Publications by authors named "Amit Vasanji"

70 Publications

miR-467 regulates inflammation and blood insulin and glucose.

J Cell Mol Med 2021 Mar 10;25(5):2549-2562. Epub 2021 Feb 10.

Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic, Cleveland, OH, USA.

Obesity is associated with inflammation and insulin resistance (IR), but the regulation of insulin sensitivity (IS) and connections between IS and inflammation remain unclear. We investigated the role of miR-467a-5p, a miRNA induced by hyperglycaemia, in regulating inflammation and blood glucose handling. We previously demonstrated that miR-467a-5p is induced by hyperglycaemia and inhibits the production of thrombospondin-1 (TSP-1), a protein implicated in regulating inflammation. To investigate the role of miR-467 in blood glucose handling and tissue inflammation, WT C57BL/6 mice were fed chow or Western diet from 5 to 32 weeks of age and injected weekly with miR-467a-5p antagonist. Inhibiting miR-467a-5p resulted in 47% increase in macrophage infiltration and increased Il6 levels in adipose tissue, higher plasma insulin levels (98 ng/mL vs 63 ng/mL), and 17% decrease in glucose clearance without increase in weight or HDL/LDL. The antagonist effect was lost in mice on Western diet. Mice lacking TSP-1 lost some but not all of the miR-467 effects, suggesting Thbs1 (and other unknown transcripts) are targeted by miR-467 to regulate inflammation. miR-467a-5p provides a physiological feedback when blood glucose is elevated to avoid inflammation and increased blood glucose and insulin levels, which may prevent IR.
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http://dx.doi.org/10.1111/jcmm.16224DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7933977PMC
March 2021

Automated Quality Assessment and Image Selection of Ultra-Widefield Fluorescein Angiography Images through Deep Learning.

Transl Vis Sci Technol 2020 09 17;9(2):52. Epub 2020 Sep 17.

The Tony and Leona Campane Center for Excellence in Image-Guided Surgery and Advanced Imaging Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.

Purpose: Numerous angiographic images with high variability in quality are obtained during each ultra-widefield fluorescein angiography (UWFA) acquisition session. This study evaluated the feasibility of an automated system for image quality classification and selection using deep learning.

Methods: The training set was comprised of 3543 UWFA images. Ground-truth image quality was assessed by expert image review and classified into one of four categories (ungradable, poor, good, or best) based on contrast, field of view, media opacity, and obscuration from external features. Two test sets, including randomly selected 392 images separated from the training set and an independent balanced image set composed of 50 ungradable/poor and 50 good/best images, assessed the model performance and bias.

Results: In the randomly selected and balanced test sets, the automated quality assessment system showed overall accuracy of 89.0% and 94.0% for distinguishing between gradable and ungradable images, with sensitivity of 90.5% and 98.6% and specificity of 87.0% and 81.5%, respectively. The receiver operating characteristic curve measuring performance of two-class classification (ungradable and gradable) had an area under the curve of 0.920 in the randomly selected set and 0.980 in the balanced set.

Conclusions: A deep learning classification model demonstrates the feasibility of automatic classification of UWFA image quality. Clinical application of this system might greatly reduce manual image grading workload, allow quality-based image presentation to clinicians, and provide near-instantaneous feedback on image quality during image acquisition for photographers.

Translational Relevance: The UWFA image quality classification tool may significantly reduce manual grading for clinical- and research-related work, providing instantaneous and reliable feedback on image quality.
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http://dx.doi.org/10.1167/tvst.9.2.52DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7500112PMC
September 2020

Bioabsorbable Versus Titanium Screws in Anterior Cruciate Ligament Reconstruction Using Hamstring Autograft: A Prospective, Randomized Controlled Trial With 13-Year Follow-up.

Am J Sports Med 2020 May 17;48(6):1316-1326. Epub 2020 Apr 17.

North Sydney Orthopaedic and Sports Medicine, Sydney, Australia.

Background: Bioabsorbable screws for anterior cruciate ligament reconstruction (ACLR) have been a popular choice, with theoretical advantages in imaging and surgery. Titanium and poly-L-lactic acid with hydroxyapatite (PLLA-HA) screws have been compared, but with less than a decade of follow-up.

Purpose/hypothesis: The purpose was to compare long-term outcomes of hamstring autograft ACLR using either PLLA-HA screws or titanium screws. We hypothesized there would be no difference at 13 years in clinical scores or tunnel widening between PLLA-HA and titanium screw types, along with high-grade resorption and ossification of PLLA-HA screws.

Study Design: Randomized controlled trial; Level of evidence, 1.

Methods: Forty patients undergoing ACLR were randomized to receive either a PLLA-HA screw or a titanium screw for ACL hamstring autograft fixation. Blinded evaluation was performed at 2, 5, and 13 years using the International Knee Documentation Committee score, Lysholm knee score, and KT-1000 arthrometer. Magnetic resonance imaging (MRI) was performed at 2 or 5 years and 13 years to evaluate tunnel volumes, ossification around the screw, graft integration, and cyst formation. Computed tomography (CT) of patients with PLLA-HA was performed at 13 years to evaluate tunnel volumes and intratunnel ossification.

Results: No differences were seen in clinical outcomes at 2, 5, or 13 years between the 2 groups. At 13 years, tibial tunnel volumes were smaller for the PLLA-HA group (2.17 cm) compared with the titanium group (3.33 cm; = .004). By 13 years, the PLLA-HA group had complete or nearly complete resorption on MRI or CT scan.

Conclusion: Equivalent clinical results were found between PLLA-HA and titanium groups at 2, 5, and 13 years. Although PLLA-HA screws had complete or nearly complete resorption by 13 years, tunnel volumes remained largely unchanged, with minimal ossification.
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http://dx.doi.org/10.1177/0363546520911024DOI Listing
May 2020

Micro-CT imaging as a method for comparing perfusion in graduated-height and single-height surgical staple lines.

Med Devices (Auckl) 2018 15;11:267-273. Epub 2018 Aug 15.

Minimally Invasive Therapies Group, Medtronic, North Haven, CT, USA,

Background: Wound healing is a goal for advanced technology in the surgical space to benefit clinical outcomes. Surgical staplers are commonly used in a variety of open and minimally invasive abdominal and thoracic procedures. Assessment of wound healing traits, such as perfusion, has been challenging due to technical limitations. A novel technique that utilizes micro-computed tomography methodology to measure perfusion was designed to compare the micro-perfusion of staple lines between commercial stapler reloads that employ different staple height strategies.

Materials And Methods: Following an Institutional Animal Care and Use Committee-approved protocol, rats were euthanized and immediately heparinized prior to a subtotal gastrectomy with either graduated-height or single-height staples. Rats were then perfused with barium, following which stomachs were removed and immediately fixed in formalin to prevent degradation. Stomachs were then imaged using micro-computed tomography and subsequent analysis was utilized to quantify fluid volume and patent vasculature proximity to staples within the staple line region for each group.

