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Cellular senescence in the Aging Brain: A promising target for neurodegenerative diseases. Mech Ageing Dev 2022; 204:111675. [DOI: 10.1016/j.mad.2022.111675] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/24/2022] [Accepted: 04/07/2022] [Indexed: 01/10/2023]
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Afroze T, Yang G, Khoshbin A, Tanwir M, Tabish T, Momen A, Husain M. Calcium efflux activity of plasma membrane Ca2+ ATPase-4 (PMCA4) mediates cell cycle progression in vascular smooth muscle cells. J Biol Chem 2014; 289:7221-7231. [PMID: 24448801 DOI: 10.1074/jbc.m113.533638] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We explored the role played by plasma membrane calcium ATPase-4 (PMCA4) and its alternative splice variants in the cell cycle of vascular smooth muscle cells (VSMC). A novel variant (PMCA4e) was discovered. Quantitative real-time-PCR-quantified PMCA4 splice variant proportions differed in specific organs. The PMCA4a:4b ratio in uninjured carotid arteries (∼1:1) was significantly reduced by wire denudation injury (to ∼1:3) by modulation of alternative splicing, as confirmed by novel antibodies against PMCA4a/e and PMCA4b. Laser capture microdissection localized this shift to the media and adventitia. Primary carotid VSMC from PMCA4 knock-out (P4KO) mice showed impaired [(3)H]thymidine incorporation and G1 phase arrest as compared with wild type (P4WT). Electroporation of expression constructs encoding PMCA4a, PMCA4b, and a PMCA4b mutant lacking PDZ binding rescued this phenotype of P4KO cells, whereas a mutant with only 10% of normal Ca(2+) efflux activity could not. Microarray of early G1-synchronized VSMC showed 39-fold higher Rgs16 (NFAT (nuclear factor of activated T-cells) target; MAPK inhibitor) and 69-fold higher Decorin (G1 arrest marker) expression in P4KO versus P4WT. Validation by Western blot also revealed decreased levels of Cyclin D1 and NFATc3 in P4KO. Microarrays of P4KO VSMC rescued by PMCA4a or PMCA4b expression showed reversal of perturbed Rgs16, Decorin, and NFATc3 expression levels. However, PMCA4a rescue caused a 44-fold reduction in AP-2β, a known anti-proliferative transcription factor, whereas PMCA4b rescue resulted in a 50-fold reduction in p15 (Cyclin D1/Cdk4 inhibitor). We conclude that Ca(2+) efflux activity of PMCA4 underlies G1 progression in VSMC and that PMCA4a and PMCA4b differentially regulate specific downstream mediators.
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Affiliation(s)
- Talat Afroze
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Ge Yang
- Institute of Medical Sciences, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Amir Khoshbin
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Mansoor Tanwir
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Taha Tabish
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Abdul Momen
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada
| | - Mansoor Husain
- Division of Experimental Therapeutics, Toronto General Research Institute, University Health Network, Toronto, Ontario M5G 2C4, Canada; Institute of Medical Sciences, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Heart and Stroke Richard Lewar Centre of Excellence in Cardiovascular Research, Toronto, Ontario M5G 1L7; Department of Medicine, University of Toronto, Toronto, Ontario M5G 2C4, Canada.
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Duong CV, Yacqub-Usman K, Emes RD, Clayton RN, Farrell WE. The EFEMP1 gene: a frequent target for epigenetic silencing in multiple human pituitary adenoma subtypes. Neuroendocrinology 2013; 98:200-11. [PMID: 24080855 DOI: 10.1159/000355624] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/10/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS In a genome-wide investigation we recently identified the EGF-containing fibulin-like extracellular matrix protein 1 gene, EFEMP1, as hypermethylated in growth hormone-secreting adenoma. METHODS In an independent cohort we determined expression of EFEMP1, CpG island methylation and histone tail modification status. The causal consequences of epigenetic modification were determined through epidrug-induced reversal and enforced EFEMP1 expression in GH3 cells. RESULTS The majority of adenomas, irrespective of subtype, show reduced EFEMP1 expression. However, epigenetic change, as determined by CpG island methylation, was not invariantly associated with decreased EFEMP1 expression. Conversely, chromatin immunoprecipitation assays revealed enrichment for modifications associated with either active or silenced genes in adenoma that did or did not express EFEMP1 respectively. In AtT-20 and GH3 cells a causal relationship between epigenetic silencing and expression of EFEMP1 was established where co-incubation with the epidrugs zebularine and TSA induced expression of EFEMP1 and concomitant histone tail modifications toward those associated with expressed genes. Enforced expression of EFEMP1 in GH3 cells was without effect on cell proliferation or apoptotic end-points, however inhibition of endogenous matrix metalloproteinase (MMP)-2 expression was apparent. Primary adenomas did not show this relationship, however a positive correlation was apparent with the MMP7 transcript and perhaps reflects cell or species differences. CONCLUSIONS The protein product of the EFEMP1 gene, fibulin-3, is reported to impact on multiple pathways in a cell-specific context. Subtype-independent loss of EFEMP1 expression in the majority of primary adenomas should prompt more detailed investigation in this tumour type.
