Abstract 187: Overexpression of Calpastatin Enhances Cardiotoxicity Induced by Doxorubicin

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Tianqing Peng ◽  
Yanpeng Wang ◽  
Jian Ma
Keyword(s):  
Transgenic Mice ◽  
Glycogen Synthase ◽  
Myocardial Dysfunction ◽  
Effective Prevention ◽  
Doxorubicin Treatment ◽  
Over Expression ◽  
Calcium Dependent ◽  
Gsk 3Β ◽  
Calpain Inhibition

Background: Doxorubicin causes damage to the heart, which may present as cardiomyopathy. However, the mechanisms by which doxorubicin induces cardiotoxicity remain not fully understood and no effective prevention for doxorubicin cardiomyopathy is available. Calpains, a family of calcium-dependent thiol-proteases, have been implicated in cardiovascular diseases. Their activities are tightly controlled by calpastatin. This study employed transgenic mice over-expressing calpastatin to investigate the role of calpain in doxorubicin-induced cardiotoxicity. Methods and Results: Doxorubicin treatment decreased calpain activities in cultured neonatal mouse cardiomyocytes and in vivo mouse hearts. Over-expression of calpastatin or incubation with pharmacological calpain inhibitors enhanced caspase-3 activity and DNA fragmentation in both neonatal and adult cardiomyocytes induced by doxorubicin. Inhibition of calpain also induced down-regulation of phosphorylated protein kinase B (AKT, Thr308), and a concomitant reduction in glycogen synthase kinase-3beta (GSK-3β) phosphorylation (Ser9) in doxorubicin-treated cardiomyocytes. Blocking AKT further increased doxorubicin-induced cardiac injuries, suggesting the effects of calpain inhibition may be mediated by inactivating the AKT/GSK-3β signaling. In an in vivo model of doxorubicin-induced cardiotoxicity, over-expression of calpastatin decreased calpain activities and exacerbated myocardial dysfunction as assessed by echocardiography and hemodynamic measurement in transgenic mice (C57BL/6) 5 days after doxorubicin injection. The five-day mortality was higher in transgenic mice (29.16%) compared with their wild-type littermates (8%) after doxorubicin treatment. Conclusions: Over-expression of calpastatin enhances doxorubicin-induced cardiac injuries through inhibiting calpain and compromising AKT survival signaling. Thus, calpains may protect cardiomyocytes against doxorubicin-induced cardiotoxicity.

scholarly journals Activation of GSK-3 and phosphorylation of CRMP2 in transgenic mice expressing APP intracellular domain

2005 ◽  
Vol 171 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Kathleen A. Ryan ◽  
Sanjay W. Pimplikar
Keyword(s):  
Transgenic Mice ◽  
Cell Signaling ◽  
Glycogen Synthase ◽  
Protein A ◽  
Axonal Guidance ◽  
Intracellular Domain ◽  
Biologically Relevant ◽  
Gsk 3Β

Amyloid precursor protein (APP), implicated in Alzheimer's disease, is a trans-membrane protein of undetermined function. APP is cleaved by γ-secretase that releases the APP intracellular domain (AICD) in the cytoplasm. In vitro studies have implicated AICD in cell signaling and transcriptional regulation, but its biologic relevance has been uncertain and its in vivo function has not been examined. To investigate its functional role, we generated AICD transgenic mice, and found that AICD causes significant biologic changes in vivo. AICD transgenic mice show activation of glycogen synthase kinase-3β (GSK-3β) and phosphorylation of CRMP2 protein, a GSK-3β substrate that plays a crucial role in Semaphorin3a-mediated axonal guidance. Our data suggest that AICD is biologically relevant, causes significant alterations in cell signaling, and may play a role in axonal elongation or pathfinding.

scholarly journals GSK-3β in Pancreatic Cancer: Spotlight on 9-ING-41, Its Therapeutic Potential and Immune Modulatory Properties

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed
Keyword(s):  
Pancreatic Cancer ◽  
Therapeutic Potential ◽  
Glycogen Synthase ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
In Vivo Models ◽  
Gsk 3Β ◽  
Early Phase Clinical Trials

