1
|
Kong W, Sun X, Yu S, Liu P, Zheng X, Zhang J, Zhu L, Jiang T, Jin M, Gao J, Fan X, Liu X, Liu L. Bile duct ligation increased dopamine levels in the cerebral cortex of rats partly due to induction of tyrosine hydroxylase. Br J Pharmacol 2023. [PMID: 36692417 DOI: 10.1111/bph.16041] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 01/10/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND AND PURPOSE Liver failure is associated with psychiatric alterations, partly resulting from the increased brain dopamine levels. We investigated the relationship between increased dopamine levels and mental abnormalities using bile duct ligation (BDL) rats and the mechanism by which liver failure increased dopamine levels in SH-SY5Y cells. Behavioural tests were carried out on day 13 and 27 following BDL, along with measurements of dopamine and metabolites, expressions of enzymes and transporters related to dopamine metabolism, and its transport into the cortex and the hippocampus. SH-SY5Y cells were used to investigate whether NH4 Cl, bile acids and bilirubin affected expression of tyrosine hydroxylase or not. Tyrosine hydroxylase (TH) expression in SH-SY5Y cells co-incubated with bilirubin and signal pathway inhibitors was measured. KEY RESULTS Open-field test results demonstrated BDL rats showed anxiety-like behaviour, accompanied by increased dopamine levels and expression of TH protein in the cortex. Membrane bound long form (MB)-COMT, slightly but significantly decreased. SH-SY5Y cells indicated that increased bilirubin levels was a factor in inducing TH expression. Both inhibitor of NF-κB pathway BAY 11-7082 and silencing NF-κB p65 reversed bilirubin-induced upregulation of TH protein. NF-κB activator TNF-α increased expression of TH protein. Roles of bilirubin in increases of TH protein expressions and dopamine levels were measured using hyperbilirubinemia rats. Anxiety-like behaviour, was associated with increased dopamine levels and TH protein expressions in hyperbilirubinemia rats. CONCLUSION AND IMPLICATIONS BDL significantly increased dopamine levels in rat cortex partly due to bilirubin-mediated TH induction. Increased bilirubin induced TH expression via activating NF-κB signalling pathway.
Collapse
Affiliation(s)
- Weimin Kong
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China.,School of Pharmacy, Bengbu Medical College, 2600 Donghai Road, Bengbu, Anhui, China
| | - Xueying Sun
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Siyu Yu
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Peihua Liu
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaoke Zheng
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jiaxin Zhang
- Hunan Provincial People's Hospital (The first-affiliated hospital of Hunan Normal University), Changsha, China
| | - Liang Zhu
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Tianxin Jiang
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Mengmeng Jin
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jinghui Gao
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaomin Fan
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaodong Liu
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Li Liu
- Center of Drug Metabolism and Pharmacokinetics, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| |
Collapse
|
2
|
MR T1 mapping for quantifying brain manganese deposition in type C hepatic encephalopathy rats. Biometals 2021; 34:841-854. [PMID: 33928475 DOI: 10.1007/s10534-021-00311-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
