1
|
Kim TY, Myoung J, Lee YJ, Lee J, Kim J, Kim S, Kim MS, Beck BR, Hwang SJ, Kang NG, Jeong ET. Study of the soothing effects of troxerutin in alleviating skin sensitivity. J Cosmet Dermatol 2024; 23:2934-2942. [PMID: 38720512 DOI: 10.1111/jocd.16349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/05/2024] [Accepted: 04/16/2024] [Indexed: 08/29/2024]
Abstract
BACKGROUND Transient receptor potential vanilloid 1 (TRPV1) is associated with skin sensitivity and mainly activated by capsaicin and heat. Interestingly, troxerutin can inhibit TRPV1 activation. However, its efficacy in reducing skin sensitivity remains undetermined. AIMS We evaluated the efficacy of troxerutin in alleviating skin sensitivity using clinical tests and in vitro experiments. METHODS For the in vitro experiment, HaCaT keratinocytes were pretreated with different concentrations of troxerutin, followed by incubation with 50 μM capsaicin for 1, 24, or 48 h. The gene and protein expressions of four inflammatory cytokines involved in skin irritation were determined. Among 35 Korean women with sensitive skin recruited for the clinical trial, 13 were involved in assessing the immediate soothing effects of 0.1% and 0.0095% troxerutin following capsaicin irritation, whereas 22 participated in evaluating the preventive soothing effect of 10% and 1% troxerutin over 4 weeks against capsaicin- and heat-induced irritation. We evaluated the soothing rate using skin redness, visual analog scale, and high temperature sensitive index as evaluation indices. RESULTS Troxerutin inhibited the mRNA and protein expressions of cytokines in capsaicin-treated keratinocytes. In the clinical study, 0.1% and 0.0095% troxerutin promptly alleviated capsaicin-induced skin redness, whereas 10% troxerutin notably decreased both the visual analog scale and high temperature sensitive index for capsaicin- and heat-related irritation. However, 1% troxerutin was only effective in reducing the visual analog scale in response to capsaicin irritation. CONCLUSIONS Troxerutin can inhibit TRPV1 activation in clinical and in vitro tests.
Collapse
Affiliation(s)
- Tae-Yoon Kim
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Joonoh Myoung
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Youn Jung Lee
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Jinyong Lee
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Jongwook Kim
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Seungeun Kim
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Mi-Sun Kim
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | | | - Seung Jin Hwang
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Nae-Gyu Kang
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| | - Eui Taek Jeong
- R&D Center, LG Household & Health Care (LG H&H), Seoul, Korea
| |
Collapse
|
2
|
Anand S, Rajagopal S. A Comprehensive Review on the Regulatory Action of TRP Channels: A Potential Therapeutic Target for Nociceptive Pain. Neurosci Insights 2023; 18:26331055231220340. [PMID: 38146332 PMCID: PMC10749524 DOI: 10.1177/26331055231220340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/28/2023] [Indexed: 12/27/2023] Open
Abstract
The transient receptor potential (TRP) superfamily of ion channels in humans comprises voltage-gated, non-selective cation channels expressed both in excitable as well as non-excitable cells. Four TRP channel subunits associate to create functional homo- or heterotetramers that allow the influx of calcium, sodium, and/or potassium. These channels are highly abundant in the brain and kidney and are important mediators of diverse biological functions including thermosensation, vascular tone, flow sensing in the kidney and irritant stimuli sensing. Inherited or acquired dysfunction of TRP channels influences cellular functions and signaling pathways resulting in multifaceted disorders affecting skeletal, renal, cardiovascular, and nervous systems. Studies have demonstrated the involvement of these channels in the generation and transduction of pain. Based on the multifaceted role orchestrated by these TRP channels, modulation of the activity of these channels presents an important strategy to influence cellular function by regulating intracellular calcium levels as well as membrane excitability. Therefore, there has been a remarkable pharmaceutical inclination toward TRP channels as therapeutic interventions. Several candidate drugs influencing the activity of these channels are already in the clinical trials pipeline. The present review encompasses the current understanding of TRP channels and TRP modulators in pain and pain management.
