scholarly journals CUX1—Transcriptional Master Regulator of Tumor Progression in Pancreatic Neuroendocrine Tumors

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1957
Author(s):  
Sebastian Krug ◽  
Julia Weissbach ◽  
Annika Blank ◽  
Aurel Perren ◽  
Johannes Haybaeck ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Mouse Model ◽  
Neuroendocrine Tumours ◽  
Tumour Progression ◽  
Free Survival ◽  
Treatment Naïve ◽  
Pancreatic Neuroendocrine Tumours ◽  
The Impact

Recently, we identified the homeodomain transcription factor Cut homeobox 1 (CUX1) as mediator of tumour de-differentiation and metastatic behaviour in human insulinoma patients. In insulinomas, CUX1 enhanced tumour progression by stimulating proliferation and angiogenesis in vitro and in vivo. In patients with non-functional pancreatic neuroendocrine tumours (PanNET), however, the impact of CUX1 remains to be elucidated. Here, we analysed CUX1 expression in two large independent cohorts (n = 43 and n = 141 tissues) of non-functional treatment-naïve and pre-treated PanNET patients, as well as in the RIP1Tag2 mouse model of pancreatic neuroendocrine tumours. To further assess the functional role of CUX1, expression profiling of DNA damage-, proliferation- and apoptosis-associated genes was performed in CUX1-overexpressing Bon-1 cells. Validation of differentially regulated genes was performed in Bon-1 and QGP1 cells with knock-down and overexpression strategies. CUX1 expression assessed by a predefined immunoreactivity score (IRS) was significantly associated with shorter progression-free survival (PFS) of pre-treated PanNET patients (23 vs. 8 months; p = 0.005). In treatment-naïve patients, CUX1 was negatively correlated with grading and recurrence-free survival (mRFS of 39 versus 8 months; p = 0.022). In both groups, high CUX1 levels indicated a metastatic phenotype. Functionally, CUX1 upregulated expression of caspases and death associated protein kinase 1 (DAPK1), known as mediators of tumour progression and resistance to cytotoxic drugs. This was also confirmed in both cell lines and human tissues. In the RIP1Tag2 mouse model, CUX1 expression was associated with advanced tumour stage and resistance to apoptosis. In summary, we identified the transcription factor CUX1 as mediator of tumour progression in non-functional PanNET in vitro and in vivo, indicating that the CUX1-dependent signalling network is a promising target for future therapeutic intervention.

scholarly journals Indirect cholinergic activation slows down pancreatic cancer growth and tumor-associated inflammation

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Paulo L. Pfitzinger ◽  
Laura Fangmann ◽  
Kun Wang ◽  
Elke Demir ◽  
Engin Gürlevik ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mouse Model ◽  
Tumor Stage ◽  
Ache Inhibitors ◽  
Impact On Survival ◽  
The Impact ◽  
Ache Expression ◽  
Cholinergic Activation

Abstract Background Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine. Methods We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/−physostigmine/pyridostigmine (n = 30 mice). Human PCa specimens (n = 39) were analyzed for the impact of cancer AChE expression on tumor stage and survival. Results We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves. Conclusion For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.

scholarly journals In Vitro ELISA and Cell-Based Assays Confirm the Low Immunogenicity of VNAR Therapeutic Constructs in a Mouse Model of Human RA: An Encouraging Milestone to Further Clinical Drug Development

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Obinna C. Ubah ◽  
Andrew J. Porter ◽  
Caroline J. Barelle
Keyword(s):  
Mouse Model ◽  
Solid Phase ◽  
Molecular Architecture ◽  
Serum Samples ◽  
Complete Control ◽  
Drug Levels ◽  
Trough Serum ◽  
The Impact

