1
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Mu H, Ye L, Wang B. Detailed resume of S-methyltransferases: Categories, structures, biological functions and research advancements in related pathophysiology and pharmacotherapy. Biochem Pharmacol 2024; 226:116361. [PMID: 38876259 DOI: 10.1016/j.bcp.2024.116361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 05/19/2024] [Accepted: 06/10/2024] [Indexed: 06/16/2024]
Abstract
Methylation is a vital chemical reaction in the metabolism of many drugs, neurotransmitters, hormones, and exogenous compounds. Among them, S-methylation plays a significant role in the biotransformation of sulfur-containing compounds, particularly chemicals with sulfhydryl groups. Currently, only three S-methyltransferases have been reported: thiopurine methyltransferase (TPMT), thiol methyltransferase (TMT), and thioether methyltransferase (TEMT). These enzymes are involved in various biological processes such as gene regulation, signal transduction, protein repair, tumor progression, and biosynthesis and degradation reactions in animals, plants, and microorganisms. Furthermore, they play pivotal roles in the metabolic pathways of essential drugs and contribute to the advancement of diseases such as tumors. This paper reviews the research progress on relevant structural features, metabolic mechanisms, inhibitor development, and influencing factors (gene polymorphism, S-adenosylmethionine level, race, sex, age, and disease) of S-methyltransferases. We hope that a better comprehension of S-methyltransferases will help to provide a reference for the development of novel strategies for related disorders and improve long-term efficacy.
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Affiliation(s)
- Hongfei Mu
- Department of Drug Metabolism, Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
| | - Lisha Ye
- Department of Drug Metabolism, Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
| | - Baolian Wang
- Department of Drug Metabolism, Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD Study, State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China.
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2
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Zhang Y, Li Y. β-hydroxybutyrate inhibits malignant phenotypes of prostate cancer cells through β-hydroxybutyrylation of indoleacetamide-N-methyltransferase. Cancer Cell Int 2024; 24:121. [PMID: 38555451 PMCID: PMC10981303 DOI: 10.1186/s12935-024-03277-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/19/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Prostate cancer (PCa) is one of the most prevalent cancers in men and is associated with high mortality and disability rates. β-hydroxybutyrate (BHB), a ketone body, has received increasing attention for its role in cancer. However, its role in PCa remains unclear. This study aimed to explore the mechanism and feasibility of BHB as a treatment alternative for PCa. METHODS Colony formation assay, flow cytometry, western blot assay, and transwell assays were performed to determine the effect of BHB on the proliferation and metastasis of PCa cells. Tumor sphere formation and aldehyde dehydrogenase assays were used to identify the impact of BHB or indoleacetamide-N-methyltransferase (INMT) on the stemness of PCa cells. N6-methyladenosine (m6A)-meRIP real-time reverse transcription polymerase chain reaction and dual luciferase assays were conducted to confirm INMT upregulation via the METTL3-m6A pathway. Co-IP assay was used to detect the epigenetic modification of INMT by BHB-mediated β-hydroxybutyrylation (kbhb) and screen enzymes that regulate INMT kbhb. Mouse xenograft experiments demonstrated the antitumor effects of BHB in vivo. RESULTS BHB can inhibit the proliferation, migration, and invasion of PCa cells by suppressing their stemness. Mechanistically, INMT, whose expression is upregulated by the METTL3-m6A pathway, was demonstrated to be an oncogenic gene that promotes the stem-like characteristics of PCa cells. BHB can suppress the malignant phenotypes of PCa by kbhb of INMT, which in turn inhibits INMT expression. CONCLUSIONS Our findings indicate a role of BHB in PCa metabolic therapy, thereby suggesting an epigenetic therapeutic strategy to target INMT in aggressive PCa. TRIAL REGISTRATION Not applicable.
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Affiliation(s)
- Yifan Zhang
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Erqi District, Zhengzhou, Henan, Henan, 450000, China.
| | - Yunlong Li
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Erqi District, Zhengzhou, Henan, Henan, 450000, China
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3
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Fukumoto Y, Kyono R, Shibukawa Y, Tanaka YK, Suzuki N, Ogra Y. Differential molecular mechanisms of substrate recognition by selenium methyltransferases, INMT and TPMT, in selenium detoxification and excretion. J Biol Chem 2024; 300:105599. [PMID: 38159853 PMCID: PMC10844679 DOI: 10.1016/j.jbc.2023.105599] [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: 09/15/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
It is known that the recommended dietary allowance of selenium (Se) is dangerously close to its tolerable upper intake level. Se is detoxified and excreted in urine as trimethylselenonium ion (TMSe) when the amount ingested exceeds the nutritional level. Recently, we demonstrated that the production of TMSe requires two methyltransferases: thiopurine S-methyltransferase (TPMT) and indolethylamine N-methyltransferase (INMT). In this study, we investigated the substrate recognition mechanisms of INMT and TPMT in the Se-methylation reaction. Examination of the Se-methyltransferase activities of two paralogs of INMT, namely, nicotinamide N-methyltransferase and phenylethanolamine N-methyltransferase, revealed that only INMT exhibited Se-methyltransferase activity. Consistently, molecular dynamics simulations demonstrated that dimethylselenide was preferentially associated with the active center of INMT. Using the fragment molecular orbital method, we identified hydrophobic residues involved in the binding of dimethylselenide to the active center of INMT. The INMT-L164R mutation resulted in a deficiency in Se- and N-methyltransferase activities. Similarly, TPMT-R152, which occupies the same position as INMT-L164, played a crucial role in the Se-methyltransferase activity of TPMT. Our findings suggest that TPMT recognizes negatively charged substrates, whereas INMT recognizes electrically neutral substrates in the hydrophobic active center embedded within the protein. These observations explain the sequential requirement of the two methyltransferases in producing TMSe.
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Affiliation(s)
- Yasunori Fukumoto
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan.
| | - Rin Kyono
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Yuka Shibukawa
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Yu-Ki Tanaka
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Noriyuki Suzuki
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
| | - Yasumitsu Ogra
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba, Japan
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4
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Chen X, Li J, Yu L, Maule F, Chang L, Gallant JA, Press DJ, Raithatha SA, Hagel JM, Facchini PJ. A cane toad (Rhinella marina) N-methyltransferase converts primary indolethylamines to tertiary psychedelic amines. J Biol Chem 2023; 299:105231. [PMID: 37690691 PMCID: PMC10570959 DOI: 10.1016/j.jbc.2023.105231] [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: 06/08/2023] [Revised: 08/31/2023] [Accepted: 09/03/2023] [Indexed: 09/12/2023] Open
Abstract
Psychedelic indolethylamines have emerged as potential medicines to treat several psychiatric pathologies. Natural sources of these compounds include 'magic mushrooms' (Psilocybe spp.), plants used to prepare ayahuasca, and toads. The skin and parotid glands of certain toads accumulate a variety of specialized metabolites including toxic guanidine alkaloids, lipophilic alkaloids, poisonous steroids, and hallucinogenic indolethylamines such as DMT, 5-methoxy-DMT, and bufotenin. The occurrence of psychedelics has contributed to the ceremonial use of toads, particularly among Mesoamerican peoples. Yet, the biosynthesis of psychedelic alkaloids has not been elucidated. Herein, we report a novel indolethylamine N-methyltransferase (RmNMT) from cane toad (Rhinella marina). The RmNMT sequence was used to identify a related NMT from the common toad, Bufo bufo. Close homologs from various frog species were inactive, suggesting a role for psychedelic indolethylamine biosynthesis in toads. Enzyme kinetic analyses and comparison with functionally similar enzymes showed that recombinant RmNMT was an effective catalyst and not product inhibited. The substrate promiscuity of RmNMT enabled the bioproduction of a variety of substituted indolethylamines at levels sufficient for purification, pharmacological screening, and metabolic stability assays. Since the therapeutic potential of psychedelics has been linked to activity at serotonergic receptors, we evaluated binding of derivatives at 5-HT1A and 5-HT2A receptors. Primary amines exhibited enhanced affinity at the 5-HT1A receptor compared with tertiary amines. With the exception of 6-substituted derivatives, N,N-dimethylation also protected against catabolism by liver microsomes.
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Affiliation(s)
- Xue Chen
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | - Jing Li
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | - Lisa Yu
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | - Francesca Maule
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Limei Chang
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | | | - David J Press
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | | | - Jillian M Hagel
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada
| | - Peter J Facchini
- Discovery Group, Enveric Biosciences Inc, Calgary, Alberta, Canada; Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
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5
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Friedberg LM, Sen AK, Nguyen Q, Tonucci GP, Hellwarth EB, Gibbons WJ, Jones JA. "In vivo biosynthesis of N,N-dimethyltryptamine, 5-MeO-N,N-dimethyltryptamine, and bufotenine in E.coli". Metab Eng 2023; 78:61-71. [PMID: 37230161 DOI: 10.1016/j.ymben.2023.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 05/15/2023] [Accepted: 05/22/2023] [Indexed: 05/27/2023]
Abstract
N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and 5-hydroxy-N,N-dimethyltryptamine (bufotenine) are psychedelic tryptamines found naturally in both plants and animals and have shown clinical potential to help treat mental disorders, such as anxiety and depression. Advances in both metabolic and genetic engineering make it possible to engineer microbes as cell factories to produce DMT and its aforementioned derivatives to meet demand for ongoing clinical study. Here, we present the development of a biosynthetic production pathway for DMT, 5-MeO-DMT, and bufotenine in the model microbe Escherichia coli. Through the application of genetic optimization techniques and process optimization in benchtop fermenters, the in vivo production of DMT in E. coli was observed. DMT production with tryptophan supplementation reached maximum titers of 74.7 ± 10.5 mg/L under fed batch conditions in a 2-L bioreactor. Additionally, we show the first reported case of de novo production of DMT (from glucose) in E. coli at a maximum titer of 14.0 mg/L and report the first example of microbial 5-MeO-DMT and bufotenine production in vivo. This work provides a starting point for further genetic and fermentation optimization studies with the goal to increase methylated tryptamine production metrics to industrially competitive levels.
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Affiliation(s)
- Lucas M Friedberg
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
| | - Abhishek K Sen
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
| | - Quynh Nguyen
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
| | - Gabriel P Tonucci
- Miami University, Department of Microbiology, Oxford, OH, 45056, USA.
| | - Elle B Hellwarth
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
| | - William J Gibbons
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
| | - J Andrew Jones
- Miami University, Department of Chemical, Paper, and Biomedical Engineering, Oxford, OH, 45056, USA.
