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Janssenswillen S, Roelants K, Carpentier S, de Rooster H, Metzemaekers M, Vanschoenwinkel B, Proost P, Bossuyt F. Odorant-binding proteins in canine anal sac glands indicate an evolutionarily conserved role in mammalian chemical communication. BMC Ecol Evol 2021; 21:182. [PMID: 34565329 PMCID: PMC8474896 DOI: 10.1186/s12862-021-01910-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 09/10/2021] [Indexed: 11/29/2022] Open
Abstract
Background Chemical communication is an important aspect of the behavioural ecology of a wide range of mammals. In dogs and other carnivores, anal sac glands are thought to convey information to conspecifics by secreting a pallet of small volatile molecules produced by symbiotic bacteria. Because these glands are unique to carnivores, it is unclear how their secretions relate to those of other placental mammals that make use of different tissues and secretions for chemical communication. Here we analyse the anal sac glands of domestic dogs to verify the secretion of proteins and infer their evolutionary relationship to those involved in the chemical communication of non-carnivoran mammals. Results Proteomic analysis of anal sac gland secretions of 17 dogs revealed the consistently abundant presence of three related proteins. Homology searches against online databases indicate that these proteins are evolutionary related to ‘odorant binding proteins’ (OBPs) found in a wide range of mammalian secretions and known to contribute to chemical communication. Screening of the dog’s genome sequence show that the newly discovered OBPs are encoded by a single cluster of three genes in the pseudoautosomal region of the X-chromosome. Comparative genomic screening indicates that the same locus is shared by a wide range of placental mammals and that it originated at least before the radiation of extant placental orders. Phylogenetic analyses suggest a dynamic evolution of gene duplication and loss, resulting in large gene clusters in some placental taxa and recurrent loss of this locus in others. The homology of OBPs in canid anal sac glands and those found in other mammalian secretions implies that these proteins maintained a function in chemical communication throughout mammalian evolutionary history by multiple shifts in expression between secretory tissues involved in signal release and nasal mucosa involved in signal reception. Conclusions Our study elucidates a poorly understood part of the biology of a species that lives in close association with humans. In addition, it shows that the protein repertoire underlying chemical communication in mammals is more evolutionarily stable than the variation of involved glands and tissues would suggest. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01910-w.
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Affiliation(s)
- Sunita Janssenswillen
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Kim Roelants
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
| | - Sebastien Carpentier
- Proteomics Core - SyBioMa, Katholieke Universiteit Leuven, Herestraat 49 - 03.313, 3000, Leuven, Belgium
| | - Hilde de Rooster
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium
| | - Mieke Metzemaekers
- Rega Institute, Molecular Immunology, Katholieke Universiteit Leuven, Herestraat 49 - Bus1042, 3000, Leuven, Belgium
| | - Bram Vanschoenwinkel
- Community Ecology Lab, Biology Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.,Center for Environmental Management, University of the Free State, Bloemfontein, 9030, South Africa
| | - Paul Proost
- Rega Institute, Molecular Immunology, Katholieke Universiteit Leuven, Herestraat 49 - Bus1042, 3000, Leuven, Belgium
| | - Franky Bossuyt
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
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Loxley GM, Hooks DO, Antonopoulos A, Dell A, Haslam SM, Linklater WL, Hurst JL, Beynon RJ. Vulpeculin: a novel and abundant lipocalin in the urine of the common brushtail possum, Trichosurus vulpecula. Open Biol 2020; 10:200218. [PMID: 33022194 PMCID: PMC7653361 DOI: 10.1098/rsob.200218] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Lipocalins are a family of secreted proteins. They are capable of binding small lipophilic compounds and have been extensively studied for their role in chemosignalling in rodent urine. Urine of the common brushtail possum (Trichosurus vulpecula) contains a prominent glycoprotein of 20 kDa, expressed in both sexes. We have isolated this protein and determined its primary sequence by mass spectrometry, including the use of metabolic labelling to resolve the leucine/isoleucine isobaric ambiguity. The protein sequence was identified as a lipocalin, and phylogenetic analysis grouped the protein with other marsupial lipocalin sequences in a phylogenetic clade distinct from established cross-species lipocalin sub-families. The pattern of expression in possum urine and the similarity in sequence and structure to other lipocalins suggests this protein may have a role in brushtail possum chemosignalling.
