1
|
Rath MF. Homeobox gene-encoded transcription factors in development and mature circadian function of the rodent pineal gland. J Pineal Res 2024; 76:e12950. [PMID: 38558122 DOI: 10.1111/jpi.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 02/15/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Homeobox genes encode transcription factors that are widely known to control developmental processes. This is also the case in the pineal gland, a neuroendocrine brain structure devoted to nighttime synthesis of the hormone melatonin. Thus, in accordance with high prenatal gene expression, knockout studies have identified a specific set of homeobox genes that are essential for development of the pineal gland. However, as a special feature of the pineal gland, homeobox gene expression persists into adulthood, and gene product abundance exhibits 24 h circadian rhythms. Recent lines of evidence show that some homeobox genes even control expression of enzymes catalyzing melatonin synthesis. We here review current knowledge of homeobox genes in the rodent pineal gland and suggest a model for dual functions of homeobox gene-encoded transcription factors in developmental and circadian mature neuroendocrine function.
Collapse
Affiliation(s)
- Martin F Rath
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
2
|
Zheng J, Song W, Zhou Y, Li X, Wang M, Zhang C. Cross-species single-cell landscape of vertebrate pineal gland. J Pineal Res 2024; 76:e12927. [PMID: 38018267 DOI: 10.1111/jpi.12927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 11/04/2023] [Accepted: 11/15/2023] [Indexed: 11/30/2023]
Abstract
The pineal gland has evolved from a photoreceptive organ in fish to a neuroendocrine organ in mammals. This study integrated multiple daytime single-cell RNA-seq datasets from the pineal glands of zebrafish, rats, and monkeys, providing a detailed examination of the evolutionary transition at single-cell resolution. We identified key factors responsible for the anatomical and functional transformation of the pineal gland. We retrieved and integrated daytime single-cell transcriptomic datasets from the pineal glands of zebrafish, rats, and monkeys, resulting in a total of 22 431 cells after rigorous quality filtering. Comparative analysis was then conducted to elucidate the evolution of pineal cells, their photosensitivity, their role in melatonin production, and the signaling processes within the glands of these species. Our analysis identified distinct cellular compositions of the pineal gland in zebrafish, rats, and monkeys. Zebrafish photoreceptors exhibited comprehensive phototransduction gene expression, while specific genes, including transducin (Gngt1, Gnb3, and Gngt2) and phosducin (Pdc), were consistently present in mammalian pinealocytes. We found transcriptional similarities between the pineal gland and retina, underscoring shared evolutionary and functional pathways. Zebrafish displayed unique light-responsive circadian gene activity compared to rats and monkeys. Key ligand-receptor interactions were identified, especially involving MDK and PTN, influencing melatonin synthesis across species. Furthermore, we observed species-specific GPCR (G protein-coupled receptors) expressions related to melatonin synthesis and their alignment with retinal expressions. Our findings also highlighted specific transcription factors (TFs) and regulatory networks associated with pineal gland evolution and function. Our study provides a detailed analysis of the pineal gland's evolution from fish to mammals. We identified key transcriptional changes and controls that highlight the gland's functional diversity. Notably, we found significant ligand-receptor interactions influencing melatonin synthesis and demonstrated parallels between pineal and retinal expressions. These insights enhance our understanding of the pineal gland's role in phototransduction, melatonin production, and circadian rhythms in vertebrates.