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6
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Glynos NG, Carter L, Lee SJ, Kim Y, Kennedy RT, Mashour GA, Wang MM, Borjigin J. Indolethylamine N-methyltransferase (INMT) is not essential for endogenous tryptamine-dependent methylation activity in rats. Sci Rep 2023; 13:280. [PMID: 36609666 PMCID: PMC9822953 DOI: 10.1038/s41598-023-27538-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
Indolethylamine N-methyltransferase (INMT) is a transmethylation enzyme that utilizes the methyl donor S-adenosyl-L-methionine to transfer methyl groups to amino groups of small molecule acceptor compounds. INMT is best known for its role in the biosynthesis of N,N-Dimethyltryptamine (DMT), a psychedelic compound found in mammalian brain and other tissues. In mammals, biosynthesis of DMT is thought to occur via the double methylation of tryptamine, where INMT first catalyzes the biosynthesis of N-methyltryptamine (NMT) and then DMT. However, it is unknown whether INMT is necessary for the biosynthesis of endogenous DMT. To test this, we generated a novel INMT-knockout rat model and studied tryptamine methylation using radiometric enzyme assays, thin-layer chromatography, and ultra-high-performance liquid chromatography tandem mass spectrometry. We also studied tryptamine methylation in recombinant rat, rabbit, and human INMT. We report that brain and lung tissues from both wild type and INMT-knockout rats show equal levels of tryptamine-dependent activity, but that the enzymatic products are neither NMT nor DMT. In addition, rat INMT was not sufficient for NMT or DMT biosynthesis. These results suggest an alternative enzymatic pathway for DMT biosynthesis in rats. This work motivates the investigation of novel pathways for endogenous DMT biosynthesis in mammals.
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Affiliation(s)
- Nicolas G. Glynos
- grid.214458.e0000000086837370Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA ,grid.214458.e0000000086837370Michigan Psychedelic Center, University of Michigan, Ann Arbor, MI USA
| | - Lily Carter
- grid.214458.e0000000086837370Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA
| | - Soo Jung Lee
- grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI USA ,grid.413800.e0000 0004 0419 7525Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, MI USA
| | - Youngsoo Kim
- grid.214458.e0000000086837370Department of Chemistry, University of Michigan, Ann Arbor, MI USA
| | - Robert T. Kennedy
- grid.214458.e0000000086837370Department of Chemistry, University of Michigan, Ann Arbor, MI USA
| | - George A. Mashour
- grid.214458.e0000000086837370Michigan Psychedelic Center, University of Michigan, Ann Arbor, MI USA ,grid.214458.e0000000086837370Department of Anesthesiology, University of Michigan, Ann Arbor, MI USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI USA
| | - Michael M. Wang
- grid.214458.e0000000086837370Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI USA ,grid.214458.e0000000086837370Department of Neurology, University of Michigan, Ann Arbor, MI USA ,grid.413800.e0000 0004 0419 7525Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, MI USA ,grid.214458.e0000000086837370Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI USA
| | - Jimo Borjigin
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA. .,Michigan Psychedelic Center, University of Michigan, Ann Arbor, MI, USA. .,Department of Neurology, University of Michigan, Ann Arbor, MI, USA. .,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.
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7
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Abstract
N,N-dimethyltryptamine (DMT) is a potent psychedelic naturally produced by many plants and animals, including humans. Whether or not DMT is significant to mammalian physiology, especially within the central nervous system, is a debate that started in the early 1960s and continues to this day. This review integrates historical and recent literature to clarify this issue, giving special attention to the most controversial subjects of DMT's biosynthesis, its storage in synaptic vesicles and the activation receptors like sigma-1. Less discussed topics, like DMT's metabolic regulation or the biased activation of serotonin receptors, are highlighted. We conclude that most of the arguments dismissing endogenous DMT's relevance are based on obsolete data or misleading assumptions. Data strongly suggest that DMT can be relevant as a neurotransmitter, neuromodulator, hormone and immunomodulator, as well as being important to pregnancy and development. Key experiments are addressed to definitely prove what specific roles DMT plays in mammalian physiology.
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Affiliation(s)
- Javier Hidalgo Jiménez
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
| | - José Carlos Bouso
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
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8
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Lu S, Ke S, Wang C, Xu Y, Li Z, Song K, Bai M, Zhou M, Yu H, Yin B, Li X, Feng Z, Hua Y, Pan S, Jiang H, Li L, Wu Y, Ma Y. NNMT promotes the progression of intrahepatic cholangiocarcinoma by regulating aerobic glycolysis via the EGFR-STAT3 axis. Oncogenesis 2022; 11:39. [PMID: 35851575 PMCID: PMC9293979 DOI: 10.1038/s41389-022-00415-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 07/01/2022] [Accepted: 07/06/2022] [Indexed: 12/13/2022] Open
Abstract
Nicotinamide N-methyltransferase (NNMT), a member of the N-methyltransferase family, plays an important role in tumorigenesis. However, its expression and biological functions in intrahepatic cholangiocarcinoma (iCCA) remain to be established. In our study, we identified NNMT as an oncogene in iCCA and provided mechanistic insights into the roles of NNMT in iCCA progression. High NNMT expression in iCCA tissues was identified using western blotting and immunohistochemistry (IHC). We identified a significantly higher NNMT expression level in human iCCA tissues than that in adjacent normal tissues. Increased NNMT expression promoted iCCA cell proliferation and metastasis in vitro and in vivo. Mechanistically, NNMT inhibited the level of histone methylation in iCCA cells by consuming the methyl donor S-adenosyl methionine (SAM), thereby promoting the expression of epidermal growth factor receptor (EGFR). EGFR may activate the aerobic glycolysis pathway in iCCA cells by activating the STAT3 signaling pathway. In conclusion, we identified NNMT as an oncogene in iCCA and provided mechanistic insights into the roles of NNMT in iCCA progression.
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Affiliation(s)
- Shounan Lu
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shanjia Ke
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Chaoqun Wang
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yanan Xu
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zihao Li
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Keda Song
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Department of General Surgery, Linyi Central Hospital, Linyi, China
| | - Miaoyu Bai
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Menghua Zhou
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Hongjun Yu
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Bing Yin
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Xinglong Li
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Zhigang Feng
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,The First Department of General Surgery, Affiliated Hospital of Inner Mongolia Minzu University, Tongliao, China
| | - Yongliang Hua
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.,Department of Pediatric Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shangha Pan
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Hongchi Jiang
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China. .,Department of Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Linqiang Li
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Yaohua Wu
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China. .,Department of Thyroid Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
| | - Yong Ma
- Department of Minimal Invasive Hepatic Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, China. .,Key Laboratory of Hepatosplenic Surgery, Ministry of Education, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
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9
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Genome-wide meta-analysis of iron status biomarkers and the effect of iron on all-cause mortality in HUNT. Commun Biol 2022; 5:591. [PMID: 35710628 PMCID: PMC9203493 DOI: 10.1038/s42003-022-03529-z] [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: 09/21/2021] [Accepted: 05/24/2022] [Indexed: 01/19/2023] Open
Abstract
Iron is essential for many biological processes, but iron levels must be tightly regulated to avoid harmful effects of both iron deficiency and overload. Here, we perform genome-wide association studies on four iron-related biomarkers (serum iron, serum ferritin, transferrin saturation, total iron-binding capacity) in the Trøndelag Health Study (HUNT), the Michigan Genomics Initiative (MGI), and the SardiNIA study, followed by their meta-analysis with publicly available summary statistics, analyzing up to 257,953 individuals. We identify 123 genetic loci associated with iron traits. Among 19 novel protein-altering variants, we observe a rare missense variant (rs367731784) in HUNT, which suggests a role for DNAJC13 in transferrin recycling. We further validate recently published results using genetic risk scores for each biomarker in HUNT (6% variance in serum iron explained) and present linear and non-linear Mendelian randomization analyses of the traits on all-cause mortality. We find evidence of a harmful effect of increased serum iron and transferrin saturation in linear analyses that estimate population-averaged effects. However, there was weak evidence of a protective effect of increasing serum iron at the very low end of its distribution. Our findings contribute to our understanding of the genes affecting iron status and its consequences on human health. A GWAS on the four major iron-related biomarkers is conducted using data from the Trøndelag Health Study (HUNT), Michigan Genomics Initiative (MGI), and SardiNIA study, to identify 123 loci associated with iron homeostasis and effect on all-cause mortality.
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10
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Mahmood D, Alenezi SK, Anwar MJ, Azam F, Qureshi KA, Jaremko M. New Paradigms of Old Psychedelics in Schizophrenia. Pharmaceuticals (Basel) 2022; 15:ph15050640. [PMID: 35631466 PMCID: PMC9147282 DOI: 10.3390/ph15050640] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/08/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022] Open
Abstract
Psychedelics such as lysergic acid diethylamide (LSD), psilocybin (magic mushrooms), and mescaline exhibit intense effects on the human brain and behaviour. In recent years, there has been a surge in studies investigating these drugs because clinical studies have shown that these once banned drugs are well tolerated and efficacious in medically supervised low doses called microdosing. Psychedelics have demonstrated efficacy in treating neuropsychiatric maladies such as difficult to treat anxiety, depression, mood disorders, obsessive compulsive disorders, suicidal ideation, posttraumatic stress disorder, and also in treating substance use disorders. The primary mode of action of psychedelics is activation of serotonin 5-HT2A receptors affecting cognition and brain connectivity through the modulation of several downstream signalling pathways via complex molecular mechanisms. Some atypical antipsychotic drugs (APDs) primarily exhibit pharmacological actions through 5-HT2A receptors, which are also the target of psychedelic drugs. Psychedelic drugs including the newer second generation along with the glutamatergic APDs are thought to mediate pharmacological actions through a common pathway, i.e., a complex serotonin-glutamate receptor interaction in cortical neurons of pyramidal origin. Furthermore, psychedelic drugs have been reported to act via a complex interplay between 5HT2A, mGlu2/3, and NMDA receptors to mediate neurobehavioral and pharmacological actions. Findings from recent studies have suggested that serotoninergic and glutamatergic neurotransmissions are very closely connected in producing pharmacological responses to psychedelics and antipsychotic medication. Emerging hypotheses suggest that psychedelics work through brain resetting mechanisms. Hence, there is a need to dig deeply into psychedelic neurobiology to uncover how psychedelics could best be used as scientific tools to benefit psychiatric disorders including schizophrenia.
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Affiliation(s)
- Danish Mahmood
- Department of Pharmacology & Toxicology, Unaizah College of Pharmacy, Qassim University, Unaizah 51911, Saudi Arabia; (S.K.A.); (M.J.A.)
