1
|
Buranaamnuay K. Male reproductive phenotypes of genetically altered laboratory mice ( Mus musculus): a review based on pertinent literature from the last three decades. Front Vet Sci 2024; 11:1272757. [PMID: 38500604 PMCID: PMC10944935 DOI: 10.3389/fvets.2024.1272757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 02/20/2024] [Indexed: 03/20/2024] Open
Abstract
Laboratory mice (Mus musculus) are preferred animals for biomedical research due to the close relationship with humans in several aspects. Therefore, mice with diverse genetic traits have been generated to mimic human characteristics of interest. Some genetically altered mouse strains, on purpose or by accident, have reproductive phenotypes and/or fertility deviating from wild-type mice. The distinct reproductive phenotypes of genetically altered male mice mentioned in this paper are grouped based on reproductive organs, beginning with the brain (i.e., the hypothalamus and anterior pituitary) that regulates sexual maturity and development, the testis where male gametes and sex steroid hormones are produced, the epididymis, the accessory sex glands, and the penis which involve in sperm maturation, storage, and ejaculation. Also, distinct characteristics of mature sperm from genetically altered mice are described here. This repository will hopefully be a valuable resource for both humans, in terms of future biomedical research, and mice, in the aspect of the establishment of optimal sperm preservation protocols for individual mouse strains.
Collapse
Affiliation(s)
- Kakanang Buranaamnuay
- Molecular Agricultural Biosciences Cluster, Institute of Molecular Biosciences (MB), Mahidol University, Nakhon Pathom, Thailand
| |
Collapse
|
2
|
Qu R, Zhang Z, Wu L, Li Q, Mu J, Zhao L, Yan Z, Wang W, Zeng Y, Liu R, Dong J, Li Q, Sun X, Wang L, Sang Q, Chen B, Kuang Y. ADGB variants cause asthenozoospermia and male infertility. Hum Genet 2023; 142:735-748. [PMID: 36995441 DOI: 10.1007/s00439-023-02546-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/15/2023] [Indexed: 03/31/2023]
Abstract
Asthenozoospermia is one of the main factors leading to male infertility, but the genetic mechanisms have not been fully elucidated. Variants in the androglobin (ADGB) gene were identified in an infertile male characterized by asthenozoospermia. The variants disrupted the binding of ADGB to calmodulin. Adgb-/- male mice were infertile due to reduced sperm concentration (< 1 × 106 /mL) and motility. Spermatogenesis was also abnormal, with malformation of both elongating and elongated spermatids, and there was an approximately twofold increase in apoptotic cells in the cauda epididymis. These exacerbated the decline in sperm motility. It is surprising that ICSI with testicular spermatids allows fertilization and eventually develops into blastocyst. Through mass spectrometry, we identified 42 candidate proteins that are involved in sperm assembly, flagella formation, and sperm motility interacting with ADGB. In particular, CFAP69 and SPEF2 were confirmed to bind to ADGB. Collectively, our study suggests the potential important role of ADGB in human fertility, revealing its relevance to spermatogenesis and infertility. This expands our knowledge of the genetic causes of asthenozoospermia and provides a theoretical basis for using ADGB as an underlying genetic marker for infertile males.
Collapse
Affiliation(s)
- Ronggui Qu
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Zhihua Zhang
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Ling Wu
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Qun Li
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Jian Mu
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Lin Zhao
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Zheng Yan
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Wenjing Wang
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Yang Zeng
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Ruyi Liu
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Jie Dong
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Qiaoli Li
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Xiaoxi Sun
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, 200011, China
| | - Lei Wang
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China
| | - Qing Sang
- The Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering and the Institute of Pediatrics, Children's Hospital of Fudan University, Fudan University, Shanghai, 200032, China.
| | - Biaobang Chen
- NHC Key Lab of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), Fudan University, Shanghai, 200032, China.
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.
| |
Collapse
|
3
|
Kirat D, Alahwany AM, Arisha AH, Abdelkhalek A, Miyasho T. Role of Macroautophagy in Mammalian Male Reproductive Physiology. Cells 2023; 12:cells12091322. [PMID: 37174722 PMCID: PMC10177121 DOI: 10.3390/cells12091322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/28/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Physiologically, autophagy is an evolutionarily conserved and self-degradative process in cells. Autophagy carries out normal physiological roles throughout mammalian life. Accumulating evidence shows autophagy as a mechanism for cellular growth, development, differentiation, survival, and homeostasis. In male reproductive systems, normal spermatogenesis and steroidogenesis need a balance between degradation and energy supply to preserve cellular metabolic homeostasis. The main process of autophagy includes the formation and maturation of the phagophore, autophagosome, and autolysosome. Autophagy is controlled by a group of autophagy-related genes that form the core machinery of autophagy. Three types of autophagy mechanisms have been discovered in mammalian cells: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy is classified as non-selective or selective. Non-selective macroautophagy randomly engulfs the cytoplasmic components in autophagosomes that are degraded by lysosomal enzymes. While selective macroautophagy precisely identifies and degrades a specific element, current findings have shown the novel functional roles of autophagy in male reproduction. It has been recognized that dysfunction in the autophagy process can be associated with male infertility. Overall, this review provides an overview of the cellular and molecular basics of autophagy and summarizes the latest findings on the key role of autophagy in mammalian male reproductive physiology.
