11 results on '"Keschrumrus, Vic"'
Search Results
2. Training stem cells for treatment of malignant brain tumors
- Author
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Li, Shengwen Calvin, Kabeer, Mustafa H, Vu, Long T, Keschrumrus, Vic, Yin, Hong Zhen, Dethlefs, Brent A, Zhong, Jiang F, Weiss, John H, and Loudon, William G
- Published
- 2014
3. Cancer stem cells from a rare form of glioblastoma multiforme involving the neurogenic ventricular wall
- Author
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Li, Shengwen, Vu, Long T, Ho, Hector W, Yin, Hong, Keschrumrus, Vic, Lu, Qiang, Wang, Jun, Zhang, Heying, Ma, Zhiwei, Stover, Alexander, Weiss, John H, Schwartz, Philip H, and Loudon, William G
- Abstract
Abstract Background The cancer stem cell (CSC) hypothesis posits that deregulated neural stem cells (NSCs) form the basis of brain tumors such as glioblastoma multiforme (GBM). GBM, however, usually forms in the cerebral white matter while normal NSCs reside in subventricular and hippocampal regions. We attempted to characterize CSCs from a rare form of glioblastoma multiforme involving the neurogenic ventricular wall. Methods We described isolating CSCs from a GBM involving the lateral ventricles and characterized these cells with in vitro molecular biomarker profiling, cellular behavior, ex vivo and in vivo techniques. Results The patient’s MRI revealed a heterogeneous mass with associated edema, involving the left subventricular zone. Histological examination of the tumor established it as being a high-grade glial neoplasm, characterized by polygonal and fusiform cells with marked nuclear atypia, amphophilic cytoplasm, prominent nucleoli, frequent mitotic figures, irregular zones of necrosis and vascular hyperplasia. Recurrence of the tumor occurred shortly after the surgical resection. CD133-positive cells, isolated from the tumor, expressed stem cell markers including nestin, CD133, Ki67, Sox2, EFNB1, EFNB2, EFNB3, Cav-1, Musashi, Nucleostemin, Notch 2, Notch 4, and Pax6. Biomarkers expressed in differentiated cells included Cathepsin L, Cathepsin B, Mucin18, Mucin24, c-Myc, NSE, and TIMP1. Expression of unique cancer-related transcripts in these CD133-positive cells, such as caveolin-1 and −2, do not appear to have been previously reported in the literature. Ex vivo organotypic brain slice co-culture showed that the CD133+ cells behaved like tumor cells. The CD133-positive cells also induced tumor formation when they were stereotactically transplanted into the brains of the immune-deficient NOD/SCID mice. Conclusions This brain tumor involving the neurogenic lateral ventricular wall was comprised of tumor-forming, CD133-positive cancer stem cells, which are likely the driving force for the rapid recurrence of the tumor in the patient.
- Published
- 2012
4. Maturing Engineered Heart Tissues for Titin-Based Disease Modeling
- Author
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Tardiff, Jil C., Konhilas, John P., Colson, Brett A., Keschrumrus, Vic P., Tardiff, Jil C., Konhilas, John P., Colson, Brett A., and Keschrumrus, Vic P.
