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Santillo A, Chieffi Baccari G, Minucci S, Falvo S, Venditti M, Di Matteo L. The Harderian gland: Endocrine function and hormonal control. Gen Comp Endocrinol 2020; 297:113548. [PMID: 32679156 DOI: 10.1016/j.ygcen.2020.113548] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/30/2020] [Accepted: 07/09/2020] [Indexed: 01/17/2023]
Abstract
The Harderian gland (HG) is an exocrine gland located within the eye socket in a variety of tetrapods. During the 1980s and 1990s the HG elicited great interest in the scientific community due to its morphological and functional complexity, and from a phylogenetic point of view. A comparative approach has contributed to a better understanding of its physiology. Whereas the chemical nature of its secretions (mucous, serous or lipids) varies between different groups of tetrapods, the lipids represent the more common component among different species. Indeed, besides being an accessory to lubricate the nictitating membrane, the lipids may have a pheromonal function. Porphyrins and melatonin secretion is a feature of the rodent HG. The porphyrins, being phototransducers, could modulate HG melatonin production. The melatonin synthesis suggests an involvement of the HG in the retinal-pineal axis. Finally, StAR protein and steroidogenic enzyme activities in the rat HG suggests that the gland contributes to steroid hormone synthesis. Over the past twenty years, much has become known on the hamster (Mesocricetus auratus) HG, unique among rodents in displaying a remarkable sexual dimorphism concerning the contents of porphyrins and melatonin. Mainly for this reason, the hamster HG has been used as a model to compare, under normal conditions, the physiological oxidative stress between females (strong) and males (moderate). Androgens are responsible for the sexual dimorphism in hamster and they are known to control the HG secretory activity in different species. Furthermore, HG is a target of pituitary, pineal and thyroid hormones. This review offers a comparative panorama of the endocrine activity of the HG as well as the hormonal control of its secretory activity, with a particular emphasis on the sex dimorphic aspects of the hamster HG.
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Affiliation(s)
- Alessandra Santillo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy.
| | - Gabriella Chieffi Baccari
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy
| | - Sergio Minucci
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
| | - Sara Falvo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania 'Luigi Vanvitelli', Via Vivaldi, 43-81100 Caserta, Italy
| | - Massimo Venditti
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
| | - Loredana Di Matteo
- Dipartimento di Medicina Sperimentale, Sez. Fisiologia Umana e Funzioni Biologiche Integrate, Università degli Studi della Campania 'Luigi Vanvitelli', via Santa Maria di Costantinopoli, 16-80138 Napoli, Italy
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Bayraktaroğlu AG, Ergün E. Histomorphology of the Harderian gland in the Angora rabbit. Anat Histol Embryol 2011; 39:494-502. [PMID: 20624156 DOI: 10.1111/j.1439-0264.2010.01020.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study was aimed to demonstrate the morphological and histochemical properties of the Harderian gland in the Angora rabbit. Ten healthy adult Angora rabbits obtained from private breeders constituted the material of the study. The Harderian gland, which is composed of the pink and white lobes, consists of cells that produce a secretion of lipid character. The pink lobe contained type I cells with large lipid vacuoles. Cells with small lipid vacuoles (type II) were found in the white lobe. Type III cells containing both large and small lipid vacuoles were not observed. While type I cells reacted strongly to staining with Oil red O, type II cells reacted weakly to this stain. The number of plasma cells was greater in the white lobe when compared to the pink lobe. The apical granules within the epithelial cells lining the intralobular and inter-lobular excretory ducts of the gland were positive for periodic acid-Schiff (PAS), periodic acid-Schiff/alcian blue (PAS/AB), alcian blue (AB) and performic acid/alcian blue (PA/AB). Electron microscopic examination revealed that type I cells contain large electron-light lipid vacuoles and an eccentric heterochromatic nucleus, due to the presence of these vacuoles. The cells, which were connected by tight junctions, possessed apically located microfolds. The nucleus of type II cells was situated basally and had an oval shape. Type II cells had apical microvilli-like cytoplasmic protrusions, longer than those of type I cells. Oval shaped myoepithelial cells were observed between the glandular epithelial cells and their basal lamina. The epithelium lining the excretory ducts of the gland contained two types of granules, which were dark and lightly coloured. Histochemical and ultrastructural examinations revealed no difference in the structure of the Harderian gland between female and male Angora rabbits.