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Affiliation(s)
- Cuong V Duong
- Institute of Science and Technology in Medicine, Keele University School of Medicine, Stoke-on-Trent, UK
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Ratner LD, Gonzalez B, Ahtiainen P, Di Giorgio NP, Poutanen M, Calandra RS, Huhtaniemi IT, Rulli SB. Short-term pharmacological suppression of the hyperprolactinemia of infertile hCG-overproducing female mice persistently restores their fertility. Endocrinology 2012; 153:5980-92. [PMID: 23117930 PMCID: PMC3544356 DOI: 10.1210/en.2012-1393] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Female infertility is often associated with deregulation of hormonal networks, and hyperprolactinemia is one of the most common endocrine disorders of the hypothalamic-pituitary axis affecting the reproductive functions. We have shown previously that transgenic female mice overexpressing human chorionic gonadotropin β-subunit (hCGβ+ mice), and producing elevated levels of bioactive LH/hCG, exhibit increased production of testosterone and progesterone, are overweight and infertile, and develop hyperprolactinemia associated with pituitary lactotrope adenomas in adult age. In the present study, we analyzed the influence of the hyperprolactinemia of hCGβ+ females on their reproductive phenotype by treating them with the dopamine agonists, bromocriptine and cabergoline. Long-term bromocriptine treatment of adult mice was effective in the control of obesity, pituitary growth, and disturbances in the hormone profile, demonstrating that hyperprolactinemia was the main cause of the hCGβ+ female phenotype. Interestingly, short-term treatment (1 wk) with cabergoline applied on 5-wk-old mice corrected hyperprolactinemia, hyperandrogenism, and hyperprogesteronemia, prevented pituitary overgrowth, normalized gonadal function, and recovered fertility of adult hCGβ+ females after hormone-induced and natural ovulation. The same cabergoline treatment in the short term applied on 3-month-old hCGβ+ females failed to recover their reproductive function. Hence, we demonstrated that the short-term cabergoline treatment applied at a critical early stage of the phenotype progression effectively prevented the hyperprolactinemia-associated reproductive dysfunction of hCG-overproducing females.
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Affiliation(s)
- Laura D Ratner
- Instituto de Biología y Medicina Experimental-Consejo Nacional de Investigaciones Científicas y Técnicas, Vuelta de Obligado 2490, C1428ADN Buenos Aires, Argentina
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Toledano Y, Zonis S, Ren SG, Wawrowsky K, Chesnokova V, Melmed S. Estradiol partially recapitulates murine pituitary cell cycle response to pregnancy. Endocrinology 2012; 153:5011-22. [PMID: 22851678 PMCID: PMC3512024 DOI: 10.1210/en.2012-1492] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Because pregnancy and estrogens both induce pituitary lactotroph hyperplasia, we assessed the expression of pituitary cell cycle regulators in two models of murine pituitary hyperplasia. Female mice were assessed during nonpregnancy, pregnancy, day of delivery, and postpartum. We also implanted estradiol (E(2)) pellets in female mice and studied them for 2.5 months. Pituitary weight in female mice increased 2-fold after E(2) administration and 1.4-fold at day of delivery, compared with placebo-treated or nonpregnant females. Pituitary proliferation, as assessed by proliferating cell nuclear antigen and/or Ki-67 staining, increased dramatically during both mid-late pregnancy and E(2) administration, and lactotroph hyperplasia was also observed. Pregnancy induced pituitary cell cycle proliferative and inhibitory responses at the G(1)/S checkpoint. Differential cell cycle regulator expression included cyclin-dependent kinase inhibitors, p21(Cip1), p27(Kip1), and cyclin D1. Pituitary cell cycle responses to E(2) administration partially recapitulated those effects observed at mid-late pregnancy, coincident with elevated circulating mouse E(2), including increased expression of proliferating cell nuclear antigen, Ki-67, p15(INK4b), and p21(Cip1). Nuclear localization of pituitary p21(Cip1) was demonstrated at mid-late pregnancy but not during E(2) administration, suggesting a cell cycle inhibitory role for p21(Cip1) in pregnancy, yet a possible proproliferative role during E(2) administration. Most observed cell cycle protein alterations were reversed postpartum. Murine pituitary meets the demand for prolactin during lactation associated with induction of both cell proliferative and inhibitory pathways, mediated, at least partially, by estradiol.
