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Bi-directional modulation of hyperpolarization-activated cation currents (I h) by ethanol in rat hippocampal CA3 pyramidal neurons. Neuropharmacology 2023; 227:109423. [PMID: 36690323 DOI: 10.1016/j.neuropharm.2023.109423] [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: 09/09/2022] [Revised: 01/12/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023]
Abstract
It is widely acknowledged that ethanol (EtOH) can alter many neuronal functions, including synaptic signaling, firing discharge, and membrane excitability, through its interaction with multiple membrane proteins and intracellular pathways. Previous work has demonstrated that EtOH enhances the firing rate of hippocampal GABAergic interneurons and thus the presynaptic GABA release at CA1 and CA3 inhibitory synapses through a positive modulation of the hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels. Activation of HCN channels produce an inward current, commonly called Ih, which plays an essential role in generating/regulating specific neuronal activities in GABAergic interneurons and principal glutamatergic pyramidal neurons such as those in the CA3 subregion. Since the direct effect of EtOH on HCN channels expressed in CA3 pyramidal neurons was not thoroughly elucidated, we investigated the possible interaction between EtOH and HCN channels and the impact on excitability and postsynaptic integration of these neurons. Patch-clamp recordings were performed in single CA3 pyramidal neurons from acute male rat coronal hippocampal slices. Our results show that EtOH modulates HCN-mediated Ih in a concentration-dependent and bi-directional manner, with a positive modulation at lower (20 mM) and an inhibitory action at higher (60-80 mM) concentrations. The modulation of Ih by EtOH was mimicked by forskolin, antagonized by different drugs that selectively interfere with the AC/cAMP/PKA intracellular pathway, as well as by the selective HCN inhibitor ZD7288. Altogether, these data further support the evidence that HCN channels may represent an important molecular target through which EtOH may regulate neuronal activity.
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Hu Y, Hill RA, Yoshimura M. Role of Adenylyl Cyclase Type 7 in Functions of BV-2 Microglia. Int J Mol Sci 2022; 24:ijms24010347. [PMID: 36613790 PMCID: PMC9820266 DOI: 10.3390/ijms24010347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
To assess the role of adenylyl cyclase type 7 (AC7) in microglia's immune function, we generated AC7 gene knockout (AC7 KO) clones from a mouse microglial cell line, BV-2, using the CRISPR-Cas9 gene editing system. The ability of BV-2 cells to generate cAMP and their innate immune functions were examined in the presence or absence of ethanol. The parental BV-2 cells showed robust cAMP production when stimulated with prostaglandin-E1 (PGE1) and ethanol increased cAMP production in a dose-dependent manner. AC7 KO clones of BV-2 cells showed diminished and ethanol-insensitive cAMP production. The phagocytic activity of the parental BV-2 cells was inhibited in the presence of PGE1; AC7 KO BV-2 cells showed lower and PGE1-insensitive phagocytic activity. Innate immune activities of the parental BV-2 cells, including bacterial killing, nitric oxide synthesis, and expression of arginase 1 and interleukin 10 were activated as expected with small effects of ethanol. However, the innate immune activities of AC7 KO cells were either drastically diminished or not detected. The data presented suggest that AC7 has an important role in the innate immune functions of microglial cells. AC7's involvement in ethanol's effects on immune functions remains unclear. Further studies are needed.
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Affiliation(s)
- Yawen Hu
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine Louisiana State University, Baton Rouge, LA 70803, USA
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
| | - Rebecca A. Hill
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine Louisiana State University, Baton Rouge, LA 70803, USA
| | - Masami Yoshimura
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine Louisiana State University, Baton Rouge, LA 70803, USA
- Correspondence: ; Tel.:+1-225-578-9759
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Hu M, Zhong Y, Liu J, Zheng S, Lin L, Lin X, Liang B, Huang Y, Xian H, Li Z, Zhang B, Wang B, Meng H, Du J, Ye R, Lu Z, Yang X, Yang X, Huang Z. An adverse outcome pathway-based approach to assess aurantio-obtusin-induced hepatotoxicity. Toxicology 2022; 478:153293. [PMID: 35995123 DOI: 10.1016/j.tox.2022.153293] [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: 07/01/2022] [Revised: 08/02/2022] [Accepted: 08/17/2022] [Indexed: 12/01/2022]
Abstract
Cassiae semen (CS), a traditional Chinese medicine, has various bioactivities in preclinical and clinical practice. Aurantio-obtusin (AO) is a major anthraquinone (AQ) ingredient derived from CS, and has drawn public concerns over its potential hepatotoxicity. We previously found that AO induces hepatic necroinflammation by activating NOD-like receptor protein 3 inflammasome signaling. However, the mechanisms contributing to AO-motivated hepatotoxicity remain unclear. Herein, we evaluated hepatotoxic effects of AO on three liver cell lines by molecular and biochemical analyses. We found that AO caused cell viability inhibition and biochemistry dysfunction in the liver cells. Furthermore, AO elevated reactive oxygen species (ROS), followed by mitochondrial dysfunction (decreases in mitochondrial membrane potential and adenosine triphosphate) and apoptosis (increased Caspase-3, Cleaved caspase-3, Cytochrome c and Bax expression, and decreased Bcl-2 expression). We also found that AO increased the lipid peroxidation (LPO) and enhanced ferroptosis by activating cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element-binding (CREB) pathway (increases in PKA, p-CREB, acyl-CoA synthetase long chain family member 4). Based on these results, we used an AOP framework to explore the mechanisms underlying AO's hepatotoxicity. It starts from molecular initiating event (ROS), and follows two critical toxicity pathways (i.e., mitochondrial dysfunction-mediated apoptosis and LPO-enhanced ferroptosis) over a series of key events (KEs) to the adverse outcome of hepatotoxicity. The results of an assessment confidence in the adverse outcome pathway (AOP) framework supported the evidence concordance in dose-response, temporal and incidence relationships between KEs in AO-induced hepatotoxicity. This study's findings offer a novel toxicity pathway network for AO-caused hepatotoxicity.
