1
|
Kim SG, Sung JY, Kang YJ, Choi HC. PPARγ activation by fisetin mitigates vascular smooth muscle cell senescence via the mTORC2-FoxO3a-autophagy signaling pathway. Biochem Pharmacol 2023; 218:115892. [PMID: 37890594 DOI: 10.1016/j.bcp.2023.115892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 10/29/2023]
Abstract
Cellular senescence is caused by diverse stimuli and contributes to cardiovascular diseases. Several studies have indicated that PPARγ acts as a key mediator of lipid metabolism and shown that it has a protective effect on vascular biology. Nevertheless, the mechanism responsible for the anti-aging effects of PPARγ has not been fully elucidated in vascular smooth muscle cell (VSMC). Furthermore, although mTOR complex 2 (mTORC2) is known to be involved in cellular senescence and autophagy, relatively few studies have investigated its effects as compared with mTOR complex 1 (mTORC1). Therefore, we focused on mTORC2 function and investigated the relationship between PPARγ and mTORC2, and the anti-aging mechanism in VSMC. We found PPARγ activation dose-dependently mitigated the hydrogen peroxide (H2O2)-induced senescence. Treatment of fisetin induced the translocation of PPARγ from cytosol to nuclear and inhibited VSMC senescence. Moreover, activated PPARγ increased PTEN transcription, leading to inhibition of the mTORC2 signaling pathway. We determined mTORC2 activation contributed to senescence by suppressing the FoxO3a-autophagy signaling pathway, and dual knockdown of mTORC1 and mTORC2 decreased cellular senescence and increased autophagy activation more than respective single knockdown. Finally, fisetin acted as a PPARγ activator and inhibited VSMC senescence through the mTORC2-FoxO3a-autophagy signaling pathway. These results demonstrate PPARγ is associated with cellular senescence and that fisetin has an anti-aging effect via PPARγ activation and mTORC2 inhibition in VSMC. These results demonstrate that the mTORC2 signaling pathway regulates autophagy and cellular senescence, which suggests mTORC2 should be considered a significant target for preventing cellular senescence and age-related diseases.
Collapse
Affiliation(s)
- Seul Gi Kim
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea; Senotherapy-based Metabolic Disease Control Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea
| | - Jin Young Sung
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea; Senotherapy-based Metabolic Disease Control Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea
| | - Young Jin Kang
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea
| | - Hyoung Chul Choi
- Department of Pharmacology, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea; Senotherapy-based Metabolic Disease Control Research Center, College of Medicine, Yeungnam University, 170 Hyunchung-Ro, Nam-Gu, Daegu 42415, Republic of Korea.
| |
Collapse
|
2
|
Kumar A, Thirumurugan K. Understanding cellular senescence: pathways involved, therapeutics and longevity aiding. Cell Cycle 2023; 22:2324-2345. [PMID: 38031713 PMCID: PMC10730163 DOI: 10.1080/15384101.2023.2287929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023] Open
Abstract
A normal somatic cell undergoes cycles of finite cellular divisions. The presence of surveillance checkpoints arrests cell division in response to stress inducers: oxidative stress from excess free radicals, oncogene-induced abnormalities, genotoxic stress, and telomere attrition. When facing such stress when undergoing these damages, there is a brief pause in the cell cycle to enable repair mechanisms. Also, the nature of stress determines whether the cell goes for repair or permanent arrest. As the cells experience transient or permanent stress, they subsequently choose the quiescence or senescence stage, respectively. Quiescence is an essential stage that allows the arrested/damaged cells to go through appropriate repair mechanisms and then revert to the mainstream cell cycle. However, senescent cells are irreversible and accumulate with age, resulting in inflammation and various age-related disorders. In this review, we focus on senescence-associated pathways and therapeutics understanding cellular senescence as a cascade that leads to aging, while discussing the recent details on the molecular pathways involved in regulating senescence and the benefits of therapeutic strategies against accumulated senescent cells and their secretions.
Collapse
Affiliation(s)
- Ashish Kumar
- Pearl Research Park, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | - Kavitha Thirumurugan
- Pearl Research Park, School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| |
Collapse
|
3
|
Cha J, Aguayo-Mazzucato C, Thompson PJ. Pancreatic β-cell senescence in diabetes: mechanisms, markers and therapies. Front Endocrinol (Lausanne) 2023; 14:1212716. [PMID: 37720527 PMCID: PMC10501801 DOI: 10.3389/fendo.2023.1212716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 08/15/2023] [Indexed: 09/19/2023] Open
Abstract
Cellular senescence is a response to a wide variety of stressors, including DNA damage, oncogene activation and physiologic aging, and pathologically accelerated senescence contributes to human disease, including diabetes mellitus. Indeed, recent work in this field has demonstrated a role for pancreatic β-cell senescence in the pathogenesis of Type 1 Diabetes, Type 2 Diabetes and monogenic diabetes. Small molecule or genetic targeting of senescent β-cells has shown promise as a novel therapeutic approach for preventing and treating diabetes. Despite these advances, major questions remain around the molecular mechanisms driving senescence in the β-cell, identification of molecular markers that distinguish senescent from non-senescent β-cell subpopulations, and translation of proof-of-concept therapies into novel treatments for diabetes in humans. Here, we summarize the current state of the field of β-cell senescence, highlighting insights from mouse models as well as studies on human islets and β-cells. We identify markers that have been used to detect β-cell senescence to unify future research efforts in this field. We discuss emerging concepts of the natural history of senescence in β-cells, heterogeneity of senescent β-cells subpopulations, role of sex differences in senescent responses, and the consequences of senescence on integrated islet function and microenvironment. As a young and developing field, there remain many open research questions which need to be addressed to move senescence-targeted approaches towards clinical investigation.
Collapse
Affiliation(s)
- Jeeyeon Cha
- Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, United States
| | | | - Peter J. Thompson
- Diabetes Research Envisioned and Accomplished in Manitoba Theme, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
- Department of Physiology & Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
4
|
Li K, Bian J, Xiao Y, Wang D, Han L, He C, Gong L, Wang M. Changes in Pancreatic Senescence Mediate Pancreatic Diseases. Int J Mol Sci 2023; 24:ijms24043513. [PMID: 36834922 PMCID: PMC9962587 DOI: 10.3390/ijms24043513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/24/2023] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
In recent years, there has been a significant increase in age-related diseases due to the improvement in life expectancy worldwide. The pancreas undergoes various morphological and pathological changes with aging, such as pancreatic atrophy, fatty degeneration, fibrosis, inflammatory cell infiltration, and exocrine pancreatic metaplasia. Meanwhile, these may predispose the individuals to aging-related diseases, such as diabetes, dyspepsia, pancreatic ductal adenocarcinoma, and pancreatitis, as the endocrine and exocrine functions of the pancreas are significantly affected by aging. Pancreatic senescence is associated with various underlying factors including genetic damage, DNA methylation, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and inflammation. This paper reviews the alternations of morphologies and functions in the aging pancreas, especially β-cells, closely related to insulin secretion. Finally, we summarize the mechanisms of pancreatic senescence to provide potential targets for treating pancreatic aging-related diseases.
Collapse
Affiliation(s)
- Kailin Li
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Ji Bian
- Kolling Institute, Sydney Medical School, Royal North Shore Hospital, University of Sydney, St. Leonards, NSW 2065, Australia
| | - Yao Xiao
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Da Wang
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Lin Han
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Caian He
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
| | - Lan Gong
- Microbiome Research Centre, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW 2052, Australia
- Correspondence: (L.G.); (M.W.)
| | - Min Wang
- College of Food Science and Engineering, Northwest A & F University, Yangling, Xianyang 712100, China
- Correspondence: (L.G.); (M.W.)
| |
Collapse
|
5
|
Tu T, Alba MM, Datta AA, Hong H, Hua B, Jia Y, Khan J, Nguyen P, Niu X, Pammidimukkala P, Slarve I, Tang Q, Xu C, Zhou Y, Stiles BL. Hepatic macrophage mediated immune response in liver steatosis driven carcinogenesis. Front Oncol 2022; 12:958696. [PMID: 36276076 PMCID: PMC9581256 DOI: 10.3389/fonc.2022.958696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/17/2022] [Indexed: 12/02/2022] Open
Abstract
Obesity confers an independent risk for carcinogenesis. Classically viewed as a genetic disease, owing to the discovery of tumor suppressors and oncogenes, genetic events alone are not sufficient to explain the progression and development of cancers. Tumor development is often associated with metabolic and immunological changes. In particular, obesity is found to significantly increase the mortality rate of liver cancer. As its role is not defined, a fundamental question is whether and how metabolic changes drive the development of cancer. In this review, we will dissect the current literature demonstrating that liver lipid dysfunction is a critical component driving the progression of cancer. We will discuss the involvement of inflammation in lipid dysfunction driven liver cancer development with a focus on the involvement of liver macrophages. We will first discuss the association of steatosis with liver cancer. This will be followed with a literature summary demonstrating the importance of inflammation and particularly macrophages in the progression of liver steatosis and highlighting the evidence that macrophages and macrophage produced inflammatory mediators are critical for liver cancer development. We will then discuss the specific inflammatory mediators and their roles in steatosis driven liver cancer development. Finally, we will summarize the molecular pattern (PAMP and DAMP) as well as lipid particle signals that are involved in the activation, infiltration and reprogramming of liver macrophages. We will also discuss some of the therapies that may interfere with lipid metabolism and also affect liver cancer development.