Anti-drug antibodies (ADAs), specific for biotherapeutic drugs, are associated with reduced serum drug levels and compromised therapeutic response. The impact of ADA on the bioavailability and clinical efficacy of blockbuster anti-hTNF-α monoclonal antibodies is well recognised, especially for adalimumab and infliximab treatments, with the large and complex molecular architecture of classical immunoglobulin antibody drugs, in part, responsible for the immunogenicity seen in patients. The initial aim of this study was to develop solid-phase enzyme-linked immunosorbent assays (ELISA) and an in vitro cell-based method to accurately detect ADA and estimate its impact on the preclinical in vivo efficacy outcomes of two novel, nonimmunoglobulin VNAR fusion anti-hTNF-α biologics (Quad-X™ and D1-NDure™-C4) and Humira®, a brand of adalimumab. Serum drug levels and the presence of ADA were determined in a transgenic mouse model of polyarthritis (Tg197) when Quad-X™ and Humira® were dosed at 1 mg/kg and D1-NDure™-C4 was dosed at 30 mg/kg. The serum levels of the Quad-X™ and D1-NDure™-C4 modalities were consistently high and comparable across all mice within the same treatment groups. In 1 mg/kg and 3 mg/kg Quad-X™- and 30 mg/kg D1-NDure™-C4-treated mice, an average trough drug serum concentration of 8 μg/mL, 50 μg/mL, and 350 μg/mL, respectively, were estimated. In stark contrast, Humira® trough serum concentrations in the 1 mg/kg treatment group ranged from <0.008 μg/mL to 4 μg/mL with trace levels detected in 7 of the 8 animals treated. Trough serum Humira® and Quad-X™ concentrations in 3 mg/kg treatment samples were comparable; however, the functionality of the detected Humira® serum was significantly compromised due to neutralising ADA. The impact of ADA went beyond the simple and rapid clearance of Humira®, as 7/8 serum samples also showed no detectable capacity to neutralise hTNF-α-mediated cytotoxicity in a murine fibrosarcoma (L929) cell assay. The neutralisation capacity of all the VNAR constructs remained unchanged at the end of the experimental period (10 weeks). The data presented in this manuscript goes some way to explain the exciting outcomes of the previously published preclinical in vivo efficacy data, which showed complete control of disease at Quad-X™ concentrations of 0.5 mg/kg, equivalent to 10x the in vivo potency of Humira®. This independent corroboration also validates the robustness and reliability of the assay techniques reported in this current manuscript, and while it comes with the caveat of a mouse study, it does appear to suggest that these particular VNAR constructs, at least, are of low inherent immunogenicity.

scholarly journals Indirect cholinergic activation slows down pancreatic cancer growth and tumor-associated inflammation

2020 ◽  
Author(s):  
Paulo L. Pfitzinger ◽  
Laura Fangmann ◽  
Kun Wang ◽  
Elke Demir ◽  
Engin Gürlevik ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mouse Model ◽  
Tumor Stage ◽  
Ache Inhibitors ◽  
Impact On Survival ◽  
The Impact ◽  
Ache Expression ◽  
Cholinergic Activation

Abstract Background: Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine.Methods: We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/-physostigmine/pyridostigmine (n=30 mice). Human PCa specimens (n=39) were analyzed for the impact of cancer AChE expression on tumor stage and survival.Results: We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves.Conclusion: For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.

scholarly journals Chronic sodium bromide relieves autistic-like deficits in the Oprm1 mouse model of autism and modulates the activity of serotonin and dopamine receptors in vitro

2020 ◽  
Author(s):  
Cécile Derieux ◽  
Sébastien Roux ◽  
Thierry Plouvier ◽  
Audrey Léauté ◽  
Agathe Brugoux ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dopamine Receptors ◽  
Therapeutic Potential ◽  
Autism Spectrum ◽  
Chloride Ions ◽  
Sodium Bromide ◽  
Bromide Ion ◽  
The Impact