- Correspondence: or
| | - Sattam K. Alenezi
- Department of Pharmacology & Toxicology, Unaizah College of Pharmacy, Qassim University, Unaizah 51911, Saudi Arabia; (S.K.A.); (M.J.A.)
| | - Md. Jamir Anwar
- Department of Pharmacology & Toxicology, Unaizah College of Pharmacy, Qassim University, Unaizah 51911, Saudi Arabia; (S.K.A.); (M.J.A.)
| | - Faizul Azam
- Department of Pharmaceutical Chemistry & Pharmacognosy, Unaizah College of Pharmacy, Qassim University, Unaizah 51911, Saudi Arabia;
| | - Kamal A. Qureshi
- Department of Pharmaceutics, Unaizah College of Pharmacy, Qassim University, Unaizah 51911, Saudi Arabia;
| | - Mariusz Jaremko
- Smart-Health Initiative (SHI) and Red Sea Research Center (RSRC), Division of Biological and Environmental Sciences and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia;
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11
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Administration of N,N-dimethyltryptamine (DMT) in psychedelic therapeutics and research and the study of endogenous DMT. Psychopharmacology (Berl) 2022; 239:1749-1763. [PMID: 35064294 PMCID: PMC8782705 DOI: 10.1007/s00213-022-06065-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 01/11/2022] [Indexed: 12/20/2022]
Abstract
As with all drugs, the route, form, and/or dose of a substance administered or applied can play a defining role in its overall pharmacology and use as a therapeutic. This review will focus on these factors as they relate to the psychedelic N,N-dimethyltryptamine (DMT). It will examine the positive and negative aspects of different formulations and routes of administration of DMT and the observed effects from such administrations in the form of ayahuasca teas; oral "pharmahuasca"; injections by intravenous (IV) and intramuscular (IM) routes; inhalation, insufflation; and other routes; and high-dose, low-dose, and "micro-dose" effects. The review will consider possible oral route of administration alternatives that would not require concomitant use of a monoamine oxidase inhibitor. The review will then address the current research findings for DMT from in vivo and in vitro studies as well as the possibility that these findings may be revealing the role of endogenous DMT in normal brain function.
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12
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Zhong S, Jeong JH, Huang C, Chen X, Dickinson SI, Dhillon J, Yang L, Luo JL. Targeting INMT and interrupting its methylation pathway for the treatment of castration resistant prostate cancer. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:307. [PMID: 34587977 PMCID: PMC8482636 DOI: 10.1186/s13046-021-02109-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 09/19/2021] [Indexed: 02/07/2023]
Abstract
Background Castration-resistant prostate cancer (CRPC) is associated with a very poor prognosis, and the treatment of which remains a serious clinical challenge. Methods RNA-seq, qPCR, western blot and immunohistochemistry were employed to identify and confirm the high expression of indolethylamine N-methyltransferase (INMT) in CRPC and the clinical relevance. Chip assay was used to identify Histone-Lysine N-Methyltransferase (SMYD3) as a major epigenetic regulator of INMT. LC-MS/MS were used to identify new substrates of INMT methylation in CRPC tissues. Gene knockdown/overexpression, MTT and mouse cancer models were used to examine the role of INMT as well as the anticancer efficacy of INMT inhibitor N,N-dimethyltryptamine (DMT), the SMYD3 inhibitor BCl-12, the selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC), and the newly identified endogenous INMT substrate Bis(7)-tacrine. Results We found that the expression of INMT was highly increased in CRPC and was correlated with poor prognosis of clinical prostate cancer (PCa). INMT promoted PCa castration resistance via detoxification of anticancer metabolites. Knockdown of INMT or treatment with INMT inhibitor N,N-dimethyltryptamine (DMT) significantly suppressed CRPC development. Histone-Lysine N-Methyltransferase SMYD3 was a major epigenetic regulator of INMT expression, treatment with SMYD3 inhibitor BCl-121 suppressed INMT expression and inhibits CRPC development. Importantly, INMT knockdown significantly increased the anticancer effect of the exogenous selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC) as well as the endogenous metabolite Bis(7)-tacrine. Conclusions Our study suggests that INMT drives PCa castration resistance through detoxification of anticancer metabolites, targeting INMT or its regulator SMYD3 or/and its methylation metabolites represents an effective therapeutic avenue for CRPC treatment. Supplementary Information The online version contains supplementary material available at 10.1186/s13046-021-02109-z.
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Affiliation(s)
- Shangwei Zhong
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Ji-Hak Jeong
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA.,College of Pharmacy, Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Changhao Huang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | - Xueyan Chen
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA
| | | | - Jasreman Dhillon
- Department of Pathology, Moffitt Cancer Center, 2902 Magnolia Drive, Tampa, FL, 33612, USA
| | - Li Yang
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA. .,Department of Obstetrics and Gynecology, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China.
| | - Jun-Li Luo
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, 33458, USA.
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13
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Parsons RB, Facey PD. Nicotinamide N-Methyltransferase: An Emerging Protagonist in Cancer Macro(r)evolution. Biomolecules 2021; 11:1418. [PMID: 34680055 PMCID: PMC8533529 DOI: 10.3390/biom11101418] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/17/2021] [Accepted: 09/24/2021] [Indexed: 12/15/2022] Open
Abstract
Nicotinamide N-methyltransferase (NNMT) has progressed from being considered merely a Phase II metabolic enzyme to one with a central role in cell function and energy metabolism. Over the last three decades, a significant body of evidence has accumulated which clearly demonstrates a central role for NNMT in cancer survival, metastasis, and drug resistance. In this review, we discuss the evidence supporting a role for NNMT in the progression of the cancer phenotype and how it achieves this by driving the activity of pro-oncogenic NAD+-consuming enzymes. We also describe how increased NNMT activity supports the Warburg effect and how it promotes oncogenic changes in gene expression. We discuss the regulation of NNMT activity in cancer cells by both post-translational modification of the enzyme and transcription factor binding to the NNMT gene, and describe for the first time three long non-coding RNAs which may play a role in the regulation of NNMT transcription. We complete the review by discussing the development of novel anti-cancer therapeutics which target NNMT and provide insight into how NNMT-based therapies may be best employed clinically.
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Affiliation(s)
- Richard B. Parsons
- Institute of Pharmaceutical Science, King’s College London, 150 Stamford Street, London SE1 9NH, UK
| | - Paul D. Facey
- Singleton Park Campus, Swansea University Medical School, Swansea University, Swansea SA2 8PP, UK;
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14
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Aging, inflammation and DNA damage in the somatic testicular niche with idiopathic germ cell aplasia. Nat Commun 2021; 12:5205. [PMID: 34471128 PMCID: PMC8410861 DOI: 10.1038/s41467-021-25544-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 08/18/2021] [Indexed: 12/18/2022] Open
Abstract
Molecular mechanisms associated with human germ cell aplasia in infertile men remain undefined. Here we perform single-cell transcriptome profiling to highlight differentially expressed genes and pathways in each somatic cell type in testes of men with idiopathic germ cell aplasia. We identify immaturity of Leydig cells, chronic tissue inflammation, fibrosis, and senescence phenotype of the somatic cells, as well markers of chronic inflammation in the blood. We find that deregulated expression of parentally imprinted genes in myoid and immature Leydig cells, with relevant changes in the ratio of Lamin A/C transcripts and an active DNA damage response in Leydig and peritubular myoid cells are also indicative of senescence of the testicular niche. This study offers molecular insights into the pathogenesis of idiopathic germ cell aplasia. Molecular mechanisms associated with human germ cell aplasia in infertile men remain undefined. Here the authors perform single-cell transcriptome profiling to highlight differentially expressed genes and pathways in each somatic cell type in testes of men with idiopathic germ cell aplasia.
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15
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Hayashi K, Uehara S, Yamamoto S, Cary DR, Nishikawa J, Ueda T, Ozasa H, Mihara K, Yoshimura N, Kawai T, Ono T, Yamamoto S, Fumoto M, Mikamiyama H. Macrocyclic Peptides as a Novel Class of NNMT Inhibitors: A SAR Study Aimed at Inhibitory Activity in the Cell. ACS Med Chem Lett 2021; 12:1093-1101. [PMID: 34267879 DOI: 10.1021/acsmedchemlett.1c00134] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/24/2021] [Indexed: 12/11/2022] Open
Abstract
Nicotinamide N-methyltransferase (NNMT), which catalyzes the methylation of nicotinamide, is a cytosolic enzyme that has attracted much attention as a therapeutic target for a variety of diseases. However, despite the considerable interest in this target, reports of NNMT inhibitors have still been limited to date. In this work, utilizing in vitro translated macrocyclic peptide libraries, we identified peptide 1 as a novel class of NNMT inhibitors. Further exploration based on the X-ray cocrystal structures of the peptides with NNMT provided a dramatic improvement in inhibitory activity (peptide 23: IC50 = 0.15 nM). Furthermore, by balance of the peptides' lipophilicity and biological activity, inhibitory activity against NNMT in cell-based assay was successfully achieved (peptide 26: cell-based IC50 = 770 nM). These findings illuminate the potential of cyclic peptides as a relatively new drug discovery modality even for intracellular targets.
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Affiliation(s)
- Kyohei Hayashi
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Shota Uehara
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Shiho Yamamoto
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Douglas R. Cary
- PeptiDream Inc., 3-25-23 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-0821, Japan
| | - Junichi Nishikawa
- PeptiDream Inc., 3-25-23 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-0821, Japan
| | - Taichi Ueda
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Hiroki Ozasa
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Kousuke Mihara
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Norito Yoshimura
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Taeko Kawai
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Takashi Ono
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Saki Yamamoto
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Masataka Fumoto
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
| | - Hidenori Mikamiyama
- Pharmaceutical Research Division, Shionogi Pharmaceutical Research Center, 3-1-1 Futaba-cho, Toyonaka, Osaka 561-0825, Japan
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16
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Cozzi NV, Daley PF. Synthesis and characterization of high-purity N,N-dimethyltryptamine hemifumarate for human clinical trials. Drug Test Anal 2020; 12:1483-1493. [PMID: 32608093 DOI: 10.1002/dta.2889] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/27/2020] [Accepted: 06/27/2020] [Indexed: 11/07/2022]
Abstract
Since 2006, there has been a resurgent interest in the pharmacology and therapeutics of psychedelic drugs. Psilocybin, the 4-phosphoryl ester of N,N-dimethyltryptamine (DMT), has been studied most often, but DMT itself is also appealing because of its brief but profound psychological effects and its presence as an endogenous substance in mammalian brain. Although there have been a few studies of ayahuasca, a DMT-containing water infusion, only one human study with pure DMT has been reported since the early 2000s. Newly planned clinical trials to assess the safety and efficacy of DMT in humans with major depressive disorders require high-purity water-soluble DMT for intravenous administration. Accordingly, we synthesized and characterized DMT hemifumarate for these upcoming studies. The synthetic approach of Speeter and Anthony was slightly modified to gain some efficiency in time. In particular, this is the first known report to use aluminum hydride, generated in situ from lithium aluminum hydride, to reduce the intermediate 2-(1H-indol-3-yl)-N,N-dimethyl-2-oxoacetamide to DMT. A quench protocol was developed to produce a good yield of exceptionally pure free base DMT upon workup, which was then converted to the hemifumarate salt. Analysis of the final product included differential scanning calorimetry, thermogravimetric analysis, gas chromatography-mass spectrometry (GC-MS), 1 H and 13 C nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, residual solvent analysis by GC headspace sampling, X-ray powder diffraction analysis, and residual lithium analysis by inductively coupled plasma-mass spectrometry. The DMT hemifumarate was minimally 99.9% pure, with no significant impurities or residual solvents, thus meeting regulatory standards for administration to humans.