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Affiliation(s)
- Yoel Toledano
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
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Chesnokova V, Zonis S, Zhou C, Ben-Shlomo A, Wawrowsky K, Toledano Y, Tong Y, Kovacs K, Scheithauer B, Melmed S. Lineage-specific restraint of pituitary gonadotroph cell adenoma growth. PLoS One 2011; 6:e17924. [PMID: 21464964 PMCID: PMC3064664 DOI: 10.1371/journal.pone.0017924] [Citation(s) in RCA: 44] [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: 12/22/2010] [Accepted: 02/15/2011] [Indexed: 11/23/2022] Open
Abstract
Although pituitary adenomas are usually benign, unique trophic mechanisms restraining cell proliferation are unclear. As GH-secreting adenomas are associated with p53/p21-dependent senescence, we tested mechanisms constraining non-functioning pituitary adenoma growth. Thirty six gonadotroph-derived non-functioning pituitary adenomas all exhibited DNA damage, but undetectable p21 expression. However, these adenomas all expressed p16, and >90% abundantly expressed cytoplasmic clusterin associated with induction of the Cdk inhibitor p15 in 70% of gonadotroph and in 26% of somatotroph lineage adenomas (p = 0.006). Murine LβT2 and αT3 gonadotroph pituitary cells, and αGSU.PTTG transgenic mice with targeted gonadotroph cell adenomas also abundantly expressed clusterin and exhibited features of oncogene-induced senescence as evidenced by C/EBPβ and C/EBPδ induction. In turn, C/EBPs activated the clusterin promoter ∼5 fold, and elevated clusterin subsequently elicited p15 and p16 expression, acting to arrest murine gonadotroph cell proliferation. In contrast, specific clusterin suppression by RNAis enhanced gonadotroph proliferation. FOXL2, a tissue-specific gonadotroph lineage factor, also induced the clusterin promoter ∼3 fold in αT3 pituitary cells. As nine of 12 pituitary carcinomas were devoid of clusterin expression, this protein may limit proliferation of benign adenomatous pituitary cells. These results point to lineage-specific pathways restricting uncontrolled murine and human pituitary gonadotroph adenoma cell growth.
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Affiliation(s)
- Vera Chesnokova
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Svetlana Zonis
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Cuiqi Zhou
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Anat Ben-Shlomo
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Kolja Wawrowsky
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Yoel Toledano
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Yunguang Tong
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- Departments of Pathology, St. Michael's Hospital, Toronto, Canada
- Mayo Clinic, Rochester, Minnesota, United States of America
| | - Kalman Kovacs
- Departments of Pathology, St. Michael's Hospital, Toronto, Canada
| | | | - Shlomo Melmed
- Department of Medicine, Pituitary Center, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
- * E-mail:
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Onumah OE, Jules GE, Zhao Y, Zhou L, Yang H, Guo Z. Overexpression of catalase delays G0/G1- to S-phase transition during cell cycle progression in mouse aortic endothelial cells. Free Radic Biol Med 2009; 46:1658-67. [PMID: 19341793 PMCID: PMC2713001 DOI: 10.1016/j.freeradbiomed.2009.03.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 03/23/2009] [Accepted: 03/25/2009] [Indexed: 01/26/2023]
Abstract
Although it is understood that hydrogen peroxide (H(2)O(2)) promotes cellular proliferation, little is known about its role in endothelial cell cycle progression. To assess the regulatory role of endogenously produced H(2)O(2) in cell cycle progression, we studied the cell cycle progression in mouse aortic endothelial cells (MAECs) obtained from mice overexpressing a human catalase transgene (hCatTg), which destroys H(2)O(2). The hCatTg MAECs displayed a prolonged doubling time compared to wild-type controls (44.0 +/- 4.7 h versus 28.6 +/- 0.8 h, p<0.05), consistent with a diminished growth rate and H(2)O(2) release. Incubation with aminotriazole, a catalase