Collapse
Affiliation(s)
- Jihong Zheng
- Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Wenqi Song
- Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yihang Zhou
- Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xuan Li
- Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng Wang
- Songjiang Research Institute, Songjiang District Central Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chao Zhang
- Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), School of Life Sciences and Technology, Tongji University, Shanghai, China
| |
Collapse
|
3
|
Mattern KMJ, Blancas-Velázquez AS, Ngo MT, Bille S, Hertz H, Bering T, Rath MF. The ISL LIM-homeobox 2 transcription factor is negatively regulated by circadian adrenergic signaling to repress the expression of Aanat in pinealocytes of the rat pineal gland. J Pineal Res 2023; 75:e12905. [PMID: 37649242 DOI: 10.1111/jpi.12905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/19/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023]
Abstract
Melatonin is synthesized in the pineal gland during nighttime in response to nocturnal increase in the activity of the enzyme aralkylamine N-acetyltransferase (AANAT), the transcription of which is modulated by several homeodomain transcription factors. Recent work suggests that the homeodomain transcription factor ISL LIM homeobox 2 (ISL2) is expressed in the pineal gland, but its role is currently unknown. With the purpose of identifying the mechanisms that control pineal expression of Isl2 and the possible function of Isl2 in circadian pineal biology, we report that Isl2 is specifically expressed in the pinealocytes of the rat pineal gland. Its expression exhibits a 24 h rhythm with high transcript and protein levels during the day and a trough in the second half of the night. This rhythm persists in darkness, and lesion studies reveal that it requires intact function of the suprachiasmatic nuclei, suggesting intrinsic circadian regulation. In vivo and in vitro experiments show that pineal Isl2 expression is repressed by adrenergic signaling acting via cyclic AMP; further, Isl2 is negatively regulated by the nocturnal transcription factor cone-rod homeobox. During development, pineal Isl2 expression is detectable from embryonic day 19, preceding Aanat by several days. In vitro knockdown of Isl2 is accompanied by an increase in Aanat transcript levels suggesting that ISL2 represses its daytime expression. Thus, rhythmic expression of ISL2 in pinealocytes is under the control of the suprachiasmatic nucleus acting via adrenergic signaling in the gland to repress nocturnal expression, while ISL2 itself negatively regulates daytime pineal expression of Aanat and thereby suggestively enhances the circadian rhythm in melatonin synthesis.
Collapse
Affiliation(s)
- Kuno M-J Mattern
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Aurea S Blancas-Velázquez
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikaella T Ngo
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Signe Bille
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Hertz
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Tenna Bering
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin F Rath
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
4
|
Castellini ME, Spagnolli G, Poggi L, Biasini E, Casarosa S, Messina A. Identification of the zebrafish homologues of IMPG2, a retinal proteoglycan. Cell Tissue Res 2023; 394:93-105. [PMID: 37470839 PMCID: PMC10558372 DOI: 10.1007/s00441-023-03808-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023]
Abstract
Photoreceptor outer segments are surrounded by a carbohydrate-rich matrix, the interphotoreceptor matrix, necessary for physiological retinal function. Few roles for molecules characterizing the interphotoreceptor matrix have been clearly defined. Recent studies have found the presence of nonsense mutations in the interphotoreceptor matrix proteoglycan 2 (IMPG2) gene in patients affected by retinal dystrophies. IMPG2 encodes for a proteoglycan synthesized by photoreceptors and secreted in the interphotoreceptor matrix. Little is known about the structure and function of this protein, we thus decided to characterize zebrafish impg2. In zebrafish there are two Impg2 proteins, Impg2a and Impg2b. We generated a phylogenetic tree based on IMPG2 protein sequence similarity among vertebrates, showing a significant similarity between humans and teleosts. The human and zebrafish proteins share conserved domains, as also shown by homology models. Expression analyses of impg2a and impg2b show a continued expression in the photoreceptor layer starting from developmental stages and continuing through adulthood. Between 1 and 6 months post-fertilization, there is a significant shift of Impg2 expression toward the outer segment region, suggesting an increase in secretion. This raises intriguing hypotheses about its possible role(s) during retinal maturation, laying the groundwork for the generation of most needed models for the study of IMPG2-related inherited retinal dystrophies.
Collapse
Affiliation(s)
- M E Castellini
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy
| | - G Spagnolli
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy
- Sibylla Biotech S.R.L, Piazzetta Chiavica 2 - 37121, Verona, VR, Italy
| | - L Poggi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy
- Centre for Medical Sciences (CISMed), University of Trento, Via S. Maria Maddalena, 1, 38122, Trento, TN, Italy
| | - E Biasini
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy
- Centre for Medical Sciences (CISMed), University of Trento, Via S. Maria Maddalena, 1, 38122, Trento, TN, Italy
| | - S Casarosa
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy.