Results: Average perfusion volume was significantly higher with graduated-height staples (0.33% ± 0.18%) compared to single-height staples (0.16% ± 0.09%, =0.011). Average vessel-to-staple line distance was not significant but trended lower with graduated-height staples (0.35±0.02 mm) compared to single-height staples (0.36±0.03 mm, =0.18).

Discussion: Graduated-height staples had significantly higher perfusion volume than single-height staples, which likely has a downstream benefit on wound healing and clinical outcomes.

Conclusion: This study shows a higher perfusion volume around the staple lines using graduated-height staples as compared to single-height staples and this may contribute to better wound healing in patients.
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http://dx.doi.org/10.2147/MDER.S171357DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6101738PMC
August 2018

Comparative Effectiveness of Tumor Response Assessment Methods: Standard of Care Versus Computer-Assisted Response Evaluation.

JCO Clin Cancer Inform 2017 11;1:1-16

Brian C. Allen, Duke University Medical Center, Durham, NC; Edward Florez, Reza Sirous, Seth T. Lirette, Michael Griswold, Candace M. Howard-Claudio, J. Clark Henegan, Judd Storrs, and Andrew D. Smith, University of Mississippi Medical Center, Jackson, MS; Erick M. Remer and Brian Rini, The Cleveland Clinic; Amit Vasanji, ImageIQ, Cleveland; Jacob E. Bieszczad, University of Toledo Medical Center, Toledo, OH; Zhen J. Wang, University of California at San Francisco Medical Center, San Francisco, CA; Kelly L. Cox and Sadhna B. Nandwana, Emory University School of Medicine, Atlanta, GA; Ajit H. Goenka, The Mayo Clinic, Rochester, MN; Hyunseon C. Kang, University of Texas MD Anderson Cancer Center, Houston, TX; Rupan Sanyal, University of Alabama at Birmingham Medical Center, Birmingham, AL; Atul B. Shinagare, Dana-Farber Cancer Institute/Brigham and Women's Hospital, Harvard University, Boston, MA; Matthew S. Davenport, University of Michigan Health System, Ann Arbor, MI; and Balaji Ganeshan, University College of London, London, United Kingdom.

Purpose: To compare the effectiveness of metastatic tumor response evaluation with computed tomography using computer-assisted versus manual methods.

Materials And Methods: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, 11 readers from 10 different institutions independently categorized tumor response according to three different therapeutic response criteria by using paired baseline and initial post-therapy computed tomography studies from 20 randomly selected patients with metastatic renal cell carcinoma who were treated with sunitinib as part of a completed phase III multi-institutional study. Images were evaluated with a manual tumor response evaluation method (standard of care) and with computer-assisted response evaluation (CARE) that included stepwise guidance, interactive error identification and correction methods, automated tumor metric extraction, calculations, response categorization, and data and image archiving. A crossover design, patient randomization, and 2-week washout period were used to reduce recall bias. Comparative effectiveness metrics included error rate and mean patient evaluation time.

Results: The standard-of-care method, on average, was associated with one or more errors in 30.5% (6.1 of 20) of patients, whereas CARE had a 0.0% (0.0 of 20) error rate ( P < .001). The most common errors were related to data transfer and arithmetic calculation. In patients with errors, the median number of error types was 1 (range, 1 to 3). Mean patient evaluation time with CARE was twice as fast as the standard-of-care method (6.4 minutes v 13.1 minutes; P < .001).

Conclusion: CARE reduced errors and time of evaluation, which indicated better overall effectiveness than manual tumor response evaluation methods that are the current standard of care.
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http://dx.doi.org/10.1200/CCI.17.00026DOI Listing
November 2017

Three-dimensional structural analysis reveals a Cdk5-mediated kinase cascade regulating hepatic biliary network branching in zebrafish.

Development 2017 07;144(14):2595-2605

Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA

The intrahepatic biliary network is a highly branched three-dimensional network lined by biliary epithelial cells, but how its branching patterns are precisely established is not clear. We designed a new computer-based algorithm that quantitatively computes the structural differences of the three-dimensional networks. Utilizing the algorithm, we showed that inhibition of Cyclin-dependent kinase 5 (Cdk5) led to reduced branching in the intrahepatic biliary network in zebrafish. Further, we identified a previously unappreciated downstream kinase cascade regulated by Cdk5. Pharmacological manipulations of this downstream kinase cascade produced a crowded branching defect in the intrahepatic biliary network and influenced actin dynamics in biliary epithelial cells. We generated larvae carrying a mutation in (), an essential activator of Cdk5. mutant larvae show similar branching defects as those observed in Cdk5 inhibitor-treated larvae. A small-molecule compound that interferes with the downstream kinase cascade rescued the mutant phenotype. These results provide new insights into branching morphogenesis of the intrahepatic biliary network.
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http://dx.doi.org/10.1242/dev.147397DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5536925PMC
July 2017

Quantification of regional variations in glenoid trabecular bone architecture and mineralization using clinical computed tomography images.

J Orthop Res 2018 01 26;36(1):85-96. Epub 2017 Jun 26.

Department of Orthopaedic Surgery, Cleveland Clinic, Cleveland 44195, Ohio.

The purpose of this study was to demonstrate feasibility of a clinical CT imaging and analysis technique to quantify regional variations in trabecular bone architecture and mineralization of glenoid bones. Specifically, our objective was to determine to what extent clinical CT imaging of intact upper extremities can describe variations of trabecular bone architectures at anatomic and peri-implant regions by comparing trabecular bone architectures as measured by high-resolution, micro CT imaging of same excised glenoid bones. Bone volume fraction (BVF), trabecular bone thickness (TbTh), number of trabecular bone (TbN), spacing (TbS), pattern factor (TbPf), bone surface area (BSA), and skeletal connectivity (Conn.), in addition to bone mineral content (BMC) and bone mineral density (BMD), were quantified from both clinical and micro CT images using whole bone, anatomic, and peri-implant bone masks. Strong correlations of BVF, TbTh, TbSp, BMC, and BMD were found between clinical CT and micro CT imaging methods. The variations in BVF, TbTh, TbSp, TbN, BMC, and BMD at anatomical and peri-implant regions were larger than those at whole bone regions. In this study, we have demonstrated that this clinical CT imaging methodology can be used to quantify variations of a patient's glenoid bone at anatomic and peri-implant levels. Statement of Clinical Significance. An in vivo quantitative assessment of glenoid trabecular bone architecture in the anatomic and peri-implant regions may improve our understanding on the role of bone quality on glenoid component loosening following total shoulder arthroplasty. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:85-96, 2018.
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http://dx.doi.org/10.1002/jor.23620DOI Listing
January 2018

Automated quantitative characterisation of retinal vascular leakage and microaneurysms in ultra-widefield fluorescein angiography.