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.

scholarly journals Acute elevation of circulating fatty acids impairs downstream insulin signalling in rat skeletal muscle in vivo independent of effects on stress signalling

2008 ◽  
Vol 197 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Georgia Frangioudakis ◽  
Gregory J Cooney
Keyword(s):  
Kinase Inhibitor ◽  
Glycogen Synthase ◽  
Insulin Signalling ◽  
Plasma Free Fatty Acid ◽  
Nuclear Factor Κb ◽  
Quadriceps Muscle ◽  
Male Wistar Rats ◽  
Gsk 3Β ◽  
Stress Signalling

The aim of this study was to examine the effect of an acute, physiological increase in plasma free fatty acid (FFA) on initial signalling events in rat red quadriceps muscle (RQ). Male Wistar rats received a 7% glycerol (GLYC) or 7% Intralipid/heparin (LIP) infusion for 3 h, after which they were either killed or infused with insulin at a rate of 0.5 U/kg per h for 5 min, before RQ collection. Plasma FFAs were elevated to ∼2 mM in the LIP rats only. Insulin-stimulated insulin receptor (IR) Tyr1162/Tyr1163 phosphorylation and IR substrate (IRS)-1 Tyr612 phosphorylation were increased at least twofold over basal in GLYC rats with insulin and this increase was not significantly impaired in the LIP rats. However, there was no insulin-stimulated protein kinase B (PKB) Ser473 or glycogen synthase kinase (GSK)-3β Ser9 phosphorylation in the LIP rats, compared with at least a twofold increase over basal in GLYC rats for both proteins. c-Jun N-terminal kinase, inhibitor of κ kinase β and inhibitor of nuclear factor-κB phosphorylation and total protein expression, as well as Ser307-IRS-1 phosphorylation, were not altered by lipid infusion compared with GLYC infusion. These data indicate that acute, physiological elevation in FFA has a greater impact on insulin signalling downstream of IR and IRS-1, at the level of PKB and GSK-3β, and that under these conditions stress signalling pathways are not significantly stimulated. Decreased PKB and GSK-3β phosphorylation in RQ may therefore be primary determinants of the reduced insulin action observed in situations of acute FFA oversupply.

scholarly journals Design and Synthesis of New Benzo[d]oxazole-Based Derivatives and Their Neuroprotective Effects on β-Amyloid-Induced PC12 Cells

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5391
Author(s):  
Zheng Liu ◽  
Ming Bian ◽  
Qian-Qian Ma ◽  
Zhuo Zhang ◽  
Huan-Huan Du ◽  
...  
Keyword(s):  
Pc12 Cells ◽  
Glycogen Synthase ◽  
B Cell Lymphoma ◽  
Nuclear Factor Κb ◽  
In Vivo Studies ◽  
Neuroprotective Effects ◽  
Β Amyloid ◽  
Gsk 3Β

A series of novel synthetic substituted benzo[d]oxazole-based derivatives (5a–5v) exerted neuroprotective effects on β-amyloid (Aβ)-induced PC12 cells as a potential approach for the treatment of Alzheimer’s disease (AD). In vitro studies show that most of the synthesized compounds were potent in reducing the neurotoxicity of Aβ25-35-induced PC12 cells at 5 μg/mL. We found that compound 5c was non-neurotoxic at 30 μg/mL and significantly increased the viability of Aβ25-35-induced PC12 cells at 1.25, 2.5 and 5 μg/mL. Western blot analysis showed that compound 5c promoted the phosphorylation of Akt and glycogen synthase kinase (GSK-3β) and decreased the expression of nuclear factor-κB (NF-κB) in Aβ25-35-induced PC12 cells. In addition, our findings demonstrated that compound 5c protected PC12 cells from Aβ25-35-induced apoptosis and reduced the hyperphosphorylation of tau protein, and decreased the expression of receptor for AGE (RAGE), β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), inducible nitric oxide synthase (iNOS) and Bcl-2-associated X protein/B-cell lymphoma 2 (Bax/Bcl-2) via Akt/GSK-3β/NF-κB signaling pathway. In vivo studies suggest that compound 5c shows less toxicity than donepezil in the heart and nervous system of zebrafish.