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Affiliation(s)
- Nicholas V Cozzi
- Neuropharmacology Laboratory, 2695 Medical Sciences Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
- Alexander Shulgin Research Institute, Lafayette, California
| | - Paul F Daley
- Alexander Shulgin Research Institute, Lafayette, California
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17
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Torres B, Tyler JS, Satyshur KA, Ruoho AE. Human indole(ethyl)amine-N-methyltransferase (hINMT) catalyzed methylation of tryptamine, dimethylsulfide and dimethylselenide is enhanced under reducing conditions - A comparison between 254C and 254F, two common hINMT variants. PLoS One 2019; 14:e0219664. [PMID: 31310642 PMCID: PMC6634407 DOI: 10.1371/journal.pone.0219664] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 06/28/2019] [Indexed: 11/18/2022] Open
Abstract
Phenylalanine and cysteine comprise common miss-sense variants (i.e., single nucleotide polymorphisms [SNPs]) at amino acid position 254 of the human indole(ethyl)amine-N-methyltransferase (hINMT). The phenylalanine variant, which occurs in linkage disequilibrium with two 3’ UTR SNPs, has been reported to associate with elevated urine levels of trimethylselenonium (TMSe), the Se-methylated product of volatile dimethylselenide. hINMT allozymes expressing either cysteine (254C) or phenylalanine (254F) at position 254 were compared for enzyme activity (i.e., Km and Vmax) towards the INMT substrates tryptamine, dimethylsulfide (DMS) and dimethylselenide (DMSe) in vitro. The SNP 254C had a higher Vmax for DMS and tryptamine in the presence of reducing agent than in its absence. Conversely, Vmax for 254F was insensitive to the presence or absence of reducing agent for these substrates. SNP 254F showed a lower Km for tryptamine in the absence of reducing agent than 254C. No statistically significant difference in Vmax or Km was observed between 254C and 254F allozymes in the presence of reducing agent for DMSe, The Km values for DMSe methylation were about 10-fold (254C) or 6-fold (254F) more favorable than for tryptamine methylation with reducing agent present. These findings indicated that: 1) That phenylalanine at position 254 renders hINMT methylation of substrates DMS and tryptamine insensitive to a non reducing environment. 2) That human INMT harbors significant thioether-S-methyltransferase (TEMT) activity with a higher affinity for DMSe than tryptamine, 3) The reduction of a 44C/254C disulfide bond in hINMT that increases Vmax is proposed.
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Affiliation(s)
- Brian Torres
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
| | - James S. Tyler
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kenneth A. Satyshur
- Small Molecule Screening Facility, Carbone Cancer Center, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Arnold E. Ruoho
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
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18
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Dean JG, Liu T, Huff S, Sheler B, Barker SA, Strassman RJ, Wang MM, Borjigin J. Biosynthesis and Extracellular Concentrations of N,N-dimethyltryptamine (DMT) in Mammalian Brain. Sci Rep 2019; 9:9333. [PMID: 31249368 PMCID: PMC6597727 DOI: 10.1038/s41598-019-45812-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 06/10/2019] [Indexed: 02/07/2023] Open
Abstract
N,N-dimethyltryptamine (DMT), a psychedelic compound identified endogenously in mammals, is biosynthesized by aromatic-L-amino acid decarboxylase (AADC) and indolethylamine-N-methyltransferase (INMT). Whether DMT is biosynthesized in the mammalian brain is unknown. We investigated brain expression of INMT transcript in rats and humans, co-expression of INMT and AADC mRNA in rat brain and periphery, and brain concentrations of DMT in rats. INMT transcripts were identified in the cerebral cortex, pineal gland, and choroid plexus of both rats and humans via in situ hybridization. Notably, INMT mRNA was colocalized with AADC transcript in rat brain tissues, in contrast to rat peripheral tissues where there existed little overlapping expression of INMT with AADC transcripts. Additionally, extracellular concentrations of DMT in the cerebral cortex of normal behaving rats, with or without the pineal gland, were similar to those of canonical monoamine neurotransmitters including serotonin. A significant increase of DMT levels in the rat visual cortex was observed following induction of experimental cardiac arrest, a finding independent of an intact pineal gland. These results show for the first time that the rat brain is capable of synthesizing and releasing DMT at concentrations comparable to known monoamine neurotransmitters and raise the possibility that this phenomenon may occur similarly in human brains.
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Affiliation(s)
- Jon G Dean
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.,Center for Consciousness Science, University of Michigan, Ann Arbor, MI, USA
| | - Tiecheng Liu
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Sean Huff
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Ben Sheler
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Steven A Barker
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Rick J Strassman
- Department of Psychiatry, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Michael M Wang
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA.,VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
| | - Jimo Borjigin
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA. .,Department of Neurology, University of Michigan, Ann Arbor, MI, USA. .,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA. .,Center for Consciousness Science, University of Michigan, Ann Arbor, MI, USA.
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19
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Rodrigues AVSL, Almeida FJ, Vieira-Coelho MA. Dimethyltryptamine: Endogenous Role and Therapeutic Potential. J Psychoactive Drugs 2019; 51:299-310. [DOI: 10.1080/02791072.2019.1602291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Alexandra VSL Rodrigues
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Francisco Jcg Almeida
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Maria A Vieira-Coelho
- Department of Biomedicine-Pharmacology and Therapeutics unit, Faculty of Medicine, University of Porto, Porto, Portugal
- Psychiatry and Mental Health Clinic, Hospital de São João, Porto, Portugal
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20
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Kozaczek M, Bottje W, Greene E, Lassiter K, Kong B, Dridi S, Korourian S, Hakkak R. Comparison of liver gene expression by RNAseq and PCR analysis after 8 weeks of feeding soy protein isolate- or casein-based diets in an obese liver steatosis rat model. Food Funct 2019; 10:8218-8229. [DOI: 10.1039/c9fo01387c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Differential expression of genes provides insight into fundamental mechanisms associated with the ability of soy protein isolate to attenuate liver steatosis in genetically obese rats.
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Affiliation(s)
- Melisa Kozaczek
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Walter Bottje
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Elizabeth Greene
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Kentu Lassiter
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Byungwhi Kong
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Sami Dridi
- Department of Poultry Science & The Center of Excellence for Poultry Science
- University of Arkansas
- Fayetteville
- USA
| | - Soheila Korourian
- Department of Pathology
- University of Arkansas for Medical Sciences
- Little Rock
- USA
| | - Reza Hakkak
- Department of Dietetics and Nutrition
- University of Arkansas for Medical Sciences
- Little Rock
- USA
- Department of Pediatrics
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21
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Cameron LP, Olson DE. Dark Classics in Chemical Neuroscience: N, N-Dimethyltryptamine (DMT). ACS Chem Neurosci 2018; 9:2344-2357. [PMID: 30036036 DOI: 10.1021/acschemneuro.8b00101] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Though relatively obscure, N, N-dimethyltryptamine (DMT) is an important molecule in psychopharmacology as it is the archetype for all indole-containing serotonergic psychedelics. Its structure can be found embedded within those of better-known molecules such as lysergic acid diethylamide (LSD) and psilocybin. Unlike the latter two compounds, DMT is ubiquitous, being produced by a wide variety of plant and animal species. It is one of the principal psychoactive components of ayahuasca, a tisane made from various plant sources that has been used for centuries. Furthermore, DMT is one of the few psychedelic compounds produced endogenously by mammals, and its biological function in human physiology remains a mystery. In this review, we cover the synthesis of DMT as well as its pharmacology, metabolism, adverse effects, and potential use in medicine. Finally, we discuss the history of DMT in chemical neuroscience and why this underappreciated molecule is so important to the field of psychedelic science.
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Affiliation(s)
- Lindsay P. Cameron
- Neuroscience Graduate Program, University of California, Davis, 1544 Newton Ct., Davis, California 95618, United States
| | - David E. Olson
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
- Department of Biochemistry & Molecular Medicine, School of Medicine, University of California, Davis, 2700 Stockton Blvd., Suite 2102, Sacramento, California 95817, United States
- Center for Neuroscience, University of California, Davis, 1544 Newton Ct., Davis, California 95618, United States
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22
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Barker SA. N, N-Dimethyltryptamine (DMT), an Endogenous Hallucinogen: Past, Present, and Future Research to Determine Its Role and Function. Front Neurosci 2018; 12:536. [PMID: 30127713 PMCID: PMC6088236 DOI: 10.3389/fnins.2018.00536] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 07/17/2018] [Indexed: 01/12/2023] Open
Abstract
This report provides a historical overview of research concerning the endogenous hallucinogen N, N-dimethyltryptamine (DMT), focusing on data regarding its biosynthesis and metabolism in the brain and peripheral tissues, methods and results for DMT detection in body fluids and brain, new sites of action for DMT, and new data regarding its possible physiological and therapeutic roles. Research that further elaborates its consideration as a putative neurotransmitter is also addressed. Taking these studies together, the report proposes several new directions and experiments to ascertain the role of DMT in the brain, including brain mapping of enzymes responsible for the biosynthesis of DMT, further studies to elaborate its presence and role in the pineal gland, a reconsideration of binding site data, and new administration and imaging studies. The need to resolve the "natural" role of an endogenous hallucinogen from the effects observed from peripheral administration are also emphasized.
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Affiliation(s)
- Steven A. Barker
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, United States
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23
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Dean JG. Indolethylamine- N-methyltransferase Polymorphisms: Genetic and Biochemical Approaches for Study of Endogenous N,N,-dimethyltryptamine. Front Neurosci 2018; 12:232. [PMID: 29740267 PMCID: PMC5924808 DOI: 10.3389/fnins.2018.00232] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/23/2018] [Indexed: 12/05/2022] Open
Abstract
N,N-dimethyltryptamine (DMT) is a powerful serotonergic psychedelic whose exogenous administration elicits striking psychedelic effects in humans. Studies have identified DMT and analogous compounds (e.g., 5-hydroxy-DMT, 5-methoxy-DMT) alongside of an enzyme capable of synthesizing DMT endogenously from tryptamine, indolethylamine-N-methyltransferase (INMT), in human and several other mammalian tissues. Subsequently, multiple hypotheses for the physiological role of endogenous DMT have emerged, from proposed immunomodulatory functions to an emphasis on the overlap between the mental states generated by exogenous DMT and naturally occurring altered states of consciousness; e.g., schizophrenia. However, no clear relationship between endogenous DMT and naturally occurring altered states of consciousness has yet been established from in vivo assays of DMT in bodily fluids. The advent of genetic screening has afforded the capability to link alterations in the sequence of specific genes to behavioral and molecular phenotypes via expression of identified single nucleotide polymorphisms (SNPs) in cell and animal models. As SNPs in INMT may impact endogenous DMT synthesis and levels via changes in INMT expression and/or INMT structure and function, these combined genetic and biochemical approaches circumvent the limitations of assaying DMT in bodily fluids and may augment data from prior in vitro and in vivo work. Therefore, all reported SNPs in INMT were amassed from genetic and biochemical literature and genomic databases to consolidate a blueprint for future studies aimed at elucidating whether DMT plays a physiological role.