Br J Ophthalmol 2017 06 21;101(6):696-699. Epub 2017 Apr 21.

Ophthalmic Imaging Center, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.

Ultra-widefield fluorescein angiography (UWFA) is an emerging imaging modality used to characterise pathology in the retinal vasculature such as microaneurysms (MAs) and vascular leakage. Despite its potential value for diagnosis and disease surveillance, objective quantitative assessment of retinal pathology by UWFA is currently limited because it requires laborious manual segmentation by trained human graders. In this report, we describe a novel fully automated software platform, which segments MAs and leakage areas in native and dewarped UWFA images with retinal vascular disease. Comparison of the algorithm with human grader-generated gold standards demonstrated significant strong correlations for MA and leakage areas (intraclass correlation coefficient (ICC)=0.78-0.87 and ICC=0.70-0.86, respectively, p=2.1×10 to 3.5×10 and p=7.8×10 to 1.3×10, respectively). These results suggest the algorithm performs similarly to human graders in MA and leakage segmentation and may be of significant utility in clinical and research settings.
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http://dx.doi.org/10.1136/bjophthalmol-2016-310047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5512291PMC
June 2017

Nanophase bone substitute for craniofacial load bearing application: Pilot study in the rodent.

J Biomed Mater Res B Appl Biomater 2018 02 14;106(2):520-532. Epub 2017 Feb 14.

Department of Otolaryngology-Head & Neck Surgery, Case Western Reserve University, Cleveland, OH, USA.

An exploratory pilot study shows that a rodent mandibular defect model is useful in determining the biological response to a nanophase collagen/apatite composite designed as a biomimetic load-bearing bone substitute. Using a critical size defect, eight groups of rats (n = 3) were implanted with four renditions of the nanophase bone substitute (NBS) biomaterial. Each rendition was tested with and without recombinant human bone morphogenetic protein 2 (BMP2). NBS biomaterial renditions were: baseline, hyper-densified, d-ribose crosslinked, and d-ribose crosslinked and hyper-densified. Biological outcomes were assessed surgically, radiologically, and histologically. With the limited power available due to the small N's involved, some interesting hypotheses were generated that will be more fully investigated in future studies. BMP2 loaded NBS, when uncrosslinked, resulted in robust bone formation in the entire defect volume (regardless of porosity). Unloaded NBS were well tolerated but did not cause significant new bone formation in the defect volume. Densification alone had little effect on in vivo performance. Crosslinking thwarted implant uptake of BMP2 and resulted in fibrous encapsulation. It is concluded that the nanophase bone substitute is well tolerated in this bone defect model. When loaded with BMP2, implantation resulted in complete bony healing and defect closure with implant density (porosity) having little effect on bone healing or remodeling. Without BMP2 the biomaterial did not result in defect closure. Crosslinking, necessary to increase mechanical properties in an aqueous environment, disrupts osteointegration and BMP2 uptake. Alternate implant fabrication strategies will be necessary to achieve an improved balance between material strength and osteointegration. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 520-532, 2018.
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http://dx.doi.org/10.1002/jbm.b.33857DOI Listing
February 2018

Liver Surface Nodularity Score Allows Prediction of Cirrhosis Decompensation and Death.

Radiology 2017 06 3;283(3):711-722. Epub 2016 Nov 3.

From the Departments of Radiology (A.D.S., K.A.Z., E.F., R.S., D.S., F.S., M.R.) and Data Science (M.G., S.T.L.), University of Mississippi Medical Center, 2500 N State St, Jackson, MS 39216; and ImageIQ, Cleveland, Ohio (J.B., A.V.).

Purpose To determine whether use of the liver surface nodularity (LSN) score, a quantitative biomarker derived from routine computed tomographic (CT) images, allows prediction of cirrhosis decompensation and death. Materials and Methods For this institutional review board-approved HIPAA-compliant retrospective study, adult patients with cirrhosis and Model for End-Stage Liver Disease (MELD) score within 3 months of initial liver CT imaging between January 3, 2006, and May 30, 2012, were identified from electronic medical records (n = 830). The LSN score was measured by using CT images and quantitative software. Competing risk regression was used to determine the association of the LSN score with hepatic decompensation and overall survival. A risk model combining LSN scores (<3 or ≥3) and MELD scores (<10 or ≥10) was created for predicting liver-related events. Results In patients with compensated cirrhosis, 40% (129 of 326) experienced decompensation during a median follow-up period of 4.22 years. After adjustment for competing risks including MELD score, LSN score (hazard ratio, 1.38; 95% confidence interval: 1.06, 1.79) was found to be independently predictive of hepatic decompensation. Median times to decompensation of patients at high (1.76 years, n = 48), intermediate (3.79 years, n = 126), and low (6.14 years, n = 152) risk of hepatic decompensation were significantly different (P < .001). Among the full cohort with compensated or decompensated cirrhosis, 61% (504 of 830) died during the median follow-up period of 2.26 years. After adjustment for competing risks, LSN score (hazard ratio, 1.22; 95% confidence interval: 1.11, 1.33) and MELD score (hazard ratio, 1.08; 95% confidence interval: 1.06, 1.11) were found to be independent predictors of death. Median times to death of patients at high (0.94 years, n = 315), intermediate (2.79 years, n = 312), and low (4.69 years, n = 203) risk were significantly different (P < .001). Conclusion The LSN score derived from routine CT images allows prediction of cirrhosis decompensation and death. RSNA, 2016 Online supplemental material is available for this article.
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http://dx.doi.org/10.1148/radiol.2016160799DOI Listing
June 2017

Vascular Tumor Burden as a New Quantitative CT Biomarker for Predicting Metastatic RCC Response to Antiangiogenic Therapy.

Radiology 2016 Nov 2;281(2):484-498. Epub 2016 Sep 2.

From the Department of Radiology (A.D.S., F.S., M.R., R.S., H.Z.) and Center for Biostatistics and Bioinformatics (X.Z., M.G.), University of Mississippi Medical Center, 2500 N State St, Jackson, MS 39216; and ImageIQ, Cleveland, Ohio (J.B., A.V.).