scholarly journals RPN2 is targeted by miR-181c and mediates glioma progression and temozolomide sensitivity via the wnt/β-catenin signaling pathway

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Jikui Sun ◽  
Quanfeng Ma ◽  
Banban Li ◽  
Chen Wang ◽  
Lidong Mo ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Glycogen Synthase ◽  
Inhibitory Effect ◽  
Who Grade ◽  
Pathway Network ◽  
Mechanistic Investigation ◽  
Signaling Axis ◽  
Gsk 3Β

Abstract Accumulating evidence indicates that the dysregulation of the miRNAs/mRNA-mediated carcinogenic signaling pathway network is intimately involved in glioma initiation and progression. In the present study, by performing experiments and bioinformatics analysis, we found that RPN2 was markedly elevated in glioma specimens compared with normal controls, and its upregulation was significantly linked to WHO grade and poor prognosis. Knockdown of RPN2 inhibited tumor proliferation and invasion, promoted apoptosis, and enhanced temozolomide (TMZ) sensitivity in vitro and in vivo. Mechanistic investigation revealed that RPN2 deletion repressed β-catenin/Tcf-4 transcription activity partly through functional activation of glycogen synthase kinase-3β (GSK-3β). Furthermore, we showed that RPN2 is a direct functional target of miR-181c. Ectopic miR-181c expression suppressed β-catenin/Tcf-4 activity, while restoration of RPN2 partly reversed this inhibitory effect mediated by miR-181c, implying a molecular mechanism in which TMZ sensitivity is mediated by miR-181c. Taken together, our data revealed a new miR-181c/RPN2/wnt/β-catenin signaling axis that plays significant roles in glioma tumorigenesis and TMZ resistance, and it represents a potential therapeutic target, especially in GBM.

PRMT5 Transgenic Mice Develop Aggressive Lymphoblastic Lymphomas

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2936-2936
Author(s):  
Porsha L. Smith ◽  
Fengting Yan ◽  
John T. Patton ◽  
Lapo Alinari ◽  
Vrajesh Karkhanis ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mouse Model ◽  
Transgenic Mice ◽  
Transgenic Mouse Model ◽  
P Value ◽  
Wild Type ◽  
Over Expression ◽  
Epigenetic Modifier ◽  
F1 Generation