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Affiliation(s)
- Grace M Loxley
- Centre for Proteome Research, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - David O Hooks
- Centre for Biodiversity and Restoration Ecology, School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | | | - Anne Dell
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Stuart M Haslam
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Wayne L Linklater
- Department of Environmental Studies, California State University, Sacramento, CA 95819, USA
| | - Jane L Hurst
- Mammalian Behaviour and Evolution Group, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Leahurst Campus, Neston CH64 7TE, UK
| | - Robert J Beynon
- Centre for Proteome Research, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
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3
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Sullivan DA, Rocha EM, Aragona P, Clayton JA, Ding J, Golebiowski B, Hampel U, McDermott AM, Schaumberg DA, Srinivasan S, Versura P, Willcox MDP. TFOS DEWS II Sex, Gender, and Hormones Report. Ocul Surf 2017; 15:284-333. [PMID: 28736336 DOI: 10.1016/j.jtos.2017.04.001] [Citation(s) in RCA: 236] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 04/16/2017] [Indexed: 12/21/2022]
Abstract
One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.
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Affiliation(s)
- David A Sullivan
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
| | - Eduardo M Rocha
- Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - Pasquale Aragona
- Department of Biomedical Sciences, Ocular Surface Diseases Unit, University of Messina, Messina, Sicily, Italy
| | - Janine A Clayton
- National Institutes of Health Office of Research on Women's Health, Bethesda, MD, USA
| | - Juan Ding
- Schepens Eye Research Institute, Massachusetts Eye & Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Blanka Golebiowski
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Ulrike Hampel
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Alison M McDermott
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, TX, USA
| | - Debra A Schaumberg
- Harvard School of Public Health, Boston, MA, USA; University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Sruthi Srinivasan
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Ontario, Canada
| | - Piera Versura
- Department of Specialized, Experimental, and Diagnostic Medicine, University of Bologna, Bologna, Italy
| | - Mark D P Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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4
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Stopkova R, Klempt P, Kuntova B, Stopka P. On the tear proteome of the house mouse ( Mus musculus musculus) in relation to chemical signalling. PeerJ 2017; 5:e3541. [PMID: 28698824 PMCID: PMC5502090 DOI: 10.7717/peerj.3541] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 06/14/2017] [Indexed: 12/29/2022] Open
Abstract
Mammalian tears are produced by lacrimal glands to protect eyes and may function in chemical communication and immunity. Recent studies on the house mouse chemical signalling revealed that major urinary proteins (MUPs) are not individually unique in Mus musculus musculus. This fact stimulated us to look for other sexually dimorphic proteins that may—in combination with MUPs—contribute to a pool of chemical signals in tears. MUPs and other lipocalins including odorant binding proteins (OBPs) have the capacity to selectively transport volatile organic compounds (VOCs) in their eight-stranded beta barrel, thus we have generated the tear proteome of the house mouse to detect a wider pool of proteins that may be involved in chemical signalling. We have detected significant male-biased (7.8%) and female-biased (7%) proteins in tears. Those proteins that showed the most elevated sexual dimorphisms were highly expressed and belong to MUP, OBP, ESP (i.e., exocrine gland-secreted peptides), and SCGB/ABP (i.e., secretoglobin) families. Thus, tears may have the potential to elicit sex-specific signals in combination by different proteins. Some tear lipocalins are not sexually dimorphic—with MUP20/darcin and OBP6 being good examples—and because all proteins may flow with tears through nasolacrimal ducts to nasal and oral cavities we suggest that their roles are wider than originally thought. Also, we have also detected several sexually dimorphic bactericidal proteins, thus further supporting an idea that males and females may have adopted alternative strategies in controlling microbiota thus yielding different VOC profiles.
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Affiliation(s)
- Romana Stopkova
- BIOCEV group, Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petr Klempt
- BIOCEV group, Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Barbora Kuntova
- BIOCEV group, Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Pavel Stopka
- BIOCEV group, Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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Dubey VP, Pal B, Srikantan S, Pottabathini S, De PK, Sankaranarayanan R. Cloning, overexpression, purification, crystallization and preliminary X-ray analysis of a female-specific lipocalin (FLP) expressed in the lacrimal glands of Syrian hamsters. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:509-12. [PMID: 20445246 PMCID: PMC2864679 DOI: 10.1107/s1744309110008237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 03/03/2010] [Indexed: 11/11/2022]
Abstract
Proteins belonging to the lipocalin superfamily are usually secretory proteins of molecular mass approximately 20 kDa with a hydrophobic pocket for the binding and transport of diverse small ligands. Various lipocalins have been associated with many biological processes, e.g. immunomodulation, odorant transport, pheromonal activity, retinoid transport, cancer-cell interactions etc. However, the exact functions of many lipocalins and the ligands bound by them are unclear. Previously, the cDNA of a 20 kDa lipocalin (FLP) which is female-specifically expressed in the lacrimal glands of Syrian (golden) hamsters and secreted in the tears of females has been identified and cloned. His-tagged recombinant FLP (rFLP) has now been cloned, overexpressed in Escherichia coli as a soluble protein and purified to homogeneity using Ni-affinity followed by size-exclusion chromatography. Purified rFLP was crystallized using the sitting-drop vapour-diffusion method. The crystals tested belonged to space group P2(1)2(1)2(1) and diffracted to beyond 1.86 A resolution. Solvent-content analysis indicated the presence of one monomer in the asymmetric unit.