Collapse
Affiliation(s)
- Taojian Tu
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Mario M. Alba
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Aditi A. Datta
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Handan Hong
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Brittney Hua
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Yunyi Jia
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Jared Khan
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Phillip Nguyen
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Xiatoeng Niu
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Pranav Pammidimukkala
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Ielyzaveta Slarve
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Qi Tang
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Chenxi Xu
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Yiren Zhou
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Bangyan L. Stiles
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- *Correspondence: Bangyan L. Stiles,
| |
Collapse
|
6
|
Aggarwal R, Peng Z, Zeng N, Silva J, He L, Chen J, Debebe A, Tu T, Alba M, Chen CY, Stiles EX, Hong H, Stiles BL. Chronic Exposure to Palmitic Acid Down-Regulates AKT in Beta-Cells through Activation of mTOR. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:130-145. [PMID: 34619135 PMCID: PMC8759041 DOI: 10.1016/j.ajpath.2021.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/09/2021] [Accepted: 09/22/2021] [Indexed: 01/03/2023]
Abstract
High circulating lipids occurring in obese individuals and insulin-resistant patients are considered a contributing factor to type 2 diabetes. Exposure to high lipid concentration is proposed to both protect and damage beta-cells under different circumstances. Here, by feeding mice a high-fat diet (HFD) for 2 weeks to up to 14 months, the study showed that HFD initially causes the beta-cells to expand in population, whereas long-term exposure to HFD is associated with failure of beta-cells and the inability of animals to respond to glucose challenge. To prevent the failure of beta-cells and the development of type 2 diabetes, the molecular mechanisms that underlie this biphasic response of beta-cells to lipid exposure were explored. Using palmitic acid (PA) in cultured beta-cells and islets, the study demonstrated that chronic exposure to lipids leads to reduced viability and inhibition of cell cycle progression concurrent with down-regulation of a pro-growth/survival kinase AKT, independent of glucose. This AKT down-regulation by PA is correlated with the induction of mTOR/S6K activity. Inhibiting mTOR activity with rapamycin induced Raptor and restored AKT activity, allowing beta-cells to gain proliferation capacity that was lost after HFD exposure. In summary, a novel mechanism in which lipid exposure may cause the dipole effects on beta-cell growth was elucidated, where mTOR acts as a lipid sensor. These mechanisms can be novel targets for future therapeutic developments.
Collapse
Affiliation(s)
- Richa Aggarwal
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Zhechu Peng
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Ni Zeng
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Joshua Silva
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Lina He
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Jingyu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Anketse Debebe
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Taojian Tu
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Mario Alba
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Chien-Yu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Eileen X. Stiles
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Handan Hong
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Bangyan L. Stiles
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California,Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California,Address correspondence to Bangyan L. Stiles, Ph.D., Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033.
| |
Collapse
|
7
|
Lupse B, Annamalai K, Ibrahim H, Kaur S, Geravandi S, Sarma B, Pal A, Awal S, Joshi A, Rafizadeh S, Madduri MK, Khazaei M, Liu H, Yuan T, He W, Gorrepati KDD, Azizi Z, Qi Q, Ye K, Oberholzer J, Maedler K, Ardestani A. Inhibition of PHLPP1/2 phosphatases rescues pancreatic β-cells in diabetes. Cell Rep 2021; 36:109490. [PMID: 34348155 PMCID: PMC8421018 DOI: 10.1016/j.celrep.2021.109490] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/06/2021] [Accepted: 07/14/2021] [Indexed: 12/16/2022] Open
Abstract
Pancreatic β-cell failure is the key pathogenic element of the complex metabolic deterioration in type 2 diabetes (T2D); its underlying pathomechanism is still elusive. Here, we identify pleckstrin homology domain leucine-rich repeat protein phosphatases 1 and 2 (PHLPP1/2) as phosphatases whose upregulation leads to β-cell failure in diabetes. PHLPP levels are highly elevated in metabolically stressed human and rodent diabetic β-cells. Sustained hyper-activation of mechanistic target of rapamycin complex 1 (mTORC1) is the primary mechanism of the PHLPP upregulation linking chronic metabolic stress to ultimate β-cell death. PHLPPs directly dephosphorylate and regulate activities of β-cell survival-dependent kinases AKT and MST1, constituting a regulatory triangle loop to control β-cell apoptosis. Genetic inhibition of PHLPPs markedly improves β-cell survival and function in experimental models of diabetes in vitro, in vivo, and in primary human T2D islets. Our study presents PHLPPs as targets for functional regenerative therapy of pancreatic β cells in diabetes.
Collapse
Affiliation(s)
- Blaz Lupse
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Karthika Annamalai
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Hazem Ibrahim
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Supreet Kaur
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Shirin Geravandi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Bhavishya Sarma
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Anasua Pal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sushil Awal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Arundhati Joshi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sahar Rafizadeh
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Murali Krishna Madduri
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Mona Khazaei
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Huan Liu
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Ting Yuan
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Wei He
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | | | - Zahra Azizi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran
| | - Qi Qi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jose Oberholzer
- Charles O. Strickler Transplant Center, University of Virginia Medical Center, Charlottesville, VA 22903, USA
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany.
| | - Amin Ardestani
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran.
| |
Collapse
|
8
|
Regulation of basal expression of hepatic PEPCK and G6Pase by AKT2. Biochem J 2020; 477:1021-1031. [PMID: 32096546 DOI: 10.1042/bcj20190570] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/04/2020] [Accepted: 02/25/2020] [Indexed: 01/11/2023]
Abstract
Hepatic glucose metabolism signaling downstream of insulin can diverge to multiple pathways including AKT. Genetic studies suggest that AKT is necessary for insulin to suppress gluconeogenesis. To specifically address the role of AKT2, the dominant liver isoform of AKT in the regulation of gluconeogenesis genes, we generated hepatocytes lacking AKT2 (Akt2-/-). We found that, in the absence of insulin signal, AKT2 is required for maintaining the basal level expression of phosphoenolpyruvate carboxyl kinase (PEPCK) and to a lesser extent G6Pase, two key rate-limiting enzymes for gluconeogenesis that support glucose excursion due to pyruvate loading. We further showed that this function of AKT2 is mediated by the phosphorylation of cyclic AMP response element binding (CREB). Phosphorylation of CREB by AKT2 is needed for CREB to induce the expression of PEPCK and likely represents a priming event for unstimulated cells to poise to receive glucagon and other signals. The inhibition of gluconeogenesis by insulin is also dependent on the reduced FOXO1 transcriptional activity at the promoter of PEPCK. When insulin signal is absent, this activity appears to be inhibited by AKT2 in manner that is independent of its phosphorylation by AKT. Together, this action of AKT2 on FOXO1 and CREB to maintain basal gluconeogenesis activity may provide fine-tuning for insulin and glucocorticoid/glucagon to regulate gluconeogenesis in a timely manner to meet metabolic needs.
Collapse
|
9
|
Chi ZC. Research status and prgoress of nonalcoholic fatty pancreatic disease. Shijie Huaren Xiaohua Zazhi 2020; 28:933-950. [DOI: 10.11569/wcjd.v28.i19.933] [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] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty pancreatic disease (NAFPD) is a disease characterized by an increase in pancreatic fat accumulation. It is a component of the metabolic syndrome and often coexists with nonalcoholic fatty liver disease. Once the diagnosis is established, it is closely related to acute and chronic pancreatitis, type 2 diabetes mellitus, pancreatic fibrosis, and pancreatic cancer. In recent years, it has been confirmed that NAFPD is closely related to cardiovascular disease, liver fibrosis, and liver cancer. The prevalence of NAFPD ranges between 11% and 69%, and increases with age. It is worth noting that the prevalence in obese children is twice as high as that in non-obese children. The high prevalence rate and complexity of the disease have aroused people's high attention. Therefore, to improve the understanding of NAFPD, fully understand the clinical significance of NAFPD, and further study its pathogenesis, diagnosis, and treatment require the collaboration and joint efforts of multiple disciplines, including hepatopathy, gastroenterology, endocrine metabolism, cardiovascular disease, imaging, pathology, and others. In this paper, we review the clinical significance, pathogenesis, and imaging diagnosis of NAFPD and propose our personal understanding of the key points in future research.
Collapse
Affiliation(s)
- Zhao-Chun Chi
- Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao 266011, Shandong Province, China
| |
Collapse
|
10
|
AKT1 Regulates Endoplasmic Reticulum Stress and Mediates the Adaptive Response of Pancreatic β Cells. Mol Cell Biol 2020; 40:MCB.00031-20. [PMID: 32179553 DOI: 10.1128/mcb.00031-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/12/2020] [Indexed: 12/31/2022] Open
Abstract
Isoforms of protein kinase B (also known as AKT) play important roles in mediating insulin and growth factor signals. Previous studies have suggested that the AKT2 isoform is critical for insulin-regulated glucose metabolism, while the role of the AKT1 isoform remains less clear. This study focuses on the effects of AKT1 on the adaptive response of pancreatic β cells. Using a mouse model with inducible β-cell-specific deletion of the Akt1 gene (βA1KO mice), we showed that AKT1 is involved in high-fat-diet (HFD)-induced growth and survival of β cells but is unnecessary for them to maintain a population in the absence of metabolic stress. When unchallenged, βA1KO mice presented the same metabolic profile and β-cell phenotype as the control mice with an intact Akt1 gene. When metabolic stress was induced by HFD, β cells in control mice with intact Akt1 proliferated as a compensatory mechanism for metabolic overload. Similar effects were not observed in βA1KO mice. We further demonstrated that AKT1 protein deficiency caused endoplasmic reticulum (ER) stress and potentiated β cells to undergo apoptosis. Our results revealed that AKT1 protein loss led to the induction of eukaryotic initiation factor 2 α subunit (eIF2α) signaling and ER stress markers under normal-chow-fed conditions, indicating chronic low-level ER stress. Together, these data established a role for AKT1 as a growth and survival factor for adaptive β-cell response and suggest that ER stress induction is responsible for this effect of AKT1.
Collapse
|
11
|
de Toledo M, Lopez-Mejia IC, Cavelier P, Pratlong M, Barrachina C, Gromada X, Annicotte JS, Tazi J, Chavey C. Lamin C Counteracts Glucose Intolerance in Aging, Obesity, and Diabetes Through β-Cell Adaptation. Diabetes 2020; 69:647-660. [PMID: 32005707 DOI: 10.2337/db19-0377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 01/27/2020] [Indexed: 11/13/2022]
Abstract
Aging-dependent changes in tissue function are associated with the development of metabolic diseases. However, the molecular connections linking aging, obesity, and diabetes remain unclear. Lamin A, lamin C, and progerin, products of the Lmna gene, have antagonistic functions on energy metabolism and life span. Lamin C, albeit promoting obesity, increases life span, suggesting that this isoform is crucial for maintaining healthy conditions under metabolic stresses. Because β-cell loss during obesity or aging leads to diabetes, we investigated the contribution of lamin C to β-cell function in physiopathological conditions. We demonstrate that aged lamin C only-expressing mice (Lmna LCS/LCS ) become obese but remain glucose tolerant due to adaptive mechanisms including increased β-cell mass and insulin secretion. Triggering diabetes in young mice revealed that Lmna LCS/LCS animals normalize their fasting glycemia by both increasing insulin secretion and regenerating β-cells. Genome-wide analyses combined to functional analyses revealed an increase of mitochondrial biogenesis and global translational rate in Lmna LCS/LCS islets, two major processes involved in insulin secretion. Altogether, our results demonstrate for the first time that the sole expression of lamin C protects from glucose intolerance through a β-cell-adaptive transcriptional program during metabolic stresses, highlighting Lmna gene processing as a new therapeutic target for diabetes treatment.