- Centre for Medical Sciences (CISMed), University of Trento, Via S. Maria Maddalena, 1, 38122, Trento, TN, Italy.
| | - A Messina
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Via Sommarive, 9, 38123, Povo, TN, Italy
- Centre for Mind/Brain Sciences (CIMeC), University of Trento, Piazza Manifattura 1, 38068, Rovereto, TN, Italy
| |
Collapse
|
5
|
Seitter H, Obkircher J, Grabher P, Hartl J, Zanetti L, Lux UT, Fotakis G, Fernández-Quintero ML, Kaserer T, Koschak A. A novel calcium channel Cavβ 2 splice variant with unique properties predominates in the retina. J Biol Chem 2023; 299:102972. [PMID: 36738788 PMCID: PMC10074810 DOI: 10.1016/j.jbc.2023.102972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/15/2023] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Cavβ subunits are essential for surface expression of voltage-gated calcium channel complexes and crucially modulate biophysical properties like voltage-dependent inactivation. Here, we describe the discovery and characterization of a novel Cavβ2 variant with distinct features that predominates in the retina. We determined spliced exons in retinal transcripts of the Cacnb2 gene, coding for Cavβ2, by RNA-Seq data analysis and quantitative PCR. We cloned a novel Cavβ2 splice variant from mouse retina, which we are calling β2i, and investigated biophysical properties of calcium currents with this variant in a heterologous expression system as well as its intrinsic membrane interaction when expressed alone. Our data showed that β2i predominated in the retina with expression in photoreceptors and bipolar cells. Furthermore, we observed that the β2i N-terminus exhibited an extraordinary concentration of hydrophobic residues, a distinct feature not seen in canonical variants. The biophysical properties resembled known membrane-associated variants, and β2i exhibited both a strong membrane association and a propensity for clustering, which depended on hydrophobic residues in its N-terminus. We considered available Cavβ structure data to elucidate potential mechanisms underlying the observed characteristics but resolved N-terminus structures were lacking and thus, precluded clear conclusions. With this description of a novel N-terminus variant of Cavβ2, we expand the scope of functional variation through N-terminal splicing with a distinct form of membrane attachment. Further investigation of the molecular mechanisms underlying the features of β2i could provide new angles on the way Cavβ subunits modulate Ca2+ channels at the plasma membrane.
Collapse
Affiliation(s)
- Hartwig Seitter
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria.
| | - Jana Obkircher
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Patricia Grabher
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Julia Hartl
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Lucia Zanetti
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Uwe Thorsten Lux
- Department of Biology, Animal Physiology/Neurobiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Georgios Fotakis
- Institute of Bioinformatics, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Teresa Kaserer
- Department of Pharmaceutical Chemistry, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria
| | - Alexandra Koschak
- Department of Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, Innsbruck, Austria.
| |
Collapse
|
6
|
Sommer MJ, Cha S, Varabyou A, Rincon N, Park S, Minkin I, Pertea M, Steinegger M, Salzberg SL. Structure-guided isoform identification for the human transcriptome. eLife 2022; 11:e82556. [PMID: 36519529 PMCID: PMC9812405 DOI: 10.7554/elife.82556] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Recently developed methods to predict three-dimensional protein structure with high accuracy have opened new avenues for genome and proteome research. We explore a new hypothesis in genome annotation, namely whether computationally predicted structures can help to identify which of multiple possible gene isoforms represents a functional protein product. Guided by protein structure predictions, we evaluated over 230,000 isoforms of human protein-coding genes assembled from over 10,000 RNA sequencing experiments across many human tissues. From this set of assembled transcripts, we identified hundreds of isoforms with more confidently predicted structure and potentially superior function in comparison to canonical isoforms in the latest human gene database. We illustrate our new method with examples where structure provides a guide to function in combination with expression and evolutionary evidence. Additionally, we provide the complete set of structures as a resource to better understand the function of human genes and their isoforms. These results demonstrate the promise of protein structure prediction as a genome annotation tool, allowing us to refine even the most highly curated catalog of human proteins. More generally we demonstrate a practical, structure-guided approach that can be used to enhance the annotation of any genome.
