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Alonge MM, Greville LJS, Ma X, Faure PA, Bentley GE. Acute restraint stress rapidly impacts reproductive neuroendocrinology and downstream gonad function in big brown bats (Eptesicus fuscus). J Exp Biol 2023; 226:jeb245592. [PMID: 37827114 PMCID: PMC10629485 DOI: 10.1242/jeb.245592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 08/23/2023] [Indexed: 10/14/2023]
Abstract
Animals face unpredictable challenges that require rapid, facultative physiological reactions to support survival but may compromise reproduction. Bats have a long-standing reputation for being highly sensitive to stressors, with sensitivity and resilience varying both within and among species, yet little is known about how stress affects the signaling that regulates reproductive physiology. Here, we provide the first description of the molecular response of the hypothalamic-pituitary-gonadal (HPG) axis of male big brown bats (Eptesicus fuscus) in response to short-term stress using a standardized restraint manipulation. This acute stressor was sufficient to upregulate plasma corticosterone and resulted in a rapid decrease in circulating testosterone. While we did not find differences in the mRNA expression of key steroidogenic enzymes (StAR, aromatase, 5-alpha reductase), seminiferous tubule diameter was reduced in stressed bats coupled with a 5-fold increase in glucocorticoid receptor (GR) mRNA expression in the testes. These changes, in part, may be mediated by RFamide-related peptide (RFRP) because fewer immunoreactive cell bodies were detected in the brains of stressed bats compared with controls - suggesting a possible increase in secretion - and increased RFRP expression locally in the gonads. The rapid sensitivity of the bat testes to stress may be connected to deleterious impacts on tissue health and function as supported by significant transcriptional upregulation of key pro-apoptotic signaling molecules (Bax, cytochrome c). Experiments like this broadly contribute to our understanding of the stronger ecological predictions regarding physiological responses of bats within the context of stress, which may impact decisions surrounding animal handling and conservation approaches.
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Affiliation(s)
- Mattina M. Alonge
- University of California, Berkeley, Department of Integrative Biology, Berkeley, CA 94720-3200, USA
| | - Lucas J. S. Greville
- McMaster University, Department of Psychology, Neuroscience & Behaviour, Hamilton, ON, Canada, L8S 4L8
- University of Waterloo, Department of Biology, Waterloo, ON, Canada, N2L 3G1
| | - Xuehao Ma
- University of California, Berkeley, Department of Integrative Biology, Berkeley, CA 94720-3200, USA
- Helen Wills Neuroscience Institute, Berkeley, CA 94720, USA
| | - Paul A. Faure
- McMaster University, Department of Psychology, Neuroscience & Behaviour, Hamilton, ON, Canada, L8S 4L8
| | - George E. Bentley
- University of California, Berkeley, Department of Integrative Biology, Berkeley, CA 94720-3200, USA
- Helen Wills Neuroscience Institute, Berkeley, CA 94720, USA
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Alonge MM, Greville LJS, Faure PA, Bentley GE. Immunoreactive distribution of gonadotropin-inhibitory hormone precursor, RFRP, in a temperate bat species (Eptesicus fuscus). J Comp Neurol 2021; 530:1459-1469. [PMID: 34957555 DOI: 10.1002/cne.25291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 09/21/2021] [Revised: 11/17/2021] [Accepted: 12/07/2021] [Indexed: 11/08/2022]
Abstract
Gonadotropin-inhibitory hormone (GnIH, also known RFRP-3 in mammals) is an important regulator of the hypothalamic-pituitary-gonadal (HPG) axis and downstream reproductive physiology. Substantial species differences exist in the localization of cell bodies producing RFRP-3 and patterns of fiber immunoreactivity in the brain, raising the question of functional differences. Many temperate bat species exhibit unusual annual reproductive patterns. Male bats upregulate spermatogenesis in late spring which is asynchronous with periods of mating in the fall, while females have the physiological capacity to delay their reproductive investment over winter via sperm storage or delayed ovulation/fertilization. Neuroendocrine mechanisms regulating reproductive timing in male and female bats are not well-studied. We provide the first description of RFRP - precursor peptide of gonadotropin-inhibitory hormone - expression and localization in the brain of any bat using a widespread temperate species (Eptesicus fuscus, big brown bat) as a model. RFRP mRNA expression was detected in the hypothalamus, testes, and ovaries of big brown bats. Cellular RFRP-immunoreactivity was observed within the PVN, DMH, arcuate nucleus (Arc) and median eminence (ME). As in other vertebrates, RFRP fiber immunoreactivity was widespread, with greatest density observed in the hypothalamus, POA, ARC, ME, midbrain, and thalamic nuclei. Putative interactions between RFRP-ir fibers and gonadotropin-releasing hormone cell bodies were observed in 16% of GnRH-ir cells, suggesting direct regulation of GnRH via RFRP signaling. This characterization of RFRP distribution contributes to deeper understanding of bat neuroendocrinology which serves as foundation for manipulative approaches examining changes in reproductive neuropeptide signaling in response to environmental and physiological challenges within, and among, bat species. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mattina M Alonge