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Affiliation(s)
- A G Bayraktaroğlu
- Department of Histology and Embryology, Faculty of Veterinary Medicine, University of Ankara, 06110 Diskapi, Ankara, Turkey.
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Řezanka T, Sigler K. Odd-numbered very-long-chain fatty acids from the microbial, animal and plant kingdoms. Prog Lipid Res 2009; 48:206-38. [DOI: 10.1016/j.plipres.2009.03.003] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 03/17/2009] [Accepted: 03/23/2009] [Indexed: 10/21/2022]
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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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Kniazeva M, Crawford QT, Seiber M, Wang CY, Han M. Monomethyl branched-chain fatty acids play an essential role in Caenorhabditis elegans development. PLoS Biol 2004; 2:E257. [PMID: 15340492 PMCID: PMC514883 DOI: 10.1371/journal.pbio.0020257] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Accepted: 06/14/2004] [Indexed: 11/19/2022] Open
Abstract
Monomethyl branched-chain fatty acids (mmBCFAs) are commonly found in many organisms from bacteria to mammals. In humans, they have been detected in skin, brain, blood, and cancer cells. Despite a broad distribution, mmBCFAs remain exotic in eukaryotes, where their origin and physiological roles are not understood. Here we report our study of the function and regulation of mmBCFAs in Caenorhabditis elegans, combining genetics, gas chromatography, and DNA microarray analysis. We show that C. elegans synthesizes mmBCFAs de novo and utilizes the long-chain fatty acid elongation enzymes ELO-5 and ELO-6 to produce two mmBCFAs, C15ISO and C17ISO. These mmBCFAs are essential for C. elegans growth and development, as suppression of their biosynthesis results in a growth arrest at the first larval stage. The arrest is reversible and can be overcome by feeding the arrested animals with mmBCFA supplements. We show not only that the levels of C15ISO and C17ISO affect the expression of several genes, but also that the activities of some of these genes affect biosynthesis of mmBCFAs, suggesting a potential feedback regulation. One of the genes, lpd-1, encodes a homolog of a mammalian sterol regulatory element-binding protein (SREBP 1c). We present results suggesting that elo-5 and elo-6 may be transcriptional targets of LPD-1. This study exposes unexpected and crucial physiological functions of C15ISO and C17ISO in C. elegans and suggests a potentially important role for mmBCFAs in other eukaryotes.