Collapse
Affiliation(s)
- Marion de Toledo
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | | | - Patricia Cavelier
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Marine Pratlong
- Montpellier GenomiX, Biocampus Montpellier, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Célia Barrachina
- Montpellier GenomiX, Biocampus Montpellier, CNRS, INSERM, University of Montpellier, Montpellier, France
| | - Xavier Gromada
- Université Lille, CNRS, CHU Lille, Institut Pasteur de Lille, UMR 8199, European Genomic Institute for Diabetes, Lille, France
| | - Jean-Sébastien Annicotte
- Université Lille, CNRS, CHU Lille, Institut Pasteur de Lille, UMR 8199, European Genomic Institute for Diabetes, Lille, France
| | - Jamal Tazi
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Carine Chavey
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| |
Collapse
|
12
|
Wang P, Liu Q, Zhao H, Bishop JO, Zhou G, Olson LK, Moore A. miR-216a-targeting theranostic nanoparticles promote proliferation of insulin-secreting cells in type 1 diabetes animal model. Sci Rep 2020; 10:5302. [PMID: 32210316 PMCID: PMC7093482 DOI: 10.1038/s41598-020-62269-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/06/2020] [Indexed: 11/30/2022] Open
Abstract
Aberrant expression of miRNAs in pancreatic islets is closely related to the development of type 1 diabetes (T1D). The aim of this study was to identify key miRNAs dysregulated in pancreatic islets during T1D progression and to develop a theranostic approach to modify their expression using an MRI-based nanodrug consisting of iron oxide nanoparticles conjugated to miRNA-targeting oligonucleotides in a mouse model of T1D. Isolated pancreatic islets were derived from NOD mice of three distinct age groups (3, 8 and 18-week-old). Total RNA collected from cultured islets was purified and global miRNA profiling was performed with 3D-Gene global miRNA microarray mouse chips encompassing all mouse miRNAs available on the Sanger miRBase V16. Of the miRNAs that were found to be differentially expressed across three age groups, we identified one candidate (miR-216a) implicated in beta cell proliferation for subsequent validation by RT-PCR. Alterations in miR-216a expression within pancreatic beta cells were also examined using in situ hybridization on the frozen pancreatic sections. For in vitro studies, miR-216a mimics/inhibitors were conjugated to iron oxide nanoparticles and incubated with beta cell line, βTC-6. Cell proliferation marker Ki67 was evaluated. Expression of the phosphatase and tensin homolog (PTEN), which is one of the direct targets of miR-216a, was analyzed using western blot. For in vivo study, the miR-216a mimics/inhibitors conjugated to the nanoparticles were injected into 12-week-old female diabetic Balb/c mice via pancreatic duct. The delivery of the nanodrug was monitored by in vivo MRI. Blood glucose of the treated mice was monitored post injection. Ex vivo histological analysis of the pancreatic sections included staining for insulin, PTEN and Ki67. miRNA microarray demonstrated that the expression of miR-216a in the islets from NOD mice significantly changed during T1D progression. In vitro studies showed that treatment with a miR-216a inhibitor nanodrug suppressed proliferation of beta cells and increased the expression of PTEN, a miR-216a target. In contrast, introduction of a mimic nanodrug decreased PTEN expression and increased beta cell proliferation. Animals treated in vivo with a mimic nanodrug had higher insulin-producing functionality compared to controls. These observations were in line with downregulation of PTEN and increase in beta cell proliferation in that group. Our studies demonstrated that miR-216a could serve as a potential therapeutic target for the treatment of diabetes. miR-216a-targeting theranostic nanodrugs served as exploratory tools to define functionality of this miRNA in conjunction with in vivo MR imaging.
Collapse
Affiliation(s)
- Ping Wang
- Precision Health Program, Department of Radiology, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48823, USA.
| | - Qiong Liu
- Department of Anatomy, Histology and Embryology, School of Basic Medical Science, Fudan University, Shanghai, 200032, China
| | - Hongwei Zhao
- Shanxi Medical University, Taiyuan, Shanxi, 030001, China.,Department of Gynecologic Oncology, Shanxi Provincial Cancer Hospital, Taiyuan, Shanxi, 030013, China
| | - Jack Owen Bishop
- Precision Health Program, Department of Radiology, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48823, USA.,Department of Neuroscience, College of Natural Science, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Guoli Zhou
- Biomedical Research Informatics Core, Clinical & Translational Sciences Institute, Michigan State University, East Lansing, Michigan, 48824, USA
| | - L Karl Olson
- Department of Physiology, College of Natural Science, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Anna Moore
- Precision Health Program, Department of Radiology, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48823, USA.
| |
Collapse
|
13
|
Tu T, Chen J, Chen L, Stiles BL. Dual-Specific Protein and Lipid Phosphatase PTEN and Its Biological Functions. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a036301. [PMID: 31548229 DOI: 10.1101/cshperspect.a036301] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) encodes a 403-amino acid protein with an amino-terminal domain that shares sequence homology with the actin-binding protein tensin and the putative tyrosine-protein phosphatase auxilin. Crystal structure analysis of PTEN has revealed a C2 domain that binds to phospholipids in membranes and a phosphatase domain that displays dual-specific activity toward both tyrosine (Y), serine (S)/threonine (T), as well as lipid substrates in vitro. Characterized primarily as a lipid phosphatase, PTEN plays important roles in multiple cellular processes including cell growth/survival as well as metabolism.
Collapse
Affiliation(s)
- Taojian Tu
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA
| | - Jingyu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA
| | - Lulu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA
| | - Bangyan L Stiles
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA.,Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
| |
Collapse
|
14
|
Cottage CT, Peterson N, Kearley J, Berlin A, Xiong X, Huntley A, Zhao W, Brown C, Migneault A, Zerrouki K, Criner G, Kolbeck R, Connor J, Lemaire R. Targeting p16-induced senescence prevents cigarette smoke-induced emphysema by promoting IGF1/Akt1 signaling in mice. Commun Biol 2019; 2:307. [PMID: 31428695 PMCID: PMC6689060 DOI: 10.1038/s42003-019-0532-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 06/27/2019] [Indexed: 12/16/2022] Open
Abstract
Senescence is a mechanism associated with aging that alters tissue regeneration by depleting the stem cell pool. Chronic obstructive pulmonary disease (COPD) displays hallmarks of senescence, including a diminished stem cell population. DNA damage from cigarette smoke (CS) induces senescence via the p16 pathway. This study evaluated the contribution of p16 to CS-associated lung pathologies. p16 expression was prominent in human COPD lungs compared with normal subjects. CS induces impaired pulmonary function, emphysema, and increased alveolar epithelial cell (AECII) senescence in wild-type mice, whereas CS-exposed p16-/- mice exhibit normal pulmonary function, reduced emphysema, diminished AECII senescence, and increased pro-growth IGF1 signaling, suggesting that improved lung function in p16-/- mice was due to increased alveolar progenitor cell proliferation. In conclusion, our study suggests that targeting senescence may facilitate alveolar regeneration in COPD emphysema by promoting IGF1 proliferative signaling.
Collapse
Affiliation(s)
- Christopher T. Cottage
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Norman Peterson
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Jennifer Kearley
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Aaron Berlin
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Ximing Xiong
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Anna Huntley
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Weiguang Zhao
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Charles Brown
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Annik Migneault
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Kamelia Zerrouki
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | | | - Roland Kolbeck
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Jane Connor
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| | - Raphael Lemaire
- Research and Early Development, Respiratory, Inflammation and Autoimmune (RIA), BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878 United States
| |
Collapse
|
15
|
Oakie A, Feng ZC, Li J, Silverstein J, Yee SP, Wang R. Long-term c-Kit overexpression in beta cells compromises their function in ageing mice. Diabetologia 2019; 62:1430-1444. [PMID: 31154478 DOI: 10.1007/s00125-019-4890-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 04/04/2019] [Indexed: 12/23/2022]
Abstract
AIMS/HYPOTHESIS c-Kit signalling regulates intracellular pathways that enhance beta cell proliferation, insulin secretion and islet vascularisation in mice up to 28 weeks of age and on short-term high-fat diet. However, long-term c-Kit activation in ageing mouse islets has yet to be examined. This study utilises beta cell-specific c-Kit-overexpressing transgenic (c-KitβTg) ageing mice (~60 weeks) to determine the effect of its activation on beta cell dysfunction and insulin secretion. METHODS Wild-type and c-KitβTg mice, aged 60 weeks, were examined using metabolic tests to determine glucose tolerance and insulin secretion. Pancreas histology and proteins in isolated islets were examined to determine the expression of beta cell transcription factors, proliferation and intracellular signalling. To determine the role of insulin receptor signalling in ageing c-KitβTg mice, we generated beta cell-specific inducible insulin receptor knockout in ageing c-KitβTg mice (c-KitβTg;βIRKO mice) and examined the ageing mice for glucose tolerance and islet histology. RESULTS Ageing c-KitβTg mice progressively developed glucose intolerance, compared with age-matched wild-type littermates, due to impaired insulin secretion. Increased beta cell mass, proliferation and nuclear forkhead box transcription factor O1 (FOXO1) expression and reduced exocytotic protein levels were detected in ageing c-KitβTg mouse islets. Protein analyses of isolated islets showed increased insulin receptor, phosphorylated IRS-1Ser612 and cleaved poly(ADP-ribose) polymerase levels in ageing c-KitβTg mice. Ageing c-KitβTg mouse islets treated ex vivo with insulin demonstrated reduced Akt phosphorylation, indicating that prolonged c-Kit induced beta cell insulin insensitivity. Ageing c-KitβTg;βIRKO mice displayed improved glucose tolerance and beta cell function compared with ageing c-KitβTg mice. CONCLUSIONS/INTERPRETATION These findings indicate that long-term c-Kit overexpression in beta cells has a negative impact on insulin exocytosis and that temporally dependent regulation of c-Kit-insulin receptor signalling is important for optimal beta cell function.