Chronic sodium bromide relieves autistic-like deficits in the Oprm1 mouse model of autism and modulates the activity of serotonin and dopamine receptors in vitro C. DERIEUX 1 , S. ROUX 1 , A. LEAUTE 1 , T. PLOUVIER 2 , J.A.J. BECKER 1 , J. LE MERRER 1 1 Déficits de Récompense, GPCRs et Sociabilité, Physiologie de la Reproduction et des Comportements, INRA UMR0085, CNRS UMR7247, Université de Tours, Inserm ; 37380 Nouzilly, France 2 Térali Innov, 37230 Fondettes, France Corresponding author : [email protected] Autism spectrum disorders (ASD) are complex neurodevelopmental diseases whose diagnosis lies on the detection of impaired social skills together with restricted and repetitive behavior and interests (DSM-5). Although the etiology of ASD remains mostly unknown, impaired excitation/inhibition ratio appears as a common mechanistic feature. Bromide ion is known to reduce hyperexcitability, possibly by competing with chloride ions at channels and transporters and may thus have therapeutic potential in ASD. Aims : We evaluated the therapeutic potential of bromide ion in the Oprm1 -/- mouse model of ASD and the molecular mechanisms involved in bromide treatment, notably effects on GPCRs. Methods : In vivo , we first assessed the effect of chronically administered sodium bromide on autistic-like behavioral deficits and performed RT-qPCR on brain structures known to be involved in ASD. In vitro , we evaluated the impact of bromide ion on G-protein mediated signaling of serotonin and dopamine receptors. Results : In vivo , sodium bromide (30 to 500 mg/Kg) dose-dependently improved social interaction and preference, reduced stereotypies and decreased anxiety. Bromide also impacts the expression of genes coding for some GPCRs, chloride transporters and GABA A subunits. In vitro , bromide behaves as a positive allosteric modulator of 5-HT 6 , 5-HT 7 and D1 receptors but not 5-HT 4 and D2 receptors. Conclusions : The beneficial effects of bromide administration in a genetic murine model of ASD and its impact on both gene expression and GPCR pharmacology predicts high translational potential in patients with autism, despite high heterogeneity in etiology and symptoms.

scholarly journals HAND2 is a novel obesity-linked adipogenic transcription factor regulated by glucocorticoid signalling

Diabetologia ◽  
2021 ◽  
Author(s):  
Maude Giroud ◽  
Foivos-Filippos Tsokanos ◽  
Giorgio Caratti ◽  
Stefan Kotschi ◽  
Sajjad Khani ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Adipose Tissue ◽  
Mouse Model ◽  
Molecular Mechanisms ◽  
Adipocyte Differentiation ◽  
Gene Clusters ◽  
Data Availability ◽  
Primary Mouse

Abstract Aims/hypothesis Adipocytes are critical cornerstones of energy metabolism. While obesity-induced adipocyte dysfunction is associated with insulin resistance and systemic metabolic disturbances, adipogenesis, the formation of new adipocytes and healthy adipose tissue expansion are associated with metabolic benefits. Understanding the molecular mechanisms governing adipogenesis is of great clinical potential to efficiently restore metabolic health in obesity. Here we investigate the role of heart and neural crest derivatives-expressed 2 (HAND2) in adipogenesis. Methods Human white adipose tissue (WAT) was collected from two cross-sectional studies of 318 and 96 individuals. In vitro, for mechanistic experiments we used primary adipocytes from humans and mice as well as human multipotent adipose-derived stem (hMADS) cells. Gene silencing was performed using siRNA or genetic inactivation in primary adipocytes from loxP and or tamoxifen-inducible Cre-ERT2 mouse models with Cre-encoding mRNA or tamoxifen, respectively. Adipogenesis and adipocyte metabolism were measured by Oil Red O staining, quantitative PCR (qPCR), microarray, glucose uptake assay, western blot and lipolysis assay. A combinatorial RNA sequencing (RNAseq) and ChIP qPCR approach was used to identify target genes regulated by HAND2. In vivo, we created a conditional adipocyte Hand2 deletion mouse model using Cre under control of the Adipoq promoter (Hand2AdipoqCre) and performed a large panel of metabolic tests. Results We found that HAND2 is an obesity-linked white adipocyte transcription factor regulated by glucocorticoids that was necessary but insufficient for adipocyte differentiation in vitro. In a large cohort of humans, WAT HAND2 expression was correlated to BMI. The HAND2 gene was enriched in white adipocytes compared with brown, induced early in differentiation and responded to dexamethasone (DEX), a typical glucocorticoid receptor (GR, encoded by NR3C1) agonist. Silencing of NR3C1 in hMADS cells or deletion of GR in a transgenic conditional mouse model results in diminished HAND2 expression, establishing that adipocyte HAND2 is regulated by glucocorticoids via GR in vitro and in vivo. Furthermore, we identified gene clusters indirectly regulated by the GR–HAND2 pathway. Interestingly, silencing of HAND2 impaired adipocyte differentiation in hMADS and primary mouse adipocytes. However, a conditional adipocyte Hand2 deletion mouse model using Cre under control of the Adipoq promoter did not mirror these effects on adipose tissue differentiation, indicating that HAND2 was required at stages prior to Adipoq expression. Conclusions/interpretation In summary, our study identifies HAND2 as a novel obesity-linked adipocyte transcription factor, highlighting new mechanisms of GR-dependent adipogenesis in humans and mice. Data availability Array data have been submitted to the GEO database at NCBI (GSE148699). Graphical abstract

