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Shin H, Sharma R, Neupane C, Pham TL, Park SE, Lee SY, Kim HW, Bae YM, Stern JE, Park JB. Tonic NMDAR Currents of NR2A-Containing NMDARs Represent Altered Ambient Glutamate Concentration in the Supraoptic Nucleus. eNeuro 2024; 11:ENEURO.0279-23.2023. [PMID: 38176904 PMCID: PMC10863629 DOI: 10.1523/eneuro.0279-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/03/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
NMDA receptors (NMDARs) modulate glutamatergic excitatory tone in the brain via two complementary modalities: a phasic excitatory postsynaptic current and a tonic extrasynaptic modality. Here, we demonstrated that the tonic NMDAR-current (I NMDA) mediated by NR2A-containing NMDARs is an efficient biosensor detecting the altered ambient glutamate level in the supraoptic nucleus (SON). I NMDA of magnocellular neurosecretory cells (MNCs) measured by nonselective NMDARs antagonist, AP5, at holding potential (V holding) -70 mV in low concentration of ECF Mg2+ ([Mg2+]o) was transiently but significantly increased 1-week post induction of a DOCA salt hypertensive model rat which was compatible with that induced by a NR2A-selective antagonist, PEAQX (I PEAQX) in both DOCA-H2O and DOCA-salt groups. In agreement, NR2B antagonist, ifenprodil, or NR2C/D antagonist, PPDA, did not affect the holding current (I holding) at V holding -70 mV. Increased ambient glutamate by exogenous glutamate (10 mM) or excitatory amino acid transporters (EAATs) antagonist (TBOA, 50 mM) abolished the I PEAQX difference between two groups, suggesting that attenuated EAATs activity increased ambient glutamate concentration, leading to the larger I PEAQX in DOCA-salt rats. In contrast, only ifenprodil but not PEAQX and PPDA uncovered I NMDA at V holding +40 mV under 1.2 mM [Mg2+]o condition. I ifenprodil was not different in DOCA-H2O and DOCA-salt groups. Finally, NR2A, NR2B, and NR2D protein expression were not different in the SON of the two groups. Taken together, NR2A-containing NMDARs efficiently detected the increased ambient glutamate concentration in the SON of DOCA-salt hypertensive rats due to attenuated EAATs activity.
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Affiliation(s)
- Hyunjin Shin
- Department of Physiology & Medical Science, College of Medicine & Brain Research Institute, Chungnam National University, Daejeon 35015, South Korea
| | - Ramesh Sharma
- Department of Physiology & Medical Science, College of Medicine & Brain Research Institute, Chungnam National University, Daejeon 35015, South Korea
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Chiranjivi Neupane
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Thuy Linh Pham
- Department of Physiology & Medical Science, College of Medicine & Brain Research Institute, Chungnam National University, Daejeon 35015, South Korea
| | - Su Eun Park
- Department of Physiology & Medical Science, College of Medicine & Brain Research Institute, Chungnam National University, Daejeon 35015, South Korea
| | - So Yeong Lee
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyun-Woo Kim
- Department of Physiology & Medical Science, College of Medicine & Brain Research Institute, Chungnam National University, Daejeon 35015, South Korea
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju 27478, Republic of Korea
| | - Javier E Stern
- Neuroscience Institute and Center for Neuroinflammation and Cardiometabolic Diseases, Georgia State University, Atlanta, Georgia 30302
| | - Jin Bong Park
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea
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He J, Fang J, Wang Y, Ge C, Liu S, Jiang Y. Discovery of Small-Molecule Antagonists of Orexin 1/2 Receptors from Traditional Chinese Medicinal Plants with a Hypnotic Effect. Pharmaceuticals (Basel) 2023; 16:ph16040542. [PMID: 37111298 PMCID: PMC10146837 DOI: 10.3390/ph16040542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/25/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Insomnia is an important public health problem. The currently available treatments for insomnia can cause some adverse effects. Orexin receptors 1 (OX1R) and 2 (OX2R) are burgeoning targets for insomnia treatment. It is an effective approach to screening OX1R and OX2R antagonists from traditional Chinese medicine, which contains abundant and diverse chemical components. This study established an in-home ligand library of small-molecule compounds from medicinal plants with a definite hypnotic effect, as described in the Chinese Pharmacopoeia. Molecular docking was applied to virtually screen potential orexin receptor antagonists using molecular operating environment software, and surface plasmon resonance (SPR) technology was used to detect the binding affinity between potential active compounds and orexin receptors. Finally, the results of virtual screening and SPR analysis were verified through in vitro assays. We successfully screened one potential lead compound (neferine) as an orexin receptor antagonist from the in-home ligand library, which contained more than 1000 compounds. The screened compound was validated as a potential agent for insomnia treatment through comprehensive biological assays. This research enabled the discovery of a potential small-molecule antagonist of orexin receptors for the treatment of insomnia, providing a novel screening approach for the detection of potential candidate compounds for corresponding targets.