Collapse
Affiliation(s)
- Amanda Oakie
- Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, ON, N6C 2V5, Canada
- Department of Pathology and Laboratory Medicine, University of Western Ontario, London, ON, Canada
| | - Zhi-Chao Feng
- Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, ON, N6C 2V5, Canada
| | - Jinming Li
- Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, ON, N6C 2V5, Canada
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
| | - Jenna Silverstein
- Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, ON, N6C 2V5, Canada
| | - Siu-Pok Yee
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
- Department of Genetics and Genome Sciences, University of Connecticut Health Center, Farmington, CT, USA
| | - Rennian Wang
- Children's Health Research Institute, University of Western Ontario, Victoria Research Laboratories, Room A5-140, 800 Commissioners Road East, London, ON, N6C 2V5, Canada.
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada.
- Department of Medicine, University of Western Ontario, London, ON, Canada.
| |
Collapse
|
16
|
Tian Y, Li H, Qiu T, Dai J, Zhang Y, Chen J, Cai H. Loss of PTEN induces lung fibrosis via alveolar epithelial cell senescence depending on NF-κB activation. Aging Cell 2019; 18:e12858. [PMID: 30548445 PMCID: PMC6351835 DOI: 10.1111/acel.12858] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/27/2018] [Accepted: 09/15/2018] [Indexed: 12/13/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is an aging‐associated disease with poor prognosis. Currently, there are no effective drugs for preventing the disease process. The mechanisms underlying the role of alveolar epithelial cell (AEC) senescence in the pathogenesis of IPF remain poorly understood. We aimed to explore whether PTEN/NF‐κB activated AEC senescence thus resulting in lung fibrosis. First, we investigated the association between the activation of PTEN/NF‐κB and cellular senescence in lung tissues from IPF patients. As a result, decreased PTEN, activated NF‐κB and increased senescent markers (P21WAF1, P16ink4a, and SA‐β‐gal) were found in AECs in fibrotic lung tissues detected by immunohistochemistry (IHC) and immunofluorescence (IF). In vitro experiments showed increased expression levels of senescent markers and augmented senescence‐associated secretory phenotype (SASP) in AECs treated with bleomycin (Blm); however, PTEN was reduced significantly following IκB, IKK, and NF‐κB activation after stimulation with Blm in AECs. AEC senescence was accelerated by PTEN knockdown, whereas senescence was reversed via NF‐κB knockdown and the pharmacological inhibition (BMS‐345541) of the NF‐κB pathway. Interestingly, we observed increased collagen deposition in fibroblasts cultured with the supernatants collected from senescent AECs. Conversely, the deposition of collagen in fibroblasts was reduced with exposure to the supernatants collected from NF‐κB knockdown AECs. These findings indicated that senescent AECs controlled by the PTEN/NF‐κB pathway facilitated collagen accumulation in fibroblasts, resulting in lung fibrosis. In conclusion, our study supports the notion that as an initial step in IPF, the senescence process in AECs may be a potential therapeutic target, and the PTEN/NF‐κB pathway may be a promising candidate for intervention.
Collapse
Affiliation(s)
- Yaqiong Tian
- Department of Respiratory Medicine The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing China
| | - Hui Li
- Department of Respiratory Medicine The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing China
| | - Ting Qiu
- Department of Respiratory Medicine KunShan Hospital of Traditional Chinese Medicine Kunshan China
| | - Jinghong Dai
- Department of Respiratory Medicine The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing China
| | - Yingwei Zhang
- Department of Respiratory Medicine The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing China
| | - Jingyu Chen
- Jiangsu Key Laboratory of Organ Transplantation, Wuxi People’s Hospital Nanjing Medical University Wuxi China
| | - Hourong Cai
- Department of Respiratory Medicine The Affiliated Drum Tower Hospital of Nanjing University Medical School Nanjing China
| |
Collapse
|
17
|
Bellelli R, Vitagliano D, Federico G, Marotta P, Tamburrino A, Salerno P, Paciello O, Papparella S, Knauf JA, Fagin JA, Refetoff S, Troncone G, Santoro M. Oncogene-induced senescence and its evasion in a mouse model of thyroid neoplasia. Mol Cell Endocrinol 2018; 460:24-35. [PMID: 28652169 PMCID: PMC5741508 DOI: 10.1016/j.mce.2017.06.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 05/30/2017] [Accepted: 06/22/2017] [Indexed: 11/27/2022]
Abstract
Here we describe a conditional doxycycline-dependent mouse model of RET/PTC3 (NCOA4-RET) oncogene-induced thyroid tumorigenesis. In these mice, after 10 days of doxycycline (dox) administration, RET/PTC3 expression induced mitogen activated protein kinase (MAPK) stimulation and a proliferative response which resulted in the formation of hyperplastic thyroid lesions. This was followed, after 2 months, by growth arrest accompanied by typical features of oncogene-induced senescence (OIS), including upregulation of p16INK4A and p21CIP, positivity at the Sudan black B, activation of the DNA damage response (DDR) markers γH2AX and pChk2 T68, and induction of p53 and p19ARF. After 5 months, about half of thyroid lesions escaped OIS and formed tumors that remained dependent on RET/PTC3 expression. This progression was accompanied by activation of AKT-FOXO1/3a pathway and increased serum TSH levels.
Collapse
Affiliation(s)
- Roberto Bellelli
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita' Federico II c/o Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Via S Pansini 5, 80131 Naples, Italy
| | - Donata Vitagliano
- Dipartimento Medico-Chirurgico di Internistica Clinica e Sperimentale, Seconda Universita' di Napoli, Via S Pansini 5, 80131 Naples, Italy
| | - Giorgia Federico
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita' Federico II c/o Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Via S Pansini 5, 80131 Naples, Italy
| | - Pina Marotta
- IRGS, Biogem, Via Camporeale, Ariano Irpino, 83031 Avellino, Italy
| | - Anna Tamburrino
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita' Federico II c/o Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Via S Pansini 5, 80131 Naples, Italy
| | - Paolo Salerno
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita' Federico II c/o Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Via S Pansini 5, 80131 Naples, Italy
| | - Orlando Paciello
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Universita' Federico II, Via Delpino 1, Naples, Italy
| | - Serenella Papparella
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Universita' Federico II, Via Delpino 1, Naples, Italy
| | - Jeffrey A Knauf
- Human Oncology and Pathogenesis Program, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - James A Fagin
- Human Oncology and Pathogenesis Program, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Samuel Refetoff
- Department of Medicine, Department of Pediatrics, The Committee on Genetics, The University of Chicago, Chicago, IL, USA
| | - Giancarlo Troncone
- Dipartimento di Sanità Pubblica, Universita' Federico II, Via S Pansini 5, 80131 Naples, Italy
| | - Massimo Santoro
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Universita' Federico II c/o Istituto di Endocrinologia e Oncologia Sperimentale, CNR, Via S Pansini 5, 80131 Naples, Italy.
| |
Collapse
|
18
|
Yanai H, Fraifeld VE. The role of cellular senescence in aging through the prism of Koch-like criteria. Ageing Res Rev 2018; 41:18-33. [PMID: 29106993 DOI: 10.1016/j.arr.2017.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/11/2017] [Accepted: 10/23/2017] [Indexed: 12/13/2022]
Abstract
Since Hayflick's discovery of cellular senescence (CS), a great volume of knowledge in the field has been accumulated and intensively discussed. Here, we attempted to organize the evidence "for" and "against" the hypothesized causal role of CS in aging. For that purpose, we utilized robust Koch-like logical criteria, based on the assumption that some quantitative relationships between the accumulation of senescent cells and aging rate should exist. If so, it could be expected that (i) the "CS load" would be greater in the premature aging phenotype and lesser in longevity phenotype; (ii) CS would promote age-related diseases, and (iii) the interventions that modulate the levels of senescent cells should also modulate health/lifespan. The analysis shows that CS can be considered a causal factor of aging and an important player in various age-related diseases, though its contribution may greatly vary across species. While the relative impact of senescent cells to aging could overall be rather limited and their elimination is hardly expected to be the "fountain of youth", the potential benefits of the senolytic strategy seems a promising option in combating age-related diseases and extending healthspan.
Collapse
|
19
|
Chen CY, Chen J, He L, Stiles BL. PTEN: Tumor Suppressor and Metabolic Regulator. Front Endocrinol (Lausanne) 2018; 9:338. [PMID: 30038596 PMCID: PMC6046409 DOI: 10.3389/fendo.2018.00338] [Citation(s) in RCA: 327] [Impact Index Per Article: 54.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/05/2018] [Indexed: 12/19/2022] Open
Abstract
Phosphatase and Tensin Homolog deleted on Chromosome 10 (PTEN) is a dual phosphatase with both protein and lipid phosphatase activities. PTEN was first discovered as a tumor suppressor with growth and survival regulatory functions. In recent years, the function of PTEN as a metabolic regulator has attracted significant attention. As the lipid phosphatase that dephosphorylates phosphatidylinositol-3, 4, 5-phosphate (PIP3), PTEN reduces the level of PIP3, a critical 2nd messenger mediating the signal of not only growth factors but also insulin. In this review, we introduced the discovery of PTEN, the PTEN-regulated canonical and nuclear signals, and PTEN regulation. We then focused on the role of PTEN and PTEN-regulated signals in metabolic regulation. This included the role of PTEN in glycolysis, gluconeogenesis, glycogen synthesis, lipid metabolism as well as mitochondrial metabolism. We also included how PTEN and PTEN regulated metabolic functions may act paradoxically toward insulin sensitivity and tumor metabolism and growth. Further understanding of how PTEN regulates metabolism and how such regulations lead to different biological outcomes is necessary for interventions targeting at the PTEN-regulated signals in either cancer or diabetes treatment.