Purpose To quantify initial changes in the vascular tumor burden (VTB), a measure of the area of vascularized tumor on computed tomographic (CT) images, and predict tumor response to antiangiogenic therapy in patients with metastatic renal cell carcinoma (RCC). Materials and Methods For this institutional review board-approved HIPAA-compliant secondary analysis of a prospective phase III trial, adult patients with digital CT images and metastatic clear-cell RCC treated with sunitinib were included (n = 275). Target lesions were selected by using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 guidelines, and the CT images obtained after one cycle of sunitinib therapy were evaluated in comparison with baseline images. Tumor-response software was created to quantify tumor metrics (length, area, VTB, and mean attenuation) and automate response assessment. Progression-free survival (PFS) in responders and nonresponders according to VTB criteria was compared by using the Cox proportional hazard ratio (HR). The intraclass correlation coefficient (ICC) was used to assess interobserver agreement among three readers evaluating 28 randomly selected patients. Results VTB criteria nonresponders (n = 120) according to the initial posttherapy CT study were 5.7 times more likely to experience progression of disease (HR = 5.70; 95% confidence interval [CI]: 4.07, 7.97; P < .001) than responders (n = 155). There was not a statistically significant difference in PFS between RECIST nonresponders (n = 255) and responders (n = 20; HR = 1.54; 95% CI: 0.85, 2.77; P = .148). In a patient-level analysis, interobserver agreement was very good for assessing percentage change in length, area, and VTB (ICC = 0.82 [95% CI: 0.67, 0.91], 0.89 [95% CI: 0.79, 0.94], and 0.88 [95% CI: 0.79, 0.94], respectively) but was very poor for assessing percentage change in mean attenuation (ICC = 0.17 [95% CI: -0.05, 0.45]). Conclusion A quantitative CT imaging biomarker designed to measure initial changes in the VTB separated patients into responders and nonresponders, each with significantly different PFS, and showed very good interobserver agreement in patients with metastatic RCC treated with sunitinib. RSNA, 2016 Online supplemental material is available for this article.
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http://dx.doi.org/10.1148/radiol.2016160143DOI Listing
November 2016

Direct contact with perivascular tumor cells enhances integrin αvβ3 signaling and migration of endothelial cells.

Oncotarget 2016 Jul;7(28):43852-43867

Department of Cancer Biology, Cleveland Clinic, Cleveland, OH, USA.

The secretion of soluble pro-angiogenic factors by tumor cells and stromal cells in the perivascular niche promotes the aggressive angiogenesis that is typical of glioblastoma (GBM). Here, we show that angiogenesis also can be promoted by a direct interaction between brain tumor cells, including tumor cells with cancer stem-like properties (CSCs), and endothelial cells (ECs). As shown in vitro, this direct interaction is mediated by binding of integrin αvβ3 expressed on ECs to the RGD-peptide in L1CAM expressed on CSCs. It promotes both EC network formation and enhances directed migration toward basic fibroblast growth factor. Activation of αvβ3 and bone marrow tyrosine kinase on chromosome X (BMX) is required for migration stimulated by direct binding but not for migration stimulated by soluble factors. RGD-peptide treatment of mice with established intracerebral GBM xenografts significantly reduced the percentage of Sox2-positive tumor cells and CSCs in close proximity to ECs, decreased integrin αvβ3 and BMX activation and p130CAS phosphorylation in the ECs, and reduced the vessel surface area. These results reveal a previously unrecognized aspect of the regulation of angiogenesis in GBM that can impact therapeutic anti-angiogenic targeting.
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http://dx.doi.org/10.18632/oncotarget.9700DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5190064PMC
July 2016

Comparative systems pharmacology of HIF stabilization in the prevention of retinopathy of prematurity.

Proc Natl Acad Sci U S A 2016 May 18;113(18):E2516-25. Epub 2016 Apr 18.

Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195; Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, OH 44195;

Retinopathy of prematurity (ROP) causes 100,000 new cases of childhood blindness each year. ROP is initiated by oxygen supplementation necessary to prevent neonatal death. We used organ systems pharmacology to define the transcriptomes of mice that were cured of oxygen-induced retinopathy (OIR, ROP model) by hypoxia-inducible factor (HIF) stabilization via HIF prolyl hydroxylase inhibition using the isoquinolone Roxadustat or the 2-oxoglutarate analog dimethyloxalylglycine (DMOG). Although both molecules conferred a protective phenotype, gene expression analysis by RNA sequencing found that Roxadustat can prevent OIR by two pathways: direct retinal HIF stabilization and induction of aerobic glycolysis or indirect hepatic HIF-1 stabilization and increased serum angiokines. As predicted by pathway analysis, Roxadustat rescued the hepatic HIF-1 knockout mouse from retinal oxygen toxicity, whereas DMOG could not. The simplicity of systemic treatment that targets both the liver and the eye provides a rationale for protecting the severely premature infant from oxygen toxicity.
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http://dx.doi.org/10.1073/pnas.1523005113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4983815PMC
May 2016

Liver Surface Nodularity Quantification from Routine CT Images as a Biomarker for Detection and Evaluation of Cirrhosis.

Radiology 2016 09 18;280(3):771-81. Epub 2016 Apr 18.

From the Department of Radiology (A.D.S., C.R.B., K.Z., H.Z., K.T., R.H.), Department of Pathology (C.S.), and Center for Biostatistics and Bioinformatics (M.G., X.Z.), University of Mississippi Medical Center, 2500 N State St, Jackson, MS 39216; and ImageIQ, Cleveland, Ohio (J.B., A.V.).

Purpose To determine the accuracy, reproducibility, and intra- and interobserver agreement of a computer-based quantitative method to measure liver surface nodularity (LSN) from routine computed tomographic (CT) images as a biomarker for detection and evaluation of cirrhosis. Materials and Methods For this institutional review board-approved HIPAA-compliant retrospective study, adult patients with healthy livers (n = 24) or various stages of hepatitis C virus-induced chronic liver disease (n = 70) with routine nonenhanced and portal venous phase contrast agent-enhanced liver CT imaging with thick-section (5.0 mm) and thin-section (1.25-1.50 mm) axial images obtained between January 1, 2006, and March 31, 2011, were identified from the electronic medical records. A computer algorithm was developed to measure LSN and derive a score. LSN scores, splenic volume, and the ratio of left lateral segment (LLS) to total liver volume (TLV) were measured from the same multiphasic liver CT examinations. Accuracy for differentiating cirrhotic from noncirrhotic livers was assessed by area under the receiver operating characteristic curve. Intra- and interobserver agreement was assessed by intraclass correlation coefficient. Results Median LSN scores from nonenhanced thick-section CT images in cirrhotic livers (3.16; 56 livers) were significantly higher than in noncirrhotic livers (2.11; 38 livers; P < .001). LSN scores from the four CT imaging types (94 patients for each type) were very strongly correlated (range of Spearman r, 0.929-0.960). LSN scores from portal venous phase contrast-enhanced thick-section CT images had significantly higher accuracy (area under the receiver operating characteristic curve, 0.929) than splenic volume (area under the receiver operating characteristic curve, 0.835) or LLS-to-TLV ratio measurements (area under the receiver operating characteristic curve, 0.753) for differentiating cirrhotic from noncirrhotic livers (P = .038 and .003, respectively; n = 94). Intra- and interobserver agreements that used nonenhanced thick CT images were very good (intraclass correlation coefficient, 0.963 and 0.899, respectively). Conclusion Quantitative measurement of LSN on routine CT images accurately differentiated cirrhotic from noncirrhotic livers and was highly reproducible. (©) RSNA, 2016 Online supplemental material is available for this article.
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http://dx.doi.org/10.1148/radiol.2016151542DOI Listing
September 2016

Eotaxin-Rich Proangiogenic Hematopoietic Progenitor Cells and CCR3+ Endothelium in the Atopic Asthmatic Response.

