Alternative splicing of fibronectin: a mouse model demonstrates the identity of in vitro and in vivo systems and the processing autonomy of regulated exons in adult mice

AbstractShigellosis results from oral ingestion of the Gram-negative bacteria Shigella, and symptoms include severe diarrhea and dysentery. In the absence of vaccines, small molecule antibacterial drugs have provided treatment options for shigellosis. However, Shigella drug resistance is rapidly emerging, and Shigella strains with resistance to both third-generation cephalosporins and azithromycin have been identified in Asia. A re-conceptualization is needed regarding the development of therapeutics that target bacterial pathogens in order to reduce resistance development and alteration of gut microbiota, which is depleted upon treatment with wide spectrum antibiotics, thereby increasing susceptibility to subsequent enteric infections. A more organism-specific approach is to develop agents targeting virulence factors such as toxins, adhesins, invasins, quorum sensing, and protein secretion systems. For Shigella, there is interest in targeting transcription factors essential for Shigella infection in vivo rather than specific effectors. Here we describe the importance of the Shigella transcription factor IlvY in Shigella virulence in vitro and in vivo. This work included the development of a novel, oral mouse model of Shigella infection with wild-type adult mice. Unlike previous models, mice do not require antibiotic pretreatment or diet modifications. This mouse model was used to demonstrate the importance of IlvY for Shigella in vivo survival and that deletion of ilvY impacts host responses to infection. These results illustrate that IlvY is a potential therapeutic target for the treatment of shigellosis. In addition, the novel mouse model provides an exciting new opportunity to investigate therapeutic efficacy against Shigella infection and host responses to infection.

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A novel phosphoramide compound, DCZ0805, shows potent anti-myeloma activity via the NF-κB pathway

Cancer Cell International ◽

10.1186/s12935-021-01973-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Xuejie Gao ◽

Bo Li ◽

Anqi Ye ◽

Houcai Wang ◽

Yongsheng Xie ◽

...

Keyword(s):

Mouse Model ◽

Tumor Burden ◽

High Rate ◽

Cell Counting ◽

Tumor Xenograft ◽

Luciferase Reporter ◽

Therapeutic Effects ◽

Xenograft Mouse Model

Abstract Background Multiple myeloma (MM) is a highly aggressive and incurable clonal plasma cell disease with a high rate of recurrence. Thus, the development of new therapies is urgently needed. DCZ0805, a novel compound synthesized from osalmide and pterostilbene, has few observed side effects. In the current study, we intend to investigate the therapeutic effects of DCZ0805 in MM cells and elucidate the molecular mechanism underlying its anti-myeloma activity. Methods We used the Cell Counting Kit-8 assay, immunofluorescence staining, cell cycle assessment, apoptosis assay, western blot analysis, dual-luciferase reporter assay and a tumor xenograft mouse model to investigate the effect of DCZ0805 treatment both in vivo and in vitro. Results The results showed that DCZ0805 treatment arrested the cell at the G0/G1 phase and suppressed MM cells survival by inducing apoptosis via extrinsic and intrinsic pathways. DCZ0805 suppressed the NF-κB signaling pathway activation, which may have contributed to the inhibition of cell proliferation. DCZ0805 treatment remarkably reduced the tumor burden in the immunocompromised xenograft mouse model, with no obvious toxicity observed. Conclusion The findings of this study indicate that DCZ0805 can serve as a novel therapeutic agent for the treatment of MM.

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Selective Pseudo-irreversible Butyrylcholinesterase Inhibitors Transferring Antioxidant Moieties to the Enzyme Show Pronounced Neuroprotective Efficacy In Vitro and In Vivo in an Alzheimer’s Disease Mouse Model

Journal of Medicinal Chemistry ◽

10.1021/acs.jmedchem.1c00534 ◽

2021 ◽

Author(s):

Matthias Scheiner ◽

Matthias Hoffmann ◽

Feng He ◽

Eleonora Poeta ◽

Arnaud Chatonnet ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Mouse Model ◽

Neuroprotective Efficacy

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MODL-12. DEVELOPMENT OF A NOVEL IMMUNOCOMPETENT MOUSE MODEL FOR DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.586 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii413-iii413

Author(s):

Maggie Seblani ◽

Markella Zannikou ◽

Katarzyna Pituch ◽

Liliana Ilut ◽

Oren Becher ◽

...

Keyword(s):

Flow Cytometry ◽

Mouse Model ◽

Growth Factor Receptor ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Time Of Application ◽

Tumor Associated Antigen ◽

Sarcoma Virus

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.

