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Cerebral Blood Flow in Predator Stress-Resilient and -Susceptible Rats and Mechanisms of Resilience. Int J Mol Sci 2022; 23:ijms232314729. [PMID: 36499055 PMCID: PMC9738343 DOI: 10.3390/ijms232314729] [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: 08/30/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Stress-induced conditions are associated with impaired cerebral blood flow (CBF) and increased risk of dementia and stroke. However, these conditions do not develop in resilient humans and animals. Here the effects of predator stress (PS, cat urine scent, ten days) on CBF and mechanisms of CBF regulation were compared in PS-susceptible (PSs) and PS-resilient (PSr) rats. Fourteen days post-stress, the rats were segregated into PSs and PSr groups based on a behavior-related anxiety index (AI). CBF and its endothelium-dependent changes were measured in the parietal cortex by laser Doppler flowmetry. The major findings are: (1) PS susceptibility was associated with reduced basal CBF and endothelial dysfunction. In PSr rats, the basal CBF was higher, and endothelial dysfunction was attenuated. (2) CBF was inversely correlated with the AI of PS-exposed rats. (3) Endothelial dysfunction was associated with a decrease in eNOS mRNA in PSs rats compared to the PSr and control rats. (4) Brain dopamine was reduced in PSs rats and increased in PSr rats. (5) Plasma corticosterone of PSs was reduced compared to PSr and control rats. (6) A hypercoagulation state was present in PSs rats but not in PSr rats. Thus, potential stress resilience mechanisms that are protective for CBF were identified.
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He D, Ren H, Wang H, Jose PA, Zeng C, Xia T, Yang J. Effect of D4 Dopamine Receptor on Na+-K+-ATPase Activity in Renal Proximal Tubule Cells. CARDIOLOGY DISCOVERY 2022; 3:24-29. [PMID: 36969984 PMCID: PMC10030170 DOI: 10.1097/cd9.0000000000000076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 07/18/2022] [Indexed: 11/05/2022]
Abstract
Dopamine, via its receptors, plays a vital role in the maintenance of blood pressure by modulating renal sodium transport. However, the role of the D4 dopamine receptor (D4 receptor) in renal proximal tubules (PRTs) is still unclear. This study aimed to verify the hypothesis that activation of D4 receptor directly inhibits the activity of the Na+-K+-ATPase (NKA) in RPT cells. Methods NKA activity, nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) levels were measured in RPT cells treated with the D4 receptor agonist PD168077 and/or the D4 receptor antagonist L745870, the NO synthase inhibitor NG-nitro-L-arginine-methyl ester (L-NAME) or the soluble guanylyl cyclase inhibitor 1H-[1,2,4] oxadiazolo-[4,3-a] quinoxalin-1-one (ODQ). Total D4 receptor expression and its expression in the plasma membrane were investigated by immunoblotting in RPT cells from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Results Activation of D4 receptors with PD168077, inhibited NKA activity in RPT cells from WKY rats in a concentration- and time-dependent manner. The inhibitory effect of PD168077 on NKA activity was prevented by the addition of the D4 receptor antagonist L745870, which by itself had no effect. The NO synthase inhibitor L-NAME and the soluble guanylyl cyclase inhibitor ODQ, which by themselves had no effect on NKA activity, eliminated the inhibitory effect of PD168077 on NKA activity. Activation of D4 receptors also increased NO levels in the culture medium and cGMP levels in RPT cells. However, the inhibitory effect of D4 receptors on NKA activity was absent in RPT cells from SHRs, which could be related to decreased plasma membrane expression of D4 receptors in SHR RPT cells. Conclusions Activation of D4 receptors directly inhibits NKA activity via the NO/cGMP signaling pathway in RPT cells from WKY rats but not SHRs. Aberrant regulation of NKA activity in RPT cells may be involved in the pathogenesis of hypertension.
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Stofkova A, Zloh M, Andreanska D, Fiserova I, Kubovciak J, Hejda J, Kutilek P, Murakami M. Depletion of Retinal Dopaminergic Activity in a Mouse Model of Rod Dysfunction Exacerbates Experimental Autoimmune Uveoretinitis: A Role for the Gateway Reflex. Int J Mol Sci 2021; 23:ijms23010453. [PMID: 35008877 PMCID: PMC8745287 DOI: 10.3390/ijms23010453] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/24/2021] [Accepted: 12/29/2021] [Indexed: 12/20/2022] Open
Abstract
The gateway reflex is a mechanism by which neural inputs regulate chemokine expression at endothelial cell barriers, thereby establishing gateways for the invasion of autoreactive T cells into barrier-protected tissues. In this study, we hypothesized that rod photoreceptor dysfunction causes remodeling of retinal neural activity, which influences the blood–retinal barrier and the development of retinal inflammation. We evaluated this hypothesis using Gnat1rd17 mice, a model of night blindness with late-onset rod-cone dystrophy, and experimental autoimmune uveoretinitis (EAU). Retinal remodeling and its effect on EAU development were investigated by transcriptome profiling, target identification, and functional validation. We showed that Gnat1rd17 mice primarily underwent alterations in their retinal dopaminergic system, triggering the development of an exacerbated EAU, which was counteracted by dopamine replacement with L-DOPA administered either systemically or locally. Remarkably, dopamine acted on retinal endothelial cells to inhibit NF-κB and STAT3 activity and the expression of downstream target genes such as chemokines involved in T cell recruitment. These results suggest that rod-mediated dopamine release functions in a gateway reflex manner in the homeostatic control of immune cell entry into the retina, and the loss of retinal dopaminergic activity in conditions associated with rod dysfunction increases the susceptibility to autoimmune uveitis.