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Affiliation(s)
- Jia He
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Jing Fang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yuxin Wang
- College of Pharmacy, Dali University, Dali 671000, China
| | - Chengyu Ge
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Shao Liu
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Yueping Jiang
- Department of Pharmacy, Xiangya Hospital, Central South University, Changsha 410008, China
- Institute for Rational and Safe Medication Practices, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, China
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Kinin B1 Receptor Mediates Bidirectional Interaction between Neuroinflammation and Oxidative Stress. Antioxidants (Basel) 2023; 12:antiox12010150. [PMID: 36671012 PMCID: PMC9854481 DOI: 10.3390/antiox12010150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/10/2023] Open
Abstract
Hypertension is associated with increased expression of kinin B1 receptors (B1R) and increased levels of pro-inflammatory cytokines within the neurons. We previously reported that angiotensin II (Ang II) upregulates B1R expression and can induce neuroinflammation and oxidative stress in primary hypothalamic neurons. However, the order in which B1R activation, neuroinflammation, and oxidative stress occur has not yet been studied. Using primary hypothalamic neurons from neonatal mice, we show that tumor necrosis factor (TNF), lipopolysaccharides (LPS), and hydrogen peroxide (H2O2) can upregulate B1R expression and increase oxidative stress. Furthermore, our study shows that B1R blockade with R715, a specific B1R antagonist, can attenuate these effects. To further confirm our findings, we used a deoxycorticosterone acetate (DOCA)-salt model of hypertension to show that oxidative stress is upregulated in the hypothalamic paraventricular nucleus (PVN) of the brain. Together, these data provide novel evidence that relationship between oxidative stress, neuroinflammation, and B1R upregulation in the brain is bidirectional, and that B1R antagonism may have beneficial effects on neuroinflammation and oxidative stress in various disease pathologies.
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Kinin B1 receptor deficiency protects mice fed by cafeteria diet from abnormal glucose homeostasis. PLoS One 2022; 17:e0267845. [PMID: 35617279 PMCID: PMC9135186 DOI: 10.1371/journal.pone.0267845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/14/2022] [Indexed: 11/24/2022] Open
Abstract
The kallikrein–kinin system has been implicated in body weight and glucose homeostasis. Their major effectors act by binding to the kinin B2 and B1 receptors. It was assessed the role of the kinin B1 receptor in weight and glucose homeostasis in B1 receptor knockout mice (B1RKO) subjected to a cafeteria diet (CAF). Wild-type (WT) and B1RKO male mice (C57BL/6 background; 8 weeks old) were fed a standard diet (SD) or CAF for 14 weeks, ad libitum, and four groups were formed: WT-SD; B1RKO-SD; WT-CAF; B1RKO-CAF. Body weight and food intake were assessed weekly. It was performed glucose tolerance (GTT) and insulin tolerance tests (ITT), and HOMA-IR, HOMA-β and HOMA-β* 1/HOMA-IR were calculated. Islets from WT and B1RKO were isolated in order to measure the insulin secretion. Western blot was used to assess the hepatic AKT phosphorylation and qPCR to assess gene expression. CAF induced a higher body mass gain in B1RKO compared to WT mice. CAF diet increased epididymal fat depot mass, hepatic fat infiltration and hepatic AKT phosphorylation in both genotypes. However, B1RKO mice presented lower glycemic response during GTT when fed with CAF, and a lower glucose decrease in the ITT. This higher resistance was overcomed with higher insulin secretion when stimulated by high glucose, resulting in higher glucose uptake in the GTT when submitted to CAF, despite lower insulin sensitivity. Islets from B1RKO delivered 4 times more insulin in 3-month-old mice than islets from WT. The higher insulin disposition index and high insulin delivery of B1RKO can explain the decreased glucose excursion during GTT. In conclusion, CAF increased the β-cell function in B1RKO mice, compensated by the diet-induced insulin resistance and resulting in a healthier glycemic response despite the higher weight gain.
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White A, Parekh RU, Theobald D, Pakala P, Myers AL, Van Dross R, Sriramula S. Kinin B1R Activation Induces Endoplasmic Reticulum Stress in Primary Hypothalamic Neurons. Front Pharmacol 2022; 13:841068. [PMID: 35350763 PMCID: PMC8957924 DOI: 10.3389/fphar.2022.841068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/07/2022] [Indexed: 11/30/2022] Open
Abstract
The endoplasmic reticulum (ER) is a key organelle involved in homeostatic functions including protein synthesis and transport, and the storage of free calcium. ER stress potentiates neuroinflammation and neurodegeneration and is a key contributor to the pathogenesis of neurogenic hypertension. Recently, we showed that kinin B1 receptor (B1R) activation plays a vital role in modulating neuroinflammation and hypertension. However, whether B1R activation results in the progression and enhancement of ER stress has not yet been studied. In this brief research report, we tested the hypothesis that B1R activation in neurons contributes to unfolded protein response (UPR) and the development of ER stress. To test this hypothesis, we treated primary hypothalamic neuronal cultures with B1R specific agonist Lys-Des-Arg9-Bradykinin (LDABK) and measured the components of UPR and ER stress. Our data show that B1R stimulation via LDABK, induced the upregulation of GRP78, a molecular chaperone of ER stress. B1R stimulation was associated with an increased expression and activation of transmembrane ER stress sensors, ATF6, IRE1α, and PERK, the critical components of UPR. In the presence of overwhelming ER stress, activated ER stress sensors can lead to oxidative stress, autophagy, or apoptosis. To determine whether B1R activation induces apoptosis we measured intracellular Ca2+ and extracellular ATP levels, caspases 3/7 activity, and cell viability. Our data show that LDABK treatment does increase Ca2+ and ATP levels but does not alter caspase activity or cell viability. These findings suggest that B1R activation initiates the UPR and is a key factor in the ER stress pathway.
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Affiliation(s)
- Acacia White
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Rohan Umesh Parekh
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Drew Theobald
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Pranaya Pakala
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Ariel Lynn Myers
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Rukiyah Van Dross
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
| | - Srinivas Sriramula
- Department of Pharmacology and Toxicology, Brody School of Medicine at East Carolina University, Greenville, NC, United States
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