaging was retrospectively reviewed. Statistical analysis was performed using Chi square and Wilcoxon signed-rank test to compare pre-and post-sirolimus data. RESULTS Ten patients had been started and followed on sirolimus. Median age at sirolimus initiation was 25 months with median weight of 10.6 kg and average follow-up of 1 year. Median total catheterizations were 7 for patients prior to starting sirolimus and 2 after starting treatment (p = 0.014). Comparing pre- and post-sirolimus, patients were catheterized every 3 months vs every 11 months (p = 0.011), median procedure time was 203 min vs 145 min (p = 0.036) and fluoroscopy time, 80 min vs 57.2 min (p = 0.036). 23 veins had severe in-stent tissue ingrowth prior to SST (luminal diameter < 30% of stent diameter). Post-sirolimus, 23 pulmonary veins had moderate to severe in-stent tissue ingrowth that responded to non-compliant balloon inflation only with stent luminal improvement of > 75%. CONCLUSION Our study suggests that the addition of sirolimus in patients with moderate-severe PVS helps to decrease disease progression with decrease frequency of interventions. Reaching therapeutic levels for sirolimus is critical and medication interactions and side-effects need careful consideration. OCT continues to be important for evaluation and treatment guidance in this patient population.
Collapse
|
3
|
Karagianni F, Pavlidis A, Malakou LS, Piperi C, Papadavid E. Predominant Role of mTOR Signaling in Skin Diseases with Therapeutic Potential. Int J Mol Sci 2022; 23:ijms23031693. [PMID: 35163615 PMCID: PMC8835793 DOI: 10.3390/ijms23031693] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/30/2022] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
The serine/threonine kinase mechanistic target of rapamycin (mTOR) plays a pivotal role in the regulation of cell proliferation, survival, and motility in response to availability of energy and nutrients as well as mitogens. The mTOR signaling axis regulates important biological processes, including cellular growth, metabolism, and survival in many tissues. In the skin, dysregulation of PI3K/AKT/mTOR pathway may lead to severe pathological conditions characterized by uncontrolled proliferation and inflammation, including skin hyperproliferative as well as malignant diseases. Herein, we provide an update on the current knowledge regarding the pathogenic implication of the mTOR pathway in skin diseases with inflammatory features (such as psoriasis, atopic dermatitis, pemphigus, and acne) and malignant characteristics (such as cutaneous T cell lymphoma and melanoma) while we critically discuss current and future perspectives for therapeutic targeting of mTOR axis in clinical practice.
Collapse
Affiliation(s)
- Fani Karagianni
- National Center of Rare Diseases—Cutaneous Lymphoma, Second Department of Dermatology and Venereal Diseases, Attikon University General Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece; (F.K.); (A.P.); (E.P.)
| | - Antreas Pavlidis
- National Center of Rare Diseases—Cutaneous Lymphoma, Second Department of Dermatology and Venereal Diseases, Attikon University General Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece; (F.K.); (A.P.); (E.P.)
| | - Lina S. Malakou
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Christina Piperi
- Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
- Correspondence:
| | - Evangelia Papadavid
- National Center of Rare Diseases—Cutaneous Lymphoma, Second Department of Dermatology and Venereal Diseases, Attikon University General Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece; (F.K.); (A.P.); (E.P.)
| |
Collapse
|
4
|
Zhang W, Wu C, Ni R, Yang Q, Luo L, He J. Formimidoyltransferase cyclodeaminase prevents the starvation-induced liver hepatomegaly and dysfunction through downregulating mTORC1. PLoS Genet 2021; 17:e1009980. [PMID: 34941873 PMCID: PMC8741050 DOI: 10.1371/journal.pgen.1009980] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 01/07/2022] [Accepted: 12/06/2021] [Indexed: 11/18/2022] Open
Abstract
The liver is a crucial center in the regulation of energy homeostasis under starvation. Although downregulation of mammalian target of rapamycin complex 1 (mTORC1) has been reported to play pivotal roles in the starvation responses, the underpinning mechanisms in particular upstream factors that downregulate mTORC1 remain largely unknown. To identify genetic variants that cause liver energy disorders during starvation, we conduct a zebrafish forward genetic screen. We identify a liver hulk (lvh) mutant with normal liver under feeding, but exhibiting liver hypertrophy under fasting. The hepatomegaly in lvh is caused by enlarged hepatocyte size and leads to liver dysfunction as well as limited tolerance to starvation. Positional cloning reveals that lvh phenotypes are caused by mutation in the ftcd gene, which encodes the formimidoyltransferase cyclodeaminase (FTCD). Further studies show that in response to starvation, the phosphorylated ribosomal S6 protein (p-RS6), a downstream effector of mTORC1, becomes downregulated in the wild-type liver, but remains at high level in lvh. Inhibition of mTORC1 by rapamycin rescues the hepatomegaly and liver dysfunction of lvh. Thus, we characterize the roles of FTCD in starvation response, which acts as an important upstream factor to downregulate mTORC1, thus preventing liver hypertrophy and dysfunction. Under starvation, the liver initiates a series of metabolic adaptations to maintain energy homeostasis that is critical for survival. During this process, mTORC1 pathway is downregulated to reduce anabolism and promote catabolism, ensuring adequate usage of limited resources. However, mechanisms underlying the downregulation of mTORC1 remain incompletely understood. In a zebrafish genetic screen aiming to characterize factors important for starvation response in the liver, we identify an ftcd mutation that causes liver hypertrophy and dysfunction under fasting. FTCD acts upstream to inactivate mTORC1 in response to starvation. Our work reveals previously unappreciated roles of FTCD in the responses to energy stress through modulating mTORC1 activities, moreover implicates a potential liver disorder risk of FTCD deficiency under the circumstances of starvation.
Collapse
Affiliation(s)
- Wenfeng Zhang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Yubei, Chongqing, China
| | - Chaoying Wu
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Rui Ni
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Qifen Yang
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
| | - Lingfei Luo
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- * E-mail: (LL); (JH)
| | - Jianbo He
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, China
- * E-mail: (LL); (JH)
| |
Collapse
|
5
|
Cattelani C, Lesiak D, Liebscher G, Singer II, Stasyk T, Wallnöfer MH, Heberle AM, Corti C, Hess MW, Pfaller K, Kwiatkowski M, Pramstaller PP, Hicks AA, Thedieck K, Müller T, Huber LA, Eca Guimaraes de Araujo M. The SZT2 Interactome Unravels New Functions of the KICSTOR Complex. Cells 2021; 10:2711. [PMID: 34685691 PMCID: PMC8534408 DOI: 10.3390/cells10102711] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/20/2021] [Accepted: 10/05/2021] [Indexed: 12/25/2022] Open
Abstract
Seizure threshold 2 (SZT2) is a component of the KICSTOR complex which, under catabolic conditions, functions as a negative regulator in the amino acid-sensing branch of mTORC1. Mutations in this gene cause a severe neurodevelopmental and epileptic encephalopathy whose main symptoms include epilepsy, intellectual disability, and macrocephaly. As SZT2 remains one of the least characterized regulators of mTORC1, in this work we performed a systematic interactome analysis under catabolic and anabolic conditions. Besides numerous mTORC1 and AMPK signaling components, we identified clusters of proteins related to autophagy, ciliogenesis regulation, neurogenesis, and neurodegenerative processes. Moreover, analysis of SZT2 ablated cells revealed increased mTORC1 signaling activation that could be reversed by Rapamycin or Torin treatments. Strikingly, SZT2 KO cells also exhibited higher levels of autophagic components, independent of the physiological conditions tested. These results are consistent with our interactome data, in which we detected an enriched pool of selective autophagy receptors/regulators. Moreover, preliminary analyses indicated that SZT2 alters ciliogenesis. Overall, the data presented form the basis to comprehensively investigate the physiological functions of SZT2 that could explain major molecular events in the pathophysiology of developmental and epileptic encephalopathy in patients with SZT2 mutations.
Collapse
Affiliation(s)
- Cecilia Cattelani
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Dominik Lesiak
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Gudrun Liebscher
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Isabel I. Singer
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Taras Stasyk
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Moritz H. Wallnöfer
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| | - Alexander M. Heberle
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
- Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
| | - Corrado Corti
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Michael W. Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.W.H.); (K.P.)
| | - Kristian Pfaller
- Institute of Histology and Embryology, Medical University of Innsbruck, 6020 Innsbruck, Austria; (M.W.H.); (K.P.)
| | - Marcel Kwiatkowski
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy; (C.C.); (P.P.P.); (A.A.H.)
| | - Kathrin Thedieck
- Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria; (A.M.H.); (M.K.); (K.T.)
- Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
- Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Lukas A. Huber
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
- Austrian Drug Screening Institute, ADSI, 6020 Innsbruck, Austria
| | - Mariana Eca Guimaraes de Araujo
- Institute of Cell Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria; (C.C.); (D.L.); (G.L.); (I.I.S.); (T.S.); (M.H.W.); (L.A.H.)
| |
Collapse
|
6
|
Systemic Sirolimus Therapy for Infants and Children With Pulmonary Vein Stenosis. J Am Coll Cardiol 2021; 77:2807-2818. [PMID: 34082911 DOI: 10.1016/j.jacc.2021.04.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/01/2021] [Accepted: 04/02/2021] [Indexed: 01/10/2023]
Abstract
BACKGROUND Anatomic interventions for pulmonary vein stenosis (PVS) in infants and children have been met with limited success. Sirolimus, a mammalian target of rapamycin inhibitor, has demonstrated promise as a primary medical therapy for PVS, but the impact on patient survival is unknown. OBJECTIVES The authors sought to investigate whether mTOR inhibition with sirolimus as a primary medical therapy would improve outcomes in high-risk infants and children with PVS. METHODS In this single-center study, patients with severe PVS were considered for systemic sirolimus therapy (SST) following a strict protocol while receiving standardized surveillance and anatomic therapies. The SST cohort was compared with a contemporary control group. The primary endpoint for this study was survival. The primary safety endpoint was adverse events (AEs) related to SST. RESULTS Between 2015 and 2020, our PVS program diagnosed and treated 67 patients with ≥moderate PVS. Of these, 15 patients were treated with sirolimus, whereas the remaining patients represent the control group. There was 100% survival in the SST group compared with 45% survival in the control group (log-rank p = 0.004). A sensitivity analysis was completed to address survival bias using median time from diagnosis of PVS to SST. A survival advantage persisted (log-rank p = 0.027). Two patients on sirolimus developed treatable AEs. Patients in the SST group underwent frequent transcatheter interventions with 3.7 catheterizations per person-year (25th to 75th percentile: 2.7 to 4.4 person-years). Median follow up time was 2.2 years (25th to 75th percentile: 1.2 to 2.9 years) in the SST group versus 0.9 years (25th to 75th percentile: 0.5 to 2.7 years) in the control group. CONCLUSIONS The authors found a survival benefit associated with SST in infants and children with moderate-to-severe PVS. This survival benefit persisted after adjusting the analysis for survival bias. There were 2 mild AEs associated with SST during the study period; both patients were able to resume therapy without recurrence.
Collapse
|
7
|
O'Toole D, Zaeri AAI, Nicklin SA, French AT, Loughrey CM, Martin TP. Signalling pathways linking cysteine cathepsins to adverse cardiac remodelling. Cell Signal 2020; 76:109770. [PMID: 32891693 DOI: 10.1016/j.cellsig.2020.109770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022]
Abstract
Adverse cardiac remodelling clinically manifests as deleterious changes to heart architecture (size, mass and geometry) and function. These changes, which include alterations to ventricular wall thickness, chamber dilation and poor contractility, are important because they progressively drive patients with cardiac disease towards heart failure and are associated with poor prognosis. Cysteine cathepsins contribute to key signalling pathways involved in adverse cardiac remodelling including synthesis and degradation of the cardiac extracellular matrix (ECM), cardiomyocyte hypertrophy, impaired cardiomyocyte contractility and apoptosis. In this review, we highlight the role of cathepsins in these signalling pathways as well as their translational potential as therapeutic targets in cardiac disease.