Collapse
Affiliation(s)
- Doaa Kirat
- Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Ahmed Mohamed Alahwany
- Department of Animal Physiology and Biochemistry, Faculty of Veterinary Medicine, Badr University in Cairo (BUC), Cairo, Badr City 11829, Egypt
| | - Ahmed Hamed Arisha
- Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
- Department of Animal Physiology and Biochemistry, Faculty of Veterinary Medicine, Badr University in Cairo (BUC), Cairo, Badr City 11829, Egypt
| | - Adel Abdelkhalek
- Faculty of Veterinary Medicine, Badr University in Cairo (BUC), Cairo, Badr City 11829, Egypt
| | - Taku Miyasho
- Laboratory of Animal Biological Responses, Department of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan
| |
Collapse
|
4
|
Chen DM, Dong R, Kachuri L, Hoffmann T, Jiang Y, Berndt SI, Shelley JP, Schaffer KR, Machiela MJ, Freedman ND, Huang WY, Li SA, Lilja H, Van Den Eeden SK, Chanock S, Haiman CA, Conti DV, Klein RJ, Mosley JD, Witte JS, Graff RE. Transcriptome-Wide Association Analysis Identifies Novel Candidate Susceptibility Genes for Prostate-Specific Antigen Levels in Men Without Prostate Cancer. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.04.23289526. [PMID: 37205487 PMCID: PMC10187439 DOI: 10.1101/2023.05.04.23289526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Deciphering the genetic basis of prostate-specific antigen (PSA) levels may improve their utility to screen for prostate cancer (PCa). We thus conducted a transcriptome-wide association study (TWAS) of PSA levels using genome-wide summary statistics from 95,768 PCa-free men, the MetaXcan framework, and gene prediction models trained in Genotype-Tissue Expression (GTEx) project data. Tissue-specific analyses identified 41 statistically significant (p < 0.05/12,192 = 4.10e-6) associations in whole blood and 39 statistically significant (p < 0.05/13,844 = 3.61e-6) associations in prostate tissue, with 18 genes associated in both tissues. Cross-tissue analyses that combined associations across 45 tissues identified 155 genes that were statistically significantly (p < 0.05/22,249 = 2.25e-6) associated with PSA levels. Based on conditional analyses that assessed whether TWAS associations were attributable to a lead GWAS variant, we found 20 novel genes (11 single-tissue, 9 cross-tissue) that were associated with PSA levels in the TWAS. Of these novel genes, five showed evidence of colocalization (colocalization probability > 0.5): EXOSC9, CCNA2, HIST1H2BN, RP11-182L21.6, and RP11-327J17.2. Six of the 20 novel genes are not known to impact PCa risk. These findings yield new hypotheses for genetic factors underlying PSA levels that should be further explored toward improving our understanding of PSA biology.