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Affiliation(s)
- Ved Prakash Dubey
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
| | - Biswajit Pal
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
| | - Subramanya Srikantan
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
| | - Sambhavi Pottabathini
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
| | - Prabir Kumar De
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
| | - Rajan Sankaranarayanan
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Uppal Road, Hyderabad 500 007, India
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6
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Stopková R, Zdráhal Z, Ryba S, Sedo O, Sandera M, Stopka P. Novel OBP genes similar to hamster Aphrodisin in the bank vole, Myodes glareolus. BMC Genomics 2010; 11:45. [PMID: 20085627 PMCID: PMC2824723 DOI: 10.1186/1471-2164-11-45] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 01/19/2010] [Indexed: 12/03/2022] Open
Abstract
Background Chemical communication in mammals involves globular lipocalins that protect and transport pheromones during their passage out of the body. Efficient communication via this protein - pheromone complex is essential for triggering multiple responses including aggression, mate choice, copulatory behaviour, and onset and synchronization of oestrus. The roles of lipocalins in communication were studied in many organisms and especially in mice (i.e. Mus musculus domesticus) which excrete Major Urinary Proteins (Mup) in excessive amounts in saliva and urine. Other mammals, however, often lack the genes for Mups or their expression is very low. Therefore, we aimed at characterization of candidate lipocalins in Myodes glareolus which are potentially linked to chemical communication. One of them is Aphrodisin which is a unique lipocalin that was previously described from hamster vaginal discharge and is known to carry pheromones stimulating copulatory behaviour in males. Results Here we show that Aphrodisin-like proteins exist in other species, belong to a group of Odorant Binding Proteins (Obp), and contrary to the expression of Aphrodisin only in hamster genital tract and parotid glands of females, we have detected these transcripts in both sexes of M. glareolus with the expression confirmed in various tissues including prostate, prepucial and salivary glands, liver and uterus. On the level of mRNA, we have detected three different gene variants. To assess their relevance for chemical communication we investigated the occurrence of particular proteins in saliva, urine and vaginal discharge. On the protein level we confirmed the presence of Obp2 and Obp3 in both saliva and urine. Appropriate bands in the range of 17-20 kDa from vaginal discharge were, however, beyond the MS detection limits. Conclusion Our results demonstrate that three novel Obps (Obp1, Obp2, and Obp3) are predominant lipocalins in Myodes urine and saliva. On the protein level we have detected further variants and thus we assume that similarly as Major Urinary Proteins in mice, these proteins may be important in chemical communication in this Cricetid rodent.
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Affiliation(s)
- Romana Stopková
- Department of Zoology, Faculty of Science, Charles University in Prague, Prague, CZ-128 44, Czech Republic
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7
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Srikantan S, De PK. Sex differences in expression and differential regulation by androgen and estrogen of two odorant-binding tear lipocalins in lacrimal glands of immature hamsters. Gen Comp Endocrinol 2008; 158:268-76. [PMID: 18703064 DOI: 10.1016/j.ygcen.2008.07.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 06/14/2008] [Accepted: 07/28/2008] [Indexed: 10/21/2022]
Abstract
In adults of several mammalian species, lacrimal glands (LG) have sex differences but there is no report of any sexual dimorphism in LG of immatures. In LG and tears of adult hamsters, we found female-specific expression of two closely related odorant-/pheromone-binding lipocalins, FLP (female lacrimal protein) and MSP (male-specific protein; initially identified in salivary glands of males). Although, both androgens and estrogens markedly repress FLP and MSP in LG of adults, the expression of these lipocalins in females is due to their incomplete repression by endogenous estrogens. Here we report a marked sexual dimorphism in the expression of FLP and MSP in LG and tears of 20-day-old immature hamsters. The age-dependant expression of these lipocalins and effect of neonatal-gonadectomy and sex hormone treatments on their expression in immatures was investigated. FLP and MSP are detectable in LG at 10-day age in both sexes of hamster but by 20-day age levels of both lipocalins show sex differences wherein FLP is several fold higher in males and MSP is obliterated in males. Thereafter, FLP declines in male LG and is obliterated by 36-day age, resulting in female-specific expression of both LG lipocalins as seen in adults. In LG of 20-day-old immatures, FLP and MSP are insensitive to repression by androgen and estrogen, respectively, which was unlike the androgen/estrogen-repressed regulation of both lipocalins in adult LG. The estrogenic repression of FLP and androgenic repression of MSP in LG of immature hamsters could be prevented by treatment with tamoxifen and flutamide, respectively. Our studies indicate that (i) presence of gonads in immatures can have significant effects on LG lipocalins resulting in their sexually dimorphic expression, (ii) in immatures, unlike adults, the repressive effects of estrogen and androgen on LG lipocalins are selective for FLP and MSP, respectively, and (iii) these repressions are likely to be mediated by sex hormone receptors.