Collapse
Affiliation(s)
- Chien-Yu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Jingyu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Lina He
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
| | - Bangyan L. Stiles
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- *Correspondence: Bangyan L. Stiles
| |
Collapse
|
20
|
Moullé VS, Ghislain J, Poitout V. Nutrient regulation of pancreatic β-cell proliferation. Biochimie 2017; 143:10-17. [PMID: 28987628 DOI: 10.1016/j.biochi.2017.09.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/28/2017] [Indexed: 12/17/2022]
Abstract
Excess consumption of energy-dense foods combined with a sedentary lifestyle is driving an obesity epidemic. Although obesity is closely associated with insulin resistance, most individuals meet the insulin demand by increasing their functional β-cell mass. Those who eventually develop type 2 diabetes are distinguished by a failure in this compensatory process. Although a causal role of insulin resistance in compensatory β-cell responses has received considerable experimental support, precisely how the β cell senses changes in the metabolic environment is still unknown. As metabolism of glucose, lipids and amino acids is profoundly altered in obesity, it is not surprising that these nutrients are conspicuous among the factors proposed to contribute. In this review we summarise our understanding of the role of nutrients, in particular glucose, fatty acids and amino acids in β-cell compensation with a particular emphasis on their relation to insulin resistance-induced factors and their underlying mechanism of action. Finally, we describe the concept of epigenetic programming and review recent studies illustrating how the status of the β cell epigenome is a product of its nutrient environment, and how metabolic programming of the β cell contributes to diabetes risk.
Collapse
Affiliation(s)
- Valentine S Moullé
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada.
| | - Julien Ghislain
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada.
| | - Vincent Poitout
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada; Department of Medicine, University of Montreal, QC, Canada; Department of Biochemistry and Molecular Medicine, University of Montreal, QC, Canada.
| |
Collapse
|
21
|
Gao Y, Lin P, Lydon JP, Li Q. Conditional abrogation of transforming growth factor-β receptor 1 in PTEN-inactivated endometrium promotes endometrial cancer progression in mice. J Pathol 2017; 243:89-99. [PMID: 28657664 DOI: 10.1002/path.4930] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/10/2017] [Accepted: 05/28/2017] [Indexed: 12/16/2022]
Abstract
Although a putative role for transforming growth factor-β (TGFB) signalling in the pathogenesis of human endometrial cancer has long been proposed, the precise function of TGFB signalling in the development and progression of endometrial cancer remains elusive. Depletion of phosphatase and tensin homologue (PTEN) in the mouse uterus causes endometrial cancer. To identify the potential role of TGFB signalling in endometrial cancer, we simultaneously deleted TGFB receptor 1 (Tgfbr1) and Pten in the mouse uterus by using Cre-recombinase driven by the progesterone receptor (termed Ptend/d ;Tgfbr1d/d ). We found that Ptend/d ;Tgfbr1d/d mice developed severe endometrial lesions that progressed more rapidly than those resulting from conditional deletion of Pten alone, suggesting that TGFB signalling synergizes with PTEN to suppress endometrial cancer progression. Remarkably, Ptend/d ;Tgfbr1d/d mice developed distant pulmonary metastases, leading to a significantly reduced lifespan. The development of metastasis and accelerated tumour progression in Ptend/d ;Tgfbr1d/d mice are associated with increased production of proinflammatory chemokines, enhanced cancer cell motility, as shown by myometrial invasion and disruption, and an altered tumour microenvironment characterized by recruitment of tumour-associated macrophages. Thus, conditional deletion of Tgfbr1 in PTEN-inactivated endometrium leads to a disease that recapitulates invasive and lethal human endometrial cancer. This mouse model may be valuable for preclinical testing of new cancer therapies, particularly those targeting metastasis, one of the hallmarks of cancer and a major cause of death in endometrial cancer patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Yang Gao
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA
| | - Pengfei Lin
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA.,Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, PR China
| | - John P Lydon
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Qinglei Li
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX, USA
| |
Collapse
|
22
|
Wen J, Xue T, Huang Y, Chen X, Xue Y, Lin W, Zhang L, Yao J, Huang H, Liang J, Li L, Lin L, Shi L, Cai L, Zhu Z, Chen G. Is β-cell aging involved in the pathogenesis of diabetes? J Diabetes 2017; 9:707-716. [PMID: 27613695 DOI: 10.1111/1753-0407.12481] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 08/22/2016] [Accepted: 09/03/2016] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND β-Cells at different stages have different functions and capacity for proliferation, regenerative and apoptosis. The aim of the present study was to investigate whether there are changes in β-cell phonotype in the development of diabetes to identify potential β-cell targets to prevent the progression of diabetes. METHODS A cross-sectional study was performed on pancreatic tissues obtained from 80 patients classified into three groups: 25 with type 2 diabetes (T2D), 25 with impaired fasting glucose (IFG), and 30 non-diabetics (ND). The ratio of the insulin-positive area to pancreatic area was used as an indirect marker of β-cell mass. Insulin-positive duct cells and scattered β-cells were defined as newly generated β-cells, whereas insulin/neurogenin 3 (Ngn3), insulin/v-maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MafA) and insulin/P16 double-positive cells were defined as immature, mature, and senescent β-cells, respectively; Ki67 was used as a marker of cell proliferation, and terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL) was used as a marker of cell apoptosis. Data were analyzed using the Kruskal-Wallis test. RESULTS There were no significant differences in β-cell mass, the prevalence of insulin-positive duct cells, scattered β-cells, or insulin/Ngn3, insulin/MafA, and Insulin/Ki67 double-positive cells among groups. The incidence of insulin/P16 double-positive cells was significantly higher in T2D than ND. β-Cell apoptosis was significantly higher in T2D and IFG than ND. CONCLUSION The senescence and apoptosis of β-cells may be involved in the course of diabetes.
Collapse
Affiliation(s)
- Junping Wen
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Ting Xue
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Ying Huang
- Department of Pathology, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, China
| | - Xiaoyan Chen
- Department of Pathology, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, China
| | - Ying Xue
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Wei Lin
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Lizhen Zhang
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Jin Yao
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Huibin Huang
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Jixing Liang
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Liantao Li
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Lixiang Lin
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Lidan Shi
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Liangchun Cai
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Zhuangli Zhu
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| | - Gang Chen
- Department of Endocrinology, Fujian Provincial Hospital, Fujian Academy of Medical Sciences and, Fujian Medical University, Fuzhou, China
| |
Collapse
|
23
|
Brandmaier A, Hou SQ, Shen WH. Cell Cycle Control by PTEN. J Mol Biol 2017; 429:2265-2277. [PMID: 28602818 DOI: 10.1016/j.jmb.2017.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/28/2017] [Accepted: 06/02/2017] [Indexed: 12/26/2022]
Abstract
Continuous and error-free chromosome inheritance through the cell cycle is essential for genomic stability and tumor suppression. However, accumulation of aberrant genetic materials often causes the cell cycle to go awry, leading to malignant transformation. In response to genotoxic stress, cells employ diverse adaptive mechanisms to halt or exit the cell cycle temporarily or permanently. The intrinsic machinery of cycling, resting, and exiting shapes the cellular response to extrinsic stimuli, whereas prevalent disruption of the cell cycle machinery in tumor cells often confers resistance to anticancer therapy. Phosphatase and tensin homolog (PTEN) is a tumor suppressor and a guardian of the genome that is frequently mutated or deleted in human cancer. Moreover, it is increasingly evident that PTEN deficiency disrupts the fundamental processes of genetic transmission. Cells lacking PTEN exhibit cell cycle deregulation and cell fate reprogramming. Here, we review the role of PTEN in regulating the key processes in and out of cell cycle to optimize genomic integrity.
Collapse
Affiliation(s)
- Andrew Brandmaier
- Department of Radiation Oncology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA
| | - Sheng-Qi Hou
- Department of Radiation Oncology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA
| | - Wen H Shen
- Department of Radiation Oncology, Weill Cornell Medicine, Cornell University, New York, NY 10065, USA.
| |
Collapse
|
24
|
Jia C, Medina V, Liu C, He L, Qian D, Taojian T, Okamoto CT, Stiles BL. Crosstalk of LKB1- and PTEN-regulated signals in liver morphogenesis and tumor development. Hepatol Commun 2017; 1:153-167. [PMID: 29152604 PMCID: PMC5687583 DOI: 10.1002/hep4.1027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Liver kinase B 1 (LKB1 or STK11) and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) are two tumor suppressors that regulate the mammalian target of rapamycin signaling pathway. Deletion studies show that loss of either Lkb1 (Lkb+/–) or Pten (PtenloxP/loxP; Alb‐Cre+) leads to liver injury and development of hepatocarcinoma. In this study, we investigated the crosstalk of LKB1 and PTEN loss during tumorigenesis and liver development. We show that haplo‐insufficiency of Lkb1 in the liver leads to advanced tumor development in Pten‐null mice (PtenloxP/loxP; LkbloxP/+; Alb‐Cre+). Our analysis shows that LKB1 and PTEN interact with each other in their regulation of fatty acid synthase as well as p21 expression. The combined loss of LKB1 and PTEN (PtenloxP/loxP; LkbloxP/loxP; Alb‐Cre+) also leads to the inability to form zonal structures in the liver. The lack of metabolic zonal structures is consistent with the inability of the livers to store glycogen as well as elevated plasma bilirubin and alanine aminotransferase, indicative of liver dysfunction. These structural and functional defects are associated with cytoplasm distribution of a canalicular membrane protein multidrug resistant protein 2, which is responsible for clearing bilirubin. This observed regulation of multidrug resistant protein 2 by LKB1 likely contributes to the lack of cellular polarity and the early lethality phenotype associated with the homozygous loss of Lkb1 alone or in combination with Pten. Finally, Pten deletion does not rescue the precocious ductal plate formation reported for Lkb1‐deleted livers. Conclusion: Our study dissected the functional and molecular crosstalk of PTEN and LKB1 and elucidated key molecular targets for such interactions. (Hepatology Communications 2017;1:153‐167)
Collapse
Affiliation(s)
- Chengyou Jia
- Department of Nuclear Medicine, Central Laboratory for Medical Research, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.,Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Vivian Medina
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Chenchang Liu
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Lina He
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Daohai Qian
- Department of Nuclear Medicine, Central Laboratory for Medical Research, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China.,Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Tu Taojian
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Curtis T Okamoto
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033
| | - Bangyan L Stiles
- Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033.,Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033
| |
Collapse
|
25
|
Kong Y, Sharma RB, Nwosu BU, Alonso LC. Islet biology, the CDKN2A/B locus and type 2 diabetes risk. Diabetologia 2016; 59:1579-93. [PMID: 27155872 PMCID: PMC4930689 DOI: 10.1007/s00125-016-3967-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 03/29/2016] [Indexed: 02/06/2023]
Abstract
Type 2 diabetes, fuelled by the obesity epidemic, is an escalating worldwide cause of personal hardship and public cost. Diabetes incidence increases with age, and many studies link the classic senescence and ageing protein p16(INK4A) to diabetes pathophysiology via pancreatic islet biology. Genome-wide association studies (GWASs) have unequivocally linked the CDKN2A/B locus, which encodes p16 inhibitor of cyclin-dependent kinase (p16(INK4A)) and three other gene products, p14 alternate reading frame (p14(ARF)), p15(INK4B) and antisense non-coding RNA in the INK4 locus (ANRIL), with human diabetes risk. However, the mechanism by which the CDKN2A/B locus influences diabetes risk remains uncertain. Here, we weigh the evidence that CDKN2A/B polymorphisms impact metabolic health via islet biology vs effects in other tissues. Structured in a bedside-to-bench-to-bedside approach, we begin with a summary of the evidence that the CDKN2A/B locus impacts diabetes risk and a brief review of the basic biology of CDKN2A/B gene products. The main emphasis of this work is an in-depth look at the nuanced roles that CDKN2A/B gene products and related proteins play in the regulation of beta cell mass, proliferation and insulin secretory function, as well as roles in other metabolic tissues. We finish with a synthesis of basic biology and clinical observations, incorporating human physiology data. We conclude that it is likely that the CDKN2A/B locus influences diabetes risk through both islet and non-islet mechanisms.