scholarly journals Disrupting Ectopic Super-Enhancers to Treat Multiple Myeloma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1593-1593
Author(s):  
Seth Welsh ◽  
Daniel Riggs ◽  
Erin Meermeier ◽  
Chang-Xin Shi ◽  
Victoria Garbitt ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Transcription Factor ◽  
Mouse Model ◽  
Therapeutic Response ◽  
Genetically Engineered ◽  
Therapeutic Window ◽  
Super Enhancer ◽  
Genetically Engineered Mouse Model

Abstract Multiple myeloma (MM) is an incurable form of plasma cell cancer in which primary and secondary chromosomal translocations routinely juxtapose oncogenes to plasma cell-specific super-enhancers. Coincidentally, drugs which target super-enhancers have had success clinically. For example, immunomodulatory imide drugs (IMiDs) degrade super-enhancer-binding pioneer factors IKAROS and AIOLOS, while glucocorticoids (Dexamethasone) and proteasome inhibitors (Bortezomib) have the ability to transrepress or block the processing of super-enhancer-forming NF-κB proteins, respectively. Currently, alternative enhancer-targeting drugs are also in clinical development, like p300 inhibitors which target the acetyl-binding bromodomains and/or histone acetyl transferase activity of the chromatin-regulating coactivator homologs CBP and EP300. Despite showing therapeutic promise, our understanding of how these drugs function, alone or together, remains incomplete. Case in point, we find that IMiD-induced degradation of its target proteins IKAROS and AIOLOS does not guarantee a therapeutic response in vitro, and patients successfully treated with IMiDs eventually relapse; meanwhile, coactivator-targeting therapies like p300 inhibitors are often too toxic in vivo, and lack a therapeutic window. To improve the outcomes of MM patients we need to understand the heterogeneous genetics and transcription-factor milieus of the myeloma enhancer landscape, as well as how to increase the precision of enhancer-disrupting drugs. To accomplish this, our lab utilizes more than 60 human myeloma cell lines that have been extensively characterized at the genetic, proteomic, and drug-therapeutic-response levels. Additionally, we have generated a highly-predictive immunocompetent mouse model (Vk*MYC hCRBN+) that develops human-like MM and is sensitive to both IMiDs and a new class of therapeutics termed "degronimids" (normal mice do not respond to IMiDs or degronimids). Our central hypothesis is that combining a broad coactivator-targeting drug (e.g., the p300 inhibitor GNE-781), with a MM-specific transcription factor-targeting drug (e.g., IMiDs) restricts toxicities to myeloma cells and thus improves the therapeutic window. Currently, we are testing a variety of coactivator-targeting compounds alongside traditional IMiD therapies and other preclinical transcription factor-targeting drugs both in vivo and in vitro. We show that Vk*MYC hCRBN+ mice are exquisitely sensitive to GNE-781, requiring one fourth of the dose needed to treat other cancers and therefore avoiding the neutropenia and thrombocytopenia seen at higher doses. Second, we show that although IMiDs and GNE-781 induce an effective but transient response in vivo as single agents, the combination of the two drugs proved curative, with a progressive deepening of the anti-tumor response occurring even after therapy is discontinued. Ongoing experiments aim to determine how this drug combination, and other coactivator + transcription factor-targeting combinations, permanently disrupt myeloma-specific super-enhancers. Disclosures Neri: BMS: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Bahlis: Sanofi: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Genentech: Consultancy. Boise: AstraZeneca: Honoraria, Research Funding; AbbVie/Genentech: Membership on an entity's Board of Directors or advisory committees. Chesi: Abcuro: Patents & Royalties: Genetically engineered mouse model of myeloma; Pi Therapeutics: Patents & Royalties: Genetically engineered mouse model of myeloma; Pfizer: Consultancy; Novartis: Consultancy, Patents & Royalties: human CRBN transgenic mouse; Palleon Pharmaceuticals: Patents & Royalties: Genetically engineered mouse model of myeloma.