inhibitor, prevented the observed diminished growth rate in hCatTg MAECs. Inhibition of catalase activity with aminotriazole abrogated catalase overexpression-induced antiproliferative action. Flow cytometry analysis indicated that the prolonged doubling time was principally due to an extended G(0)/G(1) phase in hCatTg MAECs compared to the wild-type cells (25.0 +/- 0.9 h versus 15.9 +/- 1.4 h, p< 0.05). The hCatTg MAECs also exhibited decreased activities of the cyclin-dependent kinase (Cdk) complexes responsible for G(0)/G(1)- to S-phase transition in the cell cycle, including the cyclin D-Cdk4 and cyclin E-Cdk2 complexes. Moreover, the reduction in cyclin-Cdk activities in hCatTg MAECs was accompanied by increased protein levels of two Cdk inhibitors, p21 and p27, which inhibit the Cdk activity required for the G(0)/G(1)- to S-phase transition. Knockdown of p21 and/or p27 attenuated the antiproliferative effect of catalase overexpression in MAECs. These results, together with the fact that catalase is an H(2)O(2) scavenger, suggest that endogenously produced H(2)O(2) mediates MAEC proliferation by fostering the transition from G(0)/G(1) to S phase.
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Affiliation(s)
- Ogbeyalu E. Onumah
- Department of Cancer Biology, Meharry Medical College, Nashville, TN 37208
| | - George E. Jules
- Department of Cardiovascular Biology, Meharry Medical College, Nashville, TN 37208
| | - Yanfeng Zhao
- Department of Cardiovascular Biology, Meharry Medical College, Nashville, TN 37208
| | - LiChun Zhou
- Department of Cardiovascular Biology, Meharry Medical College, Nashville, TN 37208
| | - Hong Yang
- Department of Cardiovascular Biology, Meharry Medical College, Nashville, TN 37208
| | - ZhongMao Guo
- Department of Cardiovascular Biology, Meharry Medical College, Nashville, TN 37208
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Woodmansee WW, Kerr JM, Tucker EA, Mitchell JR, Haakinson DJ, Gordon DF, Ridgway EC, Wood WM. The proliferative status of thyrotropes is dependent on modulation of specific cell cycle regulators by thyroid hormone. Endocrinology 2006; 147:272-82. [PMID: 16223861 DOI: 10.1210/en.2005-1013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this report we have examined changes in cell growth parameters, cell cycle effectors, and signaling pathways that accompany thyrotrope growth arrest by thyroid hormone (TH) and growth resumption after its withdrawal. Flow cytometry and immunohistochemistry of proliferation markers demonstrated that TH treatment of thyrotrope tumors resulted in a reduction in the fraction of cells in S-phase that is restored upon TH withdrawal. This is accompanied by dephosphorylation and rephosphorylation of retinoblastoma (Rb) protein. The expression levels of cyclin-dependent kinase 2 and cyclin A, as well as cyclin-dependent kinase 1 and cyclin B, were decreased by TH, and after withdrawal not only did these regulators of Rb phosphorylation and mitosis increase in their expression but so too did the D1 and D3 cyclins. We also noted a rapid induction and subsequent disappearance of the type 5 receptor for the growth inhibitor somatostatin with TH treatment and withdrawal, respectively. Because somatostatin can arrest growth by activating MAPK pathways, we examined these pathways in TtT-97 tumors and found that the ERK pathway and several of its upstream and downstream effectors, including cAMP response element binding protein, were activated with TH treatment and deactivated after its withdrawal. This led to the hypothesis that TH, acting through increased type 5 somatostatin receptor, could activate the ERK pathway leading to cAMP response element binding protein-dependent decreased expression of critical cell cycle proteins, specifically cyclin A, resulting in hypophosphorylation of Rb and its subsequent arrest of S-phase progression. These processes are reversed when TH is withdrawn, resulting in an increase in the fraction of S-phase cells.
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Affiliation(s)
- Whitney W Woodmansee
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA
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