- Abstract
Engineered heart tissues (EHTs) are three-dimensional, fibrin-based heart muscle constructs developed as an advanced disease modeling tool for therapeutic development and personalized medicine, but at a fraction of the time and cost of traditional animal models. EHT maturity can be evaluated by identifying the isoforms of titin, a giant filamentous protein that regulates sarcomere organization and provides passive stiffness to cardiomyocytes, and has been implicated in cardiomyopathies. For example, dilated cardiomyopathy (DCM) patients have been shown to undergo eccentric remodeling with a switch from a stiffer N2B isoform to a more compliant N2BA isoform. Current neonatal rat EHTs express immature titin isoform expression patterns and require additional maturation to improve clinical relevancy. This dissertation examines different approaches to maturing titin isoform expression in EHTs using angiotensin II and triiodothyronine supplementation, chronic electrical stimulation, and extracellular matrix (ECM) modifications. Angiotensin II supplementation at 20 µM significantly increased mature N2B titin isoform expression while triiodothyronine supplementation had no significant effect. Chronic electrical stimulation at 0.5 Hz significantly enhanced the force production, fractional shortening, and contraction velocity in EHTs. However, paced EHTs exhibited a negative force-frequency relationship indicating other factors like calcium handling should also be considered for maturation. Surprisingly only N2BA titin isoform expression was significantly increased in paced EHTs. Sarcomere width and ECM, myofiber, mitochondria, and void fractional area were also significantly increase in paced EHTs while significant reduction was observed in Z-disk width, sarcomere length, collagen fibril width, and cytoplasm, cardiomyocyte, and empty fractional area. Decreasing the fibrinogen concentration lowered the Young’s Modulus of the initial fibrin gel used for generating EHTs. This c
- Published
- 2021
5. The use of poly(ethylene glycol) hydrogels to investigate the impact of ECM chemistry and mechanics on smooth muscle cells
- Author
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Peyton, Shelly R., Raub, Christopher B., Keschrumrus, Vic P., and Putnam, Andrew J.
- Published
- 2006
- Full Text
- View/download PDF
6. Single-Molecule Force Spectroscopy on the N2A Element of Titin: Effects of Phosphorylation and CARP
- Author
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Lanzicher, Thomas, primary, Zhou, Tiankun, additional, Saripalli, Chandra, additional, Keschrumrus, Vic, additional, Smith III, John E., additional, Mayans, Olga, additional, Sbaizero, Orfeo, additional, and Granzier, Henk, additional
- Published
- 2020
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- View/download PDF
7. MMP inhibitors attenuate doxorubicin cardiotoxicity by preventing intracellular and extracellular matrix remodelling
- Author
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Chan, Brandon Y H, primary, Roczkowsky, Andrej, additional, Cho, Woo Jung, additional, Poirier, Mathieu, additional, Sergi, Consolato, additional, Keschrumrus, Vic, additional, Churko, Jared M, additional, Granzier, Henk, additional, and Schulz, Richard, additional
- Published
- 2020
- Full Text
- View/download PDF
8. Correction: Tissue Elasticity Regulated Tumor Gene Expression: Implication for Diagnostic Biomarkers of Primitive Neuroectodermal Tumor
- Author
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Vu, Long T., primary, Keschrumrus, Vic, additional, Zhang, Xi, additional, Zhong, Jiang F., additional, Su, Qingning, additional, Kabeer, Mustafa H., additional, Loudon, William G., additional, and Li, Shengwen Calvin, additional
- Published
- 2015
- Full Text
- View/download PDF
9. Cancer stem cells from a rare form of glioblastoma multiforme involving the neurogenic ventricular wall.
- Author
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Shengwen Calvin Li, Vu, Long T., Ho, Hector W., Hong Zhen Yin, Keschrumrus, Vic, Qiang Lu, Jun Wang, Heying Zhang, Zhiwei Ma, Stover, Alexander, Weiss, John H., Schwartz, Philip H., and Loudon, William G.