Collapse
Affiliation(s)
- Dylan O'Toole
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, UK
| | - Ali Abdullah I Zaeri
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, UK
| | - Stuart A Nicklin
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, UK
| | - Anne T French
- Clinical Sciences Department, Ross University School of Veterinary Medicine, Basseterre, St. Kitts, West Indies, Saint Kitts and Nevis
| | - Christopher M Loughrey
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, UK.
| | - Tamara P Martin
- British Heart Foundation Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, UK.
| |
Collapse
|
8
|
Fernandes HS. Carbohydrate Consumption and Periodization Strategies Applied to Elite Soccer Players. Curr Nutr Rep 2020; 9:414-419. [PMID: 33098050 DOI: 10.1007/s13668-020-00338-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2020] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW During a soccer season, athletes tend to play intense and light matches such as decisive and qualifying games. The amount of muscle glycogen stores is a determining factor of performance during exercise, and manipulation of carbohydrate intake during the soccer season to enhance muscle glycogen stores can improve the performance of elite soccer players. The purpose of this review is to provide a holistic view of the periodization of carbohydrates and their effects on sports performance, based on what the literature recommends for the periodization of carbohydrates for endurance athletes, and of muscle glycogen recovery and compensation among professional soccer players. RECENT FINDINGS The ingestion of large amounts of carbohydrates (CHO;10 g/kg of body weight (BW)/day) is important 36 h before a match for the elite soccer player to ensure muscle glycogen supercompensation. In addition, elite soccer players should intake 1 to 1.5 g/kg BW/h within the first 4 h after a soccer game to maximize glycogen resynthesis. However, the season is comprised of away and home games that require different intensities; thus, soccer players need to periodize CHO intake based on evidence-based recommendations such as "train low," "train low, compete high," and/or "sleep low." The goal is to induce training adaptations by alternating with high or low CHO availability based on seasons, matches, and training intensities. The strategy can result in improved performance during games. Periodizing the consumption of carbohydrates, based on the intensity of training and matches, should include more carbohydrates when the matches require higher intensity and fewer carbohydrates when they require lower intensity; this is a strategy that will improve the performance of elite soccer athletes.
Collapse
Affiliation(s)
- Haniel Soares Fernandes
- Nutrition Departament, Estácio de Sá College, Fortaleza, Ceará, Brazil.
- Nutrition, Metabolism e Physiology in Sport, São Gabriel da Palha College, São Gabriel da Palha, Espírito Santo, Brazil.
- Clinical and Functional Nutrition, São Gabriel da Palha College, São Gabriel da Palha, Espírito Santo, Brazil.
| |
Collapse
|
9
|
Huang Y, Wang J, Luo M, Yan D, Zhang C. Carnosine attenuates vascular smooth muscle cells calcification through mTOR signaling pathway. Aging Med (Milton) 2020; 3:153-158. [PMID: 33103035 PMCID: PMC7574631 DOI: 10.1002/agm2.12125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 08/23/2020] [Accepted: 08/23/2020] [Indexed: 01/10/2023] Open
Abstract
Objective Vascular calcification is prevalent in the aging population, as we know that arterial calcification is associated with aging. Recent studies have demonstrated that carnosine, a naturally occurring dipeptide, performs the treatment of aging‐related diseases, such as atherosclerosis and type 2 diabetes. Here, we investigated the role of carnosine in a calcification model of vascular smooth muscle cells (VSMCs). Methods In this research, we used an in vitro model of VSMC calcification to investigate the role of carnosine in the progression of rat VSMC calcification. Results Carnosine treatment attenuated calcium deposition in a dose‐dependent manner, detected by Alizarin Red S staining and calcium content assay. Carnosine also reduced the protein level of Runx2, bone morphogenetic protein 2 (BMP‐2), and cellular reactive oxygen species (ROS) production. Further, carnosine inhibited the activation of the mammalian target of rapamycin (mTOR) pathway. Conclusion Carnosine attenuated the VSMC calcification via inhibition of osteoblastic transdifferentiation and the mTOR signaling pathway.
Collapse
Affiliation(s)
- Yi Huang
- Department of Geriatrics Institute of Gerontology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Jinli Wang
- Department of Geriatrics Institute of Gerontology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Mandi Luo
- Department of Geriatrics Institute of Gerontology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Dan Yan
- Department of Geriatrics Institute of Gerontology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| | - Cuntai Zhang
- Department of Geriatrics Institute of Gerontology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China
| |
Collapse
|
10
|
Pathogenic Pathways and Therapeutic Approaches Targeting Inflammation in Diabetic Nephropathy. Int J Mol Sci 2020; 21:ijms21113798. [PMID: 32471207 PMCID: PMC7312633 DOI: 10.3390/ijms21113798] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/20/2020] [Accepted: 05/26/2020] [Indexed: 02/06/2023] Open
Abstract
Diabetic nephropathy (DN) is associated with an increased morbidity and mortality, resulting in elevated cost for public health systems. DN is the main cause of chronic kidney disease (CKD) and its incidence increases the number of patients that develop the end-stage renal disease (ESRD). There are growing epidemiological and preclinical evidence about the close relationship between inflammatory response and the occurrence and progression of DN. Several anti-inflammatory strategies targeting specific inflammatory mediators (cell adhesion molecules, chemokines and cytokines) and intracellular signaling pathways have shown beneficial effects in experimental models of DN, decreasing proteinuria and renal lesions. A number of inflammatory molecules have been shown useful to identify diabetic patients at high risk of developing renal complications. In this review, we focus on the key role of inflammation in the genesis and progression of DN, with a special interest in effector molecules and activated intracellular pathways leading to renal damage, as well as a comprehensive update of new therapeutic strategies targeting inflammation to prevent and/or retard renal injury.
Collapse
|
11
|
Yoshinari K. Role of Nuclear Receptors PXR and CAR in Xenobiotic-Induced Hepatocyte Proliferation and Chemical Carcinogenesis. Biol Pharm Bull 2020; 42:1243-1252. [PMID: 31366862 DOI: 10.1248/bpb.b19-00267] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nuclear receptors pregnane X receptor (PXR) and constitutive active/androstane receptor (CAR) are xenobiotic-responsible transcriptional factors that belong to the same subfamily and are expressed abundantly in the liver. They play crucial roles in various liver functions including xenobiotic disposition and energy metabolism. CAR is also involved in xenobiotic-induced hepatocyte proliferation and hepatocarcinogenesis in rodents. However, there are some open questions on the association between chemical carcinogenesis and these nuclear receptors. These include the molecular mechanism for CAR-mediated hepatocyte proliferation and hepatocarcinogenesis. Another important question is whether PXR is associated with hepatocyte proliferation. We have recently reported a novel and unique function of PXR associated with murine hepatocyte proliferation: PXR activation alone does not induce hepatocyte proliferation but accelerates hepatocyte proliferation induced by various types of stimuli including CAR- or peroxisome proliferator-activated receptor alpha activating compounds, liver injury, and growth factors. We have also reported a role of yes-associated protein (YAP), a transcriptional cofactor controlling organ size and cell growth under the Hippo pathway, in CAR-mediated hepatocyte proliferation in mice. In this review, I will introduce our recent results as well as related studies on the roles of PXR and CAR in xenobiotic-induced hepatocyte proliferation and their molecular mechanisms.
Collapse
Affiliation(s)
- Kouichi Yoshinari
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| |
Collapse
|
12
|
Inactivation of TSC1 promotes epithelial-mesenchymal transition of renal tubular epithelial cells in mouse diabetic nephropathy. Acta Pharmacol Sin 2019; 40:1555-1567. [PMID: 31235817 PMCID: PMC7468253 DOI: 10.1038/s41401-019-0244-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 04/25/2019] [Indexed: 02/06/2023] Open
Abstract
Epithelial–mesenchymal transition (EMT) of renal tubular epithelial cells is one of the potential mechanisms of renal fibrosis, which promotes the development of diabetic nephropathy (DN). However, the molecular mechanisms of EMT remain largely unknown. Tuberous sclerosis proteins TSC1 and TSC2 are key integrators of growth factor signaling, and the loss of TSC1 or TSC2 function leads to a spectrum of diseases that underlie abnormalities in cell growth, proliferation, differentiation, and migration. In this study, we investigated the effects of TSC1 on high glucose (HG)-induced EMT of human proximal tubular epithelial HK-2 cells in vitro and renal fibrosis in TSC1−/− and db/db mice. We found that the exposure of HK-2 cells to HG (30 mM) time-dependently decreased TSC1 expression, increased the phosphorylation of mTORC1, P70S6K, and 4E-BP-1, and promoted cell migration, resulting in EMT. Transfection of the cells with TSC1 mimic significantly ameliorated HG-induced EMT of HK-2 cells. The tubules-specific TSC1 knockout mice (TSC1−/−) displayed a significant decline in renal function. TSC1−/− mice, similar to db/db mice, showed greatly activated mTORC1 signaling and EMT process in the renal cortex and exacerbated renal fibrosis. Overexpression of TSC1 through LV-TSC1 transfection significantly alleviated the progression of EMT and renal fibrosis in the renal cortex of db/db mice. Taken together, our results suggest that TSC1 plays a key role in mediating HG-induced EMT, and inhibition of TSC1-regulated mTORC1 signaling may be a potential approach to prevent renal fibrosis in DN.
Collapse
|
13
|
Khor ES, Noor SM, Wong PF. Understanding the Role of ztor in Aging-related Diseases Using the Zebrafish Model. In Vivo 2019; 33:1713-1720. [PMID: 31662495 DOI: 10.21873/invivo.11661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/15/2019] [Accepted: 08/16/2019] [Indexed: 12/14/2022]
Abstract
The mammalian target of rapamycin (mTOR), a 289 kDa serine/threonine protein kinase of the phosphoinositide 3-kinase (PI3K)-related family is known for its role in regulating lifespan and the aging process in humans and rodents. Aging in zebrafish very much resembles aging in humans. Aged zebrafish often manifest with spinal curvature, cataracts and cognitive frailty, akin to human age-related phenotypical effects such as osteoarthritis, dwindling vision and cognitive dysfunction. However, the role of the zebrafish orthologue of mTOR, ztor, is less defined in these areas. This review paper discusses the tale of growing old in the zebrafish, the physiological roles of ztor in normal developmental processes and its involvement in the pathogenesis of aging-related diseases such as metabolic disorders and cancers.
Collapse
Affiliation(s)
- Eng-Soon Khor
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Suzita Mohd Noor
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Pooi-Fong Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
14
|
Abe T, Amaike Y, Shizu R, Takahashi M, Kano M, Hosaka T, Sasaki T, Kodama S, Matsuzawa A, Yoshinari K. Role of YAP Activation in Nuclear Receptor CAR-Mediated Proliferation of Mouse Hepatocytes. Toxicol Sci 2019; 165:408-419. [PMID: 29893953 DOI: 10.1093/toxsci/kfy149] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Constitutive androstane receptor (CAR) is a xenobiotic-responsive nuclear receptor that is highly expressed in the liver. CAR activation induces hepatocyte proliferation and hepatocarcinogenesis in rodents, but the mechanisms remain unclear. In this study, we investigated the association of CAR-dependent cell proliferation with Yes-associated protein (YAP), which is a transcriptional cofactor controlling organ size and cell growth through the interaction with various transcriptional factors including TEA domain family member (TEAD). In mouse livers, 1,4-bis-(2-[3,5-dichloropyridyloxy])benzene (TCPOBOP) (a mouse CAR [mCAR] activator) treatment increased the nuclear YAP accumulation and mRNA levels of YAP target genes as well as cell-cycle related genes along with liver hypertrophy and verteporfin (an inhibitor of YAP/TEAD interaction) cotreatment tended to attenuate them. Furthermore, in cell-based reporter gene assays, CAR activation enhanced the YAP/TEAD-dependent transcription. To investigate the role of YAP/TEAD activation in the CAR-dependent hepatocyte proliferation, we sought to establish an in vitro system completely reproducing CAR-dependent cell proliferation. Since CAR was only slightly expressed in cultured mouse primary hepatocytes compared with mouse livers and no proliferation was observed after treatment with TCPOBOP, we overexpressed CAR using mCAR expressing adenovirus (Ad-mCAR-V5) in mouse primary hepatocytes. Ad-mCAR-V5 infection and TCPOBOP treatment induced hepatocyte proliferation. Similar results were obtained with immortalized normal mouse hepatocytes as well. In the established in vitro system, CAR-dependent proliferation was strongly inhibited by Yap knockdown and completely abolished by verteporfin treatment. Our present results obtained in in vivo and in vitro experiments suggest that YAP/TEAD activation plays key roles in CAR-dependent proliferation of murine hepatocytes.