To evaluate magnetic resonance (MR) T1 mapping for quantifying brain manganese (Mn) deposition in type C hepatic encephalopathy (CHE) rats and to investigate the mechanism of magnesium sulfate (MgSO4) therapy. Thirty Sprague-Dawley rats were randomly assigned into normal control group (NC, n = 6) and CHE groups (n = 24). Thioacetamide (TAA) was used for modeling CHE rats. CHE groups were further divided into 4 subgroups: TAA group, MgSO4 low dose (Mg-L) group, MgSO4 high dose (Mg-H) group and deionized water (DW) group (n = 6 for each group). TAA, Mg-L, Mg-H and DW groups were received intraperitoneal injections of 250 mg TAA/kg, twice a week for 8 weeks. Mg-L and Mg-H groups were orally received MgSO4 of 124 and 248 mg/kg daily, respectively, for another 8 weeks (without TAA). MR T1 mapping was performed in NC, TAA, Mg-L, Mg-H and DW groups at various time points. T1 value and Mn content in basal ganglia, hippocampus, cerebral cortex and cerebellum were evaluated. Morris water maze (MWM) and narrow beat test (NBT) were utilized to evaluate rats' learning, memory and motor ability. Contents of interleukin-6 (IL-6), tumor necrosis factor-a (TNF-a) and calcium-binding adaptor 1 protein (Iba1) were evaluated. Reduced T1 values in basal ganglia, hippocampus and cerebral cortex (P < 0.01, P < 0.05 and P < 0.05, respectively); increased Mn content in basal ganglia, hippocampus and cerebral cortex (all P < 0.05); reduced times of head contacting with region of interest (ROI), reduced times of entrance into the target quadrant (both P < 0.05); increased NBT total time (P < 0.05); increased brain contents of IL-6 (P < 0.001), TNF-α (P < 0.01) and over-expression of Iba1 were found in TAA group compared to NC group. After treated by MgSO4, increased T1 value and reduced Mn content in basal ganglia, hippocampus and cerebral cortex (all P < 0.01); increased times of head contacting with ROI, increased times of entrance into the target quadrant (both P < 0.05); reduced NBT total time (P < 0.01); reduced brain content of IL-6, TNF-α (both P < 0.05) and reduced expression of Iba1 were found. T1 values were negatively correlated with Mn contents in basal ganglia (r = - 0.834, P < 0.01), hippocampus (r = - 0.739, P < 0.05), cortex (r = - 0.801, P < 0.05) and cerebellum (r = - 0.788, P < 0.05). T1 mapping could quantify brain Mn deposition in CHE rats. MgSO4 could improve cognition and motor ability of CHE rats by reducing brain Mn deposition, alleviating neurological inflammation and achieve the effective therapy for CHE. Mn may participate in the pathogenesis of CHE through neuroinflammation.
Collapse
|
3
|
Zhuge W, Zhuge Q, Wang W, Lu X, You R, Liu L, Yu H, Wang J, Wang X, Ye Y, Ding S. Hydrogen sulphide ameliorates dopamine-induced astrocytic inflammation and neurodegeneration in minimal hepatic encephalopathy. J Cell Mol Med 2020; 24:13634-13647. [PMID: 33118312 PMCID: PMC7753993 DOI: 10.1111/jcmm.15728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/18/2020] [Accepted: 06/20/2020] [Indexed: 12/19/2022] Open
Abstract
It has been demonstrated that the action of dopamine (DA) could enhance the production of tumour necrosis factor‐α (TNF‐α) by astrocytes and potentiate neuronal apoptosis in minimal hepatic encephalopathy (MHE). Recently, sodium hydrosulfide (NaHS) has been found to have neuroprotective properties. Our study addressed whether NaHS could rescue DA‐challenged inflammation and apoptosis in neurons to ameliorate memory impairment in MHE rats and in the neuron and astrocyte coculture system. We found that NaHS suppressed DA‐induced p65 acetylation, resulting in reduced TNF‐α production in astrocytes both in vitro and in vivo. Furthermore, decreased apoptosis was observed in neurons exposed to conditioned medium from DA + NaHS‐challenged astrocytes, which was similar to the results obtained in the neurons exposed to TNF‐α + NaHS, suggesting a therapeutic effect of NaHS on the suppression of neuronal apoptosis via the reduction of TNF‐α level. DA triggered the inactivation of p70 S6 ribosomal kinase (S6K1) and dephosphorylation of Bad, resulting in the disaggregation of Bclxl and Bak and the release of cytochrome c (Cyt. c), and this process could be reversed by NaHS administration. Our work demonstrated that NaHS attenuated DA‐induced astrocytic TNF‐α release and ameliorated inflammation‐induced neuronal apoptosis in MHE. Further research into this approach may uncover future potential therapeutic strategies for MHE.
