scholarly journals Hippocampus-sensitive and striatum-sensitive learning one month after morphine or cocaine exposure in male rats

2021 ◽  
Author(s):  
Robert S Gardner ◽  
Donna L Korol ◽  
Paul E Gold
Keyword(s):  
Drug Exposure ◽  
Drugs Of Abuse ◽  
Glycogen Synthase ◽  
Memory Systems ◽  
Male Rats ◽  
Cocaine Exposure ◽  
Downstream Target ◽  
Protein Levels ◽  
Hippocampal Astrocytes ◽  
Response Task

These experiments examined whether exposure to drugs of abuse altered the balance between hippocampal and striatal memory systems as measured long after drug treatments. Male rats received injections of morphine (5 mg/kg), cocaine (20 mg/kg), or saline for five consecutive days. One month later, rats were then trained to find food on a hippocampus-sensitive place task or a striatum-sensitive response task. Relative to saline controls, morphine-treated rats exhibited impaired place learning but enhanced response learning; prior cocaine exposure did not significantly alter learning on either task. Another set of rats was trained on a dual-solution T-maze that can be solved with either place or response strategies. While a majority (67%) of control rats used place solutions in this task, morphine treatment one month prior resulted in a shift to response solutions exclusively (100%). Prior cocaine treatment did not significantly alter strategy selection. Molecular markers related to learning and drug abuse were measured in the hippocampus and striatum one month after drug exposure in behaviorally untested rats. Protein levels of glial-fibrillary acidic protein (GFAP), an intermediate filament specific to astrocytes, increased significantly in the hippocampus after morphine, but not after cocaine exposure. Exposure to morphine or cocaine did not significantly change levels of brain-derived neurotrophic factor (BDNF) or a downstream target of BDNF signaling, glycogen synthase kinase 3β (GSK3β), in the hippocampus or striatum. Thus, exposure to morphine results in a long-lasting shift from hippocampal toward striatal dominance during learning. The effects of prior morphine injections on GFAP suggest that long-lasting alterations in hippocampal astrocytes may be associated with these behavioral strategy shifts.

scholarly journals Long noncoding RNA SNHG14 promotes hepatocellular carcinoma progression by regulating miR-876-5p/SSR2 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhibin Liao ◽  
Hongwei Zhang ◽  
Chen Su ◽  
Furong Liu ◽  
Yachong Liu ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Animal Experiments ◽  
Luciferase Reporter ◽  
Western Blot Assay ◽  
Downstream Target ◽  
Protein Levels ◽  
Elevated Expression ◽  
Rna Immunoprecipitation

Abstract Background Aberrant expressions of long noncoding RNAs (lncRNAs) have been demonstrated to be related to the progress of HCC. The mechanisms that SNHG14 has participated in the development of HCC are obscure. Methods Quantitative real-time PCR (qRT-PCR) was used to measure the lncRNA, microRNA and mRNA expression level. Cell migration, invasion and proliferation ability were evaluated by transwell and CCK8 assays. The ceRNA regulatory mechanism of SNHG14 was evaluated by RNA immunoprecipitation (RIP) and dual luciferase reporter assay. Tumorigenesis mouse model was used to explore the roles of miR-876-5p in vivo. The protein levels of SSR2 were measured by western blot assay. Results In this study, we demonstrated that SNHG14 was highly expressed in HCC tissues, meanwhile, the elevated expression of SNHG14 predicted poor prognosis in patients with HCC. SNHG14 promoted proliferation and metastasis of HCC cells. We further revealed that SNHG14 functioned as a competing endogenous RNA (ceRNA) for miR-876-5p and that SSR2 was a downstream target of miR-876-5p in HCC. Transwell, CCK8 and animal experiments exhibited miR-876-5p inhibited HCC progression in vitro and in vivo. By conducting rescue experiments, we found the overexpression of SSR2 or knocking down the level of miR-876-5p could reverse the suppressive roles of SNHG14 depletion in HCC. Conclusion SNHG14 promotes HCC progress by acting as a sponge of miR-876-5p to regulate the expression of SSR2 in HCC.