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Affiliation(s)
- Jon G Dean
- Molecular and Integrative Physiology, Center for Consciousness Science, University of Michigan, Ann Arbor, MI, United States
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24
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Abstract
Because of the ethical and regulatory hurdles associated with human studies, much of what is known about the psychopharmacology of hallucinogens has been derived from animal models. However, developing reliable animal models has proven to be a challenging task due to the complexity and variability of hallucinogen effects in humans. This chapter focuses on three animal models that are frequently used to test the effects of hallucinogens on unconditioned behavior: head twitch response (HTR), prepulse inhibition of startle (PPI), and exploratory behavior. The HTR has demonstrated considerable utility in the neurochemical actions of hallucinogens. However, the latter two models have clearer conceptual bridges to human phenomenology. Consistent with the known mechanism of action of hallucinogens in humans, the behavioral effects of hallucinogens in rodents are mediated primarily by activation of 5-HT2A receptors. There is evidence, however, that other receptors may play secondary roles. The structure-activity relationships (SAR) of hallucinogens are reviewed in relation to each model, with a focus on the HTR in rats and mice.
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Affiliation(s)
- Adam L Halberstadt
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA.
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA.
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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Abstract
The pineal gland has a romantic history, from pharaonic Egypt, where it was equated with the eye of Horus, through various religious traditions, where it was considered the seat of the soul, the third eye, etc. Recent incarnations of these notions have suggested that N,N-dimethyltryptamine is secreted by the pineal gland at birth, during dreaming, and at near death to produce out of body experiences. Scientific evidence, however, is not consistent with these ideas. The adult pineal gland weighs less than 0.2 g, and its principal function is to produce about 30 µg per day of melatonin, a hormone that regulates circadian rhythm through very high affinity interactions with melatonin receptors. It is clear that very minute concentrations of N,N-dimethyltryptamine have been detected in the brain, but they are not sufficient to produce psychoactive effects. Alternative explanations are presented to explain how stress and near death can produce altered states of consciousness without invoking the intermediacy of N,N-dimethyltryptamine.
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Amorós R, Murcia M, Ballester F, Broberg K, Iñiguez C, Rebagliato M, Skröder H, González L, Lopez-Espinosa MJ, Llop S. Selenium status during pregnancy: Influential factors and effects on neuropsychological development among Spanish infants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:741-749. [PMID: 28822941 DOI: 10.1016/j.scitotenv.2017.08.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/20/2017] [Accepted: 08/04/2017] [Indexed: 05/26/2023]
Abstract
Selenium (Se) has been positively associated with neurodevelopment in early life. However, its margin of safety is rather narrow, and few prospective studies have evaluated its potential neurotoxic effects at intermediate levels. We aimed to explore the association between maternal Se concentrations and child neuropsychological development, including the genetic effect modification of the Se metabolizing gene INMT. Study subjects were 650 mother-child pairs from the Spanish Childhood and Environment Project (INMA, 2003-2005). Infant neuropsychological development was assessed around 12months of age by the Bayley Scales of Infant Development. Sociodemographic and dietary characteristics were collected by questionnaire at the first and third trimester of gestation. Se was measured in serum samples at the first trimester. The mean serum Se concentration was 79.7 (standard deviation=7.9) μg/L. In multivariate analysis, nonsignificant inverse linear associations were found between Se concentrations and standardized mental and psychomotor development scores (β (95% CI)=-0.13 (-0.29, 0.03) and β (95% CI)=-0.08 (-0.24, 0.07), respectively). Generalized additive models indicated inverted U-shaped relationships between Se concentrations and both scales. Using segmented regression, the turning point for the associations was estimated at 86μg/L for both scales. The association between Se and neuropsychological development was inverted U-shaped for children with the AG+AA genotype for rs6970396 INMT but a descending curve was suggested for the GG genotype. Further studies would be necessary in order to disentangle the complex equilibrium between the toxicity and benefits of Se exposure during the prenatal period.
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Affiliation(s)
- Rubén Amorós
- Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO, Valencia, Spain
| | - Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Ferran Ballester
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Karin Broberg
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Carmen Iñiguez
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Marisa Rebagliato
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Helena Skröder
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Llúcia González
- Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Maria-Jose Lopez-Espinosa
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid, Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain.
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The Association between the Urinary Excretion of Trimethylselenonium and Trimethylsulfonium in Humans. PLoS One 2016; 11:e0167013. [PMID: 27870899 PMCID: PMC5117766 DOI: 10.1371/journal.pone.0167013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/07/2016] [Indexed: 11/19/2022] Open
Abstract
Hydrogen sulfide is a signaling molecule that plays important roles in several physiological processes, and its methylation product trimethylsulfonium (TMS) is a natural constituent of human urine that could serve as a biomarker for hydrogen sulfide. In vitro studies showed that the enzyme indole-ethylamine N-methyltransferase (INMT) is responsible for the production of trimethylsulfonium as well as its selenium analogue trimethylselenonium (TMSe). Marked inter-individual variability in TMSe production is associated with genetic polymorphisms in the INMT gene, but it remains unclear whether these polymorphisms affect substrate specificity or general enzymatic activity. Therefore, we explore the association between the TMS and TMSe production phenotypes. Caucasian volunteers were recruited and grouped according to their TMSe status into “TMSe producers” and “TMSe non-producers”, and morning urine samples were collected over 5 consecutive days from each volunteer. A total of 125 urine samples collected from 25 volunteers (13 TMSe producers and 12 TMSe non-producers) were analyzed for total selenium and total sulfur using inductively coupled plasma mass spectrometry (ICPMS), trimethylselenonium using HPLC/ICPMS, and trimethylsulfonium using HPLC/electrospray ionization—triple quadrupole—mass spectrometry (ESI-QQQ-MS). Although there was no correlation between TMS and TMSe urinary levels within the “TMSe producers” group, the “TMSe producers” had urinary levels of TMS 10-fold higher than those of the “TMSe non-producers” (P < 0.001). This result indicates that stratification according to TMSe status or genotype is crucial for the correct interpretation of urinary TMS as a possible biomarker for hydrogen sulfide body pools.
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Carbonaro TM, Gatch MB. Neuropharmacology of N,N-dimethyltryptamine. Brain Res Bull 2016; 126:74-88. [PMID: 27126737 PMCID: PMC5048497 DOI: 10.1016/j.brainresbull.2016.04.016] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/20/2022]
Abstract
N,N-dimethyltryptamine (DMT) is an indole alkaloid widely found in plants and animals. It is best known for producing brief and intense psychedelic effects when ingested. Increasing evidence suggests that endogenous DMT plays important roles for a number of processes in the periphery and central nervous system, and may act as a neurotransmitter. This paper reviews the current literature of both the recreational use of DMT and its potential roles as an endogenous neurotransmitter. Pharmacokinetics, mechanisms of action in the periphery and central nervous system, clinical uses and adverse effects are also reviewed. DMT appears to have limited neurotoxicity and other adverse effects except for intense cardiovascular effects when administered intravenously in large doses. Because of its role in nervous system signaling, DMT may be a useful experimental tool in exploring how the brain works, and may also be a useful clinical tool for treatment of anxiety and psychosis.
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Affiliation(s)
- Theresa M Carbonaro
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Michael B Gatch
- Center for Neuroscience Discovery University of North Texas Health Science Center Fort Worth, TX, United States.
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Grammenos D, Barker SA. On the transmethylation hypothesis: stress, N,N-dimethyltryptamine, and positive symptoms of psychosis. J Neural Transm (Vienna) 2014; 122:733-9. [PMID: 25362533 DOI: 10.1007/s00702-014-1329-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/27/2014] [Indexed: 10/24/2022]
Abstract
Past research suggests a relationship between stress and positive symptoms of psychosis. However, the biological substrate of this relationship remains unknown. According to the transmethylation hypothesis, schizophrenia could result from a biochemical disruption in the stress mechanism. This biochemical disruption would lead to the production of a substance that would account for the symptoms of psychosis. Moreover, some studies have tested endogenous N,N-dimethyltryptamine (DMT) in the context of the transmethylation hypothesis. Stress has been found to elevate DMT levels in rodents. Also, elevated DMT levels have been associated with positive features of psychosis in psychiatric patients. Additionally, healthy participants treated with exogenous DMT experience predominantly positive symptoms of psychosis. The present paper examines endogenous DMT as a possible biological mediator of the relationship between stress and positive symptoms of psychosis.
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Affiliation(s)
- Dionysios Grammenos
- Department of Psychology, Faculty of Behavioural and Social Sciences, University of Groningen, Grote Kruisstraat 2/1, 9712 TS, Groningen, The Netherlands,
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Yoon S, Lee J, Lee SM. Combined treatment of isoflavone supplementation and exercise restores the changes in hepatic protein expression in ovariectomized rats - a proteomics approach. J Int Soc Sports Nutr 2014; 11:29. [PMID: 25006332 PMCID: PMC4085729 DOI: 10.1186/1550-2783-11-29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 06/11/2014] [Indexed: 12/05/2022] Open
Abstract
Background Postmenopausal women experience adverse physiological changes caused by estrogen deprivation. Here, we hypothesized that the administration of isoflavone, a phytoestrogn, and/or physical exercise could reverse changes in the levels of hepatic enzymes disturbed by loss of estrogen to ameliorate postmenopause-related health problems. Methods Thirty-week-old female Sprague–Dawley rats were divided into five groups: a sham-operated (SHAM) group, ovariectomized groups on a regular diet with exercise (EXE) and without exercise (OVX), and ovariectomized groups on an isoflavone supplemented diet with (ISO + EXE) and without exercise (ISO). Proteomic tools were employed to identify candidate hepatic proteins that were differentially expressed among the five animal groups. Results INMT was detected in the SHAM but not in all of the ovariectomized rats. Seven proteins (PPIA, AKR1C3, ALDH2, PSME2, BUCS1, OTC, and GAMT) were identified to have differential expression among the groups. When compared to the SHAM group, the ovariectomy elevated the levels of PPIA, BUCS1, PSME2, AKR1C3, and GAMT while decreasing ALDH2 and OTC. Among these OVX-induced changes, OVX-increased BUCS1 and GAMT levels were noticeably decreased by ISO or EXE and further greatly down-regulated by ISO + EXE. In the case of PSME2, ISO and EXE further increased OVX-upregulated expression levels but ISO + EXE greatly reduced OVX-increased levels. On the other hand OVX-lowered OTC levels were elevated by ISO, EXE, or ISO + EXE. The protein levels of ALDH2, PPIA, and AKR1C3 were not significantly reverted by ISO, EXE or ISO + EXE. Conclusion The combination of an isoflavone diet and exercise partly reversed ovariectomy-induced changes in hepatic protein expression levels. Our data suggest that the combinatory regimen of isoflavone supplementation and exercise may be beneficial to menopausal women through modulating hepatic protein expression profiles.
