1
|
Ortuno MJ, Schneeberger M, Ilanges A, Marchildon F, Pellegrino K, Friedman JM, Ducy P. Melanocortin 4 receptor stimulation prevents anti-depressant-associated weight gain in mice caused by long-term fluoxetine exposure. J Clin Invest 2021; 131:151976. [PMID: 34673574 DOI: 10.1172/jci151976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/19/2021] [Indexed: 11/17/2022] Open
Abstract
Contrasting with the predicted anorexigenic effect of increasing brain serotonin signaling, long-term use of selective serotonin reuptake inhibitors (SSRIs) antidepressants correlates with body weight gain. This adverse outcome increases the risk of transitioning to obesity and interferes with treatment compliance. Here we show that orally administered fluoxetine (Flx), a widely prescribed SSRI, increased body weight by enhancing food intake in healthy mice at two different time points and through two distinct mechanisms. Within hours, Flx decreased the activity of a subset of brainstem serotonergic neurons by triggering autoinhibitory signaling through the Htr1a receptor. Upon longer treatment Flx blunted Htr2c expression/signaling, decreased the phosphorylation of Creb and Stat3 and dampened the production of POMC/α-MSH in hypothalamic neurons, thereby increasing food intake. Accordingly, exogenous stimulation of the melanocortin 4 receptor (MC4R) by co-treating mice with Flx and lipocalin-2, an anorexigenic hormone signaling through this receptor, normalized feeding and body weight. Flx and other SSRIs also inhibit CREB/STAT3 phosphorylation in a human neuronal cell line suggesting that these non-canonical effects could also occur in long-term users of SSRIs. By defining the molecular basis of the long-term SSRIs-associated weight gain this study proposes a therapeutic strategy to counter it.
Collapse
Affiliation(s)
- Maria Jose Ortuno
- Department of Genetics and Development, Columbia University, New York, United States of America
| | - Marc Schneeberger
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States of America
| | - Anoj Ilanges
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States of America
| | - François Marchildon
- Laboratory of Molecular Metabolism, The Rockefeller University, New York, United States of America
| | - Kyle Pellegrino
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States of America
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, New York, United States of America
| | - Patricia Ducy
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, United States of America
| |
Collapse
|
2
|
Dinesh RK, Barnhill B, Ilanges A, Wu L, Michelson DA, Senigl F, Alinikula J, Shabanowitz J, Hunt DF, Schatz DG. Transcription factor binding at Ig enhancers is linked to somatic hypermutation targeting. Eur J Immunol 2019; 50:380-395. [PMID: 31821534 DOI: 10.1002/eji.201948357] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/05/2019] [Accepted: 12/02/2019] [Indexed: 01/15/2023]
Abstract
Secondary diversification of the Ig repertoire occurs through somatic hypermutation (SHM), gene conversion (GCV), and class switch recombination (CSR)-three processes that are initiated by activation-induced cytidine deaminase (AID). AID targets Ig genes at orders of magnitude higher than the rest of the genome, but the basis for this specificity is poorly understood. We have previously demonstrated that enhancers and enhancer-like sequences from Ig genes are capable of stimulating SHM of neighboring genes in a capacity distinct from their roles in increasing transcription. Here, we use an in vitro proteomics approach to identify E-box, MEF2, Ets, and Ikaros transcription factor family members as potential binders of these enhancers. ChIP assays in the hypermutating Ramos B cell line confirmed that many of these factors bound the endogenous Igλ enhancer and/or the IgH intronic enhancer (Eμ) in vivo. Further investigation using SHM reporter assays identified binding sites for E2A and MEF2B in Eμ and demonstrated an association between loss of factor binding and decreases in the SHM stimulating activity of Eμ mutants. Our results provide novel insights into trans-acting factors that dictate SHM targeting and link their activity to specific DNA binding sites within Ig enhancers.
Collapse
Affiliation(s)
- Ravi K Dinesh
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Benjamin Barnhill
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Anoj Ilanges
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Lizhen Wu
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Daniel A Michelson
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Filip Senigl
- Institute of Molecular Genetics, Czech Academy of Sciences, Videnska 1083, CZ-14220, Prague 4, Czech Republic
| | - Jukka Alinikula
- Institute of Biomedicine, University of Turku, Turku, Finland
| | | | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA.,Department of Pathology, University of Virginia, Charlottesville, VA, USA
| | - David G Schatz
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
3
|
Ilanges A, Jahanshahi M, Balobin DM, Pfleger CM. Alcohol interacts with genetic alteration of the Hippo tumor suppressor pathway to modulate tissue growth in Drosophila. PLoS One 2013; 8:e78880. [PMID: 24205337 PMCID: PMC3804493 DOI: 10.1371/journal.pone.0078880] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 09/16/2013] [Indexed: 12/27/2022] Open
Abstract
Alcohol-mediated cancers represent more than 3.5% of cancer-related deaths, yet how alcohol promotes cancer is a major open question. Using Drosophila, we identified novel interactions between dietary ethanol and loss of tumor suppressor components of the Hippo Pathway. The Hippo Pathway suppresses tumors in flies and mammals by inactivating transcriptional co-activator Yorkie, and the spectrum of cancers associated with impaired Hippo signaling overlaps strikingly with those associated with alcohol. Therefore, our findings may implicate loss of Hippo Pathway tumor suppression in alcohol-mediated cancers. Ethanol enhanced overgrowth from loss of the expanded, hippo, or warts tumor suppressors but, surprisingly, not from over-expressing the yorkie oncogene. We propose that in parallel to Yorkie-dependent overgrowth, impairing Hippo signaling in the presence of alcohol may promote overgrowth via additional alcohol-relevant targets. We also identified interactions between alcohol and Hippo Pathway over-activation. We propose that exceeding certain thresholds of alcohol exposure activates Hippo signaling to maintain proper growth control and prevent alcohol-mediated mis-patterning and tissue overgrowth.
Collapse
Affiliation(s)
- Anoj Ilanges
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Yale University, New Haven, Connecticut, United States of America
| | - Maryam Jahanshahi
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Denis M. Balobin
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Columbia University, New York, New York, United States of America
| | - Cathie M. Pfleger
- Department of Oncological Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- The Graduate School of Biomedical Sciences, The Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
| |
Collapse
|