scholarly journals Indirect cholinergic activation slows down pancreatic cancer growth and tumor-associated inflammation

2020 ◽  
Author(s):  
Paulo L. Pfitzinger ◽  
Laura Fangmann ◽  
Kun Wang ◽  
Elke Demir ◽  
Engin Gürlevik ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Mouse Model ◽  
Tumor Stage ◽  
Ache Inhibitors ◽  
Impact On Survival ◽  
The Impact ◽  
Ache Expression ◽  
Cholinergic Activation

Abstract Background Nerve-cancer interactions are increasingly recognized to be of paramount importance for the emergence and progression of pancreatic cancer (PCa). Here, we investigated the role of indirect cholinergic activation on PCa progression through inhibition of acetylcholinesterase (AChE) via clinically available AChE-inhibitors, i.e. physostigmine and pyridostigmine. Methods We applied immunohistochemistry, immunoblotting, MTT-viability, invasion, flow-cytometric-cell-cycle-assays, phospho-kinase arrays, multiplex ELISA and xenografted mice to assess the impact of AChE inhibition on PCa cell growth and invasiveness, and tumor-associated inflammation. Survival analyses were performed in a novel genetically-induced, surgically-resectable mouse model of PCa under adjuvant treatment with gemcitabine+/-physostigmine/pyridostigmine (n = 30 mice). Human PCa specimens (n = 39) were analyzed for the impact of cancer AChE expression on tumor stage and survival. Results We discovered a strong expression of AChE in cancer cells of human PCa specimens. Inhibition of this cancer-cell-intrinsic AChE via pyridostigmine and physostigmine, or administration of acetylcholine (ACh), diminished PCa cell viability and invasion in vitro and in vivo via suppression of pERK signaling, and reduced tumor-associated macrophage (TAM) infiltration and serum pro-inflammatory cytokine levels. In the novel genetically-induced, surgically-resectable PCa mouse model, adjuvant co-therapy with AChE blockers had no impact on survival. Accordingly, survival of resected PCa patients did not differ based on tumor AChE expression levels. Patients with higher-stage PCa also exhibited loss of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT), in their nerves. Conclusion For future clinical trials of PCa, direct cholinergic stimulation of the muscarinic signaling, rather than indirect activation via AChE blockade, may be a more effective strategy.

scholarly journals In vivo complex haploinsufficiency-based genetic analysis identifies a transcription factor circuit regulating Candida albicans oropharyngeal infection and epithelial cell endocytosis

2021 ◽  
Author(s):  
Norma V Solis ◽  
Rohan S Wakade ◽  
Tomye L Ollinger ◽  
Melanie Wellington ◽  
Aaron P Mitchell ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Epithelial Cell ◽  
Mouse Model ◽  
Genetic Interaction ◽  
Abiotic Surfaces ◽  
Oropharyngeal Infection ◽  
Wide Range