Collapse
Affiliation(s)
- Yahui Kong
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
| | - Rohit B Sharma
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
| | - Benjamin U Nwosu
- Division of Endocrinology, Department of Pediatrics, University of Massachusetts Medical School, Worcester, MA, USA
| | - Laura C Alonso
- AS7-2047, Division of Diabetes, Department of Medicine, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA.
| |
Collapse
|
26
|
Xie Y, Naizabekov S, Chen Z, Tokay T. Power of PTEN/AKT: Molecular switch between tumor suppressors and oncogenes. Oncol Lett 2016; 12:375-378. [PMID: 27347153 DOI: 10.3892/ol.2016.4636] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 04/29/2016] [Indexed: 12/25/2022] Open
Abstract
An increasing amount of evidence has shown that tumor suppressors can become oncogenes, or vice versa, but the mechanism behind this is unclear. Recent findings have suggested that phosphatase and tensin homolog (PTEN) is one of the powerful switches for the conversion between tumor suppressors and oncogenes. PTEN regulates a number of cellular processes, including cell death and proliferation, through the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Furthermore, a number of studies have suggested that PTEN deletions may alter various functions of certain tumor suppressor and oncogenic proteins. The aim of the present review was to analyze specific cases driven by PTEN loss/AKT activation, including aberrant signaling pathways and novel drug targets for clinical application in personalized medicine. The findings illustrate how PTEN loss and/or AKT activation switches MDM2-dependent p53 downregulation, and induces conversion between oncogene and tumor suppressor in enhancer of zeste homolog 2, BTB domain-containing 7A, alternative reading frame 2, p27 and breast cancer 1, early onset, through multiple mechanisms. This review highlights the genetic basis of complex drug targets and provides insights into the rationale of precision cancer therapy.
Collapse
Affiliation(s)
- Yingqiu Xie
- Department of Biology, Nazarbayev University, School of Science and Technology, Astana 010000, Republic of Kazakhstan
| | - Sanzhar Naizabekov
- Department of Biology, Nazarbayev University, School of Science and Technology, Astana 010000, Republic of Kazakhstan
| | - Zhanlin Chen
- Lipscomb University, Lipscomb Academy, Nashville, TN 37204, USA
| | - Tursonjan Tokay
- Center for Life Sciences, National Laboratory Astana, Nazarbayev University, Astana 010000, Republic of Kazakhstan
| |
Collapse
|
27
|
Kawano M, Tanaka K, Itonaga I, Iwasaki T, Tsumura H. MicroRNA-301a promotes cell proliferation via PTEN targeting in Ewing's sarcoma cells. Int J Oncol 2016; 48:1531-40. [PMID: 26846737 DOI: 10.3892/ijo.2016.3379] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 01/13/2016] [Indexed: 12/25/2022] Open
Abstract
MicroRNAs (miRNAs) regulate cell proliferation and differentiation by affecting gene expression at the post-transcriptional level by binding to complementary sequences within mRNAs in cancer cells, indicating that miRNAs can function as tumor suppressors or oncogenes. Recent studies showed that dysregulation of miRNA expression was associated with increased tumorigenicity and poor prognosis in several types of cancers, including Ewing's sarcoma (ES). To explore possible oncogenic factors in ES, we conducted microarray-based investigation and profiled the changes in miRNA expression and their effects on downstream mRNAs in five ES cell lines and human mesenchymal stem cells (hMSCs). miR-301a was significantly upregulated, while the phosphatase and tensin homolog (PTEN) expression was significantly downregulated in all tested ES cells as compared to hMSCs. When anti-miR-301a was transfected into ES cell lines, PTEN expression was significantly enhanced, suggesting that PTEN might be a target of miR-301a in ES cells. The expression of protein kinase B (Akt), which is inversely correlated with PTEN expression, was significantly downregulated in anti-miR-301a-transfected cells. Additionally, the transfection of anti-miR-301a inhibited ES cell proliferation and cell cycle progression. Furthermore, downregulation of miR-301a in ES cells significantly suppressed tumor growth in vivo. Our results demonstrated the novel mechanism controlling PTEN expression via miR-301a in ES cells. Given that PTEN is a pivotal phosphatase factor that regulates cell cycle progression, apoptosis, and proliferation, these results might lead to development of new ES-related therapeutic targets.
Collapse
Affiliation(s)
- Masanori Kawano
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Kazuhiro Tanaka
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Ichiro Itonaga
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Tatsuya Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| | - Hiroshi Tsumura
- Department of Orthopaedic Surgery, Faculty of Medicine, Oita University, Oita 879-5593, Japan
| |
Collapse
|
28
|
Abstract
OBJECTIVES In injury conditions, myofibroblasts are induced to lay down matrix proteins and support the repair process. In this study, we investigated the role of myofibroblasts, particularly stellate cells, in the growth and regeneration of pancreatic β cells. METHODS We used both in vitro and in vivo approaches to address whether stellate cells may promote the growth of β cells. RESULTS Our experiments demonstrated that activated stellate cells support the proliferation of β cells in vitro. In vivo, mesenchymals surrounding the pancreatic islets are activated (induced to proliferate) in the islet regeneration model of Pten null mice. These mesenchymals display markers of pancreatic stellate cells, such as desmin and to a lesser extent, smooth muscle actin α. We have shown previously that targeted β-cell deletion of Pten lead to a significant increase in total islet mass. This phenotype was accompanied by an increase in peri-islet mitotic activity, particularly in islets injured by streptozotocin, a β cell-specific toxin. CONCLUSIONS Together with the in vitro observations, our data, here, suggest that that these mesenchymal cells may support the regeneration of the islets. Identifying how the communication occurs may provide clinically relevant mechanism for inducing β-cell regeneration.
Collapse
|
29
|
Abstract
Three theories of regeneration dominate neuroscience today, all purporting to explain why the adult central nervous system (CNS) cannot regenerate. One theory proposes that Nogo, a molecule expressed by myelin, prevents axonal growth. The second theory emphasizes the role of glial scars. The third theory proposes that chondroitin sulfate proteoglycans (CSPGs) prevent axon growth. Blockade of Nogo, CSPG, and their receptors indeed can stop axon growth in vitro and improve functional recovery in animal spinal cord injury (SCI) models. These therapies also increase sprouting of surviving axons and plasticity. However, many investigators have reported regenerating spinal tracts without eliminating Nogo, glial scar, or CSPG. For example, many motor and sensory axons grow spontaneously in contused spinal cords, crossing gliotic tissue and white matter surrounding the injury site. Sensory axons grow long distances in injured dorsal columns after peripheral nerve lesions. Cell transplants and treatments that increase cAMP and neurotrophins stimulate motor and sensory axons to cross glial scars and to grow long distances in white matter. Genetic studies deleting all members of the Nogo family and even the Nogo receptor do not always improve regeneration in mice. A recent study reported that suppressing the phosphatase and tensin homolog (PTEN) gene promotes prolific corticospinal tract regeneration. These findings cannot be explained by the current theories proposing that Nogo and glial scars prevent regeneration. Spinal axons clearly can and will grow through glial scars and Nogo-expressing tissue under some circumstances. The observation that deleting PTEN allows corticospinal tract regeneration indicates that the PTEN/AKT/mTOR pathway regulates axonal growth. Finally, many other factors stimulate spinal axonal growth, including conditioning lesions, cAMP, glycogen synthetase kinase inhibition, and neurotrophins. To explain these disparate regenerative phenomena, I propose that the spinal cord has evolved regenerative mechanisms that are normally suppressed by multiple extrinsic and intrinsic factors but can be activated by injury, mediated by the PTEN/AKT/mTOR, cAMP, and GSK3b pathways, to stimulate neural growth and proliferation.
Collapse
Affiliation(s)
- Wise Young
- W. M. Keck Center for Collaborative Neuroscience, Rutgers, State University of New Jersey, Piscataway, NJ, USA
| |
Collapse
|
30
|
Teitelman G, Kedees M. Mouse insulin cells expressing an inducible RIPCre transgene are functionally impaired. J Biol Chem 2014; 290:3647-53. [PMID: 25533471 DOI: 10.1074/jbc.m114.615484] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We used cre-lox technology to test whether the inducible expression of Cre minimize the deleterious effect of the enzyme on beta cell function. We studied mice in which Cre is linked to a modified estrogen receptor (ER), and its expression is controlled by the rat insulin promoter (RIP). Following the injection of tamoxifen (TM), CreER- migrates to the nucleus and promotes the appearance of a reporter protein, enhanced yellow fluorescent protein (EYFP), in cells. Immunocytochemical analysis indicated that 46.6 ± 2.1% insulin cells of adult RIPCreER- EYFP expressed EYFP. RIPCreER-EYFP (+TM) mice were normoglycemic throughout the study, and their glucose tolerance test results were similar to control CD-1 mice. However, an extended exposure to reagents that stimulate insulin synthesis was detrimental to the survival of IN+EYFP+cells. The administration of an inhibitor of the enzyme dipeptidyl-peptidase (DPP4i), which prevents the cleavage of glucagon-like peptide (GLP-1), to adult RIPCreER-EYFP mice lead to a decrease in the percentage of IN+EYFP+ to 17.5 ± 1.73 and a significant increase in apoptotic cells in islets. Similarly, a 2-week administration of the GLP-1 analog exendin 4 (ex-4) induced an almost complete ablation of IN+ expressing a different reporter protein and a significant decrease in the beta cell mass and rate of beta cell proliferation. Since normal beta cells do not die when induced to increase insulin synthesis, our observations indicate that insulin cells expressing an inducible RIPCre transgene are functionally deficient. Studies employing these mice should carefully consider the pitfalls of the Cre-Lox technique.
