How to Incorporate Language Form, Function, and Structure in the SIOP Model Lessons

The paper looks at the current practice of CBI (Content-Based Instruction) and the Sheltered Instruction Observation Protocol (SIOP) Model as dominant methodological approaches of teaching a foreign or second language (FL/SL) and proposes some useful teaching strategies for the development of L2 skills not only in the public school system of the USA but for similar teaching environments in other countries where English is a medium of instruction of at least a few content subjects. The paper specifically addresses the difficulties many in-service and novice teachers experience during the SIOP lesson planning to come up with meaningful language teaching objectives in order to facilitate learning of both content and all four basic language skills such as reading, writing, listening, and speaking (Bautista & Castañeda, 2011, Bigelow & Ranney, 2005, among others). The main proposal of the paper on how to advance these skills is informed by the best practices of teaching and learning that follow English Language Development (ELD) standards of certain states and International TESOL standards. With these guiding documents and teaching principles drawn from a variety of reputable sources, the paper offers some hands-on strategies and teaching scenarios that could potentially enhance the focus on linguistic form, function, and structure during content lessons to facilitate L2 learning, and this focus includes word decomposition skills that are instrumental in vocabulary learning and complex syntactic structures such as passives during teaching Social Studies and Math lessons. The paper will be useful for both in-service teachers and teacher candidates who are preparing to deliver sheltered courses of various subjects in schools such as Math, Science, Social Studies, Language Arts, and so on. The paper also touches on the division of labor between content teachers and ELS professionals on how they need to collaborate to be able to better serve L2 learners at the various stages of L2 skill development

Treatment with pyrophosphate inhibits uremic vascular calcification

Pyrophosphate, which may be deficient in advanced renal failure, is a potent inhibitor of vascular calcification. To explore its use as a potential therapeutic, we injected exogenous pyrophosphate subcutaneously or intraperitoneally in normal rats and found that their plasma pyrophosphate concentrations peaked within 15 min. There was a single exponential decay with a half-life of 33 min. The kinetics were indistinguishable between the two routes of administration or in anephric rats. The effect of daily intraperitoneal pyrophosphate injections on uremic vascular calcification was then tested in rats fed a high-phosphate diet containing adenine for 28 days to induce uremia. Although the incidence of aortic calcification varied and was not altered by pyrophosphate, the calcium content of calcified aortas was significantly reduced by 70%. Studies were repeated in uremic rats given calcitriol to produce more consistent aortic calcification and treated with sodium pyrophosphate delivered intraperitoneally in a larger volume of glucose-containing solution to prolong plasma pyrophosphate levels. This maneuver significantly reduced both the incidence and amount of calcification. Quantitative histomorphometry of bone samples after double-labeling with calcein indicated that there was no effect of pyrophosphate on the rates of bone formation or mineralization. Thus, exogenous pyrophosphate can inhibit uremic vascular calcification without producing adverse effects on bone

Pharmacological Inhibition of PHOSPHO1 Suppresses Vascular Smooth Muscle Cell Calcification

Medial vascular calcification (MVC) is common in patients with chronic kidney disease, obesity, and aging. MVC is an actively regulated process that resembles skeletal mineralization, resulting from chondro-osteogenic transformation of vascular smooth muscle cells (VSMCs). Here, we used mineralizing murine VSMCs to study the expression of PHOSPHO1, a phosphatase that participates in the first step of matrix vesicles-mediated initiation of mineralization during endochondral ossification. Wild-type (WT) VSMCs cultured under calcifying conditions exhibited increased Phospho1 gene expression and Phospho1(-/-) VSMCs failed to mineralize in vitro. Using natural PHOSPHO1 substrates, potent and specific inhibitors of PHOSPHO1 were identified via high-throughput screening and mechanistic analysis and two, designated MLS-0390838 and MLS-0263839, were selected for further analysis. Their effectiveness in preventing VSMC calcification by targeting PHOSPHO1 function was assessed, alone and in combination with a potent tissue-nonspecific alkaline phosphatase (TNAP) inhibitor MLS-0038949. PHOSPHO1 inhibition by MLS-0263839 in mineralizing WT cells (cultured with added inorganic phosphate) reduced calcification in culture to 41.8% ± 2.0 of control. Combined inhibition of PHOSPHO1 by MLS-0263839 and TNAP by MLS-0038949 significantly reduced calcification to 20.9% ± 0.74 of control. Furthermore, the dual inhibition strategy affected the expression of several mineralization-related enzymes while increasing expression of the smooth muscle cell marker Acta2. We conclude that PHOSPHO1 plays a critical role in VSMC mineralization and that “phosphatase inhibition” may be a useful therapeutic strategy to reduce MVC