Abstract Introduction: Emerging data collected from whole genome and epigenomic studies in solid and blood cancers has pointed toward dysregulation of chromatin remodelers as a unique class of cancer drivers. Next generation sequencing of lymphoma has identified several mutations affecting enzymes that regulate epigenetic control of gene expression. The epigenetic modifier protein arginine methyltransferase 5 (PRMT5) that has been shown to be essential for Epstein-Barr virus-driven B-cell transformation, is overexpressed in several histologic subtypes of B-cell non-Hodgkin's lymphomas (NHL) and is required for the driver activity of oncogenes such as MYC and NOTCH. While these findings suggest that PRMT5 may act as a driver of lymphomagenesis, definitive experiments to address its driver activity have yet to be performed. To address this question, we developed a transgenic mouse model by immunoglobulin m heavy chain enhancer/promoter (Em)-driven PRMT5 over expression in the lymphoid compartment of FVB/N mice. Methods: Eµ-hPRMT5 transgenic mice were created by injecting a vector containing floxed human PRMT5 under the control of the Eµ enhancer/promoter into FVB/N pronuclei that were implanted into pseudo-pregnant FVB/N mice. We obtained 5 founder lines demonstrating the presence of transgene construct by genotype PCR analysis of tail snip DNA. Founder mice were crossed with wild type FVB/N mice to obtain a F1 generation. Mice were followed clinically in standard pathogen-free housing until exhibiting phenotypic features at which time necropsy was performed. Immunophenotypic analysis was performed by flow cytometry, clonality by T cell receptor (TCR) Vb PCR, and pathology by hematoxylin-eosin staining and tissue micro-arrays developed for immunohistochemical staining (IHCS). Statistical significance was determined using a two-tail t-test and survival analysis conducted using Kaplan Meier curves. Results: F1 generation Eµ-hPRMT5 mice significantly overexpressed PRMT5 mRNA in unpurified splenocytes or bone marrow relative to non-transgenic mice (p-value < 0.001). Sorting B (CD19), NK (NK1.1) and T-cell (CD3) mononuclear subsets from splenocytes collected from Eµ-hPRMT5 mice (n=3/group) revealed PRMT5 mRNA to be overexpressed 37-fold (p-value <0.01), 7-fold (p-value <0.01) and 6-fold (p-value <0.05), respectively compared to WT FVB/N mice. All 5 founder lines were found to develop aggressive lymphomas at a statistically significant higher incidence compared to wild type (WT) FVB/N mice (range 10.7-34.6% lymphomagenesis). Gross anatomical characterization of Lymphoma bearing mice demonstrated focal lymphoid tumors, lymphadenopathy, organomegaly (liver, spleen, kidney), and malignant atypical lymphocytosis. Flow cytometric and IHCS studies showed features consistent with immature pre B and T lymphoblastic lymphomas (LL). Pre B LLs were characterized by high surface IgM, TdT and CD19 expression as analyzed by flow cytometry. Pre T LL demonstrated cytoplasmic CD3, TdT, and CD43 expression. We successfully developed a T LL cell line (Tg813) from a pre T-LL tumor isolated from a thymic tumor. Tg813 was clonal (Vb-17), demonstrated complex cytogenetic features, and over-expressed PRMT5, CYCLIN D1, CYCLIN D3, C-MYC transcript and protein, and the PRMT5 histone mark, symmetric (Me2)-H4R3. Inhibition of PRMT5 with a small molecule inhibitor, shRNA or genetic deletion using CRISPR/CAS9 PRMT5-specific gRNA (targeting exon 2) led to reduced proliferation, apoptosis and loss of CYCLIN D1 and C-MYC expression in Tg813. Engraftment of the Tg813 LL into both SCID and immunocompetent FVB/N mice led to disseminated lymphomas 21 days post-engraftment. In vivo induced expression of PRMT5 gRNA in CAS9+ Tg813 tumors is currently underway. Conclusions:The spontaneous lymphomagenesis observed in the Eµ-hPRMT5 transgenic mouse model supports the hypothesis that PRMT5 over-expression can provide sufficient driver activity for this disease. We describe a novel in vivo and in vitro model of PRMT5-driven LL that provides a useful platform for studying the biologic role of this epigenetic modifier in cancer and for development of PRMT5 targeted therapeutic approaches for lymphoma. Disclosures Baiocchi: Essanex: Research Funding.

Chronic β2-adrenoceptor stimulation impairs cardiac relaxation via reduced SR Ca2+-ATPase protein and activity

2008 ◽  
Vol 294 (6) ◽  
pp. H2587-H2595 ◽  
Author(s):  
James G. Ryall ◽  
Jonathan D. Schertzer ◽  
Kate T. Murphy ◽  
Andrew M. Allen ◽  
Gordon S. Lynch
Keyword(s):  
Glycogen Synthase ◽  
Cardiovascular Effects ◽  
Negative Regulator ◽  
Initial Values ◽  
Arterial Blood ◽  
Anchoring Protein ◽  
Diastolic Relaxation ◽  
Cardiac Relaxation ◽  
Gsk 3Β