Collapse
Affiliation(s)
- Weishan Zhuge
- Gastrointestinal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qichuan Zhuge
- Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Weikan Wang
- Department of Microbiology, Immunology, and Genetics, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Xiaoai Lu
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ruimin You
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Leping Liu
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - He Yu
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jian Wang
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xuebao Wang
- Analytical and Testing Center, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yiru Ye
- School of Information and Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Saidan Ding
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| |
Collapse
|
4
|
Tarasov VV, Svistunov AA, Chubarev VN, Sologova SS, Mukhortova P, Levushkin D, Somasundaram SG, Kirkland CE, Bachurin SO, Aliev G. Alterations of Astrocytes in the Context of Schizophrenic Dementia. Front Pharmacol 2020; 10:1612. [PMID: 32116664 PMCID: PMC7020441 DOI: 10.3389/fphar.2019.01612] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/10/2019] [Indexed: 12/19/2022] Open
Abstract
The levels of the astrocyte markers (GFAP, S100B) were increased unevenly in patients with schizophrenia. Reactive astrogliosis was found in approximately 70% of patients with schizophrenia. The astrocytes play a major role in etiology and pathogenesis of schizophrenia. Astrocytes produce the components that altered in schizophrenia extracellular matrix system which are involved in inflammation, functioning of interneurons, glio-, and neurotransmitter system, especially glutamate system. Astrocytes activate the interneurons through glutamate release and ATP. Decreased expression of astrocyte glutamate transporters was observed in patients with schizophrenia. Astrocytes influence on N-methyl-d-aspartate (NMDA) receptors via D-serine, an agonist of the glycine-binding site of NMDA receptors, and kynurenic acid, an endogenous antagonist. NMDA receptors, on its turn, control the impulses of dopamine neurons. Therefore following theories of schizophrenia are proposed. They are a) activation of astrocytes for neuroinflammation, b) glutamate and dopamine theory, as astrocyte products control the activity of NMDA receptors, which influence on the dopamine neurons.
Collapse
Affiliation(s)
- Vadim V Tarasov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Andrey A Svistunov
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Vladimir N Chubarev
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Susanna S Sologova
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Polina Mukhortova
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Dmitrii Levushkin
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Siva G Somasundaram
- Department of Biological Sciences, Salem University, Salem, WV, United States
| | - Cecil E Kirkland
- Department of Biological Sciences, Salem University, Salem, WV, United States
| | - Sergey O Bachurin
- Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia
| | - Gjumrakch Aliev
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia.,Institute of Physiologically Active Compounds Russian Academy of Sciences, Chernogolovka, Russia.,Federal State Budgetary Institution, Research Institute of Human Morphology, Russian Federation, Moscow, Russia.,GALLY International Research Institute, San Antonio, TX, United States
| |
Collapse
|
5
|
Dopamine Burden Triggers Cholesterol Overload Following Disruption of Synaptogenesis in Minimal Hepatic Encephalopathy. Neuroscience 2019; 410:1-15. [PMID: 31078686 DOI: 10.1016/j.neuroscience.2019.04.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 04/27/2019] [Accepted: 04/30/2019] [Indexed: 01/05/2023]
Abstract
The contribution of Dopamine (DA) to minimal hepatic encephalopathy (MHE) has been demonstrated. However, recent studies have revealed that cholesterol (CHO) treatment substantially increased the risk of dementia. The objectives of this study were to investigate whether CHO was induced by DA overload and its involvement in DA-induced cognitive impairment in MHE. Our study showed that DA treatment triggered CHO biosynthesis via the activation of JNK3/SREBP2 signaling pathway in primary cultured astrocytes. Conditioned media from DA-treated astrocytes increased CHO uptake by primary cultured neurons and disrupted synaptic formations; at the same time, inhibition of CHO synthesis and transportation from astrocytes diminished the disruption of synaptogenesis, which indicates the involvement of CHO in the perturbation of neural synaptogenesis in vitro. Secondary secretion of DA from primary cultured neurons was stimulated by CHO secreted from astrocytes. DA induced synergistic decreases of PPARγ/pERK/pCREB expressions in the presence of CHO in neurons, leading to synergistic synaptic impairment. Memory impairments were observed in MHE/DA-treated rats, which were partially rescued by atorvastatin (ATVS) treatment, confirming the involvement of CHO burden in vivo. Overall, our study suggests that DA overload triggers obvious CHO production from astrocytes. Excessive CHO in turn triggered neurons to secrete abundant DA and DA burden in combination with CHO overload elicit the cognitive decline and memory loss via PPARγ/ERK/CREB pathway in MHE.