Collapse
Affiliation(s)
- Markus J Sommer
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of EngineeringBaltimoreUnited States
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Sooyoung Cha
- School of Biological Sciences, Seoul National UniversitySeoulRepublic of Korea
- Artificial Intelligence Institute, Seoul National UniversitySeoulRepublic of Korea
| | - Ales Varabyou
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
- Department of Computer Science, Johns Hopkins UniversityBaltimoreUnited States
| | - Natalia Rincon
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of EngineeringBaltimoreUnited States
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Sukhwan Park
- School of Biological Sciences, Seoul National UniversitySeoulRepublic of Korea
- Artificial Intelligence Institute, Seoul National UniversitySeoulRepublic of Korea
| | - Ilia Minkin
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of EngineeringBaltimoreUnited States
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Mihaela Pertea
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of EngineeringBaltimoreUnited States
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
| | - Martin Steinegger
- School of Biological Sciences, Seoul National UniversitySeoulRepublic of Korea
- Artificial Intelligence Institute, Seoul National UniversitySeoulRepublic of Korea
- Institute of Molecular Biology and Genetics, Seoul National UniversitySeoulRepublic of Korea
| | - Steven L Salzberg
- Department of Biomedical Engineering, Johns Hopkins School of Medicine and Whiting School of EngineeringBaltimoreUnited States
- Center for Computational Biology, Johns Hopkins UniversityBaltimoreUnited States
- Department of Computer Science, Johns Hopkins UniversityBaltimoreUnited States
- Department of Biostatistics, Johns Hopkins UniversityBaltimoreUnited States
| |
Collapse
|
7
|
Muñoz EM. Microglia in Circumventricular Organs: The Pineal Gland Example. ASN Neuro 2022; 14:17590914221135697. [PMID: 36317305 PMCID: PMC9629557 DOI: 10.1177/17590914221135697] [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] [Indexed: 11/08/2022] Open
Abstract
The circumventricular organs (CVOs) are unique areas within the central nervous system. They serve as a portal for the rest of the body and, as such, lack a blood-brain barrier. Microglia are the primary resident immune cells of the brain parenchyma. Within the CVOs, microglial cells find themselves continuously challenged and stimulated by local and systemic stimuli, even under steady-state conditions. Therefore, CVO microglia in their typical state often resemble the activated microglial forms found elsewhere in the brain as they are responding to pathological conditions or other stressors. In this review, I focus on the dynamics of CVO microglia, using the pineal gland as a specific CVO example. Data related to microglia heterogeneity in both homeostatic and unhealthy environments are presented and discussed, including those recently generated by using advanced single-cell and single-nucleus technology. Finally, perspectives in the CVO microglia field are also included.Summary StatementMicroglia in circumventricular organs (CVOs) continuously adapt to react differentially to the diverse challenges they face. Herein, I discuss microglia heterogeneity in CVOs, including pineal gland. Further studies are needed to better understand microglia dynamics in these unique brain areas. .
Collapse
Affiliation(s)
- Estela M. Muñoz
- Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos (IHEM), Universidad Nacional de Cuyo (UNCuyo), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mendoza, Argentina,Estela M. Muñoz, IHEM-UNCuyo-CONICET, Parque General San Martin, Ciudad de Mendoza, M5502JMA, Mendoza, Argentina.
or
| |
Collapse
|
8
|
Summers KM, Bush SJ, Wu C, Hume DA. Generation and network analysis of an RNA-seq transcriptional atlas for the rat. NAR Genom Bioinform 2022; 4:lqac017. [PMID: 35265836 PMCID: PMC8900154 DOI: 10.1093/nargab/lqac017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 01/13/2022] [Accepted: 02/15/2022] [Indexed: 12/19/2022] Open
Abstract
Abstract
The laboratory rat is an important model for biomedical research. To generate a comprehensive rat transcriptomic atlas, we curated and downloaded 7700 rat RNA-seq datasets from public repositories, downsampled them to a common depth and quantified expression. Data from 585 rat tissues and cells, averaged from each BioProject, can be visualized and queried at http://biogps.org/ratatlas. Gene co-expression network (GCN) analysis revealed clusters of transcripts that were tissue or cell type restricted and contained transcription factors implicated in lineage determination. Other clusters were enriched for transcripts associated with biological processes. Many of these clusters overlap with previous data from analysis of other species, while some (e.g. expressed specifically in immune cells, retina/pineal gland, pituitary and germ cells) are unique to these data. GCN analysis on large subsets of the data related specifically to liver, nervous system, kidney, musculoskeletal system and cardiovascular system enabled deconvolution of cell type-specific signatures. The approach is extensible and the dataset can be used as a point of reference from which to analyse the transcriptomes of cell types and tissues that have not yet been sampled. Sets of strictly co-expressed transcripts provide a resource for critical interpretation of single-cell RNA-seq data.