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Affiliation(s)
- Subramanya Srikantan
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, Andhra Pradesh, India
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8
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Sullivan DA. Tearful relationships? Sex, hormones, the lacrimal gland, and aqueous-deficient dry eye. Ocul Surf 2007; 2:92-123. [PMID: 17216082 DOI: 10.1016/s1542-0124(12)70147-7] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sex and the endocrine system exert a significant influence on the physiology and pathophysiology of the lacrimal gland. The purpose of this article is to briefly review the nature and magnitude of these interactions between sex, hormones and lacrimal tissue, and to address how they may relate to the pathogenesis of aqueous-deficient dry eye. Towards this end, this article has a 3-fold approach: first, to summarize the influence of androgens, estrogens, glucocorticoids, mineralocorticoids, retinoic acid, prolactin, alpha-melanocyte stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, thyroid-stimulating hormone, arginine vasopressin, oxytocin, thyroxine, parathyroid hormone, insulin, glucagon, melatonin, human chorionic gonadotropin and cholecystokinin on the structure and function of the lacrimal gland; second, to discuss the mechanism of action of each hormone on lacrimal tissue; and third, to discuss the clinical relevance of the endocrine-lacrimal gland interrelationship, with a particular focus on each hormone's role (i.e. if relevant) in the development of aqueous-tear deficiency.
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Affiliation(s)
- David A Sullivan
- Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA.
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9
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Srikantan S, Paliwal A, Quintanar-Stephano A, De PK. Estrogen and androgen repression of two female specific lacrimal lipocalins in hamster: Pituitary independent and sex hormone receptor mediated action. Gen Comp Endocrinol 2007; 151:172-9. [PMID: 17316636 DOI: 10.1016/j.ygcen.2007.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 01/07/2007] [Accepted: 01/10/2007] [Indexed: 11/25/2022]
Abstract
Sexual dimorphism in lacrimal gland (LG) gene expression is believed to be due to direct inductive effects of androgens mediated by androgen receptors (AR) but hypophysectomy dramatically curtails these inductive effects. Since, functional estrogen receptors (ER) could not be detected in LG, estrogen effects on LG are believed to be indirectly mediated by changes in levels of pituitary hormones. We found that two lipocalins expressed in female hamster LG display an unusual and marked repression by both androgens and estrogens, which could be detected both at the level of transcripts and proteins. Here, we investigate whether these repressions, (i) require presence of pituitary and (ii) are mediated by androgen and estrogen receptors. Pituitary-ablation but not gonadectomy reduced LG weights in hamster. However, both pituitary-ablation and gonadectomy induced abundant expression of the LG lipocalins, which were markedly repressed by androgen or estrogen treatment. AR- and ER-antagonists prevented these repressions and only ER-alpha- but not ER-beta-specific agonist could mimic the estrogenic repression. AR transcript and protein and ER-alpha transcript were also detected in hamster LG. Thus, pituitary factors are neither essential for the expression of these LG lipocalins nor for their estrogenic or androgenic repressions and these repressions are very likely mediated by functional ER and AR present in LG.