Collapse
Affiliation(s)
- Gladys Teitelman
- From the Department of Cell Biology, SUNY-Downstate Medical Center, Brooklyn, New York 11203
| | - Mamdouh Kedees
- From the Department of Cell Biology, SUNY-Downstate Medical Center, Brooklyn, New York 11203
| |
Collapse
|
31
|
Hessenkemper W, Roediger J, Bartsch S, Houtsmuller AB, van Royen ME, Petersen I, Grimm MO, Baniahmad A. A natural androgen receptor antagonist induces cellular senescence in prostate cancer cells. Mol Endocrinol 2014; 28:1831-40. [PMID: 25203674 DOI: 10.1210/me.2014-1170] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We have previously identified a natural occurring, androgen receptor-specific antagonist. Atraric acid (AA) inhibits the transactivation of the androgen receptor (AR) and androgen-mediated growth of AR-expressing human prostate cancer (PCa) cell lines. Here we show that AA treatment of living cells provokes molecular changes of AR signaling. In addition to a deceleration of nuclear translocation a block of the intramolecular amino/carboxy (N/C)-terminal interaction of the AR was observed. Furthermore, using high-resolution confocal fluorescence microscopy, a reduced speckle formation of the AR was observed in line with an increased intranuclear mobility of the receptor. This suggests decreased DNA binding of the AR, which is further indicated by an impaired chromatin recruitment of the AR to the prostate-specific antigen promoter and enhancer shown by chromatin immunoprecipitation experiments. Using inhibitors of the non-receptor tyrosine kinase Src or Akt, known interaction partners of AR, reduced the level of androgen-induced cellular senescence suggesting a partly non-genomic pathway to induce cellular senescence by AA. Using PP2 (4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine) pyrimidine or Akt inhibitors, inhibitors of the nonreceptor tyrosine kinase Src or Akt, known interaction partners of AR, reduced the level of androgen-induced cellular senescence, suggesting a partly nongenomic pathway to induce cellular senescence by AA. Treatment of LNCaP cells with AA is associated with hypophosphorylation of the retinoblastoma tumor suppressor and an increase of p16 expression, whereas the p53-p21 signaling pathway seems not be affected by AA treatment. Analyzing human PCa tissue samples treated with AA ex vivo also indicates an induction of cellular senescence associated with an increase of p16 expression but not p21. Taken together, these data indicate that AA exhibits novel features to inhibit AR amino/carboxy-terminal interaction, the AR-mediated nuclear activities and growth of PCa cells.
Collapse
Affiliation(s)
- Wiebke Hessenkemper
- Institute of Human Genetics (W.H., J.R., S.B., A.B.), Institute of Pathology (I.P.), and Institute of Urology (M.-O.G.), Jena University Hospital, 07740 Jena, Germany; Department of Pathology (A.B.H., M.E.v.R.), Josephine Nefkens Institute, and Erasmus Optical Imaging Center (A.B.H., M.E.v.R.), Erasmus Medical Center, 3000 CA Rotterdam, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Dong P, Konno Y, Watari H, Hosaka M, Noguchi M, Sakuragi N. The impact of microRNA-mediated PI3K/AKT signaling on epithelial-mesenchymal transition and cancer stemness in endometrial cancer. J Transl Med 2014; 12:231. [PMID: 25141911 PMCID: PMC4145234 DOI: 10.1186/s12967-014-0231-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 08/12/2014] [Indexed: 02/06/2023] Open
Abstract
Activation of the PI3K/AKT pathway, a common mechanism in all subtypes of endometrial cancers (endometrioid and non-endometrioid tumors), has important roles in contributing to epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) features. MicroRNAs (miRNAs) are small non-coding RNA molecules that concurrently affect multiple target genes, and regulate a wide range of genes involved in modulating EMT and CSC properties. Here we overview the recent advances revealing the impact of miRNAs on EMT and CSC phenotypes in tumors including endometrial cancer via regulating PI3K/AKT pathway. MiRNAs are crucial mediators of EMT and CSC through targeting PTEN-PI3K-AKT-mTOR axis. In endometrial cancer cells, miRNAs can activate or attenuate EMT and CSC by targeting PTEN and other EMT-associated genes, such as Twist1, ZEB1 and BMI-1. More detailed studies of miRNAs will deepen our understanding of the molecular basis underlying PI3K/AKT-induced endometrial cancer initiation and progression. Targeting key signaling components of PI3K/AKT pathway by restoring or inhibiting miRNA function holds promise as a potential therapeutic approach to suppress EMT and CSC in endometrial cancer.
Collapse
Affiliation(s)
- Peixin Dong
- Department of Women's Health Educational System, Hokkaido University School of Medicine, Hokkaido University, N15, W7, Sapporo 0608638, Japan.
| | | | | | | | | | | |
Collapse
|
33
|
MicroRNA-21 (miR-21) regulates cellular proliferation, invasion, migration, and apoptosis by targeting PTEN, RECK and Bcl-2 in lung squamous carcinoma, Gejiu City, China. PLoS One 2014; 9:e103698. [PMID: 25084400 PMCID: PMC4118890 DOI: 10.1371/journal.pone.0103698] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 07/07/2014] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND In South China (Gejiu City, Yunnan Province), lung cancer incidence and associated mortality rate is the most prevalent and observed forms of cancer. Lung cancer in this area is called Gejiu squamous cell lung carcinoma (GSQCLC). Research has demonstrated that overexpression of miR-21 occurs in many cancers. However, the unique relationship between miR-21 and its target genes in GSQCLC has never been investigated. The molecular mechanism involved in GSQCLC must be compared to other non-small cell lung cancers in order to establish a relation and identify potential therapeutic targets. METHODOLOGY/PRINCIPAL FINDINGS In the current study, we initially found overexpression of miR-21 occurring in non-small cell lung cancer (NSCLC) cell lines when compared to the immortalized lung epithelial cell line BEAS-2B. We also demonstrated that high expression of miR-21 could increase tumor cell proliferation, invasion, viability, and migration in GSQCLC cell line (YTMLC-90) and NSCLC cell line (NCI-H157). Additionally, our results revealed that miR-21 could suppress YTMLC-90 and NCI-H157 cell apoptosis through arresting cell-cycle at G2/M phase. Furthermore, we demonstrated that PTEN, RECK and Bcl-2 are common target genes of miR-21 in NSCLC. Finally, our studies showed that down-regulation of miR-21 could lead to a significant increase in PTEN and RECK and decrease in Bcl-2 at the mRNA and protein level in YTMLC-90 and NCI-H157 cell lines. However, we have not observed any remarkable difference in the levels of miR-21 and its targets in YTMLC-90 cells when compared with NCI-H157 cells. CONCLUSIONS/SIGNIFICANCE miR-21 simultaneously regulates multiple programs that enhance cell proliferation, apoptosis and tumor invasiveness by targeting PTEN, RECK and Bcl-2 in GSQCLC. Our results demonstrated that miR-21 may play a vital role in tumorigenesis and progression of lung squamous cell carcinoma and suppression of miR-21 may be a novel approach for the treatment of lung squamous cell carcinoma.
Collapse
|
34
|
Melis JPM, Jonker MJ, Vijg J, Hoeijmakers JHJ, Breit TM, van Steeg H. Aging on a different scale--chronological versus pathology-related aging. Aging (Albany NY) 2014; 5:782-8. [PMID: 24131799 PMCID: PMC3838780 DOI: 10.18632/aging.100606] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging.
Collapse
Affiliation(s)
- Joost P M Melis
- National Institute for Public Health and the Environment (RIVM), Center for Health Protection, Bilthoven, the Netherlands
| | | | | | | | | | | |
Collapse
|
35
|
Wu JB, Shao C, Li X, Li Q, Hu P, Shi C, Li Y, Chen YT, Yin F, Liao CP, Stiles BL, Zhau HE, Shih JC, Chung LWK. Monoamine oxidase A mediates prostate tumorigenesis and cancer metastasis. J Clin Invest 2014; 124:2891-908. [PMID: 24865426 DOI: 10.1172/jci70982] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 04/03/2014] [Indexed: 01/13/2023] Open
Abstract
Tumors from patients with high-grade aggressive prostate cancer (PCa) exhibit increased expression of monoamine oxidase A (MAOA), a mitochondrial enzyme that degrades monoamine neurotransmitters and dietary amines. Despite the association between MAOA and aggressive PCa, it is unclear how MAOA promotes PCa progression. Here, we found that MAOA functions to induce epithelial-to-mesenchymal transition (EMT) and stabilize the transcription factor HIF1α, which mediates hypoxia through an elevation of ROS, thus enhancing growth, invasiveness, and metastasis of PCa cells. Knockdown and overexpression of MAOA in human PCa cell lines indicated that MAOA induces EMT through activation of VEGF and its coreceptor neuropilin-1. MAOA-dependent activation of neuropilin-1 promoted AKT/FOXO1/TWIST1 signaling, allowing FOXO1 binding at the TWIST1 promoter. Importantly, the MAOA-dependent HIF1α/VEGF-A/FOXO1/TWIST1 pathway was activated in high-grade PCa specimens, and knockdown of MAOA reduced or even eliminated prostate tumor growth and metastasis in PCa xenograft mouse models. Pharmacological inhibition of MAOA activity also reduced PCa xenograft growth in mice. Moreover, high MAOA expression in PCa tissues correlated with worse clinical outcomes in PCa patients. These findings collectively characterize the contribution of MAOA in PCa pathogenesis and suggest that MAOA has potential as a therapeutic target in PCa.