Collapse
Affiliation(s)
- Santosh Anand
- Department of Biotechnology, School of Applied Sciences, REVA University, Bengaluru, Karnataka, India
| | - Senthilkumar Rajagopal
- Department of Biotechnology, School of Applied Sciences, REVA University, Bengaluru, Karnataka, India
| |
Collapse
|
3
|
Zhu K, Wang L, Liao T, Li W, Zhou J, You Y, Shi J. Progress in the development of TRPV1 small-molecule antagonists: Novel Strategies for pain management. Eur J Med Chem 2023; 261:115806. [PMID: 37713804 DOI: 10.1016/j.ejmech.2023.115806] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/17/2023]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) channels are widely distributed in sensory nerve endings, the central nervous system, and other tissues, functioning as ion channel proteins responsive to thermal pain and chemical stimuli. In recent years, the TRPV1 receptor has garnered significant interest as a potential therapeutic approach for various pain-related disorders, particularly TRPV1 antagonists. The present review offers a comprehensive, systematic exploration of both first- and second-generation TRPV1 antagonists in the context of pain management. Antagonists are categorized and explicated according to their structural characteristics. Detailed examination of binding modes, structural features, and pharmacological activities, alongside a critical appraisal of the advantages and limitations inherent to typical compounds within each structural category, are undertaken. Detailed discussions of the binding modes, structural features, pharmacological activities, advantages, and limitations of typical compounds within each structural category offer valuable insights and guidance for the future research and development of safer, more effective, and more targeted TRPV1 antagonists.
Collapse
Affiliation(s)
- Kun Zhu
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Lin Wang
- Department of Pharmacy, Personalized Drug Therapy Key Laboratory of Sichuan Province, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China; State Key Laboratory of Biotherapy, Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - TingTing Liao
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Wen Li
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Jing Zhou
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China
| | - Yaodong You
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, China; TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province, Chengdu, 610072, China.
| | - Jianyou Shi
- Department of Pharmacy, Personalized Drug Therapy Key Laboratory of Sichuan Province, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China; State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
| |
Collapse
|
4
|
Röderer P, Belu A, Heidrich L, Siobal M, Isensee J, Prolingheuer J, Janocha E, Valdor M, Hagendorf S, Bahrenberg G, Opitz T, Segschneider M, Haupt S, Nitzsche A, Brüstle O, Hucho T. Emergence of nociceptive functionality and opioid signaling in human induced pluripotent stem cell-derived sensory neurons. Pain 2023:00006396-990000000-00249. [PMID: 36727909 DOI: 10.1097/j.pain.0000000000002860] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/15/2022] [Indexed: 02/03/2023]
Abstract
ABSTRACT Induced pluripotent stem cells (iPSCs) have enabled the generation of various difficult-to-access cell types such as human nociceptors. A key challenge associated with human iPSC-derived nociceptors (hiPSCdNs) is their prolonged functional maturation. While numerous studies have addressed the expression of classic neuronal markers and ion channels in hiPSCdNs, the temporal development of key signaling cascades regulating nociceptor activity has remained largely unexplored. In this study, we used an immunocytochemical high-content imaging approach alongside electrophysiological staging to assess metabotropic and ionotropic signaling of large scale-generated hiPSCdNs across 70 days of in vitro differentiation. During this period, the resting membrane potential became more hyperpolarized, while rheobase, action potential peak amplitude, and membrane capacitance increased. After 70 days, hiPSCdNs exhibited robust physiological responses induced by GABA, pH shift, ATP, and capsaicin. Direct activation of protein kinase A type II (PKA-II) through adenylyl cyclase stimulation with forskolin resulted in PKA-II activation at all time points. Depolarization-induced activation of PKA-II emerged after 35 days of differentiation. However, effective inhibition of forskolin-induced PKA-II activation by opioid receptor agonists required 70 days of in vitro differentiation. Our results identify a pronounced time difference between early expression of functionally important ion channels and emergence of regulatory metabotropic sensitizing and desensitizing signaling only at advanced stages of in vitro cultivation, suggesting an independent regulation of ionotropic and metabotropic signaling. These data are relevant for devising future studies into the development and regulation of human nociceptor function and for defining time windows suitable for hiPSCdN-based drug discovery.
Collapse
Affiliation(s)
- Pascal Röderer
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Andreea Belu
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Luzia Heidrich
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Maike Siobal
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jörg Isensee
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Jonathan Prolingheuer
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | | | | | | | | | - Thoralf Opitz
- Institute of Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
| | - Michaela Segschneider
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
| | - Simone Haupt
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Anja Nitzsche
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Oliver Brüstle
- Institute of Reconstructive Neurobiology, University of Bonn Medical Faculty and University Hospital Bonn, Bonn
- LIFE & BRAIN GmbH, Cellomics Unit, Bonn, Germany, Germany
| | - Tim Hucho
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| |
Collapse
|
5
|
Liang Q, Qiao Z, Zhou Q, Xue D, Wang K, Shao L. Discovery of Potent and Selective Transient Receptor Potential Vanilloid 1 (TRPV1) Agonists with Analgesic Effects In Vivo Based on the Functional Conversion Induced by Altering the Orientation of the Indazole Core. J Med Chem 2022; 65:11658-11678. [PMID: 36008373 DOI: 10.1021/acs.jmedchem.2c00469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is a promising target for developing antinociceptive agents. Here, we report the synthesis of N-indazole-4-aryl piperazine carboxamide analogues as TRPV1 modulators. The structure-activity relationship (SAR) reveals that substituting indazole at the 5-/6-position leads to TRPV1 agonism, whereas the 4- and 7-positions of indazole obtain mild antagonism and loss of activity, respectively. The whole-cell clamp patch assay shows that 28 is a potent and selective TRPV1 agonist and it relieves inflammatory and thermal pain by desensitizing the native TRPV1 current in the dorsal root ganglion (DRG) in mice. Additionally, site-directed mutagenesis combined with molecular docking shows an important hydrogen interaction between Arg557 and the indazole of 28. Taken together, our findings provide insight into TRPV1 agonism-antagonism conversion based on the interaction between indazole and Arg557, which provides a strategy to obtain new TRPV1 agonists by structural modification of antagonists. Compound 28 may be used as a lead compound for further optimization.