Collapse
Affiliation(s)
- Taiki Abe
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.,Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan.,Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Yuto Amaike
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan
| | - Ryota Shizu
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.,Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan
| | - Miki Takahashi
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.,Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Makoto Kano
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan
| | - Takuomi Hosaka
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan
| | - Takamitsu Sasaki
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan
| | - Susumu Kodama
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Atsushi Matsuzawa
- Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Kouichi Yoshinari
- Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.,Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Suruga-ku, Shizuoka 422-8526, Japan.,Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| |
Collapse
|
15
|
Abe T, Shizu R, Sasaki T, Shimizu Y, Hosaka T, Kodama S, Matsuzawa A, Yoshinari K. Functional Interaction between Pregnane X Receptor and Yes-Associated Protein in Xenobiotic-Dependent Liver Hypertrophy and Drug Metabolism. J Pharmacol Exp Ther 2019; 371:590-601. [DOI: 10.1124/jpet.119.258632] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 09/10/2019] [Indexed: 01/25/2023] Open
|
16
|
Cardiac hypertrophy is stimulated by altered training intensity and correlates with autophagy modulation in male Wistar rats. BMC Sports Sci Med Rehabil 2019; 11:9. [PMID: 31198561 PMCID: PMC6558762 DOI: 10.1186/s13102-019-0121-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 05/29/2019] [Indexed: 01/01/2023]
Abstract
Background The mechanism for cardiac hypertrophy process that would be a benefit for improvement of cardiovascular endurance needed to be investigated throughly. Specific intensity of training may play a role for homeostasis process in cardiac during training. In the present study, we examine the effect of different intensity of treadmill training on cardiac hypertrophy process and autophagy related gene expression in male wistar rats. Methods Three different intensities of treadmill training were conducted on 15 male wistar rats (Low Intensity: 10 m/minute, Moderate Intensity: 20 m/minute, and High Intensity: 30 m/minute) compared to 5 sedentary rats as control. Training duration was 30 min per day, frequency was 5 days per week, during 8 weeks period. Heart weight and heart weight/body weight ratio were measured after the experiments. Left ventricle myocardium was taken for microscopic analysis with HE staining. mRNA was extracted from left ventricle myocardium for examining αMHC and autophagy related gene expression (PIK3CA, mTOR, LC3, p62) using semi quantitative PCR. Results We observed that altered training intensity might stimulate cardiac hypertrophy process. MI and HI training increased heart weight and heart weight/body weight ratio. This finding is supported by microscopic result in which cardiac hypertrophy was found in MI and HI, with focal fibrosis in HI, and increased αMHC gene expression in MI (p < 0.05) and HI (p = 0.076). We also observed decreased PIK3CA (LI 0.8 fold, MI 0.9 fold), mTOR (LI 0.9 fold, MI 0.9 fold), LC3 (LI 0.9 fold, MI 0.8 fold, HI 0.8 fold), and p62 (LI 0.8 fold, MI 0.9 fold) compared to control. Interestingly, we found increased mTOR (HI 1.1 fold) and p62 (HI 1.1 fold) compared to control. Conclusion Training with different intensity creates different cardiac hypertrophy process based on heart weight and heart weight/body weight ratio, microscopic examination and autophagy related gene expression.
Collapse
|
17
|
Carbohydrate Availability and Physical Performance: Physiological Overview and Practical Recommendations. Nutrients 2019; 11:nu11051084. [PMID: 31100798 PMCID: PMC6566225 DOI: 10.3390/nu11051084] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 12/18/2022] Open
Abstract
Strong evidence during the last few decades has highlighted the importance of nutrition for sport performance, the role of carbohydrates (CHO) being of special interest. Glycogen is currently not only considered an energy substrate but also a regulator of the signaling pathways that regulate exercise-induced adaptations. Thus, low or high CHO availabilities can result in both beneficial or negative results depending on the purpose. On the one hand, the depletion of glycogen levels is a limiting factor of performance during sessions in which high exercise intensities are required; therefore ensuring a high CHO availability before and during exercise is of major importance. A high CHO availability has also been positively related to the exercise-induced adaptations to resistance training. By contrast, a low CHO availability seems to promote endurance-exercise-induced adaptations such as mitochondrial biogenesis and enhanced lipolysis. In the present narrative review, we aim to provide a holistic overview of how CHO availability impacts physical performance as well as to provide practical recommendations on how training and nutrition might be combined to maximize performance. Attending to the existing evidence, no universal recommendations regarding CHO intake can be given to athletes as nutrition should be periodized according to training loads and objectives.
Collapse
|
18
|
Lunova M, Smolková B, Lynnyk A, Uzhytchak M, Jirsa M, Kubinová Š, Dejneka A, Lunov O. Targeting the mTOR Signaling Pathway Utilizing Nanoparticles: A Critical Overview. Cancers (Basel) 2019; 11:E82. [PMID: 30642006 PMCID: PMC6356373 DOI: 10.3390/cancers11010082] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/21/2018] [Accepted: 01/05/2019] [Indexed: 12/21/2022] Open
Abstract
Proteins of the mammalian target of rapamycin (mTOR) signaling axis are overexpressed or mutated in cancers. However, clinical inhibition of mTOR signaling as a therapeutic strategy in oncology shows rather limited progress. Nanoparticle-based mTOR targeted therapy proposes an attractive therapeutic option for various types of cancers. Along with the progress in the biomedical applications of nanoparticles, we start to realize the challenges and opportunities that lie ahead. Here, we critically analyze the current literature on the modulation of mTOR activity by nanoparticles, demonstrate the complexity of cellular responses to functionalized nanoparticles, and underline challenges lying in the identification of the molecular mechanisms of mTOR signaling affected by nanoparticles. We propose the idea that subcytotoxic doses of nanoparticles could be relevant for the induction of subcellular structural changes with possible involvement of mTORC1 signaling. The evaluation of the mechanisms and therapeutic effects of nanoparticle-based mTOR modulation will provide fundamental knowledge which could help in developing safe and efficient nano-therapeutics.
Collapse
Affiliation(s)
- Mariia Lunova
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
- Institute for Clinical & Experimental Medicine (IKEM), Prague, 140 21, Czech Republic.
| | - Barbora Smolková
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
| | - Anna Lynnyk
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
| | - Mariia Uzhytchak
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
| | - Milan Jirsa
- Institute for Clinical & Experimental Medicine (IKEM), Prague, 140 21, Czech Republic.
| | - Šárka Kubinová
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
- Institute of Experimental Medicine of the Czech Academy of Sciences, Prague, 14220, Czech Republic.
| | - Alexandr Dejneka
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
| | - Oleg Lunov
- Institute of Physics of the Czech Academy of Sciences, Prague, 18221, Czech Republic.
| |
Collapse
|
19
|
Pei H, Wang W, Zhao D, Su H, Su G, Zhao Z. G Protein-Coupled Estrogen Receptor 1 Inhibits Angiotensin II-Induced Cardiomyocyte Hypertrophy via the Regulation of PI3K-Akt-mTOR Signalling and Autophagy. Int J Biol Sci 2019; 15:81-92. [PMID: 30662349 PMCID: PMC6329915 DOI: 10.7150/ijbs.28304] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/14/2018] [Indexed: 01/20/2023] Open
Abstract
Estrogen has been demonstrated to protect the heart against cardiac remodelling and heart failure in women. G protein-coupled estrogen receptor 1 (GPER1) is a recently discovered estrogen receptor (ER) that is expressed in various tissues. However, the mechanisms by which estrogen protects the heart, especially the roles played by ERs, are not clear. In this study, we explored the effect of GPER1 activation on angiotensin II (Ang II)-induced cardiomyocyte hypertrophy and the involved signalling pathways and mechanisms. Our data demonstrated that GPER1 is expressed in cardiomyocytes, a GPER1 agonist, G1, attenuated Ang II-induced cardiomyocyte hypertrophy and downregulated the mRNA expression levels of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP). Bioinformatics analysis revealed that five proteins, including RAP1gap, might be the key proteins involved in the attenuation of Ang II-induced cardiomyocyte hypertrophy by GPER1. G1 increased the protein level of p-Akt, p-70S6K1 and p-mTOR but decreased p-4EBP1 expression. All these effects were inhibited by either G15 (a GPER1 antagonist) or MK2206 (an inhibitor of Akt). Autophagy analysis showed that the LC3II/LC3I ratio was increased in Ang II-treated cells, and the increase was inhibited by G1 treatment. The effect of G1 on autophagy was blocked by treatment with G15, rapamycin, and MK2206. These results suggest that GPER1 activation attenuates Ang II-induced cardiomyocyte hypertrophy by upregulating the PI3K-Akt-mTOR signalling pathway and inhibiting autophagy.
Collapse
Affiliation(s)
- Hui Pei
- Department of Cardiology, Jinan Central Hospital Affiliated with Shandong University, Shandong, China.,Taian Central Hospital, Taian City, Shandong, China
| | - Wei Wang
- Department of Cardiology, Shandong Provincial Chest Hospital, Shandong, China
| | - Di Zhao
- Department of Cardiology, Affiliated Hospital of Shandong Academy of Medical Sciences, Shandong, China
| | - Hongyan Su
- Department of Cardiology, Shandong Provincial Chest Hospital, Shandong, China
| | - Guohai Su
- Department of Cardiology, Jinan Central Hospital Affiliated with Shandong University, Shandong, China
| | - Zhuo Zhao
- Department of Cardiology, Jinan Central Hospital Affiliated with Shandong University, Shandong, China
| |
Collapse
|
20
|
Lu Q, Wang WW, Zhang MZ, Ma ZX, Qiu XR, Shen M, Yin XX. ROS induces epithelial-mesenchymal transition via the TGF-β1/PI3K/Akt/mTOR pathway in diabetic nephropathy. Exp Ther Med 2018; 17:835-846. [PMID: 30651870 DOI: 10.3892/etm.2018.7014] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/09/2018] [Indexed: 12/12/2022] Open
Abstract
Oxidative stress has been reported to serve an important role in the development and progression of diabetic nephropathy (DN). Epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells promotes renal fibrosis in DN, while the mechanism of reactive oxygen species (ROS)-mediated EMT is not fully understood. The aim of the present study was to investigate the effect of high glucose-induced ROS on the activation of the transforming growth factor (TGF)-β1/phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway in a normal rat kidney tubular epithelial cell line (NRK-52E) and rats with type 1 diabetes. In vitro, high glucose-stimulated ROS production resulted in increased TGF-β1 expression as well as an increase in the Akt and mTOR phosphorylation ratio, resulting in EMT. When cells were pre-treated with ROS inhibitors, changes in TGF-β1, Akt and mTOR were significantly ameliorated. In vivo, diabetic rats experienced a significant decline in renal function and severe renal fibrosis compared with control rats at 8 weeks following streptozocin injection. Levels of malondialdehyde and TGF-β1/PI3K/Akt/mTOR pathway activation were increased in the renal cortex of rats with diabetes compared with the control rats. Furthermore, renal fibrosis was further aggravated in DN compared with the control rats. The results of the present study suggest that ROS serves an important role in mediating high glucose-induced EMT and inhibits activation of the TGF-β1/PI3K/Akt/mTOR pathway. ROS may therefore have potential as a treatment approach to prevent renal fibrosis in DN.