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Affiliation(s)
- Manjiang Hu
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yizhou Zhong
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Jun Liu
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Shaozhen Zheng
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Li Lin
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Xi Lin
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Boxuan Liang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Yuji Huang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hongyi Xian
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Zhiming Li
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Bingli Zhang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Bo Wang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Hao Meng
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Jiaxin Du
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Rongyi Ye
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Zhi Lu
- Infinitus (China) Inc., Guangzhou 510623, China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Xingfen Yang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China
| | - Zhenlie Huang
- NMPA Key Laboratory for Safety Evaluation of Cosmetics, Guangdong Provincial Key Laboratory of Tropical Disease Research, Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou 510515, China.
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Deng W, He J, Tang XM, Li CY, Tong J, Qi D, Wang DX. Alcohol inhibits alveolar fluid clearance through the epithelial sodium channel via the A2 adenosine receptor in acute lung injury. Mol Med Rep 2021; 24:725. [PMID: 34396442 PMCID: PMC8404097 DOI: 10.3892/mmr.2021.12364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022] Open
Abstract
Chronic alcohol abuse increases the risk of mortality and poor outcomes in patients with acute respiratory distress syndrome. However, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effects of chronic alcohol consumption on lung injury and clarify the signaling pathways involved in the inhibition of alveolar fluid clearance (AFC). In order to produce rodent models with chronic alcohol consumption, wild‑type C57BL/6 mice were treated with alcohol. A2a adenosine receptor (AR) small interfering (si)RNA or A2bAR siRNA were transfected into the lung tissue of mice and primary rat alveolar type II (ATII) cells. The rate of AFC in lung tissue was measured during exposure to lipopolysaccharide (LPS). Epithelial sodium channel (ENaC) expression was determined to investigate the mechanisms underlying alcohol‑induced regulation of AFC. In the present study, exposure to alcohol reduced AFC, exacerbated pulmonary edema and worsened LPS‑induced lung injury. Alcohol caused a decrease in cyclic adenosine monophosphate (cAMP) levels and inhibited α‑ENaC, β‑ENaC and γ‑ENaC expression levels in the lung tissue of mice and ATII cells. Furthermore, alcohol decreased α‑ENaC, β‑ENaC and γ‑ENaC expression levels via the A2aAR or A2bAR‑cAMP signaling pathways in vitro. In conclusion, the results of the present study demonstrated that chronic alcohol consumption worsened lung injury by aggravating pulmonary edema and impairing AFC. An alcohol‑induced decrease of α‑ENaC, β‑ENaC and γ‑ENaC expression levels by the A2AR‑mediated cAMP pathway may be responsible for the exacerbated effects of chronic alcohol consumption in lung injury.
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Affiliation(s)
- Wang Deng
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jing He
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Xu-Mao Tang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Chang-Yi Li
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jin Tong
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Di Qi
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Dao-Xin Wang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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Qualls-Creekmore E, Gupta R, Yoshimura M. The effect of alcohol on recombinant proteins derived from mammalian adenylyl cyclase. Biochem Biophys Rep 2017; 10:157-164. [PMID: 28955743 PMCID: PMC5614657 DOI: 10.1016/j.bbrep.2017.03.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/07/2017] [Accepted: 03/29/2017] [Indexed: 11/26/2022] Open
Abstract
The cyclic AMP (cAMP) signaling pathway is implicated in the development of alcohol use disorder. Previous studies have demonstrated that ethanol enhances the activity of adenylyl cyclase (AC) in an isoform specific manner; AC7 is most enhanced by ethanol, and regions responsible for enhancement by ethanol are located in the cytoplasmic domains of the AC7 protein. We hypothesize that ethanol modulates AC activity by directly interacting with the protein and that ethanol effects on AC can be studied using recombinant AC in vitro. AC recombinant proteins containing only the C1a or C2 domains of AC7 and AC9 individually were expressed in bacteria, and purified. The purified recombinant AC proteins retained enzymatic activity and isoform specific alcohol responsiveness. The combination of the C1a or C2 domains of AC7 maintained the same alcohol cutoff point as full-length AC7. We also find that the recombinant AC7 responds to alcohol differently in the presence of different combinations of activators including MnCl2, forskolin, and Gsα. Through a series of concentration-response experiments and curve fitting, the values for maximum activities, Hill coefficients, and EC50 were determined in the absence and presence of butanol as a surrogate of ethanol. The results suggest that alcohol modulates AC activity by directly interacting with the AC protein and that the alcohol interaction with the AC protein occurs at multiple sites with positive cooperativity. This study indicates that the recombinant AC proteins expressed in bacteria can provide a useful model system to investigate the mechanism of alcohol action on their activity.