Collapse
Affiliation(s)
- Qianqian Liang
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China
| | - Zhen Qiao
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China
| | - Qiqi Zhou
- Department of Pharmacology, Qilu Medical University, Zibo, Shandong 255300, China
| | - Dengqi Xue
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China.,State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - KeWei Wang
- Departments of Pharmacology, School of Pharmacy, Qingdao University Medical College, #1 Ningde Road, Qingdao 266073, China.,Institute of Innovative Drug Discovery, Qingdao University, 38 Dengzhou Road, Qingdao 266021, China
| | - Liming Shao
- Department of Medicinal Chemistry, School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China.,State Key Laboratory of Medical Neurobiology, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| |
Collapse
|
6
|
Advances in TRP channel drug discovery: from target validation to clinical studies. Nat Rev Drug Discov 2021; 21:41-59. [PMID: 34526696 PMCID: PMC8442523 DOI: 10.1038/s41573-021-00268-4] [Citation(s) in RCA: 212] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2021] [Indexed: 12/20/2022]
Abstract
Transient receptor potential (TRP) channels are multifunctional signalling molecules with many roles in sensory perception and cellular physiology. Therefore, it is not surprising that TRP channels have been implicated in numerous diseases, including hereditary disorders caused by defects in genes encoding TRP channels (TRP channelopathies). Most TRP channels are located at the cell surface, which makes them generally accessible drug targets. Early drug discovery efforts to target TRP channels focused on pain, but as our knowledge of TRP channels and their role in health and disease has grown, these efforts have expanded into new clinical indications, ranging from respiratory disorders through neurological and psychiatric diseases to diabetes and cancer. In this Review, we discuss recent findings in TRP channel structural biology that can affect both drug development and clinical indications. We also discuss the clinical promise of novel TRP channel modulators, aimed at both established and emerging targets. Last, we address the challenges that these compounds may face in clinical practice, including the need for carefully targeted approaches to minimize potential side-effects due to the multifunctional roles of TRP channels.
Collapse
|
7
|
Hu J, Gao M, Zhang Y, Wang Y, Qiao Z, Zhang W, Wang Q, Yan L, Qian H. Novel piperazine urea derivatives as highly potent transient receptor potential vanilloid 1 (TRPV1) antagonists. Bioorg Chem 2021; 115:105229. [PMID: 34364049 DOI: 10.1016/j.bioorg.2021.105229] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/21/2021] [Accepted: 07/28/2021] [Indexed: 10/20/2022]
Abstract
Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel with high permeability to Ca2+, which can be activated by low pH, noxious heat and vanilloid compounds such as capsaicin. TRPV1 has been proved to be very important in the process of pain production and is considered to be a highly effective analgesic target. In this work, three series of new piperazine urea TRPV1 antagonists were designed, synthesized and evaluated based on classical TRPV1 antagonists BCTC and GRT12360. Among them, N-(4,6-dimethylpyridin-2-yl)-4-(2-(pyrrolidin-1-yl)benzyl)piperazine-1-carboxamide (5ac) was finally identified, which had excellent TRPV1 antagonistic activity (IC50 (CAP) = 9.80 nM), good bioavailability and did not cause side effects of hyperthermia. In the study of molecular docking, the compound 5ac fitted well with the amino acid residues on rTRPV1 through hydrophobic interaction. Collectively, compound 5ac is an efficient TRPV1 antagonist and can be used as a candidate for the development of analgesic drugs.