Collapse
Affiliation(s)
- Qian Lu
- Department of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Wen-Wen Wang
- Department of Pharmacy, Wuxi Higher Health Vocational Technology School, Wuxi, Jiangsu 214000, P.R. China
| | - Ming-Zhu Zhang
- Deparment of Clinical Pharmacy, Changzhou Fourth People's Hospital, Changzhou, Jiangsu 213000, P.R. China
| | - Zhong-Xuan Ma
- Department of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Xin-Ran Qiu
- Department of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Mengli Shen
- Department of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| | - Xiao-Xing Yin
- Department of Pharmacy, Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 221004, P.R. China
| |
Collapse
|
21
|
Ebrahim N, Ahmed IA, Hussien NI, Dessouky AA, Farid AS, Elshazly AM, Mostafa O, Gazzar WBE, Sorour SM, Seleem Y, Hussein AM, Sabry D. Mesenchymal Stem Cell-Derived Exosomes Ameliorated Diabetic Nephropathy by Autophagy Induction through the mTOR Signaling Pathway. Cells 2018; 7:cells7120226. [PMID: 30467302 PMCID: PMC6315695 DOI: 10.3390/cells7120226] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and a common cause of end-stage renal disease. Autophagy has a defensive role against kidney damage caused by hyperglycemia. Mesenchymal stem cell (MSC)-derived exosomes are currently considered as a new promising therapy for chronic renal injury. However, the renal-protective mechanism of exosomes on DN is not completely understood. We examined the potential role of MSC-derived exosomes for enhancement of autophagy activity and their effect on DN. In our study, we used five groups of rats: control; DN; DN treated with exosomes; DN treated with 3-methyladenine (3-MA) and chloroquine (inhibitors of autophagy); and DN treated with 3-methyladenine (3-MA), chloroquine, and exosome groups. We assessed renal function, morphology, and fibrosis. Moreover, ratios of the autophagy markers mechanistic target of rapamycin (mTOR), Beclin-1, light chain-3 (LC3-II), and LC3-II/LC3-I were detected. Additionally, electron microscopy was used for detection of autophagosomes. RESULTS Exosomes markedly improved renal function and showed histological restoration of renal tissues, with significant increase of LC3 and Beclin-1, and significant decrease of mTOR and fibrotic marker expression in renal tissue. All previous effects were partially abolished by the autophagy inhibitors chloroquine and 3-MA. CONCLUSION We conclude that autophagy induction by exosomes could attenuate DN in a rat model of streptozotocin-induced diabetes mellitus.
Collapse
Affiliation(s)
- Nesrine Ebrahim
- Department of Histology and Cell Biology, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
- Stem Cell Unit, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Inas A Ahmed
- Department of Medical Biochemistry, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
- Molecular Biology and Biotechnology Unit, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Noha I Hussien
- Department of Physiology, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Arigue A Dessouky
- Department of Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt.
| | - Ayman Samir Farid
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Benha University, Moshtohor, Toukh 13736, QG, Egypt.
| | - Amal M Elshazly
- Department of Anatomy, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Ola Mostafa
- Department of Histology and Cell Biology, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Walaa Bayoumie El Gazzar
- Department of Medical Biochemistry, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Safwa M Sorour
- Department of Clinical Pharmacology, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Yasmin Seleem
- Department of Clinical Pharmacology, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Ahmed M Hussein
- Department of Internal Medicine, Faculty of Medicine, Benha University, Benha 13518, QG, Egypt.
| | - Dina Sabry
- Department of Medical Biochemistry, Faculty of Medicine, Cairo University, Cairo 11562, Egypt.
- Molecular Biology and Stem Cell Unit, Faculty of Medicine, Cairo University, Cairo 11562, Egypt.
| |
Collapse
|
22
|
Sun J, Mao L, Yang H, Ren D. Critical role for the Tsc1-mTORC1 pathway in β-cell mass in Pdx1-deficient mice. J Endocrinol 2018; 238:151-163. [PMID: 29875165 PMCID: PMC6030447 DOI: 10.1530/joe-18-0015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/05/2018] [Indexed: 01/25/2023]
Abstract
Mutations in the pancreatic duodenal homeobox (PDX1) gene are associated with diabetes in humans. Pdx1-haploinsufficient mice also develop diabetes, but the molecular mechanism is unknown. To this end, we knocked down Pdx1 gene expression in mouse MIN6 insulinoma cells. Pdx1 suppression not only increased apoptotic cell death but also decreased cell proliferation, which was associated with a decrease in activity of mechanistic target of rapamycin complex 1 (mTORC1). We found that in Pdx1-deficient mice, tuberous sclerosis 1 (Tsc1) ablation in pancreatic β-cells restores β-cell mass, increases β-cell proliferation and size, decreases the number of TUNEL-positive cells and restores glucose tolerance after glucose challenge. In addition, Tsc1 ablation in pancreatic β-cells increases phosphorylation of initiation factor 4E-binding protein 1 (4E-BP1) phosphorylation and 40S ribosomal protein S6, two downstream targets of mTORC1 indicating that Tsc1 mediates mTORC1 downregulation induced by Pdx1 suppression. These results suggest that the Tsc1-mTORC1 pathway plays an important role in mediating the decrease in β-cell proliferation and growth and the reduction in β-cell mass that occurs in Pdx1-deficient diabetes. Thus, mTORC1 may be target for therapeutic interventions in diabetes associated with reductions in β-cell mass.
Collapse
Affiliation(s)
- Juan Sun
- Department of MedicineThe University of Chicago, Chicago, Illinois, USA
| | - Liqun Mao
- Department of MedicineThe University of Chicago, Chicago, Illinois, USA
| | - Hongyan Yang
- Department of GynecologyKey Research Laboratory of Gynecology, Guangzhou University of Traditional Chinese Medicine, Guangzhou, Guangdong, China
| | - Decheng Ren
- Department of MedicineThe University of Chicago, Chicago, Illinois, USA
- Department of GynecologyKey Research Laboratory of Gynecology, Guangzhou University of Traditional Chinese Medicine, Guangzhou, Guangdong, China
| |
Collapse
|
23
|
Activation of mTORC1 in chondrocytes does not affect proliferation or differentiation, but causes the resting zone of the growth plate to become disordered. Bone Rep 2018; 8:64-71. [PMID: 29955624 PMCID: PMC6020113 DOI: 10.1016/j.bonr.2018.02.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/22/2018] [Accepted: 02/23/2018] [Indexed: 12/18/2022] Open
Abstract
There are several pitfalls associated with research based on transgenic mice. Here, we describe our interpretation and analysis of mTORC1 activation in growth plate chondrocytes and compare these to a recent publication (Yan et al., Nature Communications 2016, 7:11151). Both laboratories employed TSC1-floxed mice crossed with collagen type 2-driven Cre (Col2-Cre), but drew substantially different conclusions. It was reported that activation of mechanistic target of rapamycin complex 1 (mTORC1) via Tsc1 ablation promotes the hypertrophy of growth plate chondrocytes, whereas we observe only disorganization in the resting zone, with no effect on chondrocyte hypertrophy or proliferation. Here, we present our data and discuss the differences in comparison to the earlier phenotypic characterization of TSC1 ablation in cartilage. Importantly, we detect Col2-Cre activity in non-cartilaginous tissues (including the brain) and discuss it in relation to other studies reporting non-cartilaginous expression of collagen alpha(1) II. Altogether, we conclude that mouse phenotypes following genetic ablation using Col2-Cre should be interpreted with care. We also conclude that activation of mTORC1 by TSC1 ablation in postnatal chondrocytes with inducible Col2-Cre (Col2-CreERt) leads to disorganization of the resting zone but causes no changes in chondrocyte proliferation or differentiation. Ablation of Tsc1 using Col2-Cre causes severe developmental abnormalities. Col2-Cre is not specific to chondrocytes during early development. Mice develop normally when Tsc1 is ablated in chondrocytes postnatally.
Collapse
|
24
|
Maity S, Bera A, Ghosh-Choudhury N, Das F, Kasinath BS, Choudhury GG. microRNA-181a downregulates deptor for TGFβ-induced glomerular mesangial cell hypertrophy and matrix protein expression. Exp Cell Res 2018; 364:5-15. [PMID: 29397070 DOI: 10.1016/j.yexcr.2018.01.021] [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: 12/14/2017] [Accepted: 01/16/2018] [Indexed: 02/06/2023]
Abstract
TGFβ contributes to mesangial cell hypertrophy and matrix protein increase in various kidney diseases including diabetic nephropathy. Deptor is an mTOR-interacting protein and suppresses mTORC1 and mTORC2 activities. We have recently shown that TGFβ-induced inhibition of deptor increases the mTOR activity. The mechanism by which TGFβ regulates deptor expression is not known. Here we identify deptor as a target of the microRNA-181a. We show that in mesangial cells, TGFβ increases the expression of miR-181a to downregulate deptor. Decrease in deptor augments mTORC2 activity, resulting in phosphorylation/activation of Akt kinase. Akt promotes inactivating phosphorylation of PRAS40 and tuberin, leading to stimulation of mTORC1. miR-181a-mimic increased mTORC1 and C2 activities, while anti-miR-181a inhibited them. mTORC1 controls protein synthesis via phosphorylation of translation initiation and elongation suppressors 4EBP-1 and eEF2 kinase. TGFβ-stimulated miR-181a increased the phosphorylation of 4EBP-1 and eEF2 kinase, resulting in their inactivation. miR-181a-dependent inactivation of eEF2 kinase caused dephosphorylation of eEF2. Consequently, miR-181a-mimic increased protein synthesis and hypertrophy of mesangial cells similar to TGFβ. Anti-miR-181a blocked these events in a deptor-dependent manner. Finally, TGFβ-miR-181a-driven deptor downregulation increased the expression of fibronectin. Our results identify a novel mechanism involving miR-181a-driven deptor downregulation, which contributes to mesangial cell pathologies in renal complications.
Collapse
Affiliation(s)
- Soumya Maity
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Amit Bera
- Department of Medicine, UT Health San Antonio, TX, United States
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, UT Health San Antonio, TX, United States
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Research Center, South Texas Veterans Health Care System, San Antonio, TX, United States.
| |
Collapse
|
25
|
Bera A, Das F, Ghosh-Choudhury N, Mariappan MM, Kasinath BS, Ghosh Choudhury G. Reciprocal regulation of miR-214 and PTEN by high glucose regulates renal glomerular mesangial and proximal tubular epithelial cell hypertrophy and matrix expansion. Am J Physiol Cell Physiol 2017; 313:C430-C447. [PMID: 28701356 PMCID: PMC5668576 DOI: 10.1152/ajpcell.00081.2017] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 02/06/2023]
Abstract
Aberrant expression of microRNAs (miRs) contributes to diabetic renal complications, including renal hypertrophy and matrix protein accumulation. Reduced expression of phosphatase and tensin homolog (PTEN) by hyperglycemia contributes to these processes. We considered involvement of miR in the downregulation of PTEN. In the renal cortex of type 1 diabetic mice, we detected increased expression of miR-214 in association with decreased levels of PTEN and enhanced Akt phosphorylation and fibronectin expression. Mesangial and proximal tubular epithelial cells exposed to high glucose showed augmented expression of miR-214. Mutagenesis studies using 3'-UTR of PTEN in a reporter construct revealed PTEN as a direct target of miR-214, which controls its expression in both of these cells. Overexpression of miR-214 decreased the levels of PTEN and increased Akt activity similar to high glucose and lead to phosphorylation of its substrates glycogen synthase kinase-3β, PRAS40, and tuberin. In contrast, quenching of miR-214 inhibited high-glucose-induced Akt activation and its substrate phosphorylation; these changes were reversed by small interfering RNAs against PTEN. Importantly, respective expression of miR-214 or anti-miR-214 increased or decreased the mammalian target of rapamycin complex 1 (mTORC1) activity induced by high glucose. Furthermore, mTORC1 activity was controlled by miR-214-targeted PTEN via Akt activation. In addition, neutralization of high-glucose-stimulated miR-214 expression significantly inhibited cell hypertrophy and expression of the matrix protein fibronectin. Finally, the anti-miR-214-induced inhibition of these processes was reversed by the expression of constitutively active Akt kinase and hyperactive mTORC1. These results uncover a significant role of miR-214 in the activation of mTORC1 that contributes to high-glucose-induced mesangial and proximal tubular cell hypertrophy and fibronectin expression.