- Subjects
CANCER stem cells ,CANCER patients ,BIOMARKERS ,MEDICAL imaging systems ,BRAIN tumors - Abstract
Background: The cancer stem cell (CSC) hypothesis posits that deregulated neural stem cells (NSCs) form the basis of brain tumors such as glioblastoma multiforme (GBM). GBM, however, usually forms in the cerebral white matter while normal NSCs reside in subventricular and hippocampal regions. We attempted to characterize CSCs from a are form of glioblastoma multiforme involving the neurogenic ventricular wall. Methods: We described isolating CSCs from a GBM involving the lateral ventricles and characterized these cells with in vitro molecular biomarker profiling, cellular behavior, ex vivo and in vivo techniques. Results: The patient's MRI revealed a heterogeneous mass with associated edema, involving the left subventricular zone. Histological examination of the tumor established it as being a high-grade glial neoplasm, characterized by polygonal and fusiform cells with marked nuclear atypia, amphophilic cytoplasm, prominent nucleoli, frequent mitotic figures, irregular zones of necrosis and vascular hyperplasia. Recurrence of the tumor occurred shortly after the surgical resection. CD133-positive cells, isolated from the tumor, expressed stem cell markers including nestin, CD133, Ki67, Sox2, EFNB1, EFNB2, EFNB3, Cav-1, Musashi, Nucleostemin, Notch 2, Notch 4, and Pax6. Biomarkers expressed in differentiated cells included Cathepsin L, Cathepsin B, Mucin18, Mucin24, c-Myc, NSE, and TIMP1. Expression of unique cancer-related transcripts in these CD133-positive cells, such as caveolin-1 and -2, do not appear to have been previously reported in the literature. Ex vivo organotypic brain slice co-culture showed that the CD133+ cells behaved like tumor cells. The CD133-positive cells also induced tumor formation when they were stereotactically transplanted into the brains of the immune-deficient NOD/SCID mice. Conclusions: This brain tumor involving the neurogenic lateral ventricular wall was comprised of tumor-forming, CD133-positive cancer stem cells, which are likely the driving force for the rapid recurrence of the tumor in the patient. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
10. Single-Molecule Force Spectroscopy on the N2A Element of Titin: Effects of Phosphorylation and CARP
- Author
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Henk Granzier, Tiankun Zhou, Vic Keschrumrus, John E. Smith, Orfeo Sbaizero, Olga Mayans, Thomas Lanzicher, Chandra Saripalli, Lanzicher, Thoma, Zhou, Tiankun, Saripalli, Chandra, Keschrumrus, Vic, Smith III, John E., Mayans, Olga, Sbaizero, Orfeo, and Granzier, Henk
- Subjects
0301 basic medicine ,mechano-signaling ,Physiology ,animal diseases ,passive stiffness ,Immunoglobulin domain ,Sarcomere ,lcsh:Physiology ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,ddc:570 ,titin ,Carp ,Original Research ,spring elements ,biology ,Strain (chemistry) ,lcsh:QP1-981 ,Chemistry ,Force spectroscopy ,Molecular spring ,post-translational modification ,biology.organism_classification ,030104 developmental biology ,biology.protein ,Biophysics ,Phosphorylation ,Titin ,passive stiffne ,spring element ,030217 neurology & neurosurgery - Abstract
Titin is a large filamentous protein that forms a sarcomeric myofilament with a molecular spring region that develops force in stretched sarcomeres. The molecular spring has a complex make-up that includes the N2A element. This element largely consists of a 104-residue unique sequence (N2A-Us) flanked by immunoglobulin domains (I80 and I81). The N2A element is of interest because it assembles a signalosome with CARP (Cardiac Ankyrin Repeat Protein) as an important component; CARP both interacts with the N2A-Us and I81 and is highly upregulated in response to mechanical stress. The mechanical properties of the N2A element were studied using single-molecule force spectroscopy, including how these properties are affected by CARP and phosphorylation. Three protein constructs were made that consisted of 0, 1, or 2 N2A-Us elements with flanking I80 and I81 domains and with specific handles at their ends for study by atomic force microscopy (AFM). The N2A-Us behaved as an entropic spring with a persistence length (Lp) of ∼0.35 nm and contour length (Lc) of ∼39 nm. CARP increased the Lp of the N2A-Us and the unfolding force of the Ig domains; force clamp experiments showed that CARP reduced the Ig domain unfolding kinetics. These findings suggest that CARP might function as a molecular chaperone that protects I81 from unfolding when mechanical stress is high. The N2A-Us was found to be a PKA substrate, and phosphorylation was blocked by CARP. Mass spectrometry revealed a PKA phosphosite (Ser-9895 in NP_001254479.2) located at the border between the N2A-Us and I81. AFM studies showed that phosphorylation affected neither the Lp of the N2A-Us nor the Ig domain unfolding force (Funfold). Simulating the force-sarcomere length relation of a single titin molecule containing all spring elements showed that the compliance of the N2A-Us only slightly reduces passive force (1.4%) with an additional small reduction by CARP (0.3%). Thus, it is improbable that the compliance of the N2A element has a mechanical function per se. Instead, it is likely that this compliance has local effects on binding of signaling molecules and that it contributes thereby to strain- and phosphorylation- dependent mechano-signaling. published
- Published
- 2020
11. MMP inhibitors attenuate doxorubicin cardiotoxicity by preventing intracellular and extracellular matrix remodelling.