J Immunol 2016 Mar 25;196(5):2377-87. Epub 2016 Jan 25.

Department of Pathobiology, Cleveland Clinic, Cleveland, OH 44195; Respiratory Institute, Cleveland Clinic, Cleveland, OH 44195;

Angiogenesis is closely linked to and precedes eosinophilic infiltration in asthma. Eosinophils are recruited into the airway by chemoattractant eotaxins, which are expressed by endothelial cells, smooth muscles cells, epithelial cells, and hematopoietic cells. We hypothesized that bone marrow-derived proangiogenic progenitor cells that contain eotaxins contribute to the initiation of angiogenesis and inflammation in asthma. Whole-lung allergen challenge of atopic asthma patients revealed vascular activation occurs within hours of challenge and before airway inflammation. The eotaxin receptor CCR3 was expressed at high levels on submucosal endothelial cells in patients and a murine model of asthma. Ex vivo exposure of murine endothelial cells to eotaxins induced migration and angiogenesis. In mechanistic studies, wild-type mice transplanted with eotaxin-1/2-deficient bone marrow had markedly less angiogenesis and inflammation in an atopic asthma model, whereas adoptive transfer of proangiogenic progenitor cells from wild-type mice in an atopic asthma model into the eotaxin-1/2-deficient mice led to angiogenesis and airway inflammation. The findings indicate that Th2-promoting hematopoietic progenitor cells are rapidly recruited to the lung upon allergen exposure and release eotaxins that coordinately activate endothelial cells, angiogenesis, and airway inflammation.
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http://dx.doi.org/10.4049/jimmunol.1500770DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4761512PMC
March 2016

Deficiency of circadian clock protein BMAL1 in mice results in a low bone mass phenotype.

Bone 2016 Mar 14;84:194-203. Epub 2016 Jan 14.

Center for Gene Regulation in Health and Diseases, BGES, Cleveland State University, 2121 Euclid Ave., Cleveland, OH 44115-2214, USA. Electronic address:

The circadian clock is an endogenous time keeping system that controls the physiology and behavior of many organisms. The transcription factor Brain and Muscle ARNT-like Protein 1 (BMAL1) is a component of the circadian clock and necessary for clock function. Bmal1(-/-) mice display accelerated aging and many accompanying age associated pathologies. Here, we report that mice deficient for BMAL1 have a low bone mass phenotype that is absent at birth and progressively worsens over their lifespan. Accelerated aging of these mice is associated with the formation of bony bridges occurring across the metaphysis to the epiphysis, resulting in shorter long bones. Using micro-computed tomography we show that Bmal1(-/-) mice have reductions in cortical and trabecular bone volume and other micro-structural parameters and a lower bone mineral density. Histology shows a deficiency of BMAL1 results in a reduced number of active osteoblasts and osteocytes in vivo. Isolation of bone marrow derived mesenchymal stem cells from Bmal1(-/-) mice demonstrate a reduced ability to differentiate into osteoblasts in vitro, which likely explains the observed reductions in osteoblasts and osteocytes, and may contribute to the observed osteopenia. Our data support the role of the circadian clock in the regulation of bone homeostasis and shows that BMAL1 deficiency results in a low bone mass phenotype.
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http://dx.doi.org/10.1016/j.bone.2016.01.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4755907PMC
March 2016

The mitotic kinesin KIF11 is a driver of invasion, proliferation, and self-renewal in glioblastoma.

Sci Transl Med 2015 Sep;7(304):304ra143

Department of Stem Cell Biology and Regenerative Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA.

The proliferative and invasive nature of malignant cancers drives lethality. In glioblastoma, these two processes are presumed mutually exclusive and hence termed "go or grow." We identified a molecular target that shuttles between these disparate cellular processes-the molecular motor KIF11. Inhibition of KIF11 with a highly specific small-molecule inhibitor stopped the growth of the more treatment-resistant glioblastoma tumor-initiating cells (TICs, or cancer stem cells) as well as non-TICs and impeded tumor initiation and self-renewal of the TIC population. Targeting KIF11 also hit the other arm of the "go or grow" cell fate decision by reducing glioma cell invasion. Administration of a KIF11 inhibitor to mice bearing orthotopic glioblastoma prolonged their survival. In its role as a shared molecular regulator of cell growth and motility across intratumoral heterogeneity, KIF11 is a compelling therapeutic target for glioblastoma.
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http://dx.doi.org/10.1126/scitranslmed.aac6762DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4743764PMC
September 2015

Volumetric ellipsoid zone mapping for enhanced visualisation of outer retinal integrity with optical coherence tomography.

Br J Ophthalmol 2016 Mar 22;100(3):295-9. Epub 2015 Jul 22.

Ophthalmic Imaging Center, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.

Objective assessment of retinal layer integrity with optical coherence tomography (OCT) is currently limited. The ellipsoid zone (EZ) has been identified as an important feature on OCT that has critical prognostic value in macular disorders. In this report, we describe a novel assessment tool for EZ integrity that provides visual and quantitative assessment across an OCT data set. Using this algorithm, we describe the findings in multiple clinical examples, including normal controls, age-related macular degeneration, drug effects (eg, ocriplasmin, hydroxychloroquine) and effects of surgical manipulation (eg, following membrane peeling using intraoperative OCT). EZ mapping provides both en face visualisation of EZ integrity and EZ-retinal pigment epithelium height. Additionally, volumetric, area and linear measurements are feasible using this assessment tool.
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http://dx.doi.org/10.1136/bjophthalmol-2015-307105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4936524PMC
March 2016

Proangiogenic Properties of Thrombospondin-4.

Arterioscler Thromb Vasc Biol 2015 Sep 2;35(9):1975-86. Epub 2015 Jul 2.

From the Department of Molecular Cardiology (S.M., E.F., R.X., I.K., E.P., O.S.-A.), and Cole Eye Institute (S.Y., G.H.), Cleveland Clinic, OH; and ImageIQ Inc, Cleveland, OH (A.V.).

Objective: Thrombospondin-4 (TSP-4) is 1 of the 5 members of the thrombospondin protein family. TSP-1 and TSP-2 are potent antiangiogenic proteins. However, angiogenic properties of the 3 other TSPs, which do not contain the domains associated with the antiangiogeneic activity of TSP-1 and TSP-2, have not been explored. In our previous studies, we found that TSP-4 is expressed in the vascular matrix of blood vessels of various sizes and is especially abundant in capillaries. We sought to identify the function of TSP-4 in the regulation of angiogenesis.