Collapse
Affiliation(s)
- Dorothy M. Chen
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Ruocheng Dong
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, 94305, USA
| | - Linda Kachuri
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, 94305, USA
- Stanford Cancer Institute, Stanford University, Stanford, CA, 94305, USA
| | - Thomas Hoffmann
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, 94158, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Yu Jiang
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Sonja I. Berndt
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - John P. Shelley
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Kerry R. Schaffer
- Division of Hematology and Oncology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Mitchell J. Machiela
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - Neal D. Freedman
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - Wen-Yi Huang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - Shengchao A. Li
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - Hans Lilja
- Departments of Pathology and Laboratory Medicine, Surgery, Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Department of Translational Medicine, Lund University, Malmö, 21428, Sweden
| | | | - Stephen Chanock
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, 20814, USA
| | - Christopher A. Haiman
- Center for Genetic Epidemiology, Department of Population and Preventive Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90032, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - David V. Conti
- Center for Genetic Epidemiology, Department of Population and Preventive Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90032, USA
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Robert J. Klein
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jonathan D. Mosley
- Departments of Internal Medicine and Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - John S. Witte
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, 94158, USA
- Department of Epidemiology and Population Health, Stanford University, Stanford, CA, 94305, USA
- Departments of Biomedical Data Science and Genetics (by courtesy), Stanford University, Stanford, CA, 94305, USA
| | - Rebecca E. Graff
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, 94158, USA
| |
Collapse
|
5
|
Kumaresan A, Sinha MK, Paul N, Nag P, Ebenezer Samuel King JP, Kumar R, Datta TK. Establishment of a repertoire of fertility associated sperm proteins and their differential abundance in buffalo bulls (Bubalus bubalis) with contrasting fertility. Sci Rep 2023; 13:2272. [PMID: 36754964 PMCID: PMC9908891 DOI: 10.1038/s41598-023-29529-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
Sperm harbours a wide range of proteins regulating their functions and fertility. In the present study, we made an effort to characterize and quantify the proteome of buffalo bull spermatozoa, and to identify fertility associated sperm proteins through comparative proteomics. Using high-throughput mass spectrometry platform, we identified 1305 proteins from buffalo spermatozoa and found that these proteins were mostly enriched in glycolytic process, mitochondrial respiratory chain, tricarboxylic acid cycle, protein folding, spermatogenesis, sperm motility and sperm binding to zona pellucida (p < 7.74E-08) besides metabolic (p = 4.42E-31) and reactive oxygen species (p = 1.81E-30) pathways. Differential proteomic analysis revealed that 844 proteins were commonly expressed in spermatozoa from both the groups while 77 and 52 proteins were exclusively expressed in high- and low-fertile bulls, respectively. In low-fertile bulls, 75 proteins were significantly (p < 0.05) upregulated and 176 proteins were significantly (p < 0.05) downregulated; these proteins were highly enriched in mitochondrial respiratory chain complex I assembly (p = 2.63E-07) and flagellated sperm motility (p = 7.02E-05) processes besides oxidative phosphorylation pathway (p = 6.61E-15). The down regulated proteins in low-fertile bulls were involved in sperm motility, metabolism, sperm-egg recognition and fertilization. These variations in the sperm proteome could be used as potential markers for the selection of buffalo bulls for fertility.
Collapse
Affiliation(s)
- Arumugam Kumaresan
- Theriogenology Laboratory, Southern Regional Station of ICAR-National Dairy Research Institute, Bengaluru, Karnataka, 560030, India.
| | - Manish Kumar Sinha
- Theriogenology Laboratory, Southern Regional Station of ICAR-National Dairy Research Institute, Bengaluru, Karnataka, 560030, India
| | - Nilendu Paul
- Theriogenology Laboratory, Southern Regional Station of ICAR-National Dairy Research Institute, Bengaluru, Karnataka, 560030, India
| | - Pradeep Nag
- Theriogenology Laboratory, Southern Regional Station of ICAR-National Dairy Research Institute, Bengaluru, Karnataka, 560030, India
| | - John Peter Ebenezer Samuel King
- Theriogenology Laboratory, Southern Regional Station of ICAR-National Dairy Research Institute, Bengaluru, Karnataka, 560030, India
| | - Rakesh Kumar
- Animal Genomics Laboratory, ICAR-National Dairy Research Institute, Karnal, Haryana, 132 001, India
| | - Tirtha Kumar Datta
- ICAR-Central Institute for Research on Buffaloes, Hisar, Haryana, 125 001, India
| |
Collapse
|
6
|
Role of autophagy in male and female fertility. CURRENT OPINION IN PHYSIOLOGY 2022. [DOI: 10.1016/j.cophys.2022.100611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
7
|
Umer N, Phadke S, Shakeri F, Arévalo L, Lohanadan K, Kirfel G, Sylvester M, Buness A, Schorle H. PFN4 is required for manchette development and acrosome biogenesis during mouse spermiogenesis. Development 2022; 149:276289. [PMID: 35950913 PMCID: PMC9481974 DOI: 10.1242/dev.200499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 07/14/2022] [Indexed: 11/26/2022]
Abstract
Profilin 4 (Pfn4) is expressed during spermiogenesis and localizes to the acrosome-acroplaxome-manchette complex. Here, we generated PFN4-deficient mice, with sperm displaying severe impairment in manchette formation. Interestingly, HOOK1 staining suggests that the perinuclear ring is established; however, ARL3 staining is disrupted, suggesting that lack of PFN4 does not interfere with the formation of the perinuclear ring and initial localization of HOOK1, but impedes microtubular organization of the manchette. Furthermore, amorphous head shape and flagellar defects were detected, resulting in reduced sperm motility. Disrupted cis- and trans-Golgi networks and aberrant production of proacrosomal vesicles caused impaired acrosome biogenesis. Proteomic analysis showed that the proteins ARF3, SPECC1L and FKBP1, which are involved in Golgi membrane trafficking and PI3K/AKT pathway, are more abundant in Pfn4−/− testes. Levels of PI3K, AKT and mTOR were elevated, whereas AMPK level was reduced, consistent with inhibition of autophagy. This seems to result in blockage of autophagic flux, which could explain the failure in acrosome formation. In vitro fertilization demonstrated that PFN4-deficient sperm is capable of fertilizing zona-free oocytes, suggesting a potential treatment for PFN4-related human infertility. Summary: PFN4-deficient male mice exhibit impaired acrosome formation and malformation of the manchette, leading to amorphous sperm head shape, flagellar abnormalities and sterility.