Collapse
Affiliation(s)
- Jing Hu
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China
| | - Mengkang Gao
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China
| | - Yang Zhang
- State Key Laboratory of Natural Medicines, Center of Drug Discovery, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China
| | - Yusui Wang
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China
| | - Zhenrui Qiao
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China
| | - Weiya Zhang
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China
| | - Qiang Wang
- School of Pharmaceutical Sciences, South-Central University for Nationalities, 182 Minyuan Road, Wuhan, Hubei 430074, China
| | - Lin Yan
- Institute for Innovative Drug Design and Evaluation, School of Pharmacy, Henan University, N. Jinming Ave., Kaifeng, Henan 475004, China; Key Laboratory of Advanced Drug Preparation Technologies, Ministry of Education, Zhengzhou University, Zhengzhou, Henan 450001, China.
| | - Hai Qian
- State Key Laboratory of Natural Medicines, Center of Drug Discovery, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, Jiangsu 210009, China.
| |
Collapse
|
8
|
Baskaran P, Nazminia K, Frantz J, O’Neal J, Thyagarajan B. Mice lacking endogenous TRPV1 express reduced levels of thermogenic proteins and are susceptible to diet-induced obesity and metabolic dysfunction. FEBS Lett 2021; 595:1768-1781. [PMID: 33977527 PMCID: PMC8277693 DOI: 10.1002/1873-3468.14105] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 11/08/2022]
Abstract
Transient receptor potential vanilloid subfamily 1 (TRPV1) is a non-selective cation channel protein expressed in neuronal and non-neuronal cells. Although TRPV1 is implicated in thermogenesis and diet-induced obesity (DIO), its precise role remains controversial. TRPV1-/- mice are protected from DIO, while TRPV1 activation enhances thermogenesis to prevent obesity. To reconcile this, we fed wild-type and TRPV1-/- mice for 32 weeks with normal chow or a high-fat diet and analyzed the weight gain, metabolic activities, and thermogenic protein expression in white and brown fats. TRPV1-/- mice became obese, exhibited reduced locomotor activity, reduced energy expenditure, enhanced hepatic steatosis, and decreased thermogenic protein expression in adipose tissues. Our data reveal that lack of TRPV1 does not prevent obesity, but rather enhances metabolic dysfunction.
Collapse
Affiliation(s)
- Padmamalini Baskaran
- Molecular Signaling Laboratory, School of Pharmacy, University of Wyoming, Laramie, WY 82072
| | - Kara Nazminia
- Molecular Signaling Laboratory, School of Pharmacy, University of Wyoming, Laramie, WY 82072
| | - Justine Frantz
- Molecular Signaling Laboratory, School of Pharmacy, University of Wyoming, Laramie, WY 82072
| | - Jessica O’Neal
- Molecular Signaling Laboratory, School of Pharmacy, University of Wyoming, Laramie, WY 82072
| | - Baskaran Thyagarajan
- Molecular Signaling Laboratory, School of Pharmacy, University of Wyoming, Laramie, WY 82072
| |
Collapse
|
9
|
Saunders PT, Horne AW. Endometriosis: Etiology, pathobiology, and therapeutic prospects. Cell 2021; 184:2807-2824. [DOI: 10.1016/j.cell.2021.04.041] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/31/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023]
|
10
|
CRISPR Deletion of a SVA Retrotransposon Demonstrates Function as a cis-Regulatory Element at the TRPV1/TRPV3 Intergenic Region. Int J Mol Sci 2021; 22:ijms22041911. [PMID: 33671852 PMCID: PMC7917899 DOI: 10.3390/ijms22041911] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 11/16/2022] Open
Abstract
SINE-VNTR-Alu (SVA) retrotransposons are a subclass of transposable elements (TEs) that exist only in primate genomes. TE insertions can be co-opted as cis-regulatory elements (CREs); however, the regulatory potential of SVAs has predominantly been demonstrated using bioinformatic approaches and reporter gene assays. The objective of this study was to demonstrate SVA cis-regulatory activity by CRISPR (clustered regularly interspaced short palindromic repeats) deletion and subsequent measurement of direct effects on local gene expression. We identified a region on chromosome 17 that was enriched with human-specific SVAs. Comparative gene expression analysis at this region revealed co-expression of TRPV1 and TRPV3 in multiple human tissues, which was not observed in mouse, highlighting key regulatory differences between the two species. Furthermore, the intergenic region between TRPV1 and TRPV3 coding sequences contained a human specific SVA insertion located upstream of the TRPV3 promoter and downstream of the 3′ end of TRPV1, highlighting this SVA as a candidate to study its potential cis-regulatory activity on both genes. Firstly, we generated SVA reporter gene constructs and demonstrated their transcriptional regulatory activity in HEK293 cells. We then devised a dual-targeting CRISPR strategy to facilitate the deletion of this entire SVA sequence and generated edited HEK293 clonal cell lines containing homozygous and heterozygous SVA deletions. In edited homozygous ∆SVA clones, we observed a significant decrease in both TRPV1 and TRPV3 mRNA expression, compared to unedited HEK293. In addition, we also observed an increase in the variability of mRNA expression levels in heterozygous ∆SVA clones. Overall, in edited HEK293 with SVA deletions, we observed a disruption to the co-expression of TRPV1 and TRPV3. Here we provide an example of a human specific SVA with cis-regulatory activity in situ, supporting the role of SVA retrotransposons as contributors to species-specific gene expression.
Collapse
|