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Affiliation(s)
- Emily Qualls-Creekmore
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, United States
| | - Ratna Gupta
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, United States
| | - Masami Yoshimura
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, United States
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Ethanol Stimulates Locomotion via a G αs-Signaling Pathway in IL2 Neurons in Caenorhabditis elegans. Genetics 2017; 207:1023-1039. [PMID: 28951527 PMCID: PMC5676223 DOI: 10.1534/genetics.117.300119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 09/23/2017] [Indexed: 01/21/2023] Open
Abstract
Alcohol abuse is among the top causes of preventable death, generating considerable financial, health, and societal burdens. Paradoxically, alcohol... Alcohol is a potent pharmacological agent when consumed acutely at sufficient quantities and repeated overuse can lead to addiction and deleterious effects on health. Alcohol is thought to modulate neuronal function through low-affinity interactions with proteins, in particular with membrane channels and receptors. Paradoxically, alcohol acts as both a stimulant and a sedative. The exact molecular mechanisms for the acute effects of ethanol on neurons, as either a stimulant or a sedative, however remain unclear. We investigated the role that the heat shock transcription factor HSF-1 played in determining a stimulatory phenotype of Caenorhabditis elegans in response to physiologically relevant concentrations of ethanol (17 mM; 0.1% v/v). Using genetic techniques, we demonstrate that either RNA interference of hsf-1 or use of an hsf-1(sy441) mutant lacked the enhancement of locomotion in response to acute ethanol exposure evident in wild-type animals. We identify that the requirement for HSF-1 in this phenotype was IL2 neuron-specific and required the downstream expression of the α-crystallin ortholog HSP-16.48. Using a combination of pharmacology, optogenetics, and phenotypic analyses we determine that ethanol activates a Gαs-cAMP-protein kinase A signaling pathway in IL2 neurons to stimulate nematode locomotion. We further implicate the phosphorylation of a specific serine residue (Ser322) on the synaptic protein UNC-18 as an end point for the Gαs-dependent signaling pathway. These findings establish and characterize a distinct neurosensory cell signaling pathway that determines the stimulatory action of ethanol and identifies HSP-16.48 and HSF-1 as novel regulators of this pathway.
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Hill RA, Xu W, Yoshimura M. Role of an adenylyl cyclase isoform in ethanol's effect on cAMP regulated gene expression in NIH 3T3 cells. Biochem Biophys Rep 2017; 8:162-167. [PMID: 28620651 PMCID: PMC5467537 DOI: 10.1016/j.bbrep.2016.08.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Previous research has indicated that the cyclic AMP (cAMP) signal transduction system plays an important role in the predisposition to and development of ethanol abuse in humans. Our laboratory has demonstrated that ethanol is capable of enhancing adenylyl cyclase (AC) activity. This effect is AC isoform-specific; type 7 AC (AC7) is most enhanced by ethanol. Therefore, we hypothesized that the expression of a specific AC isoform will play a role on the effect of ethanol on cAMP regulated gene expression. We employed NIH 3T3 cells transfected with AC7 or AC3 as a model system. To evaluate ethanol's effects on cAMP regulated gene expression, a luciferase reporter gene driven by a cAMP inducing artificial promoter was utilized. Stimulation of AC activity leads to an increase in the reporter gene activity. This increase was enhanced in the presence of ethanol in cells expressing AC7, while cells expressing AC3 did not respond to ethanol. cAMP reporter gene expression was increased in the presence of 8-bromo-cAMP; this expression was not enhanced by ethanol. These observations are consistent with our hypothesis. The basal level of CREB phosphorylation was high and did not change by cAMP stimulation or in the presence of ethanol. However, there were significant changes in the TORC3 amount in nuclei depending on stimulation conditions. The results suggest that nuclear translocation of TORC3 plays a more important role than CREB phosphorylation in the observed changes in the cAMP driven reporter gene activity. Effect of ethanol on cAMP regulated gene expression is AC isoform dependent. cAMP regulated gene expression is most enhanced by ethanol in cells expressing AC7. Gene expression increases with pharmacologically relevant ethanol concentrations. TORC3 nuclear translocation is important for cAMP reporter gene activity.
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Affiliation(s)
- Rebecca A Hill
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Wu Xu
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
| | - Masami Yoshimura
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
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