Collapse
|
6
|
Ding S, Zhuge W, Hu J, Yang J, Wang X, Wen F, Wang C, Zhuge Q. Baicalin reverses the impairment of synaptogenesis induced by dopamine burden via the stimulation of GABA AR-TrkB interaction in minimal hepatic encephalopathy. Psychopharmacology (Berl) 2018; 235:1163-1178. [PMID: 29404643 PMCID: PMC5869945 DOI: 10.1007/s00213-018-4833-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 01/08/2018] [Indexed: 01/21/2023]
Abstract
BACKGROUND It has been reported that D1 receptor (D1R) activation reduces GABAA receptor (GABAAR) current, and baicalin (BAI) displays therapeutic efficacy in diseases involving cognitive impairment. METHODS We investigated the mechanisms by which BAI could improve DA-induced minimal hepatic encephalopathy (MHE) using immunoblotting, immunofluorescence, and co-immunoprecipitation. RESULTS BAI did not induce toxicity on the primary cultured neurons. And no obvious toxicity of BAI to the brain was found in rats. DA activated D1R/dopamine and adenosine 3'5'-monophosphate-regulated phospho-protein (DARPP32) to reduce the GABAAR current; BAI treatment did not change the D1R/DARPP32 levels but blocked DA-induced reduction of GABAAR levels in primary cultured neurons. DA decreased the interaction of GABAAR with TrkB and the expression of downstream AKT, which was blocked by BAI treatment. Moreover, BAI reversed the decrease in the expression of GABAAR/TrkB/AKT and prevented the impairment of synaptogenesis and memory deficits in MHE rats. CONCLUSIONS These results suggest that BAI has neuroprotective and synaptoprotective effects on MHE which are not related to upstream D1R/DARPP32 signaling, but to the targeting of downstream GABAAR signaling to TrkB.
Collapse
Affiliation(s)
- Saidan Ding
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Weishan Zhuge
- Gastrointestinal Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Jiangnan Hu
- Institute for Healthy Aging, University of North Texas Health Science Center, Fort Worth, TX 76107 USA
| | - Jianjing Yang
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Xuebao Wang
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Fangfang Wen
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Chengde Wang
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000 People’s Republic of China
| | - Qichuan Zhuge
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Neurosurgery Department, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China.
| |
Collapse
|
7
|
Ding S, Zhuge W, Wang X, Yang J, Lin Y, Wang C, Hu J, Zhuge Q. DA Negatively Regulates IGF-I Actions Implicated in Cognitive Function via Interaction of PSD95 and nNOS in Minimal Hepatic Encephalopathy. Front Cell Neurosci 2017; 11:258. [PMID: 28932186 PMCID: PMC5592740 DOI: 10.3389/fncel.2017.00258] [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: 04/06/2017] [Accepted: 08/09/2017] [Indexed: 11/13/2022] Open
Abstract
Insulin-like growth factor I (IGF-I) has been positively correlated with cognitive ability. Cognitive decline in minimal hepatic encephalopathy (MHE) was shown to be induced by elevated intracranial dopamine (DA). The beneficial effect of IGF-I signaling in MHE remains unknown. In this study, we found that IGF-I content was reduced in MHE rats and that IGF-I administration mitigated cognitive decline of MHE rats. A protective effect of IGF-I on the DA-induced interaction between postsynaptic density protein 95 (PSD95) and neuronal nitric oxide synthase (nNOS) was found in neurons. Ribosomal S6 protein kinase (RSK) phosphorylated nNOS in response to IGF-I by recruiting extracellular signal-regulated kinase (ERK1/2). In turn, DA inactivated the ERK1/2/RSK pathway and stimulated the PSD95–nNOS interaction by downregulating IGF-I. Inhibition of the interaction between PSD95 and nNOS ameliorated DA-induced memory impairment. As DA induced deficits in the ERK1/2/RSK pathway and the interaction between PSD95 and nNOS in MHE brains, IGF-I administration exerted a protective effect via interruption of the interaction between PSD95 and nNOS. These results suggest that IGF-I antagonizes DA-induced cognitive loss by disrupting PSD95–nNOS interactions in MHE.