Oropharyngeal candidiasis (OPC) is a common infection that complicates a wide range of medical conditions which can cause either mild or severe disease depending on the patient. The pathobiology of OPC shares many features with candidal biofilms of abiotic surfaces. The transcriptional regulation of C. albicans formation of biofilms on abiotic surfaces has been extensively characterized and involves six key transcription factors (Efg1, Ndt80, Rob1, Bcr1, Brg1, and Tec1). To determine whether this same in vitro biofilm transcriptional regulatory network played a role in OPC, we have carried out the first systematic genetic interaction analysis in a mouse model of C. albicans infection. Whereas all six transcription factors are required for in vitro biofilm formation, only three homozygous deletion mutants ( tec1 ??, bcr1 ??, and rob1 ??) and one heterozygous mutant ( tec1 ?/ TEC1 ) have reduced infectivity in a mouse model of OPC, indicating the network is more robust in vivo than in vitro. Although single mutants (heterozygous or homozygous) of BRG1 and EFG1 have no effect on fungal burden, the double heterozygous and homozygous mutants have dramatically reduced infectivity, indicating a critical genetic interaction between these two transcription factors. Using epistasis analysis, we have formulated a genetic circuit [ EFG1 + BRG1 ]→ TEC1 → BCR1 that is required for OPC infectivity and oral epithelial cell endocytosis. Surprisingly, we also found transcription factor mutants with in vitro defects in filamentation such as efg1 ?? and brg1 ?? filament during oral infection and that decreased filamentation did not correlate with decreased infectivity. Taken together, these data indicate that key in vitro biofilm transcription factors are involved in OPC but that the network characteristics and functional connections are remodeled significantly during interactions with tissues.

scholarly journals MiR-30a-5p regulates GLT-1 function via a PKCα-mediated ubiquitin degradation pathway in a mouse model of Parkinson’s disease

2020 ◽  
Author(s):  
Xingjun Meng ◽  
Jianping Zhong ◽  
Chong Zeng ◽  
Ken Kin Lam Yung ◽  
Xiuping Zhang ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Mouse Model ◽  
Cell Model ◽  
Glutamate Transporters ◽  
Acid Uptake ◽  
Dependent Manner ◽  
The Impact

Abstract Background:Glutamate excitotoxicity caused by dysfunctional glutamate transporters plays an important role in the pathogenesis of Parkinson’s disease (PD); however, the mechanisms that underlie the regulation of glutamate transporters in PD are still not fully elucidated. MicroRNAs have been reported to play key roles in regulating the translation of glutamate-transporter mRNA. Methods: We established model of PD 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice in vivo and 1-methyl-4-phenylpyridinium (MPP+) treated astrocyte in vitro. Stereotaxic injection of shRNA in mouse, and miRNA inhibitor/mimic, or antagonist/agonist treated the cell model, Behavioral experiments, glutamic acid uptake, transport activity of synaptosomes, underlying mechanisms and the impact on neuronal survival were assessed.Results We demonstrated that short-hairpin RNA-mediated knockdown of miR-30a-5p ameliorated motor deficits and pathological changes like astrogliosis and reactive microgliosis in a mouse model of PD. Western blotting and immunofluorescent labeling revealed that miR-30a-5p suppressed the expression and function of GLT-1 in MPTP-treated mice and specifically in astrocytes treated with (cell model of PD). Conclusion Both in vitro and in vivo, we found that miR-30a-5p knockdown promoted glutamate uptake and increased GLT-1 expression by hindering GLT-1 ubiquitination and subsequent degradation in a PKCα-dependent manner. Therefore, miR-30a-5p represents a potential therapeutic target for the treatment of PD.