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Affiliation(s)
- Subramanya Srikantan
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India
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10
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Paliwal A, De PK. Purification, cloning and regulation of a novel acid-lipase-like protein of hamster expressed in lacrimal glands and tears during lactation. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1771:55-65. [PMID: 17141562 DOI: 10.1016/j.bbalip.2006.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2006] [Revised: 10/09/2006] [Accepted: 10/23/2006] [Indexed: 10/24/2022]
Abstract
We report a novel 48-kDa tear acid-lipase-like protein (TALLP), which is markedly induced in lacrimal glands (LG) and secreted in tears of hamster dams during lactation. TALLP is undetectable in LG and tears of normal hamsters, but is also induced after gonadectomy in both sexes and this is prevented by androgen, estrogen or thyroid hormone treatment. These observations and the obliteration of TALLP upon cessation of lactation suggest that endogenous estrogens (in females) and androgens (in males) completely repress TALLP expression. Purified TALLP is monomeric, contains approximately 18% N-glycosylation and several pI isoforms. TALLP expression was tissue-specific and immunolocalized in LG acinar cells. The cDNA deduced amino-acid sequence of TALLP precursor (398 residue, containing a 19 residues signal-peptide) showed only 43-48% identity with all known mammalian acid-lipases, including even those of other rodents, suggesting that TALLP is a prototype of a new category, within the acid-lipase family. Surprisingly, although the catalytic triad residues and other sequence features important for lipolytic activity are conserved in TALLP, it has no detectable lipase activity. However, TALLP binds the polarity sensitive hydrophobic probe, 1-aminoanthracene (K(d)=12 microM). TALLP might have a unique substrate-specificity or a lipid-binding/carrier function in tears of hamster dams. This is the first report of an acid-lipase-like protein secreted in tears of any species. Since TALLP lacks the usual lipase activity, it can be an excellent model to understand better what other structural features in acid-lipases influence their catalytic activity.
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Affiliation(s)
- Anupam Paliwal
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad-500007, Andhra Pradesh, India
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11
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Paliwal A, De PK. Marked sexual dimorphism of lacrimal gland peroxidase in hamster: repression by androgens and estrogens. Biochem Biophys Res Commun 2006; 341:1286-93. [PMID: 16469299 DOI: 10.1016/j.bbrc.2006.01.095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Accepted: 01/22/2006] [Indexed: 11/27/2022]
Abstract
Peroxidase secreted in tears by the lacrimal glands is a marker of secretory activity of these glands and is believed to have an antimicrobial function. We report for the first time a marked sex difference in lacrimal gland (LG) peroxidase in hamsters ( approximately 3.4-fold higher activity in females), which is due to an unusual repression by physiological levels of androgens in males. LG peroxidase activity was markedly induced in a time-dependent manner after gonadectomy in males and also females ( approximately 8- and 2-fold, respectively) and was strongly repressed by androgen treatment in a dose- and time-dependent manner. Estrogen treatment of gonadectomized hamsters could also repress LG peroxidase but not below female levels. These repressions by androgens and estrogens were significantly prevented upon co-treatment with their respective receptor antagonists. Western blotting showed that differences in LG peroxidase specific activity, in different sex hormonal states and treatments were due to changes in the levels of peroxidase protein in LG. A tear peroxidase with a clear sex difference suggests that it might also have other novel function(s) in hamster tears.
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Affiliation(s)
- Anupam Paliwal
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad-500007, Andhra Pradesh, India
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12
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Briand L, Trotier D, Pernollet JC. Aphrodisin, an aphrodisiac lipocalin secreted in hamster vaginal secretions. Peptides 2004; 25:1545-52. [PMID: 15374656 DOI: 10.1016/j.peptides.2003.10.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Accepted: 10/21/2003] [Indexed: 11/21/2022]
Abstract
Vertebrates communicate through pheromones, which favor biological regulations within each species. Aphrodisin, a protein belonging to the lipocalin superfamily, found in hamster vaginal secretions, is detected by the male accessory olfactory system and induces or facilitates its copulatory behavior. Although much is known about aphrodisin structure, the question of whether aphrodisin bears itself the pheromonal function or is simply a carrier for hydrophobic small pheromones has not been definitely solved. Arguments based on use of recombinant aphrodisin deprived of any natural ligand and its capability to convey hamster pheromonal compounds will be discussed, together with progresses concerning putative natural ligand(s).
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Affiliation(s)
- Loïc Briand
- Biochimie et Structure des Protéines, INRA, UR 477, F-78352 Jouy-en-Josas, France
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13
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Göbbel L. Ontogenetic and phylogenetic transformations of the lacrimal-conducting apparatus among Microchiroptera. Mamm Biol 2002. [DOI: 10.1078/1616-5047-00050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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