Collapse
Affiliation(s)
- Saidan Ding
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Department of Surgery Laboratory, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Weishan Zhuge
- Gastrointestinal Surgery, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Xuebao Wang
- Analytical and Testing Center, Wenzhou Medical UniversityWenzhou, China
| | - Jianjing Yang
- Neurosurgery Department, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Yuanshao Lin
- Neurology Department, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Chengde Wang
- Neurosurgery Department, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Jiangnan Hu
- Neurosurgery Department, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| | - Qichuan Zhuge
- Neurosurgery Department, First Affiliated Hospital of Wenzhou Medical UniversityWenzhou, China
| |
Collapse
|
8
|
Abstract
Hepatic encephalopathy describes the array of neurological alterations that occur during acute liver failure or chronic liver injury. While key players in the pathogenesis of hepatic encephalopathy, such as increases in brain ammonia, alterations in neurosteroid levels, and neuroinflammation, have been identified, there is still a paucity in our knowledge of the precise pathogenic mechanism. This review gives a brief overview of our understanding of the pathogenesis of hepatic encephalopathy and then summarizes the significant recent advances made in clinical and basic research contributing to our understanding, diagnosis, and possible treatment of hepatic encephalopathy. A literature search using the PubMed database was conducted in May 2017 using "hepatic encephalopathy" as a keyword, and selected manuscripts were limited to those research articles published since May 2014. While the authors acknowledge that many significant advances have been made in the understanding of hepatic encephalopathy prior to May 2014, we have limited the scope of this review to the previous three years only.
Collapse
Affiliation(s)
- Victoria Liere
- Department of Medical Physiology, College of Medicine, Texas A&M Health Science Center, Temple, TX, USA
| | | | - Sharon DeMorrow
- Department of Medical Physiology, College of Medicine, Texas A&M Health Science Center, Temple, TX, USA
- Central Texas Veterans Healthcare System, Temple, TX, USA
| |
Collapse
|
9
|
Ding S, Wang W, Wang X, Liang Y, Liu L, Ye Y, Yang J, Gao H, Zhuge Q. Dopamine Burden Triggers Neurodegeneration via Production and Release of TNF-α from Astrocytes in Minimal Hepatic Encephalopathy. Mol Neurobiol 2015; 53:5324-43. [PMID: 26433377 DOI: 10.1007/s12035-015-9445-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 09/15/2015] [Indexed: 12/15/2022]
Abstract
Dopamine (DA)-induced learning and memory impairment is well documented in minimal hepatic encephalopathy (MHE), but the contribution of DA to neurodegeneration and the involved underlying mechanisms are not fully understood. In this study, the effect of DA on neuronal apoptosis was initially detected. The results showed that MHE/DA (10 μg)-treated rats displayed neuronal apoptosis. However, we found that DA (10 μM) treatment did not induce evident apoptosis in primary cultured neurons (PCNs) but did produce TNF-α in primary cultured astrocytes (PCAs). Furthermore, co-cultures between PCAs and PCNs exposed to DA exhibited increased astrocytic TNF-α levels and neuronal apoptosis compared with co-cultures exposed to the vehicle, indicating the attribution of the neuronal apoptosis to astrocytic TNF-α. We also demonstrated that DA enhanced TNF-α production from astrocytes by activation of the TLR4/MyD88/NF-κB pathway, and secreted astrocytic TNF-α-potentiated neuronal apoptosis through inactivation of the PI3K/Akt/mTOR pathway. Overall, the findings from this study suggest that DA stimulates substantial production and secretion of astrocytic TNF-α, consequently and indirectly triggering progressive neurodegeneration, resulting in cognitive decline and memory loss in MHE.
Collapse
Affiliation(s)
- Saidan Ding
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Department of Surgery Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Weikan Wang
- Neurosurgery Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Xuebao Wang
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Department of Surgery Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Yong Liang
- Zhejiang Provincial Key Laboratory of Aging and Neurological Disease Research, Department of Surgery Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Leping Liu
- Analytical and Testing Center, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Yiru Ye
- School of Information and Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Jianjing Yang
- Neurosurgery Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China
| | - Hongchang Gao
- School of Pharmaceutical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China.
| | - Qichuan Zhuge
- Neurosurgery Department, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325000, People's Republic of China.
| |
Collapse
|