The HSP90 Inhibitor 17-DMAG Targets NF-κB to Induce Apoptosis in CLL and Prolongs Survival in a CLL Mouse Model.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 732-732
Author(s):  
Erin K Hertlein ◽  
Thomas S Lin ◽  
Wagner J Amy ◽  
Towns H William ◽  
Virginia M Goettl ◽  
...  
Keyword(s):  
Mouse Model ◽  
Disease Progression ◽  
Target Genes ◽  
Conflicts Of Interest ◽  
Therapeutic Option ◽  
Hsp90 Inhibitor ◽  
Client Proteins ◽  
The Impact

Abstract Abstract 732 One attractive therapeutic target currently being explored in CLL is HSP90, a chaperone which stabilizes various client proteins (AKT, Raf, ZAP-70) which are important for survival of CLL cells. Interfering with HSP90 protein binding to these client proteins leads to their rapid degradation. Our group and others have demonstrated that 17-allylamino-17-demethoxy-geldanamycin (17-AAG) depletes only select chaperone proteins and promotes modest cytotoxicity in CLL patient cells. 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG) is a novel HSP90 inhibitor with improved solubility, bioavailability and cytotoxicity in cancer cell lines as compared to 17-AAG. We demonstrate that 17-DMAG more potently induces caspase-dependent apoptosis of primary CLL cells compared to 17-AAG. This enhanced cytotoxicity is tumor cell selective as it spares normal T-cells and NK-cells, and only modestly affects normal B cells. In addition to the broad range of Hsp90 client proteins which are regulated by 17-AAG (AKT, CDK9, ZAP-70), we found that 17-DMAG was also able to deplete both IKKαa and IKKβ, the activating kinases of the NF-κB family of transcription factors. The impact of 17-DMAG on both IKKαa and β is very relevant, as there have been several studies investigating the effect of IKK inhibitors on in vitro apoptosis in CLL, however there is still no clear therapeutic option for targeting these kinases in the clinic. Most IKK inhibitors including 17-AAG are specific for the IKKβ subunit that mediates classical NF-κB signaling, leaving IKKαa and the alternative NF-κB pathway intact. This is particularly important given recent evidence by Lam et al. (Clin Can Res 2005 Jan 1;11(1):28-40) demonstrating that IKKαa is able to compensate for the loss of IKKβ in DLBCL cells lines. Therefore the ability of 17-DMAG to target both subunits of the IKK complex potentially makes it a very potent and effective NF-κB inhibitor in CLL. To validate the downstream significance of this NF-κB regulation, we show that 17-DMAG effectively reduces NF-κB nuclear localization DNA binding in CLL patient cells resulting in decreased transcript and protein levels of NF-κB targets MCL1 and BCL2, known to be major factors in CLL cell survival and drug resistance. The decrease in MCL1 and BCL2 following 17-DMAG treatment was not prevented by treatment with the caspase inhibitor zVAD-fmk even though viability was rescued, suggesting that the decrease in these survival proteins precedes cell death and is not simply a consequence of the apoptotic process. Finally, we determined the in vivo significance of 17-DMAG treatment using a TCL1-SCID transplant model. We found that NF-κB targets genes (A20, BCL2, cIAP, MCL1 and XIAP) were decreased in vivo following treatment with 17-DMAG. In addition to typical genes which are activated by NF-κB, we also determined the in vivo effect of 17-DMAG on NF-κB mediated transcriptional repression. Our group has recently determined that the transcription factor FOXD3 is transcriptionally silenced by an NF-κB repressor complex very early in the disease progression of the TCL1 mouse model, an event which facilitates subsequent global DNA methylation and gene silencing in CLL. We found that treatment with 17-DMAG leads to re-expression of FOXD3 suggesting that 17-DMAG is an effective therapeutic tool to target NF-κB mediated gene repression as well as NF-κB mediated expression of survival genes. Furthermore, 17-DMAG treatment significantly prolonged the survival of these mice (75 days vs. 66 days, p=0.027, n=10/group). Together, our data demonstrate that the HSP90 inhibitor 17-DMAG represents a novel multi-subunit IKK inhibitor leading to a decrease in anti-apoptosis genes relevant to CLL survival while increasing the expression of genes silenced during CLL disease progression. Given its oral formulation, which allows administration of 17-DMAG by continuous dosing and uninterrupted inhibition of HSP90, initiation of phase II clinical trials in CLL that include detailed pharmacodynamic studies monitoring NF-κB target genes are indicated. Disclosures: No relevant conflicts of interest to declare.

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