Collapse
Affiliation(s)
- Amit Bera
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Department of Pathology, UT Health San Antonio, San Antonio, Texas; and
| | | | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, San Antonio, Texas;
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas
| |
Collapse
|
26
|
Kim HJ, Lee WJ. Low-intensity aerobic exercise training: inhibition of skeletal muscle atrophy in high-fat-diet-induced ovariectomized rats. J Exerc Nutrition Biochem 2017; 21:19-25. [PMID: 29036762 PMCID: PMC5643201 DOI: 10.20463/jenb.2017.0022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/18/2017] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Postmenopausal women are highly susceptible to diseases, such as obesity, type 2 diabetes, osteoporosis, or skeletal muscle atrophy and many people recognize the need for regular physical activity. Aerobic exercise training is known to improve the oxidative capacity and insulin sensitivity of skeletal muscles. This study aimed to investigate the role of low-intensity aerobic exercise training on skeletal muscle protein degradation or synthesis in the plantaris muscles of high-fat-fed ovariectomized rats. METHODS Ovariectomized female rats were divided into two groups: a high-fat diet-sedentary group (HFD), and a high-fat diet-aerobic exercise group (HFD+EX). The exercise group exercised aerobically on a treadmill 5 days/week for 8 weeks. The rats progressively ran 30 min/day at 15 m/min, up to 40 min/day at 18 m/min, 0% slope, in the last 4 weeks. RESULTS Although aerobic exercise led to significantly increased AMP-activated protein kinase (AMPK) phosphorylation at Thr172, phosphorylation of the mammalian target of rapamycin (mTOR) substrate Thr389 S6K1 level did not decrease. Additionally, even though Akt activity did not increase at Ser473, the atrogin-1 level significantly decreased in the exercise group compared to the non-exercise group. Immunohistochemical staining revealed that high-fat-induced TSC2 protein expression was eliminated in response to aerobic exercise. CONCLUSION These results suggest that aerobic exercise can inhibit skeletal muscle protein degradation, but it cannot increase protein synthesis in the plantaris muscle of high-fat-fed ovariectomized rats. Our findings have implications in understanding skeletal muscle mass maintenance with low intensity aerobic exercise in post-menopausal women.
Collapse
Affiliation(s)
- Hye Jin Kim
- Department of Kinesiology and Sports Studies, College of Science and Industry Convergence, Ewha Womans University, Seoul, Republic of Korea
| | - Won Jun Lee
- Department of Kinesiology and Sports Studies, College of Science and Industry Convergence, Ewha Womans University, Seoul, Republic of Korea
| |
Collapse
|
27
|
Pereyra AS, Hasek LY, Harris KL, Berman AG, Damen FW, Goergen CJ, Ellis JM. Loss of cardiac carnitine palmitoyltransferase 2 results in rapamycin-resistant, acetylation-independent hypertrophy. J Biol Chem 2017; 292:18443-18456. [PMID: 28916721 DOI: 10.1074/jbc.m117.800839] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 09/05/2017] [Indexed: 12/20/2022] Open
Abstract
Cardiac hypertrophy is closely linked to impaired fatty acid oxidation, but the molecular basis of this link is unclear. Here, we investigated the loss of an obligate enzyme in mitochondrial long-chain fatty acid oxidation, carnitine palmitoyltransferase 2 (CPT2), on muscle and heart structure, function, and molecular signatures in a muscle- and heart-specific CPT2-deficient mouse (Cpt2M-/-) model. CPT2 loss in heart and muscle reduced complete oxidation of long-chain fatty acids by 87 and 69%, respectively, without altering body weight, energy expenditure, respiratory quotient, or adiposity. Cpt2M-/- mice developed cardiac hypertrophy and systolic dysfunction, evidenced by a 5-fold greater heart mass, 60-90% reduction in blood ejection fraction relative to control mice, and eventual lethality in the absence of cardiac fibrosis. The hypertrophy-inducing mammalian target of rapamycin complex 1 (mTORC1) pathway was activated in Cpt2M-/- hearts; however, daily rapamycin exposure failed to attenuate hypertrophy in Cpt2M-/- mice. Lysine acetylation was reduced by ∼50% in Cpt2M-/- hearts, but trichostatin A, a histone deacetylase inhibitor that improves cardiac remodeling, failed to attenuate Cpt2M-/- hypertrophy. Strikingly, a ketogenic diet increased lysine acetylation in Cpt2M-/- hearts 2.3-fold compared with littermate control mice fed a ketogenic diet, yet it did not improve cardiac hypertrophy. Together, these results suggest that a shift away from mitochondrial fatty acid oxidation initiates deleterious hypertrophic cardiac remodeling independent of fibrosis. The data also indicate that CPT2-deficient hearts are impervious to hypertrophy attenuators, that mitochondrial metabolism regulates cardiac acetylation, and that signals derived from alterations in mitochondrial metabolism are the key mediators of cardiac hypertrophic growth.
Collapse
Affiliation(s)
| | | | | | - Alycia G Berman
- the Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - Frederick W Damen
- the Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907
| | - Craig J Goergen
- the Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907
| | | |
Collapse
|
28
|
Santos-Zas I, Negroni E, Mamchaoui K, Mosteiro CS, Gallego R, Butler-Browne GS, Pazos Y, Mouly V, Camiña JP. Obestatin Increases the Regenerative Capacity of Human Myoblasts Transplanted Intramuscularly in an Immunodeficient Mouse Model. Mol Ther 2017; 25:2345-2359. [PMID: 28750736 DOI: 10.1016/j.ymthe.2017.06.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/23/2017] [Accepted: 06/24/2017] [Indexed: 02/08/2023] Open
Abstract
Although cell-based therapy is considered a promising method aiming at treating different muscular disorders, little clinical benefit has been reported. One of major hurdles limiting the efficiency of myoblast transfer therapy is the poor survival of the transplanted cells. Any intervention upon the donor cells focused on enhancing in vivo survival, proliferation, and expansion is essential to improve the effectiveness of such therapies in regenerative medicine. In the present work, we investigated the potential role of obestatin, an autocrine peptide factor regulating skeletal muscle growth and repair, to improve the outcome of myoblast-based therapy by xenotransplanting primary human myoblasts into immunodeficient mice. The data proved that short in vivo obestatin treatment of primary human myoblasts not only enhances the efficiency of engraftment, but also facilitates an even distribution of myoblasts in the host muscle. Moreover, this treatment leads to a hypertrophic response of the human-derived regenerating myofibers. Taken together, the activation of the obestatin/GPR39 pathway resulted in an overall improvement of the efficacy of cell engraftment within the host's skeletal muscle. These data suggest considerable potential for future therapeutic applications and highlight the importance of combinatorial therapies.
Collapse
Affiliation(s)
- Icia Santos-Zas
- Laboratorio de Endocrinología Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), 15706 Santiago de Compostela, Spain
| | - Elisa Negroni
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, INSERM UMRS974, Center for Research in Myology, 47 Boulevard de l'hôpital, 75013 Paris, France
| | - Kamel Mamchaoui
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, INSERM UMRS974, Center for Research in Myology, 47 Boulevard de l'hôpital, 75013 Paris, France
| | - Carlos S Mosteiro
- Laboratorio de Endocrinología Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), 15706 Santiago de Compostela, Spain
| | - Rosalia Gallego
- Departamento de Ciencias Morfológicas, Universidad de Santiago de Compostela, 15704 Santiago de Compostela, Spain
| | - Gillian S Butler-Browne
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, INSERM UMRS974, Center for Research in Myology, 47 Boulevard de l'hôpital, 75013 Paris, France
| | - Yolanda Pazos
- Laboratorio de Patología Digestiva, IDIS, CHUS, SERGAS, 15706 Santiago de Compostela, Spain
| | - Vincent Mouly
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, INSERM UMRS974, Center for Research in Myology, 47 Boulevard de l'hôpital, 75013 Paris, France.
| | - Jesus P Camiña
- Laboratorio de Endocrinología Celular, Instituto de Investigación Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Servicio Gallego de Salud (SERGAS), 15706 Santiago de Compostela, Spain.
| |
Collapse
|
29
|
Tiedemann K, Le Nihouannen D, Fong JE, Hussein O, Barralet JE, Komarova SV. Regulation of Osteoclast Growth and Fusion by mTOR/raptor and mTOR/rictor/Akt. Front Cell Dev Biol 2017; 5:54. [PMID: 28573133 PMCID: PMC5435769 DOI: 10.3389/fcell.2017.00054] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/02/2017] [Indexed: 12/31/2022] Open
Abstract
Osteoclasts are giant bone cells formed by fusion from monocytes and uniquely capable of a complete destruction of mineralized tissues. Previously, we have demonstrated that in energy-rich environment not only osteoclast fusion index (the number of nuclei each osteoclast contains), but also cytoplasm volume per single nucleus was increased. The goal of this study was to investigate the regulation of metabolic sensor mTOR during osteoclast differentiation in energy-rich environment simulated by addition of pyruvate. We have found that in the presence of pyruvate, the proportion of mTOR associated with raptor increased, while mTOR-rictor-mediated Akt phosphorylation decreased. Inhibition of mTOR with rapamycin (10 nM) significantly interfered with all aspects of osteoclastogenesis. However, rapamycin at 1 nM, which preferentially targets mTOR-raptor complex, was only effective in control cultures, while in the presence of pyruvate osteoclast fusion index was successfully increased. Inhibition of Akt drastically reduced osteoclast fusion, however in energy-rich environment, osteoclasts of comparable size were formed through increased cytoplasm growth. These data suggest that mTOR-rictor mediated Akt signaling regulates osteoclast fusion, while mTOR-raptor regulation of protein translation contributes to fusion-independent cytoplasm growth. We demonstrate that depending on the bioenergetics microenvironment osteoclastogenesis can adjust to occur through preferential multinucleation or through cell growth, implying that attaining large cell size is part of the osteoclast differentiation program.
Collapse
Affiliation(s)
- Kerstin Tiedemann
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada.,Shriners Hospital for Children-CanadaMontreal, QC, Canada
| | | | - Jenna E Fong
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada
| | - Osama Hussein
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada
| | - Jake E Barralet
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada.,Department of Surgery, Faculty of Medicine, McGill UniversityMontreal, QC, Canada
| | - Svetlana V Komarova
- Faculty of Dentistry, McGill UniversityMontreal, QC, Canada.,Shriners Hospital for Children-CanadaMontreal, QC, Canada
| |
Collapse
|
30
|
Obestatin controls skeletal muscle fiber-type determination. Sci Rep 2017; 7:2137. [PMID: 28522824 PMCID: PMC5437042 DOI: 10.1038/s41598-017-02337-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 04/11/2017] [Indexed: 01/27/2023] Open
Abstract
Obestatin/GPR39 signaling stimulates skeletal muscle growth and repair by inducing both G-protein-dependent and -independent mechanisms linking the activated GPR39 receptor with distinct sets of accessory and effector proteins. In this work, we describe a new level of activity where obestatin signaling plays a role in the formation, contractile properties and metabolic profile of skeletal muscle through determination of oxidative fiber type. Our data indicate that obestatin regulates Mef2 activity and PGC-1α expression. Both mechanisms result in a shift in muscle metabolism and function. The increase in Mef2 and PGC-1α signaling activates oxidative capacity, whereas Akt/mTOR signaling positively regulates myofiber growth. Taken together, these data indicate that the obestatin signaling acts on muscle fiber-type program in skeletal muscle.
Collapse
|
31
|
Kaur A, Sharma S. Mammalian target of rapamycin (mTOR) as a potential therapeutic target in various diseases. Inflammopharmacology 2017; 25:293-312. [PMID: 28417246 DOI: 10.1007/s10787-017-0336-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/28/2022]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that belongs to Phosphatidylinositol-3-kinase related kinase superfamily. The signaling pathways of mTOR are integrated through the protein complexes of mTORC1 and mTORC2. mTORC1 controls protein synthesis, cell growth, proliferation, autophagy, cell metabolism, and stress responses, whereas mTORC2 seems to regulate cell survival and polarity. Dysregulation of the mTOR pathway has been implicated in the pathophysiology of a number of disease conditions, including cancer, cardiovascular, neurodegenerative, and various renal diseases. The hyperactivation of the mTOR pathway leads to increase in cell growth and proliferation and also has been documented to stimulate tumor growth. Therefore, investigation of the involvement of mTOR and its downstream pathways in various diseases intensively preoccupied scientific community. The present review is focussed on recent advances in the understanding of the mTOR signaling pathway and its role in health and various diseases.