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RBMX suppresses tumorigenicity and progression of bladder cancer by interacting with the hnRNP A1 protein to regulate PKM alternative splicing

Oncogene ◽

10.1038/s41388-021-01666-z ◽

2021 ◽

Author(s):

Qiuxia Yan ◽

Peng Zeng ◽

Xiuqin Zhou ◽

Xiaoying Zhao ◽

Runqiang Chen ◽

...

Keyword(s):

Bladder Cancer ◽

Alternative Splicing ◽

Rna Binding ◽

Aerobic Glycolysis ◽

Histological Grade ◽

Migration And Invasion ◽

Binding Motif ◽

Hnrnp A1

AbstractThe prognosis for patients with metastatic bladder cancer (BCa) is poor, and it is not improved by current treatments. RNA-binding motif protein X-linked (RBMX) are involved in the regulation of the malignant progression of various tumors. However, the role of RBMX in BCa tumorigenicity and progression remains unclear. In this study, we found that RBMX was significantly downregulated in BCa tissues, especially in muscle-invasive BCa tissues. RBMX expression was negatively correlated with tumor stage, histological grade and poor patient prognosis. Functional assays demonstrated that RBMX inhibited BCa cell proliferation, colony formation, migration, and invasion in vitro and suppressed tumor growth and metastasis in vivo. Mechanistic investigations revealed that hnRNP A1 was an RBMX-binding protein. RBMX competitively inhibited the combination of the RGG motif in hnRNP A1 and the sequences flanking PKM exon 9, leading to the formation of lower PKM2 and higher PKM1 levels, which attenuated the tumorigenicity and progression of BCa. Moreover, RBMX inhibited aerobic glycolysis through hnRNP A1-dependent PKM alternative splicing and counteracted the PKM2 overexpression-induced aggressive phenotype of the BCa cells. In conclusion, our findings indicate that RBMX suppresses BCa tumorigenicity and progression via an hnRNP A1-mediated PKM alternative splicing mechanism. RBMX may serve as a novel prognostic biomarker for clinical intervention in BCa.

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TMOD-24. GENERATION AND CHARACTERIZATION OF A NOVEL TRANSGENIC IDO REPORTER MOUSE FOR IDO POSTTRANSLATIONAL MODIFICATION ANALYSIS IN SITU

Neuro-Oncology ◽

10.1093/neuonc/noaa215.974 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii233-ii233

Author(s):

April Bell ◽

Lijie Zhai ◽

Erik Ladomersky ◽

Kristen Lauing ◽

Lakshmi Bollu ◽

...

Keyword(s):

Mouse Model ◽

Tumor Cell ◽

Central Nervous System Tumor ◽

Post Translational Modifications ◽

Reporter Mouse ◽

C Terminus ◽

Human Gbm

Abstract Glioblastoma (GBM) is the most common and aggressive primary central nervous system tumor in adults with a median survival of 14.6 months. GBM is a potently immunosuppressive cancer due in-part to the prolific expression of immunosuppressive indoleamine 2,3 dioxygenase 1 (IDO). Tumor cell IDO facilitates the intratumoral accumulation of regulatory T cells (Tregs; CD4+CD25+FoxP3+). Although immunosuppressive IDO activity is canonically characterized by the conversion of tryptophan into kynurenine, we have utilized transgenic and syngeneic mouse models and mutant glioma lines to demonstrate that tumor cell IDO increases Treg accumulation independent of tryptophan metabolism. Here, we address the gap in our understanding of IDO signaling activity in vivo. Subcutaneously-engrafted human GBM expressing human IDO-GFP cDNA was isolated from immunodeficient humanized NSG-SGM3 mice. The tumor was immunoprecipitated for the GFP tag using GFP-TRAP followed by mass spectrometry which revealed a novel methylation site on a lysine residue at amino acid 373 in the IDO C-terminus region. Western blot analysis of IDO protein also revealed the presence of tyrosine phosphorylation. Additionally, we recently created a new transgenic IDO reporter mouse model whereby endogenous IDO is fused to GFP via a T2A linker (IDO→GFP). This model allows for the isolation of IDO+ cells in real-time and without causing cell death, thereby creating the opportunity for downstream molecular analysis of in situ-isolated GFP+ cells. Collectively, our work suggests that IDO non-enzyme activity may involve the post-translational modifications we recently identified. As IDO activity may differ between in vitro and in vivo modeling systems, we will use the new IDO→GFP reporter mouse model for an improved mechanistic understanding of how immunosuppressive IDO facilitates Treg accumulation in vivo.