- University of California Berkeley, Department of Integrative Biology and Helen Wills Neuroscience Institute, Berkeley, California, USA
| | - Lucas J S Greville
- McMaster University, Department of Psychology, Neuroscience & Behavior, Hamilton, Ontario, Canada
| | - Paul A Faure
- McMaster University, Department of Psychology, Neuroscience & Behavior, Hamilton, Ontario, Canada
| | - George E Bentley
- University of California Berkeley, Department of Integrative Biology and Helen Wills Neuroscience Institute, Berkeley, California, USA
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Wilsterman K, Alonge MM, Ernst DK, Limber C, Treidel LA, Bentley GE. Flexibility in an emergency life-history stage: acute food deprivation prevents sickness behaviour but not the immune response. Proc Biol Sci 2020; 287:20200842. [PMID: 32546100 DOI: 10.1098/rspb.2020.0842] [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] [Indexed: 01/20/2023] Open
Abstract
The emergency life-history stage (ELHS) can be divided into two subcategories that describe distinct, coordinated responses to disease- or non-disease-related physiological challenges. Whether an individual can simultaneously express aspects of both subcategories when faced with multiple challenges is poorly understood. Emergency life-history theory suggests that disease- and non-disease-related responses are coordinated at the level of the whole organism and therefore cannot be expressed simultaneously. However, the reactive scope and physiological regulatory network models suggest that traits can be independently regulated, allowing for components of both disease- and non-disease-related responses to be simultaneously expressed within a single organism. To test these ideas experimentally, we subjected female zebra finches to food deprivation, an immune challenge, both, or neither, and measured a suite of behavioural and physiological traits involved in the ELHS. We examined whether the trait values expressed by birds experiencing simultaneous challenges resembled trait values of birds experiencing a single challenge or if birds could express a mixture of trait values concurrently. We find that birds can respond to simultaneous challenges by regulating components of the behavioural and immune responses independently of one another. Modularity within these physio-behavioural networks adds additional dimensions to how we evaluate the intensity or quality of an ELHS. Whether modularity provides fitness advantages or costs in nature remains to be determined.
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Affiliation(s)
| | - Mattina M Alonge
- Integrative Biology, University of California, Berkeley, CA, USA
| | - Darcy K Ernst
- Department of Biology, Las Positas College, Livermore, CA, USA
| | - Cody Limber
- Integrative Biology, University of California, Berkeley, CA, USA
| | - Lisa A Treidel
- Integrative Biology, University of California, Berkeley, CA, USA
| | - George E Bentley
- Integrative Biology, University of California, Berkeley, CA, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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Wilsterman K, Alonge MM, Bao X, Conner KA, Bentley GE. Food access modifies GnIH, but not CRH, cell number in the hypothalamus in a female songbird. Gen Comp Endocrinol 2020; 292:113438. [PMID: 32060003 DOI: 10.1016/j.ygcen.2020.113438] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 02/06/2020] [Accepted: 02/10/2020] [Indexed: 11/23/2022]
Abstract
Food deprivation or restriction causes animals to mount a stereotypical behavioral and physiological response that involves overall increases in activity, elevated glucocorticoid production, and (often) inhibition of the reproductive system. Although there is increasing evidence that these responses can differ in their degree or covariation between the sexes, most studies to-date on food restriction/deprivation have focused on male songbirds. We therefore aimed to characterize the behavioral, physiological, and neuroendocrine response to acute food deprivation in a female songbird using a nomadic species, the zebra finch. We quantified behavior during a 6.5 h food deprivation and then measured physiological and neuroendocrine responses of female birds at the 6.5 h timepoint. Within 1 h of acute food deprivation, female zebra finches increased foraging behaviors, and after 6.5 h of food deprivation, females lost 5% of their body mass, on average. Change in body mass was positively associated with elevated corticosterone and (contrary to findings in male zebra finches) negatively related to the number of gonadotropin inhibitory hormone-immunoreactive cells in the hypothalamus. However, there was no effect of food deprivation on corticotropin releasing hormone-immunoreactive cells in the hypothalamus. There was also no relationship between corticotropin releasing hormone-immunoreactive cell number and circulating corticosterone. Our results are consistent with the hypothesis that neuroendocrine responses to food deprivation differ between male and female songbirds. Future studies should work to incorporate sex comparisons to evaluate sex-specific neuroendocrine responses to acute stress.