Collapse
Affiliation(s)
- Naila Umer
- Institute of Pathology, University Hospital Bonn 1 Department of Developmental Pathology , , 53127 Bonn , Germany
| | - Sharang Phadke
- Institute of Pathology, University Hospital Bonn 1 Department of Developmental Pathology , , 53127 Bonn , Germany
| | - Farhad Shakeri
- Institute for Medical Biometry, Informatics and Epidemiology 2 , Medical Faculty , , 53127 Bonn , Germany
- University of Bonn 2 , Medical Faculty , , 53127 Bonn , Germany
- Institute for Genomic Statistics and Bioinformatics 3 , Medical Faculty , , 53127 Bonn , Germany
- University of Bonn 3 , Medical Faculty , , 53127 Bonn , Germany
| | - Lena Arévalo
- Institute of Pathology, University Hospital Bonn 1 Department of Developmental Pathology , , 53127 Bonn , Germany
| | | | - Gregor Kirfel
- Institute for Cell Biology, University of Bonn 4 , 53121 Bonn , Germany
| | - Marc Sylvester
- Institute of Biochemistry and Molecular Biology 5 Core Facility Mass Spectrometry , , Medical Faculty , , 53115 Bonn , Germany
- University of Bonn 5 Core Facility Mass Spectrometry , , Medical Faculty , , 53115 Bonn , Germany
| | - Andreas Buness
- Institute for Medical Biometry, Informatics and Epidemiology 2 , Medical Faculty , , 53127 Bonn , Germany
- University of Bonn 2 , Medical Faculty , , 53127 Bonn , Germany
- Institute for Genomic Statistics and Bioinformatics 3 , Medical Faculty , , 53127 Bonn , Germany
- University of Bonn 3 , Medical Faculty , , 53127 Bonn , Germany
| | - Hubert Schorle
- Institute of Pathology, University Hospital Bonn 1 Department of Developmental Pathology , , 53127 Bonn , Germany
| |
Collapse
|
8
|
Interdependent Transcription of a Natural Sense/Antisense Transcripts Pair (SLC34A1/PFN3). Noncoding RNA 2022; 8:ncrna8010019. [PMID: 35202092 PMCID: PMC8877773 DOI: 10.3390/ncrna8010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/17/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022] Open
Abstract
Natural antisense transcripts (NATs) constitute a significant group of regulatory, long noncoding RNAs. They are prominently expressed in testis but are also detectable in other organs. NATs are transcribed at low levels and co-expressed with related protein coding sense transcripts. Nowadays NATs are generally considered as regulatory, long noncoding RNAs without closer focus on the inevitable interference between sense and antisense expression. This work describes a cellular system where sense and antisense transcription of a specific locus (SLC34A1/PFN3) is induced using epigenetic modifiers and CRISPR-Cas9. The renal cell lines HEK293 and HKC-8 do not express SLC34A1/PFN3 under normal culture conditions. Five-day exposure to dexamethasone significantly stimulates sense transcript (SLC34A1) levels and antisense (PFN3) minimally; the effect is only seen in HEK293 cells. Enhanced expression is paralleled by reduced sense promoter methylation and an increase in activating histone marks. Expression is further modulated by cassettes that stimulate the expression of sense or antisense transcript but disrupt protein coding potential. Constitutive expression of a 5′-truncated SLC34A1 transcript increases sense expression independent of dexamethasone induction but also stimulates antisense expression. Concordant expression is confirmed with the antisense knock-in that also enhances sense expression. The antisense effect acts on transcription in cis since transient transfection with sense or antisense constructs fails to stimulate the expression of the opposite transcript. These results suggest that bi-directional transcription of the SLC34A1/PFN3 locus has a stimulatory influence on the expression of the opposite transcript involving epigenetic changes of the promoters. In perspective of extensive, previous research into bi-directionally transcribed SLC34A loci, the findings underpin a hypothesis where NATs display different biological roles in soma and germ cells. Accordingly, we propose that in somatic cells, NATs act like lncRNAs–with the benefit of close proximity to a potential target gene. In germ cells, however, recent evidence suggests different biological roles for NATs that require RNA complementarity and double-stranded RNA formation.
Collapse
|