Approach And Results: The effect of TSP-4 in in vivo angiogenesis models and its effect on angiogenesis-related properties in cultured cells were assessed using Thbs4(-/-) mice, endothelial cells (EC) derived from these mice, and recombinant TSP-4. Angiogenesis was decreased in Thbs4(-/-) mice compared with wild-type mice. TSP-4 was detected in the lumen of the growing blood vessels. Mice expressing the P387 TSP-4 variant, which was previously associated with coronary artery disease and found to be more active in its cellular interactions, displayed greater angiogenesis compared with A387 form. Lung EC from Thbs4(-/-) mice exhibited decreased adhesion, migration, and proliferation capacities compared with EC from wild-type mice. Recombinant TSP-4 promoted proliferation and the migration of EC. Integrin α2 and gabapentin receptor α2δ-1 were identified as receptors involved in regulation of EC adhesion, migration, and proliferation by TSP-4.

Conclusion: TSP-4, an extracellular matrix protein previously associated with tissue remodeling, is now demonstrated to possess proangiogenic activity.
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http://dx.doi.org/10.1161/ATVBAHA.115.305912DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4629500PMC
September 2015

Automated Analysis of Anterior Chamber Inflammation by Spectral-Domain Optical Coherence Tomography.

Ophthalmology 2015 Jul 4;122(7):1464-70. Epub 2015 Apr 4.

Cleveland Clinic, Cole Eye Institute, Cleveland, Ohio. Electronic address:

Purpose: This study was designed to determine the feasibility of anterior segment optical coherence tomography (AS-OCT) to objectively image and quantify the degree of AC inflammation.

Design: Prospective evaluation of a diagnostic test.

Participants: Patients with anterior segment involving uveitis.

Methods: Observational case series of patients with uveitis. Single-line and 3-dimensional (3D) volume AS-OCT scans were manually graded to evaluate for the presence or absence of cells in the AC. Clinical grading scores were correlated to the number of cells seen in each line scan. An automated algorithm was developed to measure the number of cells seen in the 3D volume scan and compared with manual measurements and clinical grading scores.

Main Outcome Measures: Degree of anterior segment inflammation.

Results: A total of 114 eyes from 76 patients were imaged, 83 eyes with line scans and 31 eyes with volume scans. The average number of cells on line scans was 0.13 for grade 0, 1.2 for grade 1/2+, 2.6 for grade 1+, 5.7 for grade 2+, 15.5 for grade 3+, and 41.2 for grade 4+. Spearman correlation coefficient comparing clinical grade with the individual AS-OCT line scans was 0.967 (P < 0.0001). The range of cells in the automated cell count of 3D volume scans was 13.60 to 1222; the range for manual cell counts was from 9.2 to 2245. The Spearman correlation coefficients were r = 0.7765 (P < 0.0001) and r = 0.7484 (P < 0.0001) comparing the manual and automated cell counts with the clinical grade, respectively. Spearman correlation coefficient comparing the automatic cell counts with manual cell count in the 3D volume scan was 0.997 (P < 0.0001).

Conclusions: Anterior segment OCT can be used to image and grade the degree of AC inflammation. Clinical grading strongly correlates with the number of cells on AS-OCT line scans and volume scans. The automated algorithm to measure cell count had a high correlation to manual measurement of cells in the 3D volume scans. This modality could be used to objectively grade response to treatment.
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http://dx.doi.org/10.1016/j.ophtha.2015.02.032DOI Listing
July 2015

Development of a Sox2 reporter system modeling cellular heterogeneity in glioma.

Neuro Oncol 2015 Mar 21;17(3):361-71. Epub 2014 Nov 21.

Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (K.S., M.S., J.S.H., B.O., J.D.L.); Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio (Q.W., J.N.R.); Department of Biological, Geological, and Environmental Sciences, Cleveland State University, Cleveland, Ohio (M.S., J.D.L.); Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama (K.W., A.B.H.); Image I.Q., Cleveland, Ohio (A.V.); Case Comprehensive Cancer Center, Cleveland, Ohio (J.N.R., J.D.L.).

Background: Malignant gliomas are complex systems containing a number of factors that drive tumor initiation and progression, including genetic aberrations that lead to extensive cellular heterogeneity within the neoplastic compartment. Mouse models recapitulate these genetic aberrations, but readily observable heterogeneity remains challenging.

Methods: To interrogate cellular heterogeneity in mouse glioma models, we utilized a replication-competent avian sarcoma-leukosis virus long terminal repeat with splice acceptor/tumor virus A (RCAS-tva) system to generate spontaneous mouse gliomas that contained a Sox2-enhanced green fluorescent protein (EGFP) reporter. Glial fibrillary acidic protein-tva mice were crossed with Sox2-EGFP mice, and tumors were initiated that contained a subpopulation of Sox2-EGFP-high cells enriched for tumor-initiating cell properties such as self-renewal, multilineage differentiation potential, and perivascular localization.

Results: Following implantation into recipient mice, Sox2-EGFP-high cells generated tumors containing Sox2-EGFP-high and Sox2-EGFP-low cells. Kinomic analysis of Sox2-EGFP-high cells revealed activation of known glioma signaling pathways that are strongly correlated with patient survival including platelet-derived growth factor receptor beta, phosphoinositide-3 kinase, and vascular endothelial growth factor. Our functional analysis identified active feline sarcoma (Fes) signaling in Sox2-EGFP-high cells. Fes negatively correlated with glioma patient survival and was coexpressed with Sox2-positive cells in glioma xenografts and primary patient-derived tissue.

Conclusions: Our RCAS-tva/Sox2-EGFP model will empower closer examination of cellular heterogeneity and will be useful for identifying novel glioma pathways as well as testing preclinical treatment efficacy.
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http://dx.doi.org/10.1093/neuonc/nou320DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4483103PMC
March 2015

Control of organization and function of muscle and tendon by thrombospondin-4.

Matrix Biol 2014 Jul 1;37:35-48. Epub 2014 Mar 1.

Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States. Electronic address:

Thrombospondins (TSPs) are multifunctional proteins that are deposited in the extracellular matrix where they directly affect the function of vascular and other cell types. TSP-4, one of the 5 TSP family members, is expressed abundantly in tendon and muscle. We have examined the effect of TSP-4 deficiency on tendon collagen and skeletal muscle morphology and function. In Thbs4(-/-) mice, tendon collagen fibrils are significantly larger than in wild-type mice, and there is no compensatory over-expression of TSP-3 and TSP-5, the two TSPs most highly homologous to TSP-4, in the deficient mice. TSP-4 is expressed in skeletal muscle, and higher levels of TSP-4 protein are associated with the microvasculature of red skeletal muscle with high oxidative metabolism. Lack of TSP-4 in medial soleus, red skeletal muscle with predominant oxidative metabolism, is associated with decreased levels of several specific glycosaminoglycan modifications, decreased expression of a TGFβ receptor beta-glycan, decreased activity of lipoprotein lipase, which associates with vascular cell surfaces by binding to glycosaminoglycans, and decreased uptake of VLDL. The soleus muscle is smaller and hind- and fore-limb grip strength is reduced in Thbs4(-/-) mice compared to wild-type mice. These observations suggest that TSP-4 regulates the composition of the ECM at major sites of its deposition, tendon and muscle, and the absence of TSP-4 alters the organization, composition and physiological functions of these tissues.
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http://dx.doi.org/10.1016/j.matbio.2014.02.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4150858PMC
July 2014

Hyperglycemia diverts dividing osteoblastic precursor cells to an adipogenic pathway and induces synthesis of a hyaluronan matrix that is adhesive for monocytes.

J Biol Chem 2014 Apr 25;289(16):11410-11420. Epub 2014 Feb 25.

Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio 44195.

Isolated rat bone marrow stromal cells cultured in osteogenic medium in which the normal 5.6 mm glucose is changed to hyperglycemic 25.6 mm glucose greatly increase lipid formation between 21-31 days of culture that is associated with decreased biomineralization, up-regulate expression of cyclin D3 and two adipogenic markers (CCAAT/enhancer binding protein α and peroxisome proliferator-activated receptor γ) within 5 days of culture, increase neutral and polar lipid synthesis within 5 days of culture, and form a monocyte-adhesive hyaluronan matrix through an endoplasmic reticulum stress-induced autophagic mechanism. Evidence is also provided that, by 4 weeks after diabetes onset in the streptozotocin-induced diabetic rat model, there is a large loss of trabecular bone mineral density without apparent proportional changes in underlying collagen matrices, a large accumulation of a hyaluronan matrix within the trabecular bone marrow, and adipocytes and macrophages embedded in this hyaluronan matrix. These results support the hypothesis that hyperglycemia in bone marrow diverts dividing osteoblastic precursor cells (bone marrow stromal cells) to a metabolically stressed adipogenic pathway that induces synthesis of a hyaluronan matrix that recruits inflammatory cells and establishes a chronic inflammatory process that demineralizes trabecular cancellous bone.
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http://dx.doi.org/10.1074/jbc.M113.541458DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036277PMC
April 2014

Chemotherapy activates cancer-associated fibroblasts to maintain colorectal cancer-initiating cells by IL-17A.

J Exp Med 2013 Dec 9;210(13):2851-72. Epub 2013 Dec 9.

Department of Stem Cell Biology and Regenerative Medicine, 2 Department of Cellular and Molecular Medicine, and 3 Department of Cancer Biology, Lerner Research Institute; 4 Department of Colorectal Surgery, Digestive Disease Institute; 5 Department of Anatomical Pathology, Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH 44195.

Many solid cancers display cellular hierarchies with self-renewing, tumorigenic stemlike cells, or cancer-initiating cells (CICs) at the apex. Whereas CICs often exhibit relative resistance to conventional cancer therapies, they also receive critical maintenance cues from supportive stromal elements that also respond to cytotoxic therapies. To interrogate the interplay between chemotherapy and CICs, we investigated cellular heterogeneity in human colorectal cancers. Colorectal CICs were resistant to conventional chemotherapy in cell-autonomous assays, but CIC chemoresistance was also increased by cancer-associated fibroblasts (CAFs). Comparative analysis of matched colorectal cancer specimens from patients before and after cytotoxic treatment revealed a significant increase in CAFs. Chemotherapy-treated human CAFs promoted CIC self-renewal and in vivo tumor growth associated with increased secretion of specific cytokines and chemokines, including interleukin-17A (IL-17A). Exogenous IL-17A increased CIC self-renewal and invasion, and targeting IL-17A signaling impaired CIC growth. Notably, IL-17A was overexpressed by colorectal CAFs in response to chemotherapy with expression validated directly in patient-derived specimens without culture. These data suggest that chemotherapy induces remodeling of the tumor microenvironment to support the tumor cellular hierarchy through secreted factors. Incorporating simultaneous disruption of CIC mechanisms and interplay with the tumor microenvironment could optimize therapeutic targeting of cancer.
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http://dx.doi.org/10.1084/jem.20131195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865474PMC
December 2013

Leptin receptor maintains cancer stem-like properties in triple negative breast cancer cells.

Endocr Relat Cancer 2013 Dec 14;20(6):797-808. Epub 2013 Oct 14.

Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, NC10, Cleveland, Ohio 44195, USA Department of Nutritional Sciences, The University of Texas, Austin, Texas, USA Department of Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Smithville, Texas, USA Department of Stem Cell Biology and Regenerative Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA ImageIQ, Cleveland, Ohio, USA Case Comprehensive Cancer Center, Cleveland, Ohio, USA.

Despite new therapies, breast cancer continues to be the second leading cause of cancer mortality in women, a consequence of recurrence and metastasis. In recent years, a population of cancer cells has been identified, called cancer stem cells (CSCs) with self-renewal capacity, proposed to underlie tumor recurrence and metastasis. We previously showed that the adipose tissue cytokine LEPTIN, increased in obesity, promotes the survival of CSCs in vivo. Here, we tested the hypothesis that the leptin receptor (LEPR), expressed in mammary cancer cells, is necessary for maintaining CSC-like and metastatic properties. We silenced LEPR via shRNA lentivirus transduction and determined that the expression of stem cell self-renewal transcription factors NANOG, SOX2, and OCT4 (POU5F1) is inhibited. LEPR-NANOG signaling pathway is conserved between species because we can rescue NANOG expression in human LEPR-silenced cells with the mouse LepR. Using a NANOG promoter GFP reporter, we showed that LEPR is enriched in NANOG promoter active (GFP+) cells. In lineage tracing studies, we showed that the GFP+ cells divide in a symmetric and asymmetric manner. LEPR-silenced MDA-MB-231 cells exhibit a mesenchymal to epithelial transition morphologically, increased E-CADHERIN and decreased VIMENTIN expression compared with control cells. Finally, LEPR-silenced cells exhibit reduced cell proliferation, self-renewal in tumor sphere assays, and tumor outgrowth in xenotransplant studies. Given the emergence of NANOG as a pro-carcinogenic protein in multiple cancers, these studies suggest that inhibition of LEPR may be a promising therapeutic approach to inhibit NANOG and thereby neutralize CSC functions.
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http://dx.doi.org/10.1530/ERC-13-0329DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3843956PMC
December 2013

The cytoplasmic domain of neuropilin-1 regulates focal adhesion turnover.

FEBS Lett 2013 Nov 8;587(21):3392-9. Epub 2013 Sep 8.