Collapse
|
36
|
McCauley BS, Dang W. Histone methylation and aging: lessons learned from model systems. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:1454-62. [PMID: 24859460 DOI: 10.1016/j.bbagrm.2014.05.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 03/16/2014] [Accepted: 05/13/2014] [Indexed: 01/06/2023]
Abstract
Aging induces myriad cellular and, ultimately, physiological changes that cause a decline in an organism's functional capabilities. Although the aging process and the pathways that regulate it have been extensively studied, only in the last decade have we begun to appreciate that dynamic histone methylation may contribute to this process. In this review, we discuss recent work implicating histone methylation in aging. Loss of certain histone methyltransferases and demethylases changes lifespan in invertebrates, and alterations in histone methylation in aged organisms regulate lifespan and aging phenotypes, including oxidative stress-induced hormesis in yeast, insulin signaling in Caenorhabiditis elegans and mammals, and the senescence-associated secretory phenotype in mammals. In all cases where histone methylation has been shown to impact aging and aging phenotypes, it does so by regulating transcription, suggesting that this is a major mechanism of its action in this context. Histone methylation additionally regulates or is regulated by other cellular pathways that contribute to or combat aging. Given the numerous processes that regulate aging and histone methylation, and are in turn regulated by them, the role of histone methylation in aging is almost certainly underappreciated.
Collapse
Affiliation(s)
- Brenna S McCauley
- Huffington Center on Aging, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA.
| | - Weiwei Dang
- Huffington Center on Aging, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA.
| |
Collapse
|
37
|
Hakonen E, Ustinov J, Eizirik DL, Sariola H, Miettinen PJ, Otonkoski T. In vivo activation of the PI3K-Akt pathway in mouse beta cells by the EGFR mutation L858R protects against diabetes. Diabetologia 2014; 57:970-9. [PMID: 24493201 DOI: 10.1007/s00125-014-3175-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 01/06/2014] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS EGF receptor (EGFR) signalling is required for normal beta cell development and postnatal beta cell proliferation. We tested whether beta cell proliferation can be triggered by EGFR activation at any age and whether this can protect beta cells against apoptosis induced by diabetogenic insults in a mouse model. METHODS We generated transgenic mice with doxycycline-inducible expression of constitutively active EGFR (L858R) (CA-EGFR) under the insulin promoter. Mice were given doxycycline at various ages for different time periods, and beta cell proliferation and mass were analysed. Mice were also challenged with streptozotocin and isolated islets exposed to cytokines. RESULTS Expression of EGFR (L858R) led to increased phosphorylation of EGFR and Akt in pancreatic islets. CA-EGFR expression during pancreatic development (embryonic day [E]12.5 to postnatal day [P]1) increased beta cell proliferation and mass in newborn mice. However, CA-EGFR expression in adult mice did not affect beta cell mass. Expression of the transgene improved glycaemia and markedly inhibited beta cell apoptosis after a single high dose, as well as after multiple low doses of streptozotocin. In vitro mechanistic studies showed that CA-EGFR protected isolated islets from cytokine-mediated beta cell death, possibly by repressing the proapoptotic protein BCL2-like 11 (BIM). CONCLUSIONS/INTERPRETATION Our findings show that the expression of CA-EGFR in the developing, but not in the adult pancreas stimulates beta cell replication and leads to increased beta cell mass. Importantly, CA-EGFR protects beta cells against streptozotocin- and cytokine-induced death.
Collapse
Affiliation(s)
- Elina Hakonen
- Research Programs Unit, Molecular Neurology, Biomedicum Stem Cell Center, University of Helsinki, Biomedicum Helsinki, PO Box 63 (Haartmaninkatu 8), 00014, Helsinki, Finland,
| | | | | | | | | | | |
Collapse
|
38
|
Wansleeben C, Bowie E, Hotten DF, Yu YRA, Hogan BLM. Age-related changes in the cellular composition and epithelial organization of the mouse trachea. PLoS One 2014; 9:e93496. [PMID: 24675804 PMCID: PMC3968161 DOI: 10.1371/journal.pone.0093496] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 03/05/2014] [Indexed: 01/25/2023] Open
Abstract
We report here senescent changes in the structure and organization of the mucociliary pseudostratified epithelium of the mouse trachea and main stem bronchi. We confirm previous reports of the gradual appearance of age-related, gland-like structures (ARGLS) in the submucosa, especially in the intercartilage regions and carina. Immunohistochemistry shows these structures contain ciliated and secretory cells and Krt5+ basal cells, but not the myoepithelial cells or ciliated ducts typical of normal submucosal glands. Data suggest they arise de novo by budding from the surface epithelium rather than by delayed growth of rudimentary or cryptic submucosal glands. In old mice the surface epithelium contains fewer cells per unit length than in young mice and the proportion of Krt5+, p63+ basal cells is reduced in both males and females. However, there appears to be no significant difference in the ability of basal stem cells isolated from individual young and old mice to form clonal tracheospheres in culture or in the ability of the epithelium to repair after damage by inhaled sulfur dioxide. Gene expression analysis by Affymetrix microarray and quantitative PCR, as well as immunohistochemistry and flow sorting studies, are consistent with low-grade chronic inflammation in the tracheas of old versus young mice and an increase in the number of immune cells. The significance of these changes for ARGL formation are not clear since several treatments that induce acute inflammation in young mice did not result in budding of the surface epithelium.
Collapse
Affiliation(s)
- Carolien Wansleeben
- Department of Cell Biology, Duke University Medical Centre, Durham, North Carolina, United States of America
| | - Emily Bowie
- Department of Cell Biology, Duke University Medical Centre, Durham, North Carolina, United States of America
| | - Danielle F. Hotten
- Department of Medicine, Duke University Medical Centre, Durham, North Carolina, United States of America
| | - Yen-Rei A. Yu
- Department of Medicine, Duke University Medical Centre, Durham, North Carolina, United States of America
| | - Brigid L. M. Hogan
- Department of Cell Biology, Duke University Medical Centre, Durham, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
39
|
Vetere A, Choudhary A, Burns SM, Wagner BK. Targeting the pancreatic β-cell to treat diabetes. Nat Rev Drug Discov 2014; 13:278-89. [PMID: 24525781 DOI: 10.1038/nrd4231] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Diabetes is a leading cause of morbidity and mortality worldwide, and predicted to affect over 500 million people by 2030. However, this growing burden of disease has not been met with a comparable expansion in therapeutic options. The appreciation of the pancreatic β-cell as a central player in the pathogenesis of both type 1 and type 2 diabetes has renewed focus on ways to improve glucose homeostasis by preserving, expanding and improving the function of this key cell type. Here, we provide an overview of the latest developments in this field, with an emphasis on the most promising strategies identified to date for treating diabetes by targeting the β-cell.
Collapse
Affiliation(s)
- Amedeo Vetere
- Chemical Biology Program, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Amit Choudhary
- 1] Chemical Biology Program, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA. [2] Society of Fellows, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Sean M Burns
- Medical & Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Bridget K Wagner
- Chemical Biology Program, Center for the Science of Therapeutics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| |
Collapse
|
40
|
Affiliation(s)
- Aaron Bender
- Diabetes, Obesity and Metabolism Institute, The Icahn School of Medicine at Mount Sinai, Atran 5, 1 Gustave L. Levy Place, Box 1152, New York, NY, 10029, USA
| | | |
Collapse
|
41
|
Yang KT, Bayan JA, Zeng N, Aggarwal R, He L, Peng Z, Kassa A, Kim M, Luo Z, Shi Z, Medina V, Boddupally K, Stiles BL. Adult-onset deletion of Pten increases islet mass and beta cell proliferation in mice. Diabetologia 2014; 57:352-61. [PMID: 24162585 PMCID: PMC3918745 DOI: 10.1007/s00125-013-3085-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 09/27/2013] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS Adult beta cells have a diminished ability to proliferate. Phosphatase and tensin homologue (PTEN) is a lipid phosphatase that antagonises the function of the mitogenic phosphatidylinositol 3-kinase (PI3K) pathway. The objective of this study was to understand the role of PTEN and PI3K signalling in the maintenance of beta cells postnatally. METHODS We developed a Pten (lox/lox); Rosa26 (lacZ); RIP-CreER (+) model that permitted us to induce Pten deletion by treatment with tamoxifen in mature animals. We evaluated islet mass and function as well as beta cell proliferation in 3- and 12-month-old mice treated with tamoxifen (Pten deleted) vs mice treated with vehicle (Pten control). RESULTS Deletion of Pten in juvenile (3-month-old) beta cells significantly induced their proliferation and increased islet mass. The expansion of islet mass occurred concomitantly with the enhanced ability of the Pten-deleted mice to maintain euglycaemia in response to streptozotocin treatment. In older mice (>12 months of age), deletion of Pten similarly increased islet mass and beta cell proliferation. This novel finding suggests that PTEN-regulated mechanisms may override the age-onset diminished ability of beta cells to respond to mitogenic stimulation. We also found that proteins regulating G1/S cell-cycle transition, such as cyclin D1, cyclin D2, p27 and p16, were altered when PTEN was lost, suggesting that they may play a role in PTEN/PI3K-regulated beta cell proliferation in adult tissue. CONCLUSIONS/INTERPRETATION The signals regulated by the PTEN/PI3K pathway are important for postnatal maintenance of beta cells and regulation of their proliferation in adult tissues.
Collapse
Affiliation(s)
- Kai-Ting Yang
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
De Tata V. Age-related impairment of pancreatic Beta-cell function: pathophysiological and cellular mechanisms. Front Endocrinol (Lausanne) 2014; 5:138. [PMID: 25232350 PMCID: PMC4153315 DOI: 10.3389/fendo.2014.00138] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 08/07/2014] [Indexed: 12/13/2022] Open
Abstract
The incidence of type 2 diabetes significantly increases with age. The relevance of this association is dramatically magnified by the concomitant global aging of the population, but the underlying mechanisms remain to be fully elucidated. Here, some recent advances in this field are reviewed at the level of both the pathophysiology of glucose homeostasis and the cellular senescence of pancreatic islets. Overall, recent results highlight the crucial role of beta-cell dysfunction in the age-related impairment of pancreatic endocrine function and delineate the possibility of new original therapeutic interventions.
Collapse
Affiliation(s)
- Vincenzo De Tata
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- *Correspondence: Vincenzo De Tata, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Via Roma, 55 Scuola Medica, Pisa 56126, Italy e-mail:
| |
Collapse
|