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Affiliation(s)
- Andrea Stofkova
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic; (M.Z.); (D.A.); (I.F.)
- Correspondence: ; Tel.: +420-224-902-718
| | - Miloslav Zloh
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic; (M.Z.); (D.A.); (I.F.)
| | - Dominika Andreanska
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic; (M.Z.); (D.A.); (I.F.)
| | - Ivana Fiserova
- Department of Physiology, Third Faculty of Medicine, Charles University, Ke Karlovu 4, 120 00 Prague, Czech Republic; (M.Z.); (D.A.); (I.F.)
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Ruska 87, 100 00 Prague, Czech Republic
| | - Jan Kubovciak
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic;
| | - Jan Hejda
- Department of Health Care and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna Sq. 3105, 272 01 Kladno, Czech Republic; (J.H.); (P.K.)
| | - Patrik Kutilek
- Department of Health Care and Population Protection, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna Sq. 3105, 272 01 Kladno, Czech Republic; (J.H.); (P.K.)
| | - Masaaki Murakami
- Division of Molecular Psychoimmunology, Institute for Genetic Medicine and Graduate School of Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-0815, Japan;
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Liu XS, Zeng J, Yang YX, Qi CL, Xiong T, Wu GZ, Zeng CY, Wang DX. DRD4 Mitigates Myocardial Ischemia/Reperfusion Injury in Association With PI3K/AKT Mediated Glucose Metabolism. Front Pharmacol 2021; 11:619426. [PMID: 33584304 PMCID: PMC7873565 DOI: 10.3389/fphar.2020.619426] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/07/2020] [Indexed: 11/13/2022] Open
Abstract
Ischemia-reperfusion (I/R) could cause heart irreversible damage, which is tightly combined with glucose metabolism disorder. It is demonstrated that GLUT4 (glucose transporter 4) translocation is critical for glucose metabolism in the cardiomyocytes under I/R injury. Moreover, DRD4 (dopamine receptor D4) modulate glucose metabolism, and protect neurocytes from anoxia/reoxygenation (A/R) injury. Thus, DRD4 might regulate myocardial I/R injury in association with GLUT4-mediated glucose metabolism. However, the effects and mechanisms are largely unknown. In the present study, the effect of DRD4 in heart I/R injury were studied ex vivo and in vitro. For I/R injury ex vivo, DRD4 agonist (PD168077) was perfused by Langendorff system in the isolated rat heart. DRD4 activated by PD168077 improved cardiac function in the I/R-injured heart as determined by the left ventricular developed pressure (LVDP), +dp/dt, and left ventricular end diastolic pressure (LVEDP), and reduced heart damage evidenced by infarct size, the release of troponin T (TNT) and lactate dehydrogenase (LDH). DRD4 activation diminished I/R injury induced apoptosis and enhanced cell viability impaired by I/R injury in cardiomyocyte, showed by TUNEL staining, flow cytometer and CCK8 assay. Furthermore, DRD4 activation did not change total GULT4 protein expression level but increased the membrane GULT4 localization determined by western blot. In terms of mechanism, DRD4 activation increased pPI3K/p-AKT but not the total PI3K/AKT during anoxia/reoxygenation (A/R) injury in vitro. Interestingly, PI3K inhibitor, Wortmannin, blocked PI3K/AKT pathway and depleted the membrane GULT4, and further promoted apoptosis showed by TUNEL staining, flow cytometer, western blot of cleaved caspase 3, BAX and BCL2 expression. Thus, DRD4 activation exerted a protective effect against I/R injury by promoting GLUT4 translocation depended on PI3K/AKT pathway, which enhanced the ability of glucose uptake, and ultimately reduced the apoptosis in cardiomyocytes.