Department of Molecular Cardiology, Lerner Research Institute, the Cleveland Clinic, Cleveland, OH 44195, United States.

Though the vascular endothelial growth factor coreceptor neuropilin-1 (Nrp1) plays a critical role in vascular development, its precise function is not fully understood. We identified a group of novel binding partners of the cytoplasmic domain of Nrp1 that includes the focal adhesion regulator, Filamin A (FlnA). Endothelial cells (ECs) expressing a Nrp1 mutant devoid of the cytoplasmic domain (nrp1(cyto)(Δ/Δ)) migrated significantly slower in response to VEGF relative to the cells expressing wild-type Nrp1 (nrp1(+/+) cells). The rate of FA turnover in VEGF-treated nrp1(cyto)(Δ/Δ) ECs was an order of magnitude lower in comparison to nrp1(+/+) ECs, thus accounting for the slower migration rate of the nrp1(cyto)(Δ/Δ) ECs.
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http://dx.doi.org/10.1016/j.febslet.2013.08.040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3856898PMC
November 2013

Interaction of G-protein βγ complex with chromatin modulates GPCR-dependent gene regulation.

PLoS One 2013 9;8(1):e52689. Epub 2013 Jan 9.

Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.

Heterotrimeric G-protein signal transduction initiated by G-protein-coupled receptors (GPCRs) in the plasma membrane is thought to propagate through protein-protein interactions of subunits, Gα and Gβγ in the cytosol. In this study, we show novel nuclear functions of Gβγ through demonstrating interaction of Gβ(2) with integral components of chromatin and effects of Gβ(2) depletion on global gene expression. Agonist activation of several GPCRs including the angiotensin II type 1 receptor specifically augmented Gβ(2) levels in the nucleus and Gβ(2) interacted with specific nucleosome core histones and transcriptional modulators. Depletion of Gβ(2) repressed the basal and angiotensin II-dependent transcriptional activities of myocyte enhancer factor 2. Gβ(2) interacted with a sequence motif that was present in several transcription factors, whose genome-wide binding accounted for the Gβ(2)-dependent regulation of approximately 2% genes. These findings suggest a wide-ranging mechanism by which direct interaction of Gβγ with specific chromatin bound transcription factors regulates functional gene networks in response to GPCR activation in cells.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0052689PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3541368PMC
July 2013

Randomized controlled trial of osteoconductive fixation screws for anterior cruciate ligament reconstruction: a comparison of the Calaxo and Milagro screws.

Arthroscopy 2013 Jan;29(1):74-82

North Sydney Orthopaedic and Sports Medicine Centre, The Mater Clinic, Wollstonecraft, Australia.

Purpose: To compare the outcome of 2 bioabsorbable screws for tibial interference fixation in anterior cruciate ligament reconstruction with reference to rate of absorption, osteoconductive properties, and clinical outcome.

Methods: Patients undergoing primary anterior cruciate ligament reconstruction with hamstring autograft in a single unit were invited to participate in this study. Patients were randomized to receive either the Calaxo screw (Smith & Nephew, Andover, MA) or Milagro screw (DePuy Mitek, Raynham, MA) for tibial fixation. Patients were reviewed with subjective and objective evaluation by use of the International Knee Documentation Committee form, Lysholm score, KT-1000 arthrometry (MEDmetric, San Diego, CA), and clinical examination. Magnetic resonance imaging was performed at 1 year and computed tomography scanning at 1 week and at 6, 12, and 24 months.

Results: Sixty patients agreed to participate in the study, with 32 patients randomized to the Calaxo screw and 28 to the Milagro screw for tibial fixation. There was no significant difference in subjective or objective clinical outcome between the 2 groups. At 24 months, 88% of Calaxo screws showed complete screw resorption compared with 0% of Milagro screws (P < .001). Tibial cysts were present in 88% of the Calaxo group and 7% of the Milagro group (P = .001). At 24 months, the mean volume of new bone formation for the Calaxo group was 21% of original screw volume. Ossification of the Milagro screw was unable to be accurately assessed as a result of incomplete screw resorption.

Conclusions: Both screws showed similar favorable objective and subjective outcomes at 2 years. The Calaxo screw resorbed completely over a period of 6 months and was associated with a high incidence of intra-tunnel cyst formation. The Milagro screw increased in volume over a period of 6 months, followed by a gradual resorption, which was still ongoing at 2 years. Both screws were associated with tunnel widening, and neither showed evidence of significant tunnel ossification. We conclude that, despite satisfactory clinical outcomes, the addition of "osteoconductive" materials to bioabsorbable screws is not associated with bone formation at the screw site at 2 years.

Level Of Evidence: Level I, randomized controlled trial.
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http://dx.doi.org/10.1016/j.arthro.2012.10.021DOI Listing
January 2013

Evaluation of osteoconductive scaffolds in the canine femoral multi-defect model.

Tissue Eng Part A 2013 Mar;19(5-6):634-48

Department of Biomedical Engineering, Cleveland Clinic, Cleveland, Ohio, USA.

Treatment of large segmental bone defects remains an unsolved clinical challenge, despite a wide array of existing bone graft materials. This project was designed to rapidly assess and compare promising biodegradable osteoconductive scaffolds for use in the systematic development of new bone regeneration methodologies that combine scaffolds, sources of osteogenic cells, and bioactive scaffold modifications. Promising biomaterials and scaffold fabrication methods were identified in laboratories at Rutgers, MIT, Integra Life Sciences, and Mayo Clinic. Scaffolds were fabricated from various materials, including poly(L-lactide-co-glycolide) (PLGA), poly(L-lactide-co-ɛ-caprolactone) (PLCL), tyrosine-derived polycarbonate (TyrPC), and poly(propylene fumarate) (PPF). Highly porous three-dimensional (3D) scaffolds were fabricated by 3D printing, laser stereolithography, or solvent casting followed by porogen leaching. The canine femoral multi-defect model was used to systematically compare scaffold performance and enable selection of the most promising substrate(s) on which to add cell sourcing options and bioactive surface modifications. Mineralized cancellous allograft (MCA) was used to provide a comparative reference to the current clinical standard for osteoconductive scaffolds. Percent bone volume within the defect was assessed 4 weeks after implantation using both MicroCT and limited histomorphometry. Bone formed at the periphery of all scaffolds with varying levels of radial ingrowth. MCA produced a rapid and advanced stage of bone formation and remodeling throughout the defect in 4 weeks, greatly exceeding the performance of all polymer scaffolds. Two scaffold constructs, TyrPC(PL)/TCP and PPF4(SLA)/HA(PLGA) (Dip), proved to be significantly better than alternative PLGA and PLCL scaffolds, justifying further development. MCA remains the current standard for osteoconductive scaffolds.
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http://dx.doi.org/10.1089/ten.TEA.2012.0289DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3568967PMC
March 2013