Collapse
Affiliation(s)
- Kim M Summers
- Mater Research Institute—University of Queensland, Translational Research Institute, 37 Kent St, Woolloongabba, QLD 4102, Australia
| | - Stephen J Bush
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, OX3 9DS, UK
| | - Chunlei Wu
- Department of Integrative and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - David A Hume
- Mater Research Institute—University of Queensland, Translational Research Institute, 37 Kent St, Woolloongabba, QLD 4102, Australia
| |
Collapse
|
9
|
Serotonin modulates melatonin synthesis as an autocrine neurotransmitter in the pineal gland. Proc Natl Acad Sci U S A 2021; 118:2113852118. [PMID: 34675083 DOI: 10.1073/pnas.2113852118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2021] [Indexed: 01/23/2023] Open
Abstract
The pineal gland secretes melatonin principally at night. Regulated by norepinephrine released from sympathetic nerve terminals, adrenergic receptors on pinealocytes activate aralkylamine N-acetyltransferase that converts 5-hydroxytryptamine (5-HT, serotonin) to N-acetylserotonin, the precursor of melatonin. Previous studies from our group and others reveal significant constitutive secretion of 5-HT from pinealocytes. Here, using mass spectrometry, we demonstrated that the 5-HT is secreted primarily via a decynium-22-sensitive equilibrative plasma membrane monoamine transporter instead of by typical exocytotic quantal secretion. Activation of the endogenous 5-HT receptors on pinealocytes evoked an intracellular Ca2+ rise that was blocked by RS-102221, an antagonist of 5-HT2C receptors. Applied 5-HT did not evoke melatonin secretion by itself, but it did potentiate melatonin secretion evoked by submaximal norepinephrine. In addition, RS-102221 reduced the norepinephrine-induced melatonin secretion in strips of pineal gland, even when no exogenous 5-HT was added, suggesting that the 5-HT that is constitutively released from pinealocytes accumulates enough in the tissue to act as an autocrine feedback signal sensitizing melatonin release.
Collapse
|
10
|
Hertz H, Blancas-Velazquez AS, Rath MF. The role of homeobox gene-encoded transcription factors in regulation of phototransduction: Implementing the primary pinealocyte culture as a photoreceptor model. J Pineal Res 2021; 71:e12753. [PMID: 34129741 DOI: 10.1111/jpi.12753] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 10/21/2022]
Abstract
Homeobox genes encode transcription factors controlling development; however, a number of homeobox genes are expressed postnatally specifically in melatonin-producing pinealocytes of the pineal gland and photoreceptors of the retina along with transcripts devoted to melatonin synthesis and phototransduction. Homeobox genes regulate melatonin synthesis in pinealocytes, but some homeobox genes also seem to be involved in regulation of retinal phototransduction. Due to the lack of photoreceptor models, we here introduce the rat pinealocyte culture as an in vitro model for studying retinal phototransduction. Systematic qPCR analyses were performed on the rat retina and pineal gland in 24 hour in vivo series and on primary cultures of rat pinealocytes: All homeobox genes and melatonin synthesis components, as well as nine out of ten phototransduction genes, were readily detectable in all three experimental settings, confirming molecular similarity between cultured pinealocytes and in vivo retinal tissue. 24 hours circadian expression was mostly confined to transcripts in the pineal gland, including a novel rhythm in arrestin (Sag). Individual knockdown of the homeobox genes orthodenticle homeobox 2 (Otx2), cone-rod homeobox (Crx) and LIM homeobox 4 (Lhx4) in pinealocyte culture using siRNA resulted in specific downregulation of transcripts representing all levels of phototransduction; thus, all phototransduction genes studied in culture were affected by one or several siRNA treatments. Histological colocalization of homeobox and phototransduction transcripts in the rat retinal photoreceptor was confirmed by RNAscope in situ hybridization, thus suggesting that homeobox gene-encoded transcription factors control postnatal expression of phototransduction genes in the retinal photoreceptor.