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Affiliation(s)
- Xue-Song Liu
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Jing Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Yu-Xue Yang
- Clinical Medical College, Yangzhou University, Yangzhou, China
| | - Chun-Lei Qi
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Ting Xiong
- Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Geng-Ze Wu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Chun-Yu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Da-Xin Wang
- The Hospital Affiliated to Medical School of Yangzhou University (Taizhou people's Hospital), Taizhou, China
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Giorgioni G, Del Bello F, Pavletić P, Quaglia W, Botticelli L, Cifani C, Micioni Di Bonaventura E, Micioni Di Bonaventura MV, Piergentili A. Recent findings leading to the discovery of selective dopamine D 4 receptor ligands for the treatment of widespread diseases. Eur J Med Chem 2020; 212:113141. [PMID: 33422983 DOI: 10.1016/j.ejmech.2020.113141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/14/2022]
Abstract
Since its discovery, the dopamine D4 receptor (D4R) has been suggested to be an attractive target for the treatment of neuropsychiatric diseases. Novel findings have renewed the interest in such a receptor as an emerging target for the management of different diseases, including cancer, Parkinson's disease, alcohol or substance use disorders, eating disorders, erectile dysfunction and cognitive deficits. The recently resolved crystal structures of D4R in complexes with the potent ligands nemonapride and L-745870 strongly improved the knowledge on the molecular mechanisms involving the D4R functions and may help medicinal chemists in drug design. This review is focused on the recent development of the subtype selective D4R ligands belonging to classical or new chemotypes. Moreover, ligands showing functional selectivity toward G protein activation or β-arrestin recruitment and the effects of selective D4R ligands on the above-mentioned diseases are discussed.
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Affiliation(s)
- Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy.
| | - Pegi Pavletić
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
| | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy.
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna Delle Carceri 9, 62032, Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna Delle Carceri 9, 62032, Camerino, Italy
| | | | | | - Alessandro Piergentili
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
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Increasing the expression of microRNA-126-5p in the temporal muscle can promote angiogenesis in the chronically ischemic brains of rats subjected to two-vessel occlusion plus encephalo-myo-synangiosis. Aging (Albany NY) 2020; 12:13234-13254. [PMID: 32644942 PMCID: PMC7377842 DOI: 10.18632/aging.103431] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 04/27/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND miR-126-5p plays an important role in promoting endothelial cell (EC) proliferation. We thus explored whether miR-126-5p can promote EC proliferation and angiogenesis in chronically ischemic brains (CIBs). RESULTS Improved revascularization in moyamoya patients was correlated with upregulated miR-126-5p expression in the TM and DM. In vitro experiments showed that miR-126-5p promoted EC proliferation through the PI3K/Akt pathway. CIBs from the agomir group exhibited significantly higher p-Akt, VEGF, CD31 and eNOS expression compared with the control CIBs. The ICBP and the RCF were significantly better in the agomir compared with the control group. CONCLUSION Increasing miR-126-5p expression in the TM can promote EC proliferation and angiogenesis in CIBs of 2VO+EMS rats through the PI3K/Akt pathway. METHODS We assessed the correlation between revascularization and miR-126-5p expression in the temporal muscle (TM) and dura mater (DM) of moyamoya patients. The effect of miR-126-5p on EC proliferation and downstream signaling pathways was explored in vitro. We established an animal model of two-vessel occlusion plus encephalo-myo-synangiosis (2VO+EMS), transfected the TM with miR-126-5p agomir/antagomir, compared the expression of miR-126-5p and relevant downstream cytokines in brain tissue among different groups, and investigated the improvement in cerebral blood perfusion (ICBP) and the recovery of cognitive function (RCF).
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The role of spinally located dopamine D 2 receptors in the regulation of the blood glucose level in mice. Pharmacol Rep 2020; 72:1666-1675. [PMID: 32627115 DOI: 10.1007/s43440-020-00126-x] [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: 02/05/2020] [Revised: 06/22/2020] [Accepted: 07/01/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The possible role of dopamine D2 receptors located in the spinal cord in the regulation of the blood glucose level have not been investigated before. METHODS In the present study, the effect of D2 receptor agonist and antagonist administered intrathecal (it) injection on the blood glucose level were examined in the Institute of Cancer Research (ICR) mice. RESULTS We found that it injection with carmoxirole (D2 receptor agonist) caused an elevation of the blood glucose level in a dose-dependent manner. Carmoxirole-induced increase of the blood glucose was significantly attenuated by L-741,626 (D2 receptor antagonist). Previously, we indicated that intrathecal (it) treatment with 0.1 μg/5 μl pertussis toxin (PTX, a Gi/Go inhibitor) produces a hypoglycemic effect in ICR in a long-term manner. In the present study, it pretreatment with PTX for 6 days almost abolished the hyperglycemic effect induced by carmoxirole. The plasma insulin level was elevated by carmoxirole, and L-741,626 or PTX pretreatment reduced carmoxirole-induced increment of the insulin level. In addition, the plasma corticosterone level was increased by carmoxirole but it pretreatment with L-741,626 or PTX did not affect carmoxirole-induced increment of the corticosterone level. CONCLUSION Our results suggest that D2 receptors located in the spinal cord play an important role in the elevation of the blood glucose level. Spinally located inhibitory G-proteins appear to be involved in hyperglycemic effect induced by carmoxirole.
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