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Affiliation(s)
| | - Mattina M Alonge
- Integrative Biology, Univ. of California - Berkeley, Berkeley, CA, USA
| | - Xinmiao Bao
- Integrative Biology, Univ. of California - Berkeley, Berkeley, CA, USA
| | - Kristin A Conner
- Integrative Biology, Univ. of California - Berkeley, Berkeley, CA, USA
| | - George E Bentley
- Integrative Biology, Univ. of California - Berkeley, Berkeley, CA, USA; Helen Wills Neuroscience Institute, Univ. of California - Berkeley, Berkeley, CA, USA
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Rosebeck S, Alonge MM, Kandarpa M, Mayampurath A, Volchenboum SL, Jasielec J, Dytfeld D, Maxwell SP, Kraftson SJ, McCauley D, Shacham S, Kauffman M, Jakubowiak AJ. Synergistic Myeloma Cell Death via Novel Intracellular Activation of Caspase-10-Dependent Apoptosis by Carfilzomib and Selinexor. Mol Cancer Ther 2015; 15:60-71. [PMID: 26637366 DOI: 10.1158/1535-7163.mct-15-0488] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/14/2015] [Indexed: 11/16/2022]
Abstract
Exportin1 (XPO1; also known as chromosome maintenance region 1, or CRM1) controls nucleo-cytoplasmic transport of most tumor suppressors and is overexpressed in many cancers, including multiple myeloma, functionally impairing tumor suppressive function via target mislocalization. Selective inhibitor of nuclear export (SINE) compounds block XPO1-mediated nuclear escape by disrupting cargo protein binding, leading to retention of tumor suppressors, induction of cancer cell death, and sensitization to other drugs. Combined treatment with the clinical stage SINE compound selinexor and the irreversible proteasome inhibitor (PI) carfilzomib induced synergistic cell death of myeloma cell lines and primary plasma cells derived from relapsing/refractory myeloma patients and completely impaired the growth of myeloma cell line-derived tumors in mice. Investigating the details of SINE/PI-induced cell death revealed (i) reduced Bcl-2 expression and cleavage and inactivation of Akt, two prosurvival regulators of apoptosis and autophagy; (ii) intracellular membrane-associated aggregation of active caspases, which depended on caspase-10 protease activity; and (iii) novel association of caspase-10 and autophagy-associated proteins p62 and LC3 II, which may prime activation of the caspase cascade. Overall, our findings provide novel mechanistic rationale behind the potent cell death induced by combining selinexor with carfilzomib and support their use in the treatment of relapsed/refractory myeloma and potentially other cancers.
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Affiliation(s)
- Shaun Rosebeck
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Mattina M Alonge
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Malathi Kandarpa
- University of Michigan Comprehensive Cancer Center, Ann Arbor, Michigan
| | | | | | - Jagoda Jasielec
- Department of Medicine, University of Chicago, Chicago, Illinois
| | | | - Sean P Maxwell
- Department of Medicine, University of Chicago, Chicago, Illinois
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Dytfeld D, Rosebeck S, Kandarpa M, Mayampurath A, Mellacheruvu D, Alonge MM, Ngoka L, Jasielec J, Richardson PG, Volchenboum S, Nesvizhskii AI, Sreekumar A, Jakubowiak AJ. Proteomic profiling of naïve multiple myeloma patient plasma cells identifies pathways associated with favourable response to bortezomib-based treatment regimens. Br J Haematol 2015; 170:66-79. [DOI: 10.1111/bjh.13394] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 02/04/2015] [Indexed: 01/08/2023]
Affiliation(s)
- Dominik Dytfeld
- University of Chicago; Chicago IL USA
- Karol Marcinkowski University of Medical Sciences; Poznan Poland
| | | | - Malathi Kandarpa
- Hematology/Oncology; University of Michigan Comprehensive Cancer Center; Ann Arbor MI USA
| | - Anoop Mayampurath
- Center for Research Informatics; Computation Institute and Department of Pediatrics; University of Chicago; Chicago IL USA
| | - Dattatreya Mellacheruvu
- Department of Pathology; University of Michigan; Ann Arbor MI USA
- Department of Computational Medicine & Bioinformatics; Ann Arbor MI USA
| | | | | | | | | | - Samuel Volchenboum
- Center for Research Informatics; Computation Institute and Department of Pediatrics; University of Chicago; Chicago IL USA
| | | | - Arun Sreekumar
- Department of Pathology; University of Michigan; Ann Arbor MI USA
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