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Affiliation(s)
- Sun Yoon
- Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul 120-749, South Korea
| | - Joomin Lee
- Department of Food and Nutrition, College of Natural Sciences, Chosun University, Gwangju 501-759, South Korea
| | - Seung-Min Lee
- Department of Food and Nutrition, College of Human Ecology, Yonsei University, Seoul 120-749, South Korea
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Chu UB, Vorperian SK, Satyshur K, Eickstaedt K, Cozzi NV, Mavlyutov T, Hajipour AR, Ruoho AE. Noncompetitive inhibition of indolethylamine-N-methyltransferase by N,N-dimethyltryptamine and N,N-dimethylaminopropyltryptamine. Biochemistry 2014; 53:2956-65. [PMID: 24730580 PMCID: PMC4025572 DOI: 10.1021/bi500175p] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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Indolethylamine-N-methyltransferase (INMT) is
a Class 1 transmethylation enzyme known for its production of N,N-dimethyltryptamine (DMT), a hallucinogen
with affinity for various serotonergic, adrenergic, histaminergic,
dopaminergic, and sigma-1 receptors. DMT is produced via the action
of INMT on the endogenous substrates tryptamine and S-adenosyl-l-methionine (SAM). The biological, biochemical,
and selective small molecule regulation of INMT enzyme activity remain
largely unknown. Kinetic mechanisms for inhibition of rabbit lung
INMT (rabINMT) by the product, DMT, and by a new novel tryptamine
derivative were determined. After Michaelis–Menten and Lineweaver–Burk
analyses had been applied to study inhibition, DMT was found to be
a mixed competitive and noncompetitive inhibitor when measured against
tryptamine. The novel tryptamine derivative, N-[2-(1H-indol-3-yl)ethyl]-N′,N′-dimethylpropane-1,3-diamine (propyl dimethyl amino tryptamine
or PDAT), was shown to inhibit rabINMT by a pure noncompetitive mechanism
when measured against tryptamine with a Ki of 84 μM. No inhibition by PDAT was observed at 2 mM when
it was tested against structurally similar Class 1 methyltransferases,
such as human phenylethanolamine-N-methyltransferase
(hPNMT) and human nicotinamide-N-methyltransferase
(hNNMT), indicating selectivity for INMT. The demonstration of noncompetitive
mechanisms for INMT inhibition implies the presence of an inhibitory
allosteric site. In silico analyses using the computer
modeling software Autodock and the rabINMT sequence threaded onto
the human INMT (hINMT) structure (Protein Data Bank entry 2A14) identified an N-terminal
helix–loop–helix non-active site binding region of the
enzyme. The energies for binding of DMT and PDAT to this region of
rabINMT, as determined by Autodock, were −6.34 and −7.58
kcal/mol, respectively. Assessment of the allosteric control of INMT
may illuminate new biochemical pathway(s) underlying the biology of
INMT.
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Affiliation(s)
- Uyen B Chu
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health , 1300 University Avenue, Madison, Wisconsin 53706, United States
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Abstract
OBJECTIVES Comprehensively review the evidence regarding the use of ayahuasca, an Amerindian medicine traditionally used to treat many different illnesses and diseases, to treat some types of cancer. METHODS An in-depth review of the literature was conducted using PubMed, books, institutional magazines, conferences and online texts in nonprofessional sources regarding the biomedical knowledge about ayahuasca in general with a specific focus in its possible relations to the treatment of cancer. RESULTS At least nine case reports regarding the use of ayahuasca in the treatment of prostate, brain, ovarian, uterine, stomach, breast, and colon cancers were found. Several of these were considered improvements, one case was considered worse, and one case was rated as difficult to evaluate. A theoretical model is presented which explains these effects at the cellular, molecular, and psychosocial levels. Particular attention is given to ayahuasca's pharmacological effects through the activity of N,N-dimethyltryptamine at intracellular sigma-1 receptors. The effects of other components of ayahuasca, such as harmine, tetrahydroharmine, and harmaline, are also considered. CONCLUSION The proposed model, based on the molecular and cellular biology of ayahuasca's known active components and the available clinical reports, suggests that these accounts may have consistent biological underpinnings. Further study of ayahuasca's possible antitumor effects is important because cancer patients continue to seek out this traditional medicine. Consequently, based on the social and anthropological observations of the use of this brew, suggestions are provided for further research into the safety and efficacy of ayahuasca as a possible medicinal aid in the treatment of cancer.
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Affiliation(s)
- Eduardo E Schenberg
- Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, Brazil; Instituto Plantando Consciencia, São Paulo, Brazil
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Frecska E, Szabo A, Winkelman MJ, Luna LE, McKenna DJ. A possibly sigma-1 receptor mediated role of dimethyltryptamine in tissue protection, regeneration, and immunity. J Neural Transm (Vienna) 2013; 120:1295-303. [PMID: 23619992 DOI: 10.1007/s00702-013-1024-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/01/2013] [Indexed: 01/20/2023]
Abstract
N,N-dimethyltryptamine (DMT) is classified as a naturally occurring serotonergic hallucinogen of plant origin. It has also been found in animal tissues and regarded as an endogenous trace amine transmitter. The vast majority of research on DMT has targeted its psychotropic/psychedelic properties with less focus on its effects beyond the nervous system. The recent discovery that DMT is an endogenous ligand of the sigma-1 receptor may shed light on yet undiscovered physiological mechanisms of DMT activity and reveal some of its putative biological functions. A three-step active uptake process of DMT from peripheral sources to neurons underscores a presumed physiological significance of this endogenous hallucinogen. In this paper, we overview the literature on the effects of sigma-1 receptor ligands on cellular bioenergetics, the role of serotonin, and serotoninergic analogues in immunoregulation and the data regarding gene expression of the DMT synthesizing enzyme indolethylamine-N-methyltransferase in carcinogenesis. We conclude that the function of DMT may extend central nervous activity and involve a more universal role in cellular protective mechanisms. Suggestions are offered for future directions of indole alkaloid research in the general medical field. We provide converging evidence that while DMT is a substance which produces powerful psychedelic experiences, it is better understood not as a hallucinogenic drug of abuse, but rather an agent of significant adaptive mechanisms that can also serve as a promising tool in the development of future medical therapies.
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Affiliation(s)
- Ede Frecska
- Department of Psychiatry, Medical and Health Science Center, University of Debrecen, Nagyerdei krt. 98, 4012, Debrecen, Hungary.
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Barker SA, Borjigin J, Lomnicka I, Strassman R. LC/MS/MS analysis of the endogenous dimethyltryptamine hallucinogens, their precursors, and major metabolites in rat pineal gland microdialysate. Biomed Chromatogr 2013; 27:1690-700. [PMID: 23881860 DOI: 10.1002/bmc.2981] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/20/2013] [Accepted: 05/23/2013] [Indexed: 01/11/2023]
Abstract
We report a qualitative liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous analysis of the three known N,N-dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid (aCSF) as the matrix and was subsequently applied to the analysis of rat brain pineal gland-aCSF microdialysate. The method describes the simultaneous analysis of 23 chemically diverse compounds plus a deuterated internal standard by direct injection, requiring no dilution or extraction of the samples. The results demonstrate that this is a simple, sensitive, specific and direct approach to the qualitative analysis of these compounds in this matrix. The protocol also employs stringent MS confirmatory criteria for the detection and confirmation of the compounds examined, including exact mass measurements. The excellent limits of detection and broad scope make it a valuable research tool for examining the endogenous hallucinogen pathways in the central nervous system. We report here, for the first time, the presence of N,N-dimethyltryptamine in pineal gland microdialysate obtained from the rat.
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Affiliation(s)
- Steven A Barker
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, 70803, USA
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Tourino MC, de Oliveira EM, Bellé LP, Knebel FH, Albuquerque RC, Dörr FA, Okada SS, Migliorini S, Soares IS, Campa A. Tryptamine and dimethyltryptamine inhibit indoleamine 2,3 dioxygenase and increase the tumor-reactive effect of peripheral blood mononuclear cells. Cell Biochem Funct 2013; 31:361-4. [PMID: 23754498 DOI: 10.1002/cbf.2980] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 04/06/2013] [Accepted: 04/08/2013] [Indexed: 11/07/2022]
Abstract
Indoleamine 2,3-dioxygenase (IDO) is an interferon-γ (IFN-γ)-induced tryptophan-degrading enzyme, producing kynurenine (KYN) that participates in the mechanism of tumor immune tolerance. Thus, IDO inhibition has been considered a strategy for anticancer therapy. The aim of this study was to identify whether the metabolites originated from the competitive routes of tryptophan metabolism, such as the serotonergic or N, N-dimethyltryptamine (DMT) pathways, have inhibitory effects on recombinant human IDO (rhIDO) activity. Serotonin and melatonin had no effect; on the other hand, tryptamine (TRY) and DMT modulated the activity of rhIDO as classical non-competitive inhibitors, with Ki values of 156 and 506 μM, respectively. This inhibitory effect was also observed on constitutively expressed or IFN-γ-induced IDO in the A172 human glioma cell line. TRY and DMT increased the cytotoxic activity of peripheral blood mononuclear cells (PBMCs) in co-culture assays. We conclude that the IDO inhibition by TRY and DMT contributed to a more effective tumor-reactive response by the PBMCs.
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MESH Headings
- Binding, Competitive
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Coculture Techniques
- Cytotoxicity, Immunologic/drug effects
- Enzyme Assays
- Humans
- Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors
- Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism
- Kinetics
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/enzymology
- Leukocytes, Mononuclear/immunology
- N,N-Dimethyltryptamine/pharmacology
- Protein Binding
- Recombinant Proteins/metabolism
- Tryptamines/pharmacology
- Tryptophan/metabolism
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Affiliation(s)
- Melissa Cavalheiro Tourino
- Department of Clinical Chemistry and Toxicology, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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Laux-Biehlmann A, Mouheiche J, Vérièpe J, Goumon Y. Endogenous morphine and its metabolites in mammals: History, synthesis, localization and perspectives. Neuroscience 2013; 233:95-117. [DOI: 10.1016/j.neuroscience.2012.12.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/07/2012] [Indexed: 10/27/2022]
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Mavlyutov TA, Epstein ML, Liu P, Verbny YI, Ziskind-Conhaim L, Ruoho AE. Development of the sigma-1 receptor in C-terminals of motoneurons and colocalization with the N,N'-dimethyltryptamine forming enzyme, indole-N-methyl transferase. Neuroscience 2012; 206:60-8. [PMID: 22265729 PMCID: PMC3321351 DOI: 10.1016/j.neuroscience.2011.12.040] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/22/2011] [Accepted: 12/22/2011] [Indexed: 11/17/2022]
Abstract
The function of the sigma-1 receptor (S1R) has been linked to modulating the activities of ion channels and G-protein-coupled receptors (GPCR). In the CNS, the S1R is expressed ubiquitously but is enriched in mouse motoneurons (MN), where it is localized to subsurface cisternae of cholinergic postsynaptic densities, also known as C-terminals. We found that S1R is enriched in mouse spinal MN at late stages of embryonic development when it is first visualized in the endoplasmic reticulum. S1Rs appear to concentrate at C-terminals of mouse MN only on the second week of postnatal development. We found that indole-N-methyl transferase (INMT), an enzyme that converts tryptamine into the sigma-1 ligand dimethyltryptamine (DMT), is also localized to postsynaptic sites of C-terminals in close proximity to the S1R. This close association of INMT and S1Rs suggest that DMT is synthesized locally to effectively activate S1R in MN.