scholarly journals BIOM-55. DGKζ-TARGETED REGULATION OF MIR-34A IN THE PROLIFERATION AND TUMORIGENICITY OF HUMAN GLIOBLASTOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii13-ii13
Author(s):  
Wangxian Gu ◽  
Guoqing Wan ◽  
Yanjun Zheng ◽  
Xintong Yang ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Precancerous Lesions ◽  
Lipid Kinase ◽  
Human Glioblastoma ◽  
Kinase Substrate ◽  
Downstream Target ◽  
Protein Levels ◽  
Type Iv

Abstract Diacylglycerol kinase (DGK) is a lipid kinase that catalyzes the phosphorylation of diacylglycerol (DAG) to produce phosphatidic acid (PA), which uses ATP as a phosphate donor. Diacylglycerol kinases ζ(DGKζ) is characterized as specific type IV due to its myristoylated alanine-rich C-kinase substrate (MARCKS), ankyrin, and PDZ binding domain. Similar to other DGKs, DGKζ is also reported to be abnormally expressed in human colorectal cancer cells, and it is indispensable for the proliferation of cancer cells. However, its implications in human glioblastoma (GBM) is largely unknown. Both the mRNA and protein levels of DGKζ were significantly higher in GBM tissues than in precancerous lesions. Knockdown of DGKζ inhibited GBM cell proliferation, cell cycle and promoted apoptosis of GBM cells. Moreover, down-regulation of DGKζ markedly reduced in vitro colony formation and in vivo tumorigenic capability. Furthermore, we confirmed that DGKζ was the downstream target of miR-34a. The expression level of DGKζ was negatively correlated with miR-34a in GBM tissues. Overexpression of DGKζ reversed the tumor suppressive roles of miR-34a in GBM cells. Taken together, DGKζ can act as a potential prognostic biomarker for GBM patients and promote the growth of GBM cells was regulated by miR-34a, and it may represent a promising therapeutic target for patients with GBM.

scholarly journals HSP105 Recruits Protein Phosphatase 2A To Dephosphorylate β-Catenin

2015 ◽  
Vol 35 (8) ◽  
pp. 1390-1400 ◽  
Author(s):  
Nancy Yu ◽  
Michael Kakunda ◽  
Victoria Pham ◽  
Jennie R. Lill ◽  
Pan Du ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Target Gene ◽  
Target Genes ◽  
Glycogen Synthase ◽  
Protein Phosphatase 2A ◽  
Breast Cancer Patients ◽  
Poor Overall Survival ◽  
Protein Levels ◽  
Phosphatase 2A ◽  
Unidentified Component

The Wnt/β-catenin pathway causes accumulation of β-catenin in the cytoplasm and its subsequent translocation into the nucleus to initiate the transcription of the target genes. Without Wnt stimulation, β-catenin forms a complex with axin (axis inhibitor), adenomatous polyposis coli (APC), casein kinase 1α (CK1α), and glycogen synthase kinase 3β (GSK3β) and undergoes phosphorylation-dependent ubiquitination. Phosphatases, such as protein phosphatase 2A (PP2A), interestingly, also are components of this degradation complex; therefore, a balance must be reached between phosphorylation and dephosphorylation. How this balance is regulated is largely unknown. Here we show that a heat shock protein, HSP105, is a previously unidentified component of the β-catenin degradation complex. HSP105 is required for Wnt signaling, since depletion of HSP105 compromises β-catenin accumulation and target gene transcription upon Wnt stimulation. Mechanistically, HSP105 depletion disrupts the integration of PP2A into the β-catenin degradation complex, favoring the hyperphosphorylation and degradation of β-catenin. HSP105 is overexpressed in many types of tumors, correlating with increased nuclear β-catenin protein levels and Wnt target gene upregulation. Furthermore, overexpression of HSP105 is a prognostic biomarker that correlates with poor overall survival in breast cancer patients as well as melanoma patients participating in the BRIM2 clinical study.