Collapse
Affiliation(s)
- Henrik Hertz
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Martin Fredensborg Rath
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
11
|
Ge W, Yan ZH, Wang L, Tan SJ, Liu J, Reiter RJ, Luo SM, Sun QY, Shen W. A hypothetical role for autophagy during the day/night rhythm-regulated melatonin synthesis in the rat pineal gland. J Pineal Res 2021; 71:e12742. [PMID: 33960014 DOI: 10.1111/jpi.12742] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 04/12/2021] [Accepted: 04/27/2021] [Indexed: 12/18/2022]
Abstract
Melatonin is a highly conserved molecule that regulates day/night rhythms; it is associated with sleep improvement, reactive oxygen species (ROS) scavenging, anti-aging effects, and seasonal and circadian rhythms and has been a hot topic of research for decades. Using single-cell RNA sequencing, a recent study describes a single-cell transcriptome atlas for the rat pineal gland. Based on a more comprehensive analysis of the retrieved data (Mays et al., PLoS One, 2018, 13, e0205883), results from the current study unveiled the underappreciated gene regulatory network behind different cell populations in the pineal gland. More importantly, our study here characterized, for the first time, the day/night activation of autophagy flux in the rat pineal gland, indicating a potential role of autophagy in regulating melatonin synthesis in the rat pineal gland. These findings emphasized a hypothetical role of day/night autophagy in linking the biological clock with melatonin synthesis. Furthermore, ultrastructure analysis of pinealocytes provided fascinating insights into differences in their intracellular structure between daytime and nighttime. In addition, we also provide a preliminary description of cell-cell communication in the rat pineal gland. In summary, the current study unveils the day/night regulation of autophagy in the rat pineal gland, raising a potential role of autophagy in day/night-regulated melatonin synthesis.
Collapse
Affiliation(s)
- Wei Ge
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Zi-Hui Yan
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Lu Wang
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Shao-Jing Tan
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Jing Liu
- Central Laboratory of Qingdao Agricultural University, Qingdao Agricultural University, Qingdao, China
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, Long School of Medicine, UT Health, San Antonio, TX, USA
| | - Shi-Ming Luo
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Wei Shen
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| |
Collapse
|
12
|
Chang E, Fu C, Coon SL, Alon S, Bozinoski M, Breymaier M, Bustos DM, Clokie SJ, Gothilf Y, Esnault C, Michael Iuvone P, Mason CE, Ochocinska MJ, Tovin A, Wang C, Xu P, Zhu J, Dale R, Klein DC. Resource: A multi-species multi-timepoint transcriptome database and webpage for the pineal gland and retina. J Pineal Res 2020; 69:e12673. [PMID: 32533862 PMCID: PMC7513311 DOI: 10.1111/jpi.12673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/12/2023]
Abstract
The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi-species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re-processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user-friendly format that is expected to broadly influence pineal research.
Collapse
Affiliation(s)
- Eric Chang
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Cong Fu
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Key Laboratory of Organ Regeneration & Transplantation of the Ministry of EducationThe First Hospital of Jilin UniversityChangchunChina
- Laboratory of Theoretical and Computational ChemistryInstitute of Theoretical ChemistryJilin UniversityChangchunChina
- National‐Local Joint Engineering Laboratory of Animal Models for Human DiseasesChangchunChina
| | - Steven L. Coon
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Molecular Genomics CoreOffice of the Scientific DirectorEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Shahar Alon
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
- Present address:
The Alexander Kofkin Faculty of EngineeringBar‐Ilan UniversityRamat‐GanIsrael
| | - Marjan Bozinoski
- Department of Physiology and Biophysics and the Institute for Computational BiomedicineWeill Cornell Medical CollegeNew YorkNYUSA
| | - Matthew Breymaier
- Computer Support Services CoreEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Diego M. Bustos
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
Instituto de Histología y Embriología de MendozaConsejo Nacional de Investigaciones Científicas y TécnicasMendozaArgentina
| | - Samuel J. Clokie
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
West Midlands Regional Genetics LaboratoriesBirmingham, Women’s and Children’s NHS Foundation TrustBirminghamUK
| | - Yoav Gothilf
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
| | - Caroline Esnault
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology & Chemical BiologyEmory University School of MedicineAtlantaGAUSA
| | - Christopher E. Mason
- Department of Physiology and Biophysics and the Institute for Computational BiomedicineWeill Cornell Medical CollegeNew YorkNYUSA
| | - Margaret J. Ochocinska
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
National Heart, Lung and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Adi Tovin
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
- Present address:
The Faculty of Life SciencesBar‐Ilan UniversityRamat‐GanIsrael
| | - Charles Wang
- Center for GenomicsSchool of MedicineLoma Linda UniversityLoma LindaCAUSA
| | - Pinxian Xu
- Department of Genetics and Genomic SciencesMount Sinai School of Medicine Icahn Medical InstituteNew YorkNYUSA
| | - Jinhang Zhu
- United States Food and Drug Administration’s National Center for Toxicological Research, Food and Drug AdministrationJeffersonARUSA
- Department of PhysiologySchool of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Ryan Dale
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - David C. Klein
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Office of the Scientific DirectorEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| |
Collapse
|