1
|
Pandey RS, Krebs MP, Bolisetty MT, Charette JR, Naggert JK, Robson P, Nishina PM, Carter GW. Single-Cell RNA Sequencing Reveals Molecular Features of Heterogeneity in the Murine Retinal Pigment Epithelium. Int J Mol Sci 2022; 23:10419. [PMID: 36142331 PMCID: PMC9499471 DOI: 10.3390/ijms231810419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/09/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Transcriptomic analysis of the mammalian retinal pigment epithelium (RPE) aims to identify cellular networks that influence ocular development, maintenance, function, and disease. However, available evidence points to RPE cell heterogeneity within native tissue, which adds complexity to global transcriptomic analysis. Here, to assess cell heterogeneity, we performed single-cell RNA sequencing of RPE cells from two young adult male C57BL/6J mice. Following quality control to ensure robust transcript identification limited to cell singlets, we detected 13,858 transcripts among 2667 and 2846 RPE cells. Dimensional reduction by principal component analysis and uniform manifold approximation and projection revealed six distinct cell populations. All clusters expressed transcripts typical of RPE cells; the smallest (C1, containing 1-2% of total cells) exhibited the hallmarks of stem and/or progenitor (SP) cells. Placing C1-6 along a pseudotime axis suggested a relative decrease in melanogenesis and SP gene expression and a corresponding increase in visual cycle gene expression upon RPE maturation. K-means clustering of all detected transcripts identified additional expression patterns that may advance the understanding of RPE SP cell maintenance and the evolution of cellular metabolic networks during development. This work provides new insights into the transcriptome of the mouse RPE and a baseline for identifying experimentally induced transcriptional changes in future studies of this tissue.
Collapse
Affiliation(s)
- Ravi S. Pandey
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | - Mark P. Krebs
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Mohan T. Bolisetty
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | | | | | - Paul Robson
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | - Patsy M. Nishina
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
| | | |
Collapse
|
2
|
Thompson B, Davidson EA, Liu W, Nebert DW, Bruford EA, Zhao H, Dermitzakis ET, Thompson DC, Vasiliou V. Overview of PAX gene family: analysis of human tissue-specific variant expression and involvement in human disease. Hum Genet 2021; 140:381-400. [PMID: 32728807 PMCID: PMC7939107 DOI: 10.1007/s00439-020-02212-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 07/25/2020] [Indexed: 12/18/2022]
Abstract
Paired-box (PAX) genes encode a family of highly conserved transcription factors found in vertebrates and invertebrates. PAX proteins are defined by the presence of a paired domain that is evolutionarily conserved across phylogenies. Inclusion of a homeodomain and/or an octapeptide linker subdivides PAX proteins into four groups. Often termed "master regulators", PAX proteins orchestrate tissue and organ development throughout cell differentiation and lineage determination, and are essential for tissue structure and function through maintenance of cell identity. Mutations in PAX genes are associated with myriad human diseases (e.g., microphthalmia, anophthalmia, coloboma, hypothyroidism, acute lymphoblastic leukemia). Transcriptional regulation by PAX proteins is, in part, modulated by expression of alternatively spliced transcripts. Herein, we provide a genomics update on the nine human PAX family members and PAX homologs in 16 additional species. We also present a comprehensive summary of human tissue-specific PAX transcript variant expression and describe potential functional significance of PAX isoforms. While the functional roles of PAX proteins in developmental diseases and cancer are well characterized, much remains to be understood regarding the functional roles of PAX isoforms in human health. We anticipate the analysis of tissue-specific PAX transcript variant expression presented herein can serve as a starting point for such research endeavors.
Collapse
Affiliation(s)
- Brian Thompson
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College Street, New Haven, CT, 06510, USA
| | - Emily A Davidson
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College Street, New Haven, CT, 06510, USA
| | - Wei Liu
- Program of Computational Biology and Bioinformatics, Yale University, New Haven, CT, 06510, USA
| | - Daniel W Nebert
- Department of Environmental Health and Center for Environmental Genetics, Cincinnati Children's Research Center, University of Cincinnati Medical Center, Cincinnati, OH, 45267, USA
- Department of Pediatrics and Molecular and Developmental Biology, Cincinnati Children's Research Center, University of Cincinnati Medical Center, Cincinnati, OH, 45267, USA
| | - Elspeth A Bruford
- HUGO Gene Nomenclature Committee, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
- Department of Haematology, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, CB2 0AW, UK
| | - Hongyu Zhao
- Program of Computational Biology and Bioinformatics, Yale University, New Haven, CT, 06510, USA
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, 06510, USA
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06510, USA
| | - Emmanouil T Dermitzakis
- Department of Genetic Medicine and Development, University of Geneva Medical School, 1211, Geneva, Switzerland
- Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, 1211, Geneva, Switzerland
- Swiss Institute of Bioinformatics, Geneva, Switzerland
| | - David C Thompson
- Department of Clinical Pharmacy, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO, 80045, USA
| | - Vasilis Vasiliou
- Department of Environmental Health Sciences, Yale School of Public Health, 60 College Street, New Haven, CT, 06510, USA.