Collapse
Affiliation(s)
- Avileen Kaur
- Cardiovascular Division, Department of Pharmacology, I. S. F. College of Pharmacy, Moga, Punjab, 142001, India
| | - Saurabh Sharma
- Cardiovascular Division, Department of Pharmacology, I. S. F. College of Pharmacy, Moga, Punjab, 142001, India.
| |
Collapse
|
32
|
Gnimassou O, Francaux M, Deldicque L. Hippo Pathway and Skeletal Muscle Mass Regulation in Mammals: A Controversial Relationship. Front Physiol 2017; 8:190. [PMID: 28424630 PMCID: PMC5372825 DOI: 10.3389/fphys.2017.00190] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 03/14/2017] [Indexed: 01/01/2023] Open
Abstract
Skeletal muscle mass reflects a dynamic turnover between net protein synthesis and degradation. In addition, satellite cell inclusion may contribute to increase muscle mass while fiber loss results in a reduction of muscle mass. Since 2010, a few studies looked at the involvement of the newly discovered Hippo pathway in the regulation of muscle mass. In line with its roles in other organs, it has been hypothesized that the Hippo pathway could play a role in different regulatory mechanisms in skeletal muscle as well, namely proliferation and renewal of satellite cells, differentiation, death, and growth of myogenic cells. While the Hippo components have been identified in skeletal muscle, their role in muscle mass regulation has been less investigated and conflicting results have been reported. Indeed, the first studies described both atrophic and hypertrophic roles of the Hippo pathway and its effectors Yap/Taz using different biochemical approaches. Further, investigation is therefore warranted to determine the role of the Hippo pathway in the regulation of skeletal muscle mass. New components of the pathway will probably emerge and unsuspected roles will likely be discovered due to its numerous interactions with different cellular processes. This mini-review aims to summarize the current literature concerning the roles of the Hippo pathway in the regulation of muscle mass and to develop the hypothesis that this pathway could contribute to muscle mass adaptation after exercise.
Collapse
Affiliation(s)
- Olouyomi Gnimassou
- Institute of Neuroscience, Université catholique de LouvainLouvain-la-Neuve, Belgium
| | - Marc Francaux
- Institute of Neuroscience, Université catholique de LouvainLouvain-la-Neuve, Belgium
| | - Louise Deldicque
- Institute of Neuroscience, Université catholique de LouvainLouvain-la-Neuve, Belgium
| |
Collapse
|
33
|
Jeong J, Park CH, Kim I, Kim YH, Yoon JM, Kim KS, Kim JB. Korean mistletoe (Viscum album coloratum) extract regulates gene expression related to muscle atrophy and muscle hypertrophy. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:68. [PMID: 28109285 PMCID: PMC5251312 DOI: 10.1186/s12906-017-1575-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 01/11/2017] [Indexed: 02/05/2023]
Abstract
Background Korean mistletoe (Viscum album coloratum) is a semi-parasitic plant that grows on various trees and has a diverse range of effects on biological functions, being implicated in having anti-tumor, immunostimulatory, anti-diabetic, and anti-obesity properties. Recently, we also reported that Korean mistletoe extract (KME) improves endurance exercise in mice, suggesting its beneficial roles in enhancing the capacity of skeletal muscle. Methods We examined the expression pattern of several genes concerned with muscle physiology in C2C12 myotubes cells to identify whether KME inhibits muscle atrophy or promotes muscle hypertrophy. We also investigated these effects of KME in denervated mice model. Results Interestingly, KME induced the mRNA expression of SREBP-1c, PGC-1α, and GLUT4, known positive regulators of muscle hypertrophy, in C2C12 cells. On the contrary, KME reduced the expression of Atrogin-1, which is directly involved in the induction of muscle atrophy. In animal models, KME mitigated the decrease of muscle weight in denervated mice. The expression of Atrogin-1 was also diminished in those mice. Moreover, KME enhanced the grip strength and muscle weight in long-term feeding mice. Conclusions Our results suggest that KME has beneficial effects on muscle atrophy and muscle hypertrophy.
Collapse
|
34
|
Erdogan CS, Mørup-Lendal M, Dalgaard LT, Vang O. Sirtuin 1 independent effects of resveratrol in INS-1E β-cells. Chem Biol Interact 2017; 264:52-60. [PMID: 28108221 DOI: 10.1016/j.cbi.2017.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/22/2016] [Accepted: 01/16/2017] [Indexed: 11/26/2022]
Abstract
Resveratrol (Resv), a natural polyphenol, is suggested to have various health benefits including improved insulin sensitivity. Resv activates Sirtuin (Sirt1) in several species and tissues. Sirt1 is a protein deacetylase with an important role in ageing, metabolism and β-cell function. In insulinoma β-cells (INS-1E), Resv is previously shown to improve glucose-stimulated insulin secretion in a Sirt1-dependent mechanism and to protect against β-cell dedifferentiation in non-human primates, while inducing hypertrophy in myoblasts. Mammalian (mechanistic) Target of Rapamycin (mTOR), is a key regulator of cellular metabolism and regulates the cell size, β-cell survival and proliferation. In order to understand the interaction of Sirt1 and mTOR cascade activity with Resv-induced changes in the INS-1E cell line, we generated stable Sirt1-down-regulated INS-1E cells, and analysed Sirt1-dependent effects of Resv with respect to mTOR cascade activity. Sirt1-knockdown (KD) had a significant increase in cell size compared to negative-control (NEG CTR) cells. Resveratrol treatment increased cell size in both cell types in a dose-dependent manner at 24 h (Resv conc: 15-60 μM), and decreased the cell number (Resv conc: 30-60 μM). Cell area was increased in NEG CTR cells (Resv conc: 60 μM) at 24 h and KD cells at 48 h (Resv conc: 15-60 μM). Rapamycin, a specific mTOR inhibitor, counteracted the Resv-induced cell enlargement (both cell diameter and area). Furthermore, Sirt1-downregulation by itself did not affect the mTOR cascade activities as measured by Western blotting for total and phosphorylated Akt and mTOR. Rapamycin decreased the mTORC1 activity, while increasing the pAkt levels. Resveratrol did not interfere with the mTOR activity or with Sirt1 expression. Altogether, this work indicates that Sirt1 is a negative regulator of cell size. Moreover, the effect of Resv on cell size increase is mTOR-cascade dependent.
Collapse
Affiliation(s)
- Cihan S Erdogan
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | | | - Louise T Dalgaard
- Department of Science and Environment, Roskilde University, Roskilde, Denmark
| | - Ole Vang
- Department of Science and Environment, Roskilde University, Roskilde, Denmark.
| |
Collapse
|
35
|
Scuron MD, Boesze-Battaglia K, Dlakić M, Shenker BJ. The Cytolethal Distending Toxin Contributes to Microbial Virulence and Disease Pathogenesis by Acting As a Tri-Perditious Toxin. Front Cell Infect Microbiol 2016; 6:168. [PMID: 27995094 PMCID: PMC5136569 DOI: 10.3389/fcimb.2016.00168] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 11/15/2016] [Indexed: 12/11/2022] Open
Abstract
This review summarizes the current status and recent advances in our understanding of the role that the cytolethal distending toxin (Cdt) plays as a virulence factor in promoting disease by toxin-producing pathogens. A major focus of this review is on the relationship between structure and function of the individual subunits that comprise the AB2 Cdt holotoxin. In particular, we concentrate on the molecular mechanisms that characterize this toxin and which account for the ability of Cdt to intoxicate multiple cell types by utilizing a ubiquitous binding partner on the cell membrane. Furthermore, we propose a paradigm shift for the molecular mode of action by which the active Cdt subunit, CdtB, is able to block a key signaling cascade and thereby lead to outcomes based upon programming and the role of the phosphatidylinositol 3-kinase (PI-3K) in a variety of cells. Based upon the collective Cdt literature, we now propose that Cdt is a unique and potent virulence factor capable of acting as a tri-perditious toxin that impairs host defenses by: (1) disrupting epithelial barriers; (2) suppressing acquired immunity; (3) promoting pro-inflammatory responses. Thus, Cdt plays a key role in facilitating the early stages of infection and the later stages of disease progression by contributing to persistence and impairing host elimination.
Collapse
Affiliation(s)
- Monika D Scuron
- Department of Pathology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Mensur Dlakić
- Department of Microbiology and Immunology, Montana State University Bozeman, MT, USA
| | - Bruce J Shenker
- Department of Pathology, School of Dental Medicine, University of Pennsylvania Philadelphia, PA, USA
| |
Collapse
|
36
|
Elshazly SM, Mahmoud AA, Barakat W. Pentoxifylline abrogates cardiotoxicity induced by the administration of a single high dose or multiple low doses of doxorubicin in rats. Can J Physiol Pharmacol 2016; 94:1170-1177. [DOI: 10.1139/cjpp-2016-0115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Doxorubicin (DOX) possesses a broad-spectrum antineoplastic activity; however, its clinical application is impeded by cardiotoxicity. This study aimed to investigate the protective effect of pentoxifylline (PXF), which possesses antioxidant and anti-inflammatory properties against cardiotoxicity induced by a single high dose (15 mg/kg, i.p.) or multiple low doses (2.5 mg/kg, i.p., three times per week for 2 weeks) of DOX. At the end of the experimental period, the serum creatine kinase (CK)-MB and lactate dehydrogenase (LDH) activities were measured. The hearts were then removed for evaluating TNF-α, NO, malondialdehyde (MDA), and reduced glutathione (GSH) levels, superoxide dismutase (SOD) and catalase (CAT) activities, and the expression of iNOS, NF-κB, Fas ligand (FasL), and caspase-3. The administration of DOX in both dose regimens caused increases in serum CK-MB and LDH activities, in cardiac TNF-α, NO and MDA levels, as well as in the cardiac expression of iNOS, NF-κB, FasL and caspase-3, whereas it significantly reduced the cardiac GSH level, as well as SOD and CAT activities (P < 0.05). Prophylactic treatment of rats with PXF diminished DOX-induced alterations in theses parameters. Our results warrant the clinical use of PXF as an adjuvant therapy to abrogate cardiotoxicity of DOX and extend its clinical applications.
Collapse
Affiliation(s)
- Shimaa M. Elshazly
- Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Amr A.A. Mahmoud
- Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Waleed Barakat
- Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
- Department of Pharmacology, Faculty of Pharmacy, Tabuk University, Tabuk 71491, Kingdom of Saudi Arabia
| |
Collapse
|
37
|
Fang X, Stroud MJ, Ouyang K, Fang L, Zhang J, Dalton ND, Gu Y, Wu T, Peterson KL, Huang HD, Chen J, Wang N. Adipocyte-specific loss of PPAR γ attenuates cardiac hypertrophy. JCI Insight 2016; 1:e89908. [PMID: 27734035 DOI: 10.1172/jci.insight.89908] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Adipose tissue is a key endocrine organ that governs systemic homeostasis. PPARγ is a master regulator of adipose tissue signaling that plays an essential role in insulin sensitivity, making it an important therapeutic target. The selective PPARγ agonist rosiglitazone (RSG) has been used to treat diabetes. However, adverse cardiovascular effects have seriously hindered its clinical application. Experimental models have revealed that PPARγ activation increases cardiac hypertrophy. RSG stimulates cardiac hypertrophy and oxidative stress in cardiomyocyte-specific PPARγ knockout mice, implying that RSG might stimulate cardiac hypertrophy independently of cardiomyocyte PPARγ. However, candidate cell types responsible for RSG-induced cardiomyocyte hypertrophy remain unexplored. Utilizing cocultures of adipocytes and cardiomyocytes, we found that stimulation of PPARγ signaling in adipocytes increased miR-200a expression and secretion. Delivery of miR-200a in adipocyte-derived exosomes to cardiomyocytes resulted in decreased TSC1 and subsequent mTOR activation, leading to cardiomyocyte hypertrophy. Treatment with an antagomir to miR-200a blunted this hypertrophic response in cardiomyocytes. In vivo, specific ablation of PPARγ in adipocytes was sufficient to blunt hypertrophy induced by RSG treatment. By delineating mechanisms by which RSG elicits cardiac hypertrophy, we have identified pathways that mediate the crosstalk between adipocytes and cardiomyocytes to regulate cardiac remodeling.