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Affiliation(s)
- T A Mavlyutov
- Department of Neuroscience, University of Wisconsin, School of Medicine and Public Health, 1300 University Ave, Madison, WI 53706, USA.
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Barker SA, McIlhenny EH, Strassman R. A critical review of reports of endogenous psychedelic N, N-dimethyltryptamines in humans: 1955-2010. Drug Test Anal 2012; 4:617-35. [DOI: 10.1002/dta.422] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/03/2012] [Accepted: 01/03/2012] [Indexed: 11/11/2022]
Affiliation(s)
- Steven A. Barker
- School of Veterinary Medicine; Louisiana State University; Baton Rouge; LA; USA
| | - Ethan H. McIlhenny
- School of Veterinary Medicine; Louisiana State University; Baton Rouge; LA; USA
| | - Rick Strassman
- School of Medicine, University of New Mexico; Albuquerque, and Cottonwood Research Foundation; Taos; New Mexico; USA
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The expression of nicotinamide N-methyltransferase increases ATP synthesis and protects SH-SY5Y neuroblastoma cells against the toxicity of Complex I inhibitors. Biochem J 2011; 436:145-55. [PMID: 21352099 DOI: 10.1042/bj20101685] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
NNMT (nicotinamide N-methyltransferase, E.C. 2.1.1.1) catalyses the N-methylation of nicotinamide to 1-methylnicotinamide. NNMT expression is significantly elevated in a number of cancers, and we have previously demonstrated that NNMT expression is significantly increased in the brains of patients who have died of Parkinson's disease. To investigate the cellular effects of NNMT overexpression, we overexpressed NNMT in the SH-SY5Y cell line, a tumour-derived human dopaminergic neuroblastoma cell line with no endogenous expression of NNMT. NNMT expression significantly decreased SH-SY5Y cell death, which correlated with increased intracellular ATP content, ATP/ADP ratio and Complex I activity, and a reduction in the degradation of the NDUFS3 [NADH dehydrogenase (ubiquinone) iron-sulfur protein 3] subunit of Complex I. These effects were replicated by incubation of SH-SY5Y cells with 1-methylnicotinamide, suggesting that 1-methylnicotinamide mediates the cellular effects of NNMT. Both NNMT expression and 1-methylnicotinamide protected SH-SY5Y cells from the toxicity of the Complex I inhibitors MPP+ (1-methyl-4-phenylpyridinium ion) and rotenone by reversing their effects upon ATP synthesis, the ATP/ADP ratio, Complex I activity and the NDUFS3 subunit. The results of the present study raise the possibility that the increase in NNMT expression that we observed in vivo may be a stress response of the cell to the underlying pathogenic process. Furthermore, the results of the present study also raise the possibility of using inhibitors of NNMT for the treatment of cancer.
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Grobe N, Ren X, Kutchan TM, Zenk MH. An (R)-specific N-methyltransferase involved in human morphine biosynthesis. Arch Biochem Biophys 2010; 506:42-7. [PMID: 21093406 DOI: 10.1016/j.abb.2010.11.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 11/11/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
Abstract
The biosynthesis of morphine, a stereochemically complex alkaloid, has been shown to occur in plants and animals. A search in the human genome for methyltransferases capable of catalyzing the N-methylation of benzylisoquinoline alkaloids, as biosynthetic precursors of morphine, yielded two enzymes, PNMT (EC 2.1.1.28) and NMT (EC 2.1.1.49). Introduction of an N-terminal poly-histidine tag enabled purification of both proteins by immobilized metal affinity chromatography. Recombinant PNMT and NMT were characterized for their catalytic activity towards four benzylisoquinolines: tetrahydropapaveroline (THP), 6-O-methyl-THP, 4'-O-methyl-THP and norreticuline. Human PNMT accepted none of the offered alkaloids and was only active with its established substrate, phenylethanolamine. The second enzyme, human NMT, converted all four benzylisoquinolines, however, with a strict preference for (R)-configured morphine precursors. Determination of kinetic parameters of NMT for the four (R)-configured benzylisoquinoline alkaloids by LC-MS/MS revealed (R)-norreticuline to be the best substrate with an even higher catalytic activity as compared to the previously reported natural substrate tryptamine. In addition, isolation of the morphine precursor salutaridine from urine of mice injected (i.p.) with (R)-THP provides new evidence that the initial steps of morphine biosynthesis in mammals occur stereochemically and sequentially differently than in plants and suggests an involvement of the herein characterized (R)-specific NMT.
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Affiliation(s)
- Nadja Grobe
- Donald Danforth Plant Science Center, 975 North Warson Road, St. Louis, MO 63132, USA.
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Dimethyltryptamine and other hallucinogenic tryptamines exhibit substrate behavior at the serotonin uptake transporter and the vesicle monoamine transporter. J Neural Transm (Vienna) 2009; 116:1591-9. [PMID: 19756361 DOI: 10.1007/s00702-009-0308-8] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Accepted: 08/24/2009] [Indexed: 10/20/2022]
Abstract
N,N-dimethyltryptamine (DMT) is a potent plant hallucinogen that has also been found in human tissues. When ingested, DMT and related N,N-dialkyltryptamines produce an intense hallucinogenic state. Behavioral effects are mediated through various neurochemical mechanisms including activity at sigma-1 and serotonin receptors, modification of monoamine uptake and release, and competition for metabolic enzymes. To further clarify the pharmacology of hallucinogenic tryptamines, we synthesized DMT, N-methyl-N-isopropyltryptamine (MIPT), N,N-dipropyltryptamine (DPT), and N,N-diisopropyltryptamine. We then tested the abilities of these N,N-dialkyltryptamines to inhibit [(3)H]5-HT uptake via the plasma membrane serotonin transporter (SERT) in human platelets and via the vesicle monoamine transporter (VMAT2) in Sf9 cells expressing the rat VMAT2. The tryptamines were also tested as inhibitors of [(3)H]paroxetine binding to the SERT and [(3)H]dihydrotetrabenazine binding to VMAT2. Our results show that DMT, MIPT, DPT, and DIPT inhibit [(3)H]5-HT transport at the SERT with K ( I ) values of 4.00 +/- 0.70, 8.88 +/- 4.7, 0.594 +/- 0.12, and 2.32 +/- 0.46 microM, respectively. At VMAT2, the tryptamines inhibited [(3)H]5-HT transport with K ( I ) values of 93 +/- 6.8, 20 +/- 4.3, 19 +/- 2.3, and 19 +/- 3.1 muM, respectively. On the other hand, the tryptamines were very poor inhibitors of [(3)H]paroxetine binding to SERT and of [(3)H]dihydrotetrabenazine binding to VMAT2, resulting in high binding-to-uptake ratios. High binding-to-uptake ratios support the hypothesis that the tryptamines are transporter substrates, not uptake blockers, at both SERT and VMAT2, and also indicate that there are separate substrate and inhibitor binding sites within these transporters. The transporters may allow the accumulation of tryptamines within neurons to reach relatively high levels for sigma-1 receptor activation and to function as releasable transmitters.
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Kärkkäinen J, Forsström T, Tornaeus J, Wähälä K, Kiuru P, Honkanen A, Stenman UH, Turpeinen U, Hesso A. Potentially hallucinogenic 5‐hydroxytryptamine receptor ligands bufotenine and dimethyltryptamine in blood and tissues. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 65:189-99. [PMID: 16095048 DOI: 10.1080/00365510510013604] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Bufotenine and N,N-dimethyltryptamine (DMT) are hallucinogenic dimethylated indolethylamines (DMIAs) formed from serotonin and tryptamine by the enzyme indolethylamine N-methyltransferase (INMT) ubiquitously present in non-neural tissues. In mammals, endogenous bufotenine and DMT have been identified only in human urine. The DMIAs bind effectively to 5HT receptors and their administration causes a variety of autonomic effects, which may reflect their actual physiological function. Endogenous levels of bufotenine and DMT in blood and a number of animal and human tissues were determined using highly sensitive and specific quantitative mass spectrometric techniques. A new finding was the detection of large amounts of bufotenine in stools, which may be an indication of its role in intestinal function. It is suggested that fecal and urinary bufotenine originate from epithelial cells of the intestine and the kidney, respectively, although the possibility of their synthesis by intestinal bacteria cannot be excluded. Only small amounts of the DMIAs were found in somatic or neural tissues and none in blood. This can be explained by rapid catabolism of the DMIAs by mitochondrial monoamino-oxidase or by the fact that the dimethylated products of serotonin and tryptamine are not formed in significant amounts in most mammalian tissues despite the widespread presence of INMT in tissues.
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Affiliation(s)
- J Kärkkäinen
- Peijas Hospital, Helsinki University Central Hospital, Vantaa, Finland.
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Feng Q, Keshtgarpour M, Pelleymounter LL, Moon I, Kalari KR, Eckloff BW, Wieben ED, Weinshilboum RM. Human S-adenosylhomocysteine hydrolase: common gene sequence variation and functional genomic characterization. J Neurochem 2009; 110:1806-17. [PMID: 19619139 DOI: 10.1111/j.1471-4159.2009.06276.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
S-Adenosylhomocysteine hydrolase (AHCY) is the only mammalian enzyme known to catalyze the hydrolysis of S-adenosylhomocysteine. We have used a genotype-to-phenotype strategy to study this important enzyme by resequencing AHCY in 240 DNA samples from four ethnic groups. Thirty-nine polymorphisms were identified - 28 of which were novel. Functional genomic studies for wild type AHCY and the three variant allozymes identified showed that two variant allozymes had slight, but significant decreases in enzyme activity, but with no significant differences in levels of immunoreactive protein. Luciferase reporter gene assays for common 5'-flanking region haplotypes revealed that one haplotype with a frequency of approximately 2% in Caucasian-American subjects displayed a decreased ability to drive transcription. The variant nucleotide at 5'-flanking region single nucleotide polymorphism (SNP) (-34) in that haplotype altered the DNA-protein binding pattern during electrophoresis mobility shift assay. Finally, an AHCY genotype-phenotype association study for expression in lymphoblastoid cells identified four SNPs that were associated with decreased expression. For the IVS6 (intervening sequence 6, i.e., intron 6) G56 > C SNP among those four, electrophoresis mobility shift assay showed that a C > G nucleotide change resulted in an additional shifted band. These results represent a step toward understanding the functional consequences of common genetic variation in AHCY for the regulation of neurotransmitter, drug and macromolecule methylation.