Abstract 15295: Molecular Mechanism of Chronic Sildenafil-Caused Regression of Heart Failure: Effects on the Express of Cardiac SR Ca2+-ATPase, Subtype of β-Adrenergic Receptors and Nitric Oxide Synthase Isoforms

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Heng-Jie Cheng ◽  
Tiankai Li ◽  
Che Ping Cheng
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Nitric Oxide Synthase ◽  
Adrenergic Receptors ◽  
Left Ventricular ◽  
Male Rats ◽  
Protein Levels ◽  
Myocyte Function ◽  
Oxide Synthase ◽  
Β Adrenergic Receptors

Background: Sildenafil (SIL), a selective inhibitor of PDE5 has been shown to exert profound beneficial effects in heart failure (HF). Recently we further found that SIL caused regression of cardiac dysfunction in a rat model with isoproterenol (ISO)-induced progressive HF. However, the molecular basis is unclear. We hypothesized that reversal of HF-induced detrimental alterations on the expressions of cardiac SR Ca 2+ -ATPase (SERCA2a), β-adrenergic receptors (AR) and nitric oxide synthase (NOS) isoforms by SIL may play a key role for its salutary role in HF. Methods: Left ventricular (LV) and myocyte function and the protein levels of myocyte β 1 - and β 3 - AR, SERCA2a, phospholamban (PLB) and three NOS were simultaneously evaluated in 3 groups of male rats (6/group): HF , 3 months (M) after receiving ISO (170 mg/kg sq for 2 days); HF/SIL , 2 M after receiving ISO, SIL (70 μg/kg/day sq via mini pump) was initiated and given for 1 M; and Controls (C). Results: Compared with controls, ISO-treated rats progressed to severe HF at 3 M after ISO followed by significantly decreased LV contractility (E ES , HF: 0.7 vs C: 1.2 mmHg/μl) and slowed LV relaxation, reductions in the peak velocity of myocyte shortening (77 vs 136 μm/sec), relengthening (62 vs 104 μm/sec) and [Ca 2+ ] iT (0.15 vs 0.24) accompanied by a diminished myocyte inotropic response to β-AR agonist, ISO (10 -8 M). These abnormalities were associated with concomitant significant decreases in myocyte protein levels of β 1 -AR (0.23 vs 0.64), SERCA2a (0.46 vs 0.80), PLB Ser16 /PLB ratio (0.24 vs 0.40) and eNOS (0.28 vs 0.46), but significantly increases in protein levels of β 3 -AR (0.29 vs 0.10) and iNOS (0.18 vs 0.08) with relatively unchanged nNOS. Chronic SIL prevented the HF-induced decreases in LV and myocyte contraction, relaxation, peak [Ca 2+ ] iT , and restored normal myocyte contractile response to ISO stimulation. With SIL, protein levels of myocyte β 1 - and β 3 -AR, SERCA2a were restored close to control values, but eNOS was significantly elevated than controls (0.77). Conclusions: Chronic SIL prevents HF-caused downregulation of cardiac β 1 -AR and reverse contrast changes between iNOS and β 3 -AR with SERCA 2a and eNOS expression, leading to the preservation of LV and myocyte function, [Ca 2+ ] iT , and β-adrenergic reserve.

Effect of microgravity on the expression of mitochondrial enzymes in rat cardiac and skeletal muscles

1998 ◽  
Vol 84 (2) ◽  
pp. 593-598 ◽  
Author(s):  
Michael K. Connor ◽  
David A. Hood
Keyword(s):  
Skeletal Muscle ◽  
Enzyme Activity ◽  
Skeletal Muscles ◽  
Male Rats ◽  
Mitochondrial Enzymes ◽  
Mrna Levels ◽  
Triceps Brachii ◽  
Protein Levels ◽  
Functional Consequences ◽  
Microgravity Conditions

Connor, Michael K., and David A. Hood. Effect of microgravity on the expression of mitochondrial enzymes in rat cardiac and skeletal muscles. J. Appl. Physiol. 84(2): 593–598, 1998.—The purpose of this study was to examine the expression of nuclear and mitochondrial genes in cardiac and skeletal muscle (triceps brachii) in response to short-duration microgravity exposure. Six adult male rats were exposed to microgravity for 6 days and were compared with six ground-based control animals. We observed a significant 32% increase in heart malate dehydrogenase (MDH) enzyme activity, which was accompanied by a 62% elevation in heart MDH mRNA levels after microgravity exposure. Despite modest elevations in the mRNAs encoding subunits III, IV, and VIc as well as a 2.2-fold higher subunit IV protein content after exposure to microgravity, heart cytochrome c oxidase (CytOx) enzyme activity remained unchanged. In skeletal muscle, MDH expression was unaffected by microgravity, but CytOx activity was significantly reduced 41% by microgravity, whereas subunit III, IV, and VIc mRNA levels and subunit IV protein levels were unaltered. Thus tissue-specific (i.e., heart vs. skeletal muscle) differences exist in the regulation of nuclear-encoded mitochondrial proteins in response to microgravity. In addition, the expression of nuclear-encoded proteins such as CytOx subunit IV and expression of MDH are differentially regulated within a tissue. Our data also illustrate that the heart undergoes previously unidentified mitochondrial adaptations in response to short-term microgravity conditions more dramatic than those evident in skeletal muscle. Further studies evaluating the functional consequences of these adaptations in the heart, as well as those designed to measure protein turnover, are warranted in response to microgravity.