Collapse
Affiliation(s)
- Xi Fang
- Institute of Cardiovascular Science, Peking University Health Science Center, Beijing, China.,Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Matthew J Stroud
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Kunfu Ouyang
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Li Fang
- Institute of Cardiovascular Science, Peking University Health Science Center, Beijing, China
| | - Jianlin Zhang
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Nancy D Dalton
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Yusu Gu
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Tongbin Wu
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Kirk L Peterson
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Hsien-Da Huang
- Institute of Bioinformatics and Systems Biology, Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu, Taiwan
| | - Ju Chen
- Department of Medicine, School of Medicine, UCSD, La Jolla, California, USA
| | - Nanping Wang
- Institute of Cardiovascular Science, Peking University Health Science Center, Beijing, China.,The Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
| |
Collapse
|
38
|
Siedlecka M, Grajkowska W, Galus R, Dembowska-Bagińska B, Jóźwiak J. Focal cortical dysplasia: Molecular disturbances and clinicopathological classification (Review). Int J Mol Med 2016; 38:1327-1337. [DOI: 10.3892/ijmm.2016.2760] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 06/23/2016] [Indexed: 11/05/2022] Open
|
39
|
Burley SD, Whittingham-Dowd J, Allen J, Grosset JF, Onambele-Pearson GL. The Differential Hormonal Milieu of Morning versus Evening May Have an Impact on Muscle Hypertrophic Potential. PLoS One 2016; 11:e0161500. [PMID: 27583459 PMCID: PMC5008805 DOI: 10.1371/journal.pone.0161500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 08/05/2016] [Indexed: 11/21/2022] Open
Abstract
Substantial gains in muscle strength and hypertrophy are clearly associated with the routine performance of resistance training. What is less evident is the optimal timing of the resistance training stimulus to elicit these significant functional and structural skeletal muscle changes. Therefore, this investigation determined the impact of a single bout of resistance training performed either in the morning or evening upon acute anabolic signalling (insulin-like growth factor-binding protein-3 (IGFBP-3), myogenic index and differentiation) and catabolic processes (cortisol). Twenty-four male participants (age 21.4±1.9yrs, mass 83.7±13.7kg) with no sustained resistance training experience were allocated to a resistance exercise group (REP). Sixteen of the 24 participants were randomly selected to perform an additional non-exercising control group (CP) protocol. REP performed two bouts of resistance exercise (80% 1RM) in the morning (AM: 0800 hrs) and evening (PM: 1800 hrs), with the sessions separated by a minimum of 72 hours. Venous blood was collected immediately prior to, and 5 min after, each resistance exercise and control sessions. Serum cortisol and IGFBP-3 levels, myogenic index, myotube width, were determined at each sampling period. All data are reported as mean ± SEM, statistical significance was set at P≤0.05. As expected a significant reduction in evening cortisol concentration was observed at pre (AM: 98.4±10.5, PM: 49.8±4.4 ng/ml, P<0.001) and post (AM: 98.0±9.0, PM: 52.7±6.0 ng/ml, P<0.001) exercise. Interestingly, individual cortisol differences pre vs post exercise indicate a time-of-day effect (AM difference: -2±2.6%, PM difference: 14.0±6.7%, P = 0.03). A time-of-day related elevation in serum IGFBP-3 (AM: 3274.9 ± 345.2, PM: 3605.1 ± 367.5, p = 0.032) was also evident. Pre exercise myogenic index (AM: 8.0±0.6%, PM: 16.8±1.1%) and myotube width (AM: 48.0±3.0, PM: 71.6±1.9 μm) were significantly elevated (P<0.001) in the evening. Post exercise myogenic index was greater AM (11.5±1.6%) compared with PM (4.6±0.9%). No difference was observed in myotube width (AM: 48.5±1.5, PM: 47.8±1.8 μm) (P>0.05). Timing of resistance training regimen in the evening appears to augment some markers of hypertrophic potential, with elevated IGFBP-3, suppressed cortisol and a superior cellular environment. Further investigation, to further elucidate the time course of peak anabolic signalling in morning vs evening training conditions, are timely.
Collapse
Affiliation(s)
- Simon D. Burley
- HEAL Research Centre, Exercise & Sport Science, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, United Kingdom
| | - Jayde Whittingham-Dowd
- Faculty of Life Sciences, The University of Manchester, AV Hill Building, Oxford Road, Manchester, M13 9PT, United Kingdom
| | - Jeremy Allen
- School of Health, Sport & Rehabilitation Sciences, University of Salford, Salford, Greater Manchester M5 4WT, United Kingdom
| | - Jean-Francois Grosset
- HEAL Research Centre, Exercise & Sport Science, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, United Kingdom
- CNRS UMR 7338, Biomécanique et Bioingénierie, Université de Technologie de Compiègne, 60205 Compiègne cedex, France
| | - Gladys L. Onambele-Pearson
- HEAL Research Centre, Exercise & Sport Science, Manchester Metropolitan University, Crewe Green Road, Crewe, CW1 5DU, United Kingdom
- * E-mail:
| |
Collapse
|
40
|
Liu R, Kenney JW, Manousopoulou A, Johnston HE, Kamei M, Woelk CH, Xie J, Schwarzer M, Garbis SD, Proud CG. Quantitative Non-canonical Amino Acid Tagging (QuaNCAT) Proteomics Identifies Distinct Patterns of Protein Synthesis Rapidly Induced by Hypertrophic Agents in Cardiomyocytes, Revealing New Aspects of Metabolic Remodeling. Mol Cell Proteomics 2016; 15:3170-3189. [PMID: 27512079 PMCID: PMC5054342 DOI: 10.1074/mcp.m115.054312] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Indexed: 01/16/2023] Open
Abstract
Cardiomyocytes undergo growth and remodeling in response to specific pathological or physiological conditions. In the former, myocardial growth is a risk factor for cardiac failure and faster protein synthesis is a major factor driving cardiomyocyte growth. Our goal was to quantify the rapid effects of different pro-hypertrophic stimuli on the synthesis of specific proteins in ARVC and to determine whether such effects are caused by alterations on mRNA abundance or the translation of specific mRNAs. Cardiomyocytes have very low rates of protein synthesis, posing a challenging problem in terms of studying changes in the synthesis of specific proteins, which also applies to other nondividing primary cells. To study the rates of accumulation of specific proteins in these cells, we developed an optimized version of the Quantitative Noncanonical Amino acid Tagging LC/MS proteomic method to label and selectively enrich newly synthesized proteins in these primary cells while eliminating the suppressive effects of pre-existing and highly abundant nonisotope-tagged polypeptides. Our data revealed that a classical pathologic (phenylephrine; PE) and the recently identified insulin stimulus that also contributes to the development of pathological cardiac hypertrophy (insulin), both increased the synthesis of proteins involved in, e.g. glycolysis, the Krebs cycle and beta-oxidation, and sarcomeric components. However, insulin increased synthesis of many metabolic enzymes to a greater extent than PE. Using a novel validation method, we confirmed that synthesis of selected candidates is indeed up-regulated by PE and insulin. Synthesis of all proteins studied was up-regulated by signaling through mammalian target of rapamycin complex 1 without changes in their mRNA levels, showing the key importance of translational control in the rapid effects of hypertrophic stimuli. Expression of PKM2 was up-regulated in rat hearts following TAC. This isoform possesses specific regulatory properties, so this finding indicates it may be involved in metabolic remodeling and also serve as a novel candidate biomarker. Levels of translation factor eEF1 also increased during TAC, likely contributing to faster cell mass accumulation. Interestingly those two candidates were not up-regulated in pregnancy or exercise induced CH, indicating PKM2 and eEF1 were pathological CH specific markers. We anticipate that the methodologies described here will be valuable for other researchers studying protein synthesis in primary cells.
Collapse
Affiliation(s)
- Rui Liu
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom; §South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia
| | - Justin W Kenney
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Antigoni Manousopoulou
- From the ‡Center for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom; ¶Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Harvey E Johnston
- From the ‡Center for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom; ‖Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Makoto Kamei
- §South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia
| | - Christopher H Woelk
- ¶Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Jianling Xie
- §South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia
| | - Michael Schwarzer
- **Department of Cardiovascular Surgery, Jena University Hospital-Friedrich Schiller University of Jena, Erlanger Allee 101, 07747 Jena, Germany
| | - Spiros D Garbis
- From the ‡Center for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom; ¶Clinical and Experimental Sciences Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK; ‖Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK;
| | - Christopher G Proud
- From the ‡Center for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom; §South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA5005, Australia
| |
Collapse
|
41
|
Bloch L, Ndongson-Dongmo B, Kusch A, Dragun D, Heller R, Huber O. Real-time monitoring of hypertrophy in HL-1 cardiomyocytes by impedance measurements reveals different modes of growth. Cytotechnology 2016; 68:1897-907. [PMID: 27380966 DOI: 10.1007/s10616-016-0001-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 06/28/2016] [Indexed: 02/07/2023] Open
Abstract
Hypertrophic growth is a response of the heart to increased mechanical load or physiological stress. Thereby, cardiomyocytes grow in length and/or width to maintain cardiac pump function. Major signaling pathways involved in cardiomyocyte growth and remodeling have been identified during recent years including calcineurin-NFAT and PI3K-Akt signaling. Modulation of these pathways is of certain interest for therapeutic treatment of cardiac hypertrophy. However, quantification and characterization of hypertrophy in response to different stimuli or modulators is difficult. This study aims to test different read-out systems for detection and quantification of differences in hypertrophic growth in response to prohypertrophic stimuli. Real-time impedance measurements allowed the detection of distinct differences in hypertrophic growth in response to endothelin, norepinephrine, phenylephrine or BIO, which were not observable by other methods such as flow cytometry. Endothelin treatment induced a rapid and strong peak in the impedance signal concomitant with a massive reorientation of the actin cytoskeleton. Changes in expression of hypertrophy-associated genes were detected and stabilization of β-catenin was identified as a common response to all hypertrophic stimuli used in this study. Hypertrophic growth was blocked by the PI3K/mTOR inhibitor PI-103.
Collapse
Affiliation(s)
- Laura Bloch
- Institute of Biochemistry II, Jena University Hospital, Friedrich-Schiller-University Jena, Nonnenplan 2-4, 07743, Jena, Germany
| | - Bernadin Ndongson-Dongmo
- Institute of Molecular Cell Biology, Center of Molecular Biomedicine, Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany.,Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Postboks 1057, Blindern, 0316, Oslo, Norway
| | - Angelika Kusch
- Department of Nephrology and Intensive Care Medicine Campus Virchow Klinikum, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.,Center for Cardiovascular Research, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, 10115, Berlin, Germany
| | - Duska Dragun
- Department of Nephrology and Intensive Care Medicine Campus Virchow Klinikum, Charité - Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.,Center for Cardiovascular Research, Charité - Universitätsmedizin Berlin, Hessische Str. 3-4, 10115, Berlin, Germany
| | - Regine Heller
- Institute of Molecular Cell Biology, Center of Molecular Biomedicine, Jena University Hospital, Hans-Knöll-Str. 2, 07745, Jena, Germany
| | - Otmar Huber
- Institute of Biochemistry II, Jena University Hospital, Friedrich-Schiller-University Jena, Nonnenplan 2-4, 07743, Jena, Germany.
| |
Collapse
|
42
|
Pascual F, Coleman RA. Fuel availability and fate in cardiac metabolism: A tale of two substrates. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1425-33. [PMID: 26993579 DOI: 10.1016/j.bbalip.2016.03.014] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 12/12/2022]
Abstract
The heart's extraordinary metabolic flexibility allows it to adapt to normal changes in physiology in order to preserve its function. Alterations in the metabolic profile of the heart have also been attributed to pathological conditions such as ischemia and hypertrophy; however, research during the past decade has established that cardiac metabolic adaptations can precede the onset of pathologies. It is therefore critical to understand how changes in cardiac substrate availability and use trigger events that ultimately result in heart dysfunction. This review examines the mechanisms by which the heart obtains fuels from the circulation or from mobilization of intracellular stores. We next describe experimental models that exhibit either an increase in glucose use or a decrease in FA oxidation, and how these aberrant conditions affect cardiac metabolism and function. Finally, we highlight the importance of alternative, relatively under-investigated strategies for the treatment of heart failure. This article is part of a Special Issue entitled: Heart Lipid Metabolism edited by G.D. Lopaschuk.