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Affiliation(s)
- Qiping Feng
- Division of Clinical Pharmacology, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic-Mayo Medical School, Rochester, Minnesota 55905, USA
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Kopantzev EP, Monastyrskaya GS, Vinogradova TV, Zinovyeva MV, Kostina MB, Filyukova OB, Tonevitsky AG, Sukhikh GT, Sverdlov ED. Differences in gene expression levels between early and later stages of human lung development are opposite to those between normal lung tissue and non-small lung cell carcinoma. Lung Cancer 2008; 62:23-34. [DOI: 10.1016/j.lungcan.2008.02.011] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 12/21/2007] [Accepted: 02/14/2008] [Indexed: 12/12/2022]
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Burchett SA, Hicks TP. The mysterious trace amines: protean neuromodulators of synaptic transmission in mammalian brain. Prog Neurobiol 2006; 79:223-46. [PMID: 16962229 DOI: 10.1016/j.pneurobio.2006.07.003] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 07/09/2006] [Accepted: 07/25/2006] [Indexed: 11/19/2022]
Abstract
The trace amines are a structurally related group of amines and their isomers synthesized in mammalian brain and peripheral nervous tissues. They are closely associated metabolically with the dopamine, noradrenaline and serotonin neurotransmitter systems in mammalian brain. Like dopamine, noradrenaline and serotonin the trace amines have been implicated in a vast array of human disorders of affect and cognition. The trace amines are unique as they are present in trace concentrations, exhibit high rates of metabolism and are distributed heterogeneously in mammalian brain. While some are synthesized in their parent amine neurotransmitter systems, there is also evidence to suggest other trace amines may comprise their own independent neurotransmitter systems. A substantial body of evidence suggests that the trace amines may play very significant roles in the coordination of biogenic amine-based synaptic physiology. At high concentrations, they have well-characterized presynaptic "amphetamine-like" effects on catecholamine and indolamine release, reuptake and biosynthesis; at lower concentrations, they possess postsynaptic modulatory effects that potentiate the activity of other neurotransmitters, particularly dopamine and serotonin. The trace amines also possess electrophysiological effects that are in opposition to these neurotransmitters, indicating to some researchers the existence of receptors specific for the trace amines. While binding sites or receptors for a few of the trace amines have been advanced, the absence of cloned receptor protein has impeded significant development of their detailed mechanistic roles in the coordination of catecholamine and indolamine synaptic physiology. The recent discovery and characterization of a family of mammalian G protein-coupled receptors responsive to trace amines such as beta-phenylethylamine, tyramine, and octopamine, including socially ingested psychotropic drugs such as amphetamine, 3,4-methylenedioxymethamphetamine, N,N-dimethyltryptamine, and lysergic acid diethylamide, have revitalized the field of scientific studies investigating trace amine synaptic physiology, and its association with major human disorders of affect and cognition.
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Affiliation(s)
- Scott A Burchett
- University of California at San Francisco, Department of Psychiatry, Langley-Porter Psychiatric Institute, Nina Ireland Laboratory of Developmental Neurobiology, 401 Parnassus Avenue, San Francisco, CA 94143, United States.
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Weinshilboum RM. Pharmacogenomics: catechol O-methyltransferase to thiopurine S-methyltransferase. Cell Mol Neurobiol 2006; 26:539-61. [PMID: 16807786 DOI: 10.1007/s10571-006-9095-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 01/26/2006] [Indexed: 10/24/2022]
Abstract
1. Pharmacogenomics is the study of the role of inheritance in variation in the drug response phenotype-a phenotype that can vary from adverse drug reactions at one end of the spectrum to lack of therapeutic efficacy at the other. 2. The thiopurine S-methyltransferase (TPMT) genetic polymorphism represents one of the best characterized and most clinically relevant examples of pharmacogenomics. This polymorphism has also served as a valuable "model system" for studies of the ways in which variation in DNA sequence might influence function. 3. The discovery and characterization of the TPMT polymorphism grew directly out of pharmacogenomic studies of catechol O-methyltransferase (COMT), an enzyme discovered by Julius (Julie) Axelrod and his coworkers. 4. This review will outline the process by which common, functionally significant genetic polymorphisms for both COMT and TPMT were discovered and will use these two methyltransferase enzymes to illustrate general principles of pharmacogenomic research-both basic mechanistic and clinical translational research-principles that have been applied to a series of genes encoding methyltransferase enzymes.
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Affiliation(s)
- Richard M Weinshilboum
- Division of Clinical Pharmacology, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Abstract
Nicotine is of importance as the addictive chemical in tobacco, pharmacotherapy for smoking cessation, a potential medication for several diseases, and a useful probe drug for phenotyping cytochrome P450 2A6 (CYP2A6). We review current knowledge about the metabolism and disposition kinetics of nicotine, some other naturally occurring tobacco alkaloids, and nicotine analogs that are under development as potential therapeutic agents. The focus is on studies in humans, but animal data are mentioned when relevant to the interpretation of human data. The pathways of nicotine metabolism are described in detail. Absorption, distribution, metabolism, and excretion of nicotine and related compounds are reviewed. Enzymes involved in nicotine metabolism including cytochrome P450 enzymes, aldehyde oxidase, flavin-containing monooxygenase 3, amine N-methyltransferase, and UDP-glucuronosyltransferases are represented, as well as factors affecting metabolism, such as genetic variations in metabolic enzymes, effects of diet, age, gender, pregnancy, liver and kidney diseases, and racial and ethnic differences. Also effects of smoking and various inhibitors and inducers, including oral contraceptives, on nicotine metabolism are discussed. Due to the significance of the CYP2A6 enzyme in nicotine clearance, special emphasis is given to the effects and population distributions of CYP2A6 alleles and the regulation of CYP2A6 enzyme.
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Affiliation(s)
- Janne Hukkanen
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco Genreral Hospital Medical Center, and the Department of Medicine, University of California, San Francisco, Box 1220, San Francisco, CA 94143-1220, USA
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Jacob MS, Presti DE. Endogenous psychoactive tryptamines reconsidered: an anxiolytic role for dimethyltryptamine. Med Hypotheses 2005; 64:930-7. [PMID: 15780487 DOI: 10.1016/j.mehy.2004.11.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2004] [Accepted: 11/04/2004] [Indexed: 12/17/2022]
Abstract
The presence of the potent hallucinogenic psychoactive chemical N,N-dimethyltryptamine (DMT) in the human body has puzzled scientists for decades. Endogenous DMT was investigated in the 1960s and 1970s and it was proposed that DMT was involved in psychosis and schizophrenia. This hypothesis developed from comparisons of the blood and urine of schizophrenic and control subjects. However, much of this research proved inconclusive and conventional thinking has since held that trace levels of DMT, and other endogenous psychoactive tryptamines, are insignificant metabolic byproducts. The recent discovery of a G-protein-coupled, human trace amine receptor has triggered a reappraisal of the role of compounds present in limited concentrations in biological systems. Interestingly enough, DMT and other psychoactive tryptamine hallucinogens elicit a robust response at the trace amine receptor. While it is currently accepted that serotonin 5-HT(2A) receptors play a pivotal role in the activity of hallucinogenic/psychedelic compounds, we propose that the effects induced by exogenous DMT administration, especially at low doses, are due in part to activity at the trace amine receptor. Furthermore, we suggest that endogenous DMT interacts with the TA receptor to produce a calm and relaxed mental state, which may suppress, rather than promote, symptoms of psychosis. This hypothesis may help explain the inconsistency in the early analysis of endogenous DMT in humans. Finally, we propose that amphetamine action at the TA receptor may contribute to the calming effects of amphetamine and related drugs, especially at low doses.
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Affiliation(s)
- Michael S Jacob
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
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Kitano T, Saitou N. Evolutionary Conservation of 5' upstream Sequence of Nine Genes between Human and Great Apes. Genes Genet Syst 2005; 80:225-32. [PMID: 16172534 DOI: 10.1266/ggs.80.225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Nucleotide sequences of nine 5' upstream gene regions for human, chimpanzee, gorilla, and orangutan were determined. We estimated nucleotide differences (d) for each region between human and great apes. The overall d was 0.027 (ranged from 0.004 to 0.052). Rates of nucleotide substitution were estimated by using d and divergence times of human, chimpanzee, gorilla, and orangutan. The overall rate of nucleotide substitution between human and other hominoids was estimated to be 0.52-0.85 x 10(-9). This rate in 5' upstream regions was lower than that of synonymous sites, suggesting that 5' upstream regions have evolved under some functional constraints. Because lower rates have been reported for coding sequences in primates compared to rodents, we also estimated the rate (1.17-1.76 x 10(-9)) of nucleotide substitutions for the corresponding 5' upstream regions in rodents (mouse/rat comparison). Thus the primate rate was lower than rodent rate also for the 5' upstream regions.
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Affiliation(s)
- Takashi Kitano
- Division of Population Genetics, National Institute of Genetics Mishima, Japan
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Gearhart DA, Neafsey EJ, Collins MA. Phenylethanolamine N-methyltransferase has beta-carboline 2N-methyltransferase activity: hypothetical relevance to Parkinson's disease. Neurochem Int 2002; 40:611-20. [PMID: 11900856 DOI: 10.1016/s0197-0186(01)00115-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Mammalian brain has a beta-carboline 2N-methyltransferase activity that converts beta-carbolines, such as norharman and harman, into 2N-methylated beta-carbolinium cations, which are structural and functional analogs of the Parkinsonian-inducing toxin 1-methyl-4-phenylpyridinium cation (MPP+). The identity and physiological function of this beta-carboline 2N-methylation activity was previously unknown. We report pharmacological and biochemical evidence that phenylethanolamine N-methyltransferase (EC 2.1.1.28) has beta-carboline 2N-methyltransferase activity. Specifically, purified phenylethanolamine N-methyltransferase (PNMT) catalyzes the 2N-methylation (21.1 pmol/h per unit PNMT) of 9-methylnorharman, but not the 9N-methylation of 2-methylnorharmanium cation. LY134046, a selective inhibitor of phenylethanolamine N-methyltransferase, inhibits (IC50 1.9 microM) the 2N-methylation of 9-methylnorharman, a substrate for beta-carboline 2N-methyltransferase. Substrates of phenylethanolamine N-methyltransferase also inhibit beta-carboline 2N-methyltransferase activity in a concentration-dependent manner. beta-Carboline 2N-methyltransferase activity (43.7pmol/h/mg protein) is present in human adrenal medulla, a tissue with high phenylethanolamine N-methyltransferase activity. We are investigating the potential role of N-methylated beta-carbolinium cations in the pathogenesis of idiopathic Parkinson's disease. Presuming that phenylethanolamine N-methyltransferase activity forms toxic 2N-methylated beta-carbolinium cations, we propose a novel hypothesis regarding Parkinson's disease-a hypothesis that includes a role for phenylethanolamine N-methyltransferase-catalyzed formation of MPP+ -like 2N-methylated beta-carbolinium cations.
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Affiliation(s)
- Debra A Gearhart
- Department of Cellular Biology and Anatomy, Veterans Affairs Medical Center, Medical College of Georgia, Augusta 30912-2000, USA.
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