Simulated microgravity effects on the rat carotid and femoral arteries: role of contractile protein expression and mechanical properties of the vessel wall

2007 ◽  
Vol 102 (4) ◽  
pp. 1595-1603 ◽  
Author(s):  
Sunup Hwang ◽  
Stanislav A. Shelkovnikov ◽  
Ralph E. Purdy
Keyword(s):  
Carotid Artery ◽  
Protein Expression ◽  
Femoral Artery ◽  
Vessel Wall ◽  
Male Rats ◽  
Force Analysis ◽  
Western Blots ◽  
Active Length ◽  
Femoral Arteries ◽  
Protein Levels

The goal of this study was to determine the effects of microgravity on myofilament protein expression and both passive and active length-force relationships in carotid and femoral arteries. Microgravity was simulated by 20-day hindlimb unweighting (HU) in Wistar male rats, and carotid and femoral artery segments were isolated from both HU and control (CTL) rats for Western blot and length-force analysis. Western blots revealed that HU significantly decreased myosin light chain-20 (MLC-20) protein levels in both carotid and femoral arteries and decreased myosin heavy chain (MHC) in femoral artery. α-Actin levels were not altered by HU treatment in either artery. Length-force analysis demonstrated that HU did not change either passive or active length-force relationships in the femoral artery. HU-treated arterial rings developed significantly less force to 100 mM K+ than CTL, but optimal lengths were identical. In the carotid artery, length-active force curves were identical for both CTL and HU; however the length-passive force curve for HU-treated rings exhibited a steeper slope than CTL, suggesting decreased compliance of the artery wall. In conclusion, our data suggest that the HU-induced decreases in both MLC-20 and MHC in femoral artery are responsible for the decreased contraction to 100 mM K+ in HU-treated femoral artery rings. In the carotid artery, the HU-induced decrease in vessel wall compliance may counter any decrease in contractility caused by the decreased MLC-20 levels.

scholarly journals ATP citrate-lyase and glycogen synthase kinase-3β in 3T3-L1 cells during differentiation into adipocytes

1994 ◽  
Vol 300 (2) ◽  
pp. 477-482 ◽  
Author(s):  
W B Benjamin ◽  
S N Pentyala ◽  
J R Woodgett ◽  
Y Hod ◽  
D Marshak
Keyword(s):  
Glycogen Synthase ◽  
Protein Band ◽  
Glycogen Synthase Kinase ◽  
Fat Cells ◽  
Apparent Mass ◽  
Atp Citrate Lyase ◽  
Protein Levels ◽  
Citrate Lyase ◽  
Sds Page ◽  
Dependent Protein