Collapse
Affiliation(s)
- Florencia Pascual
- Department of Nutrition, University of North Carolina at Chapel Hill, 27599, USA.
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina at Chapel Hill, 27599, USA.
| |
Collapse
|
43
|
Podocyte directed therapy of nephrotic syndrome-can we bring the inside out? Pediatr Nephrol 2016; 31:393-405. [PMID: 25939817 DOI: 10.1007/s00467-015-3116-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/08/2015] [Accepted: 04/09/2015] [Indexed: 12/15/2022]
Abstract
Several of the drugs currently used for the treatment of glomerular diseases are prescribed for their immunotherapeutic or anti-inflammatory properties, based on the current understanding that glomerular diseases are mediated by immune responses. In recent years our understanding of podocytic signalling pathways and the crucial role of genetic predispositions in the pathology of glomerular diseases has broadened. Delineation of those signalling pathways supports the hypothesis that several of the medications and immunosuppressive agents used to treat glomerular diseases directly target glomerular podocytes. Several central downstream signalling pathways merge into regulatory pathways of the podocytic actin cytoskeleton and its connection to the slit diaphragm. The slit diaphragm and the cytoskeleton of the foot process represent a functional unit. A breakdown of the cytoskeletal backbone of the foot processes leads to internalization of slit diaphragm molecules, and internalization of slit diaphragm components in turn negatively affects cytoskeletal signalling pathways. Podocytes display a remarkable ability to recover from complete effacement and to re-form interdigitating foot processes and intact slit diaphragms after pharmacological intervention. This ability indicates an active inside-out signalling machinery which stabilizes integrin complex formations and triggers the recycling of slit diaphragm molecules from intracellular compartments to the cell surface. In this review we summarize current evidence from patient studies and model organisms on the direct impact of immunosuppressive and supportive drugs on podocyte signalling pathways. We highlight new therapeutic targets that may open novel opportunities to enhance and stabilize inside-out pathways in podocytes.
Collapse
|
44
|
Li Q, Xie J, Wang B, Li R, Bai J, Ding L, Gu R, Wang L, Xu B. Overexpression of microRNA-99a Attenuates Cardiac Hypertrophy. PLoS One 2016; 11:e0148480. [PMID: 26914935 PMCID: PMC4767297 DOI: 10.1371/journal.pone.0148480] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 01/20/2016] [Indexed: 11/18/2022] Open
Abstract
Pathological cardiomyocyte hypertrophy is associated with significantly increased risk of heart failure, one of the leading medical causes of mortality worldwide. MicroRNAs are known to be involved in pathological cardiac remodeling. However, whether miR-99a participates in the signaling cascade leading to cardiac hypertrophy is unknown. To evaluate the role of miR-99a in cardiac hypertrophy, we assessed the expression of miR-99a in hypertrophic cardiomyocytes induced by isoprenaline (ISO)/angiotensin-II (Ang II) and in mice model of cardiac hypertrophy induced by transverse aortic constriction (TAC). Expression of miR-99a was evaluated in these hypertrophic cells and hearts. We also found that miR-99a expression was highly correlated with cardiac function of mice with heart failure (8 weeks after TAC surgery). Overexpression of miR-99a attenuated cardiac hypertrophy in TAC mice and cellular hypertrophy in stimuli treated cardiomyocytes through down-regulation of expression of mammalian target of rapamycin (mTOR). These results indicate that miR-99a negatively regulates physiological hypertrophy through mTOR signaling pathway, which may provide a new therapeutic approach for pressure-overload heart failure.
Collapse
Affiliation(s)
- Qiaoling Li
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Jun Xie
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Bingjian Wang
- From the Department of Cardiology, Drum Tower Clinic Hospital, Nanjing Medical University, Nanjing, China
| | - Ran Li
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Jian Bai
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Liang Ding
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Rong Gu
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Lian Wang
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
| | - Biao Xu
- Department of Cardiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, 210008, China
- * E-mail:
| |
Collapse
|
45
|
McLeod M, Breen L, Hamilton DL, Philp A. Live strong and prosper: the importance of skeletal muscle strength for healthy ageing. Biogerontology 2016; 17:497-510. [PMID: 26791164 PMCID: PMC4889643 DOI: 10.1007/s10522-015-9631-7] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/22/2015] [Indexed: 12/19/2022]
Abstract
Due to improved health care, diet and infrastructure in developed countries, since 1840 life expectancy has increased by approximately 2 years per decade. Accordingly, by 2050, a quarter of Europe’s population will be over 65 years, representing a 10 % rise in half a century. With this rapid rise comes an increased prevalence of diseases of ageing and associated healthcare expenditure. To address the health consequences of global ageing, research in model systems (worms, flies and mice) has indicated that reducing the rate of organ growth, via reductions in protein synthetic rates, has multi-organ health benefits that collectively lead to improvements in lifespan. In contrast, human pre-clinical, clinical and large cohort prospective studies demonstrate that ageing leads to anabolic (i.e. growth) impairments in skeletal muscle, which in turn leads to reductions in muscle mass and strength, factors directly associated with mortality rates in the elderly. As such, increasing muscle protein synthesis via exercise or protein-based nutrition maintains a strong, healthy muscle mass, which in turn leads to improved health, independence and functionality. The aim of this review is to critique current literature relating to the maintenance of muscle mass across lifespan and discuss whether maintaining or reducing protein synthesis is the most logical approach to support musculoskeletal function and by extension healthy human ageing.
Collapse
Affiliation(s)
- Michael McLeod
- MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, B15 2TT, UK.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Leigh Breen
- MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, B15 2TT, UK.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | | | - Andrew Philp
- MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, B15 2TT, UK. .,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
| |
Collapse
|
46
|
Affiliation(s)
- Shohei Ikeda
- Department of Cell Biology and Molecular Medicine, Rutgers – New Jersey Medical School
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine, Rutgers – New Jersey Medical School
| |
Collapse
|
47
|
Zhou Y, He X, Chen Y, Huang Y, Wu L, He J. Exendin-4 attenuates cardiac hypertrophy via AMPK/mTOR signaling pathway activation. Biochem Biophys Res Commun 2015; 468:394-9. [DOI: 10.1016/j.bbrc.2015.09.179] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 09/29/2015] [Indexed: 12/29/2022]
|
48
|
Shenker BJ, Boesze-Battaglia K, Scuron MD, Walker LP, Zekavat A, Dlakić M. The toxicity of the Aggregatibacter actinomycetemcomitans cytolethal distending toxin correlates with its phosphatidylinositol-3,4,5-triphosphate phosphatase activity. Cell Microbiol 2015; 18:223-43. [PMID: 26247396 DOI: 10.1111/cmi.12497] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/22/2015] [Accepted: 07/26/2015] [Indexed: 12/22/2022]
Abstract
The Aggregatibacter actinomycetemcomitans cytolethal distending toxin (Cdt) induces G2 arrest and apoptosis in lymphocytes and other cell types. We have shown that the active subunit, CdtB, exhibits phosphatidylinositol-3,4,5-triphosphate (PIP3) phosphatase activity, leading us to propose that Cdt toxicity is the result of PIP3 depletion and perturbation of phosphatidylinositol-3-kinase (PI-3K)/PIP3/Akt signalling. To further explore this relationship, we have focused our analysis on identifying residues that comprise the catalytic pocket and are critical to substrate binding rather than catalysis. In this context, we have generated several CdtB mutants and demonstrate that, in each instance, the ability of the toxin to induce cell cycle arrest correlates with retention of phosphatase activity. We have also assessed the effect of Cdt on downstream components of the PI-3K signalling pathway. In addition to depletion of intracellular concentrations of PIP3, toxin-treated lymphocytes exhibit decreases in pAkt and pGSK3β. Further analysis indicates that toxin-treated cells exhibit a concomitant loss in Akt activity and increase in GSK3β kinase activity consistent with observed changes in their phosphorylation status. We demonstrate that cell susceptibility to Cdt is dependent upon dephosphorylation and concomitant activation of GSK3β. Finally, we demonstrate that, in addition to lymphocytes, HeLa cells exposed to a CdtB mutant that retains phosphatase activity and not DNase activity undergo G2 arrest in the absence of H2AX phosphorylation. Our results provide further insight into the mode of action by which Cdt may function as an immunotoxin and induce cell cycle arrest in target cells such as lymphocytes.
Collapse
Affiliation(s)
- Bruce J Shenker
- Department of Pathology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
| | - Monika Damek Scuron
- Department of Pathology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
| | - Lisa P Walker
- Department of Pathology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
| | - Ali Zekavat
- Department of Pathology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
| | - Mensur Dlakić
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| |
Collapse
|
49
|
Ribosomal Protein S6 Phosphorylation: Four Decades of Research. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 320:41-73. [PMID: 26614871 DOI: 10.1016/bs.ircmb.2015.07.006] [Citation(s) in RCA: 182] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The phosphorylation of ribosomal protein S6 (rpS6) has been described for the first time about four decades ago. Since then, numerous studies have shown that this modification occurs in response to a wide variety of stimuli on five evolutionarily conserved serine residues. However, despite a large body of information on the respective kinases and the signal transduction pathways, the physiological role of rpS6 phosphorylation remained obscure until genetic manipulations were applied in both yeast and mammals in an attempt to block this modification. Thus, studies based on both mice and cultured cells subjected to disruption of the genes encoding rpS6 and the respective kinases, as well as the substitution of the phosphorylatable serine residues in rpS6, have laid the ground for the elucidation of the multiple roles of this protein and its posttranslational modification. This review focuses primarily on newly identified kinases that phosphorylate rpS6, pathways that transduce various signals into rpS6 phosphorylation, and the recently established physiological functions of this modification. It should be noted, however, that despite the significant progress made in the last decade, the molecular mechanism(s) underlying the diverse effects of rpS6 phosphorylation on cellular and organismal physiology are still poorly understood.
Collapse
|
50
|
Dey N, Bera A, Das F, Ghosh-Choudhury N, Kasinath BS, Choudhury GG. High glucose enhances microRNA-26a to activate mTORC1 for mesangial cell hypertrophy and matrix protein expression. Cell Signal 2015; 27:1276-85. [PMID: 25797045 PMCID: PMC4437875 DOI: 10.1016/j.cellsig.2015.03.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 03/06/2015] [Accepted: 03/15/2015] [Indexed: 02/06/2023]
Abstract
High glucose milieu inhibits PTEN expression to activate Akt kinase and induces glomerular mesangial cell hypertrophy and matrix protein expression in diabetic nephropathy. Specific mechanism by which high glucose inhibits PTEN expression is not clear. We found that high glucose increased the expression of the microRNA-26a (miR-26a) in mesangial cells. Using a sensor plasmid with 3'UTR-driven luciferase, we showed PTEN as a target of miR-26a in response to high glucose. Overexpression of miR-26a reduced the PTEN protein levels resulting in increased Akt kinase activity similar to high glucose treatment. In contrast, anti-miR-26a reversed high glucose-induced suppression of PTEN with concomitant inhibition of Akt kinase activity. Akt-mediated phosphorylation of tuberin and PRAS40 regulates mTORC1, which is necessary for mesangial cell hypertrophy and matrix protein expression. Inhibition of high glucose-induced miR-26a blocked phosphorylation of tuberin and PRAS40, which lead to suppression of phosphorylation of S6 kinase and 4EBP-1, two substrates of mTORC1. Furthermore, we show that expression of miR-26a induced mesangial cell hypertrophy and increased fibronectin and collagen I (α2) expression similar to that observed with the cells incubated with high glucose. Anti-miR-26a inhibited these phenomena in response to high glucose. Together our results provide the first evidence for the involvement of miR-26a in high glucose-induced mesangial cell hypertrophy and matrix protein expression. These data indicate the potential therapeutic utility of anti-miR-26a for the complications of diabetic kidney disease.
Collapse
Affiliation(s)
- Nirmalya Dey
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Amit Bera
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Falguni Das
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States
| | - Nandini Ghosh-Choudhury
- VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, University of Texas Health Science Center at San Antonio, Texas, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States; VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio Texas, United States; VA Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, United States.
| |
Collapse
|