Systemic Correlates of Angiographic Coronary Artery Disease

Coronary angiography allows a direct evaluation of coronary anatomy. The aim of the present investigation was to search for correlations between the magnitude of coronary artery disease, as assessed by angiography, and a number of systemic parameters. A group of 116 patients (80 male, 36 female) with coronary heart disease diagnosed by angiography, aged 62.0±10.5 years, was the subject of an observational study. Correlation and linear regression analysis using coronary artery disease burden (CADB - sum of the percentage of the luminal stenosis encountered in all the lesions of the coronary arterial trees) as dependent variable, and age, sex, plasma calcium, phosphorus, magnesium, glucose, HDL cholesterol, LDL cholesterol, triglycerides, uric acid, estimated glomerular filtration rate and body mass index as independent variables, were carried out. Significant correlation values versus CADB were seen with age (r 0.19, p 0.04), uric acid (r 0.18, p 0.048) and fasting plasma glucose (r 0.33, p<0.001). Linear regression analysis, yielding a global significance level of 0.002, showed a significant value for glucose (p 0.018) and for sex (0.008). In conclusion, among several systemic parameters studied, plasma glucose was found to be correlated to coronary artery atherosclerosis lesions

Bone-specific alkaline phosphatase concentrations are less variable than those of parathyroid hormone in stable hemodialysis patients

Abnormalities of bone mineral metabolism and vascular calcification are prevalent in patients with kidney failure. Clinical management is based on biochemical targets, in particular parathyroid hormone (PTH) concentrations, but this has many limitations including high biological variation. A possible alternative is bone-specific alkaline phosphatase (ALP); therefore, we evaluated the biological variation of this marker in patients undergoing hemodialysis. Bone ALP was measured in non-fasting serum samples taken twice a week over a 6-week period in 22 stable hemodialysis patients and 12 healthy volunteers. The within-individual coefficients of variance were calculated and used to derive the critical difference required to be certain that an observed change was significant. The coefficient of variance for bone ALP was significantly higher in hemodialysis patients compared to healthy individuals. Seven samples were required to estimate the homeostatic set point of bone ALP, within 10%, in a hemodialysis patient. The concentration of serial bone ALP measurements would need to change by 36% between any two measurements before it can be considered a significant change. Since the biological variation of bone ALP is less than half that reported for PTH, our study provides further support for the use of bone ALP as an alternative marker of bone mineral metabolism in the setting of chronic kidney disease–mineral and bone disorder