- Author
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Chan BYH, Roczkowsky A, Cho WJ, Poirier M, Sergi C, Keschrumrus V, Churko JM, Granzier H, and Schulz R
- Subjects
- Animals, Cardiotoxicity, Cell Line, Disease Models, Animal, Doxorubicin, Extracellular Matrix enzymology, Extracellular Matrix pathology, Fibrosis, Heart Diseases chemically induced, Heart Diseases enzymology, Heart Diseases physiopathology, Human Embryonic Stem Cells drug effects, Human Embryonic Stem Cells enzymology, Humans, Male, Mice, Inbred C57BL, Mitochondria, Heart drug effects, Mitochondria, Heart enzymology, Mitochondria, Heart ultrastructure, Myocytes, Cardiac enzymology, Myocytes, Cardiac ultrastructure, Protein Kinases metabolism, Proteolysis, Mice, Doxycycline pharmacology, Extracellular Matrix drug effects, Heart Diseases prevention & control, Matrix Metalloproteinase 2 metabolism, Matrix Metalloproteinase Inhibitors pharmacology, Myocytes, Cardiac drug effects, Phenyl Ethers pharmacology, Ventricular Function, Left drug effects, Ventricular Remodeling drug effects
- Abstract
Aims: Heart failure is a major complication in cancer treatment due to the cardiotoxic effects of anticancer drugs, especially from the anthracyclines such as doxorubicin (DXR). DXR enhances oxidative stress and stimulates matrix metalloproteinase-2 (MMP-2) in cardiomyocytes. We investigated whether MMP inhibitors protect against DXR cardiotoxicity given the role of MMP-2 in proteolyzing sarcomeric proteins in the heart and remodelling the extracellular matrix., Methods and Results: Eight-week-old male C57BL/6J mice were treated with DXR weekly with or without MMP inhibitors doxycycline or ONO-4817 by daily oral gavage for 4 weeks. Echocardiography was used to determine cardiac function and left ventricular remodelling before and after treatment. MMP inhibitors ameliorated DXR-induced systolic and diastolic dysfunction by reducing the loss in left ventricular ejection fraction, fractional shortening, and E'/A'. MMP inhibitors attenuated adverse left ventricular remodelling, reduced cardiomyocyte dropout, and prevented myocardial fibrosis. DXR increased myocardial MMP-2 activity in part also by upregulating N-terminal truncated MMP-2. Immunogold transmission electron microscopy showed that DXR elevated MMP-2 levels within the sarcomere and mitochondria which were associated with myofilament lysis, mitochondrial degeneration, and T-tubule distention. DXR-induced myofilament lysis was associated with increased titin proteolysis in the heart which was prevented by ONO-4817. DXR also increased the level and activity of MMP-2 in human embryonic stem cell-derived cardiomyocytes, which was reduced by ONO-4817., Conclusions: MMP-2 activation is an early event in DXR cardiotoxicity and contributes to myofilament lysis by proteolyzing cardiac titin. Two orally available MMP inhibitors ameliorated DXR cardiotoxicity by attenuating intracellular and extracellular matrix remodelling, suggesting their use may be a potential prophylactic strategy to prevent heart injury during chemotherapy., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2021
- Full Text
- View/download PDF
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