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Affiliation(s)
- Marina Kniazeva
- 1Howard Hughes Medical Institute and Department of Molecular, Cellularand Developmental Biology, University of Colorado at Boulder, Boulder, Colorado, United States of America
| | - Quinn T Crawford
- 1Howard Hughes Medical Institute and Department of Molecular, Cellularand Developmental Biology, University of Colorado at Boulder, Boulder, Colorado, United States of America
| | - Matt Seiber
- 1Howard Hughes Medical Institute and Department of Molecular, Cellularand Developmental Biology, University of Colorado at Boulder, Boulder, Colorado, United States of America
| | - Cun-Yu Wang
- 2Laboratory of Molecular Signaling and Apoptosis, Department of Biological and Materials SciencesUniversity of Michigan School of Dentistry, Ann Arbor, MichiganUnited States of America
| | - Min Han
- 1Howard Hughes Medical Institute and Department of Molecular, Cellularand Developmental Biology, University of Colorado at Boulder, Boulder, Colorado, United States of America
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Sbarbati A, Calderan L, Nicolato E, Marzola P, Lunati E, Donatella B, Bernardi P, Osculati F. Magnetic resonance imaging of the rat Harderian gland. J Anat 2002; 201:231-8. [PMID: 12363274 PMCID: PMC1570910 DOI: 10.1046/j.1469-7580.2002.00086.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The intra-orbital lacrimal gland (Harderian gland, or HG) of the female rat was studied by magnetic resonance imaging (MRI) to evaluate whether MRI can be used to visualize the gland in vivo and localized-1H-spectroscopy detect its lipid content. The results were correlated with post-mortem anatomical sections, and with light and electron microscopy. On MRI, HG presented as a mass located between the ocular bulb and the orbit. In strongly T2W sequences the secretory structures had a reduced signal while intraparenchymal connective tissue was visible. T2-quantitative maps values of HG (60.12 +/- 8.15 ms, mean +/- SD) were different from other tissues (i.e. muscular tissue, T2 = 44.79 +/- 3.43 ms and olfactory bulb, T2 = 79.26 +/- 4.25 ms). In contrast-enhanced-MRI, HG had a signal-intensity-drop of 0.074 +/- 0.072 (mean +/- SD), after injection of AMI-25, significantly different from the muscle (0.17 +/- 0.10). Localized MRI spectra gave a large part of the signal originating from fat protons, but with a significant percentage from water protons. At light and electron microscopy the lipid deposition appeared to be composed of low-density material filling a large part of the cytoplasm, and the porphyrin aggregates were easily recognizable. The data demonstrate that an in vivo study of the HG was feasible and that high-field MRI allowed analysis of the gross anatomy detecting the lipid content of the gland.
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Affiliation(s)
- Andrea Sbarbati
- Department of Morphological and Biomedical Sciences, Medical Faculty, University of Verona, Italy.
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Coto-Montes A, Tomás-Zapico C, Rodríguez-Colunga MJ, Tolivia-Cadrecha D, Martínez-Fraga J, Hardeland R, Tolivia D. Effects of the circadian mutation 'tau' on the Harderian glands of Syrian hamsters. J Cell Biochem 2001; 83:426-34. [PMID: 11596111 DOI: 10.1002/jcb.1240] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Syrian hamster Harderian gland (HG) is an organ continually exposed to oxidative stress caused by high concentrations of porphyric metabolites. According to previous studies, melatonin, which is rhythmically secreted by the pineal gland and tonically produced by the HG, antagonizes the oxidative damage. HGs exhibit a strong gender-dependent correlation between porphyrins, melatonin, and histological appearance. In HGs of both sexes, we have investigated effects of a single gene defect in the circadian clock system (tau mutation) causing a shortened free-running period and an advanced maximum of circulating melatonin. Comparisons were made with wild-type animals, one group of which received daily pharmacological injections of melatonin in late photophase. Changes were observed in histological characteristics, porphyrin content, antioxidant enzyme activities, and damage of proteins and lipids. HGs of tau hamsters showed morphological changes which can be partially interpreted in terms of increased damage. Additionally, tau females exhibited a many-fold augmentation in the percentage of so-called type II cells, which are otherwise typical for the male glands. In tau hamsters of both sexes, major antioxidative enzyme activities (superoxide dismutase, glutathione reductase, and catalase) were markedly enhanced, a presumably compensatory response to increased oxidative stress. Higher oxidative damage in tau HGs was directly demonstrable by a many-fold increase in protein carbonyl. Rises in antioxidative enzymes were also observed upon injections of melatonin; this was, however, not accompanied by changes in protein carbonyl, so that enzyme inductions by the hormone should be understood as protective actions. Our data are not only in accordance with findings on protective effects by melatonin, but also with our earlier observation made in Drosophila that perturbations in the circadian system lead to increased oxidative stress.
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Affiliation(s)
- A Coto-Montes
- Departamento de Morfología y Biología Celular, Universidad de Oviedo, E-33006 Oviedo, Asturias, Spain.
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