ATP citrate-lyase (CL), acetyl-CoA carboxylase (ACC) and glycogen synthase kinase-3 beta (GSK-3 beta) levels were measured in cytosol from 3T3-L1 cells during differentiation from fibroblasts into fat-cells. Protein levels were estimated from immunoblots using specific antisera. Cytosol from confluent cells contain significant amounts of GSK-3 beta, which fell during differentiation of these cells into adipocytes. CL from confluent cells was found to be mostly in the form of a single protein band of apparent mass 110 kDa. Levels of CL and ACC increased during cell differentiation into adipocytes. During the first 3 days of differentiation, CL migration changed, and it was expressed as a complex of protein bands of apparent mass 110 kDa, 113 kDa and 115 kDa. At later stages of differentiation, when these cells had assumed the phenotype of fat-cells, they expressed CL mainly as protein bands of 110 and 113 kDa. When samples containing these bands were treated with alkaline phosphatase, the 113 kDa protein band collapsed into the 110 kDa species. This suggests that the slower-migrating species of CL is a higher-order phosphorylation state of the same protein. Furthermore, when purified CL, mostly expressed as the 110 kDa species, was phosphorylated with cyclic AMP-dependent protein kinase alone or together with GSK-3 and resolved by SDS/PAGE, the phosphorylated CL now migrated more slowly as the 113 kDa and 115 kDa forms. CL phosphorylation was hormone-regulated, since, in samples from fat-cells that had the complex two-band pattern, when cultured in medium without serum or hormones, CL migration reverted to a single band of 110 kDa, similar to confluent cells. Treatment of these ‘down-regulated’ cells with insulin rapidly induced substantial amounts of the 113 kDa species, with a concomitant decrease in the 110 kDa species.

Neuroendocrinology of Stress and Addiction

2021 ◽  
Author(s):  
Steven Kinsey ◽  
Olivia Vanegas ◽  
Kristen Trexler ◽  
Floyd Steele ◽  
Matthew Eckard
Keyword(s):  
Stress Response ◽  
Psychotropic Drugs ◽  
Drug Exposure ◽  
Drugs Of Abuse ◽  
Drug Withdrawal ◽  
Host Organism ◽  
Repeated Use ◽  
Drug Abstinence ◽  
Withdrawal Syndromes ◽  
Development Of Tolerance

The stress response evolved as a series of neural and endocrine mechanisms that protect the host organism from threats to homeostasis. Repeated use of psychotropic drugs can lead to the development of tolerance (i.e., decreased drug activity at a given dose) and drug dependence, as indicated by withdrawal syndromes following drug abstinence. Drug withdrawal is often overtly stressful, although acute drug exposure may also represent a threat to homeostasis. This article explores the neuroendocrine effects of drugs of abuse and some of the ways in which stress and appetitive mechanisms interact.

Protective effect of hydralazine on a cellular model of Parkinson’s disease: a possible role of hypoxia-inducible factor (HIF)-1α

2020 ◽  
Vol 98 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Mehrnaz Mehrabani ◽  
Mohammad Hadi Nematollahi ◽  
Mojde Esmaeili Tarzi ◽  
Kobra Bahrampour Juybari ◽  
Moslem Abolhassani ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Target Genes ◽  
Hypoxia Inducible Factor ◽  
Antioxidant Power ◽  
Expression Levels ◽  
Downstream Target ◽  
Protein Levels ◽  
Ferric Reducing Antioxidant Power ◽  
6 Hydroxydopamine

Parkinson’s disease (PD) is a neurodegenerative disease accompanied by a low expression level of cerebral hypoxia-inducible factor (HIF-1α). Hence, activating the hypoxia-signaling pathway may be a favorable therapeutic approach for curing PD. This study explored the efficacy of hydralazine, a well-known antihypertensive agent, for restoring the impaired HIF-1 signaling in PD, with the aid of 6-hydroxydopamine (6-OHDA)-exposed SH-SY5Y cells. The cytotoxicity of hydralazine and 6-OHDA on the SH-SY5Y cells were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and apoptosis detection assays. The activities of malondialdehyde, nitric oxide (NO), ferric reducing antioxidant power (FRAP), and superoxide dismutase (SOD) were also measured. Expression levels of HIF-1α and its downstream genes at the protein level were assessed by Western blotting. Hydralazine showed no toxic effects on SH-SY5Y cells, at the concentration of ≤50 μmol/L. Hydralazine decreased the levels of apoptosis, malondialdehyde, and NO, and increased the activities of FRAP and SOD in cells exposed to 6-OHDA. Furthermore, hydralazine up-regulated the protein expression levels of HIF-1α, vascular endothelial growth factor, tyrosine hydroxylase, and dopamine transporter in the cells also exposed to 6-OHDA, by comparison with the cells exposed to 6-OHDA alone. In summary, hydralazine priming could attenuate the deleterious effects of 6-OHDA on SH-SY5Y cells by increasing cellular antioxidant capacity, as well as the protein levels of HIF-1α and its downstream target genes.

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