| |
Collapse
|
3
|
Petrosyan T, Hovsepyan A. Bacterial melanin crosses the blood-brain barrier in rat experimental model. Fluids Barriers CNS 2014; 11:20. [PMID: 25184034 PMCID: PMC4147389 DOI: 10.1186/2045-8118-11-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 08/19/2014] [Indexed: 11/14/2022] Open
Abstract
Background Bacterial melanin has been proven to stimulate regeneration after CNS lesions. The purpose of this study was to test, whether bacterial melanin can enter the brain via the blood–brain barrier (BBB). Methods Bacterial melanin (BM) was radioactively labeled by the iodobead method and used to test the BBB permeability after systemic injection into rats. The unidirectional influx rate from the blood was calculated by multiple-time regression analysis. A subgroup of the animals was co-injected with non-labeled BM to determine if BM has a saturable transport across the BBB. The levels of radioactivity were determined in the serum and tissues. Arterial blood was sampled to obtain the level of I-BM at different time points after injection. After systemic perfusion with saline, animals were decapitated and brain, spinal cord, liver and kidney samples were obtained and homogenized to test the I-BM level. Results Study results showed that radioactively-labeled bacterial melanin crossed the BBB, was enzymatically stable in blood and in brain parenchyma. Entry to brain was reduced when non-labeled BM was also present. Circulating melanin entered all regions of the CNS but the uptake was higher in lumbar spinal cord, thalamus, hypothalamus and substantia nigra. Liver and kidneys had high uptake rates of BM. Conclusions These results show that bacterial melanin has saturable transport across the BBB and selectively targets some CNS regions. Such transport may contribute to the neuroprotective action of bacterial melanin.
Collapse
Affiliation(s)
- Tigran Petrosyan
- Armenian State Institute of Physical Education, 11 Alex Manukian, Yerevan 0028, Armenia
| | | |
Collapse
|
4
|
Darias MJ, Andree KB, Boglino A, Rotllant J, Cerdá-Reverter JM, Estévez A, Gisbert E. Morphological and molecular characterization of dietary-induced pseudo-albinism during post-embryonic development of Solea senegalensis (Kaup, 1858). PLoS One 2013; 8:e68844. [PMID: 23874785 PMCID: PMC3712922 DOI: 10.1371/journal.pone.0068844] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 06/01/2013] [Indexed: 12/28/2022] Open
Abstract
The appearance of the pseudo-albino phenotype was investigated in developing Senegalese sole (Solea senegalensis, Kaup 1858) larvae at morphological and molecular levels. In order to induce the development of pseudo-albinos, Senegalese sole larvae were fed Artemia enriched with high levels of arachidonic acid (ARA). The development of their skin pigmentation was compared to that of a control group fed Artemia enriched with a reference commercial product. The relative amount of skin melanophores, xanthophores and iridophores revealed that larval pigmentation developed similarly in both groups. However, results from different relative proportions, allocation patterns, shapes and sizes of skin chromatophores revealed changes in the pigmentation pattern between ARA and control groups from 33 days post hatching onwards. The new populations of chromatophores that should appear at post-metamorphosis were not formed in the ARA group. Further, spatial patterns of distribution between the already present larval xanthophores and melanophores were suggestive of short-range interaction that seemed to be implicated in the degradation of these chromatophores, leading to the appearance of the pseudo-albino phenotype. The expression profile of several key pigmentation-related genes revealed that melanophore development was promoted in pseudo-albinos without a sufficient degree of terminal differentiation, thus preventing melanogenesis. Present results suggest the potential roles of asip1 and slc24a5 genes on the down-regulation of trp1 expression, leading to defects in melanin production. Moreover, gene expression data supports the involvement of pax3, mitf and asip1 genes in the developmental disruption of the new post-metamorphic populations of melanophores, xanthophores and iridophores.
Collapse
Affiliation(s)
- Maria J Darias
- Cultius Experimentals, Institut de Recerca i Tecnologia Agroalimentàries, Sant Carles de la Ràpita, Catalunya, Spain.
| | | | | | | | | | | | | |
Collapse
|
5
|
Darias MJ, Andree KB, Boglino A, Fernández I, Estévez A, Gisbert E. Coordinated regulation of chromatophore differentiation and melanogenesis during the ontogeny of skin pigmentation of Solea senegalensis (Kaup, 1858). PLoS One 2013; 8:e63005. [PMID: 23671650 PMCID: PMC3650040 DOI: 10.1371/journal.pone.0063005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 03/27/2013] [Indexed: 12/23/2022] Open
Abstract
Abnormal pigmentation of Senegalese sole has been described as one problem facing the full exploitation of its commercial production. To improve our understanding of flatfish pigmentation of this commercially important species we have evaluated eleven genes related to two different processes of pigmentation: melanophore differentiation, and melanin production. The temporal distribution of gene expression peaks corresponds well with changes in pigmentation patterns and the intensity of skin melanization. Several gene ratios were also examined to put in perspective possible genetic markers for the different stages of normal pigmentation development. Further, the phenotypic changes that occur during morphogenesis correspond well with the main transitions in gene expression that occur. Given the dramatic phenotypic alterations which flatfish undergo, including the asymmetric coloration that occurs between the ocular and the blind side, and the synchrony of the two processes of morphogenesis and pigmentation ontogenesis, these species constitute an interesting model for the study of pigmentation. In this study we present a first approximation towards explaining the genetic mechanisms for regulating pigmentation ontogeny in Senegalese sole, Solea senegalensis.
Collapse
Affiliation(s)
- Maria J Darias
- Centre de Sant Carles de la Ràpita, Unitat de Cultius Experimentals, Institut de Recerca i Tecnologia Agroalimentàries, Sant Carles de la Ràpita, Catalònia, Spain.
| | | | | | | | | | | |
Collapse
|