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Exosome-transported circRNA_0001236 enhances chondrogenesis and suppress cartilage degradation via the miR-3677-3p/Sox9 axis

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02431-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Guping Mao ◽

Yiyang Xu ◽

Dianbo Long ◽

Hong Sun ◽

Hongyi Li ◽

...

Keyword(s):

Bone Marrow ◽

Mouse Model ◽

Chondrogenic Differentiation ◽

Cartilage Degradation ◽

Human Bone ◽

Human Bone Marrow ◽

Luciferase Reporter ◽

Gene And Protein Expression

Abstract Objectives Aberrations in exosomal circular RNA (circRNA) expression have been identified in various human diseases. In this study, we investigated whether exosomal circRNAs could act as competing endogenous RNAs (ceRNAs) to regulate the pathological process of osteoarthritis (OA). This study aimed to elucidate the specific MSC-derived exosomal circRNAs responsible for MSC-mediated chondrogenic differentiation using human bone marrow-derived MSCs (hMSCs) and a destabilization of the medial meniscus (DMM) mouse model of OA. Methods Exosomal circRNA deep sequencing was performed to evaluate the expression of circRNAs in human bone marrow-derived MSCs (hMSCs) induced to undergo chondrogenesis from day 0 to day 21. The regulatory and functional roles of exosomal circRNA_0001236 were examined on day 21 after inducing chondrogenesis in hMSCs and were validated in vitro and in vivo. The downstream target of circRNA_0001236 was also explored in vitro and in vivo using bioinformatics analyses. A luciferase reporter assay was used to evaluate the interaction between circRNA_0001236 and miR-3677-3p as well as the target gene sex-determining region Y-box 9 (Sox9). The function and mechanism of exosomal circRNA_0001236 in OA were explored in the DMM mouse model. Results Upregulation of exosomal circRNA_0001236 enhanced the expression of Col2a1 and Sox9 but inhibited that of MMP13 in hMSCs induced to undergo chondrogenesis. Moreover, circRNA_0001236 acted as an miR-3677-3p sponge and functioned in human chondrocytes via targeting miR-3677-3p and Sox9. Intra-articular injection of exosomal circRNA_0001236 attenuated OA in the DMM mouse model. Conclusions Our results reveal an important role for a novel exosomal circRNA_0001236 in chondrogenic differentiation. Overexpression of exosomal circRNA_0001236 promoted cartilage-specific gene and protein expression through the miR-3677-3p/Sox9 axis. Thus, circRNA_0001236-overexpressing exosomes may alleviate cartilage degradation, suppressing OA progression and enhancing cartilage repair. Our findings provide a potentially effective therapeutic strategy for treating OA.

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

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-020-01796-4 ◽

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.

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Inhibition of Kirsten-Ras reduces fibrosis and protects against renal dysfunction in a mouse model of chronic folic acid nephropathy

Scientific Reports ◽

10.1038/s41598-019-50422-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Lucy J. Newbury ◽

Jui-Hui Wang ◽

Gene Hung ◽

Bruce M. Hendry ◽

Claire C. Sharpe

Keyword(s):

Folic Acid ◽

Kidney Disease ◽

Mouse Model ◽

Renal Dysfunction ◽

Antisense Oligonucleotides ◽

Underlying Mechanism ◽

Therapeutic Benefit ◽

End Stage

Abstract Chronic Kidney Disease is a growing problem across the world and can lead to end-stage kidney disease and cardiovascular disease. Fibrosis is the underlying mechanism that leads to organ dysfunction, but as yet we have no therapeutics that can influence this process. Ras monomeric GTPases are master regulators that direct many of the cytokines known to drive fibrosis to downstream effector cascades. We have previously shown that K-Ras is a key isoform that drives fibrosis in the kidney. Here we demonstrate that K-Ras expression and activation are increased in rodent models of CKD. By knocking down expression of K-Ras using antisense oligonucleotides in a mouse model of chronic folic acid nephropathy we can reduce fibrosis by 50% and prevent the loss of renal function over 3 months. In addition, we have demonstrated in vitro and in vivo that reduction of K-Ras expression is associated with a reduction in Jag1 expression; we hypothesise this is the mechanism by which targeting K-Ras has therapeutic benefit. In conclusion, targeting K-Ras expression with antisense oligonucleotides in a mouse model of CKD prevents fibrosis and protects against renal dysfunction.

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