We determined the cardiovascular effects of chronic β2-adrenoceptor (β2-AR) stimulation in vivo and examined the mechanism for the previously observed prolonged diastolic relaxation. Rats (3 mo old; n = 6), instrumented with implantable radiotelemeters, received the selective β2-AR agonist formoterol (25 μg·kg−1·day−1 ip) for 4 wk, with selected cardiovascular parameters measured daily throughout this period, and for a further 7 days after cessation of treatment. Chronic β2-AR stimulation was associated with an increase in heart rate (HR) of 17% ( days 1– 14) and 5% ( days 15–28); a 11% ( days 1– 14) and 6% ( days 15– 28) decrease in mean arterial blood pressure; and a 24% ( days 1– 14) increase in the rate of cardiac relaxation (−dP/d t) compared with initial values ( P < 0.05). Cessation of β2-AR stimulation resulted in an 8% decrease in HR and a 7% decrease in −dP/d t, compared with initial values ( P < 0.05). The prolonged cardiac relaxation with chronic β2-AR stimulation was associated with a 30% decrease in the maximal rate ( Vmax) of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) activity, likely attributed to a 50% decrease in SERCA2a protein ( P < 0.05). glycogen synthase kinase-3β (GSK-3β) has been implicated as a negative regulator of SERCA2 gene transcription, and we observed a ∼60% decrease ( P < 0.05) in phosphorylated GSK-3β protein after chronic β2-AR stimulation. Finally, we found a 40% decrease ( P < 0.05) in the mRNA expression of the novel A kinase anchoring protein AKAP18, also implicated in β2-AR-mediated cardiac relaxation. These findings highlight some detrimental cardiovascular effects of chronic β2-AR agonist administration and identify concerns for their current and future use for treating asthma or for conditions where muscle wasting and weakness are indicated.

scholarly journals Upregulation of TREM2 Ameliorates Neuroinflammatory Responses and Improves Cognitive Deficits Triggered by Surgical Trauma in Appswe/PS1dE9 Mice

2018 ◽  
Vol 46 (4) ◽  
pp. 1398-1411 ◽  
Author(s):  
Yanhua Jiang ◽  
Zhe Li ◽  
Hong Ma ◽  
Xuezhao Cao ◽  
Fang Liu ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Cognitive Deficits ◽  
Calcium Binding ◽  
Glycogen Synthase ◽  
Morris Water Maze Test ◽  
Surgical Trauma ◽  
Tau Hyperphosphorylation ◽  
Particle Injection ◽  
Model Of Alzheimer’S Disease ◽  
Gsk 3Β

Background/Aims: TREM2 plays a crucial role in modulating microglial function through interaction with DAP12, the adapter for TREM2. Emerging evidence has demonstrated that TREM2 could suppress neuroinflammatory responses by repression of microglia-mediated cytokine production. This study investigated the potential role of TREM2 in surgery-induced cognitive deficits and neuroinflammatory responses in wild-type (WT) and APPswe/PS1dE9 mice. Methods: Adult APPswe/PS1dE9 transgenic male mice (a classic transgenic model of Alzheimer’s disease, 3 months old) and their age-matched WT mice received intracerebral lentiviral particles encoding the mouse TREM2 gene and then were subjected to partial hepatectomy at 1 month after the lentiviral particle injection. The behavioral changes were evaluated with an open-field test and Morris water maze test on postoperative days 3, 7, and 14. Hippocampal TREM2, DAP12, and interleukin (IL)-1β were measured at each time point. Ionized calcium-binding adapter molecule 1 (Iba-1), microglial M2 phenotype marker Arg1, synaptophysin, tau hyperphosphorylation (T396), and glycogen synthase kinase-3β (GSK-3β) were also examined in the hippocampus. Results: Surgical trauma induced an exacerbated cognitive impairment and enhanced hippocampal IL-1β expression in the transgenic mice on postoperative days 3 and 7. A corresponding decline in the levels of TREM2 was also found on postoperative days 3, 7, and 14. Overexpression of TREM2 downregulated the levels of IL-1β, ameliorated T396 expression, inhibited the activity of GSK-3β, and improved sickness behavior. Increased Arg1 expression and a high level of synaptophysin were also observed in the transgenic mice following TREM2 overexpression. Conclusion: The downregulation of TREM2 exacerbated surgery-induced cognitive deficits and exaggerated neuroinflammatory responses in this rodent model. Overexpression of TREM2 potentially attenuated these effects by decreasing the associated production of proinflammatory cytokines, inhibiting tau hyperphosphorylation, and enhancing synaptophysin expression.

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