Label-Free Pyrophosphate Recognition with Functionalized Asymmetric Nanopores

[EN] The label¿free detection of pyrophosphate (PPi) anions with a nanofluidic sensing device based on asymmetric nanopores is demonstrated. The pore surface is functionalized with zinc complexes based on two di(2¿picolyl)amine [bis(DPA)] moieties using carbodiimide coupling chemistry. The complexation of zinc (Zn2+) ion is achieved by exposing the modified pore to a solution of zinc chloride to form bis(Zn2+¿DPA) complexes. The chemical functionalization is demonstrated by recording the changes in the observed current¿voltage (I¿V) curves before and after pore modification. The bis(Zn2+¿DPA) complexes on the pore walls serve as recognition sites for pyrophosphate anion. The experimental results show that the proposed nanofluidic sensor has the ability to sense picomolar concentrations of PPi anion in the surrounding environment. On the contrary, it does not respond to other phosphate anions, including monohydrogen phosphate, dihydrogen phosphate, adenosine monophosphate, adenosine diphosphate, and adenosine triphosphate. The experimental results are described theoretically by using a model based on the Poisson¿Nernst¿Planck equations.M.A., S.N., and W.E. acknowledge the funding from the Hessen State Ministry of Higher Education, Research and the Arts, Germany, under the LOEWE project iNAPO. P.R. and S.M. acknowledge financial support by the Generalitat Valenciana (Program of Excellence Prometeo/GV/0069), the Spanish Ministry of Economic Affairs and Competitiveness (MAT2015-65011-P), and FEDER. I. A. and C.M.N. acknowledge financial support through the Helmholtz programme BioInterfaces in Technology and Medicine. The authors are also thankful to Prof. C. Trautmann, Department of Materials Research from GSI, for support with irradiation experiments.Ali, M.; Ahmed, I.; Ramirez Hoyos, P.; Nasir, S.; Niemeyer, CM.; Mafe, S.; Ensinger, W. (2016). Label-Free Pyrophosphate Recognition with Functionalized Asymmetric Nanopores. Small. 12(15):2014-2021. https://doi.org/10.1002/smll.201600160S201420211215Gyurcsányi, R. E. (2008). Chemically-modified nanopores for sensing. TrAC Trends in Analytical Chemistry, 27(7), 627-639. doi:10.1016/j.trac.2008.06.002Hou, X., Guo, W., & Jiang, L. (2011). Biomimetic smart nanopores and nanochannels. Chemical Society Reviews, 40(5), 2385. doi:10.1039/c0cs00053aHou, X., & Jiang, L. (2009). Learning from Nature: Building Bio-Inspired Smart Nanochannels. ACS Nano, 3(11), 3339-3342. doi:10.1021/nn901402bHou, X., Zhang, H., & Jiang, L. (2012). Building Bio-Inspired Artificial Functional Nanochannels: From Symmetric to Asymmetric Modification. Angewandte Chemie International Edition, 51(22), 5296-5307. doi:10.1002/anie.201104904Ali, M., Neumann, R., & Ensinger, W. (2010). Sequence-Specific Recognition of DNA Oligomer Using Peptide Nucleic Acid (PNA)-Modified Synthetic Ion Channels: PNA/DNA Hybridization in Nanoconfined Environment. ACS Nano, 4(12), 7267-7274. doi:10.1021/nn102119qAli, M., Schiedt, B., Neumann, R., & Ensinger, W. (2010). Biosensing with Functionalized Single Asymmetric Polymer Nanochannels. Macromolecular Bioscience, 10(1), 28-32. doi:10.1002/mabi.200900198Ali, M., Yameen, B., Neumann, R., Ensinger, W., Knoll, W., & Azzaroni, O. (2008). Biosensing and Supramolecular Bioconjugation in Single Conical Polymer Nanochannels. Facile Incorporation of Biorecognition Elements into Nanoconfined Geometries. Journal of the American Chemical Society, 130(48), 16351-16357. doi:10.1021/ja8071258Fologea, D., Gershow, M., Ledden, B., McNabb, D. S., Golovchenko, J. A., & Li, J. (2005). Detecting Single Stranded DNA with a Solid State Nanopore. Nano Letters, 5(10), 1905-1909. doi:10.1021/nl051199mIqbal, S. M., Akin, D., & Bashir, R. (2007). Solid-state nanopore channels with DNA selectivity. Nature Nanotechnology, 2(4), 243-248. doi:10.1038/nnano.2007.78Mara, A., Siwy, Z., Trautmann, C., Wan, J., & Kamme, F. (2004). An Asymmetric Polymer Nanopore for Single Molecule Detection. Nano Letters, 4(3), 497-501. doi:10.1021/nl035141oStorm, A. J., Storm, C., Chen, J., Zandbergen, H., Joanny, J.-F., & Dekker, C. (2005). Fast DNA Translocation through a Solid-State Nanopore. Nano Letters, 5(7), 1193-1197. doi:10.1021/nl048030dVlassiouk, I., Kozel, T. R., & Siwy, Z. S. (2009). Biosensing with Nanofluidic Diodes. Journal of the American Chemical Society, 131(23), 8211-8220. doi:10.1021/ja901120fBayley, H., Braha, O., Cheley, S., & Gu, L.-Q. (2005). Engineered Nanopores. Nanobiotechnology, 93-112. doi:10.1002/3527602453.ch7Bayley, H., Braha, O., & Gu, L.-Q. (2000). Stochastic Sensing with Protein Pores. Advanced Materials, 12(2), 139-142. doi:10.1002/(sici)1521-4095(200001)12:23.0.co;2-qBayley, H., & Cremer, P. S. (2001). Stochastic sensors inspired by biology. Nature, 413(6852), 226-230. doi:10.1038/35093038Dekker, C. (2007). Solid-state nanopores. Nature Nanotechnology, 2(4), 209-215. doi:10.1038/nnano.2007.27Healy, K., Schiedt, B., & Morrison, A. P. (2007). Solid-state nanopore technologies for nanopore-based DNA analysis. Nanomedicine, 2(6), 875-897. doi:10.2217/17435889.2.6.875Siwy, Z. S., & Howorka, S. (2010). Engineered voltage-responsive nanopores. Chem. Soc. Rev., 39(3), 1115-1132. doi:10.1039/b909105jSpohr, R. (2005). Status of ion track technology—Prospects of single tracks. Radiation Measurements, 40(2-6), 191-202. doi:10.1016/j.radmeas.2005.03.008Korchev, Y. E., Bashford, C. L., Alder, G. M., Apel, P. Y., Edmonds, D. T., Lev, A. A., … Pasternak, C. A. (1997). A novel explanation for fluctuations of ion current through narrow pores. The FASEB Journal, 11(7), 600-608. doi:10.1096/fasebj.11.7.9212084Siwy, Z., Apel, P., Dobrev, D., Neumann, R., Spohr, R., Trautmann, C., & Voss, K. (2003). Ion transport through asymmetric nanopores prepared by ion track etching. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 208, 143-148. doi:10.1016/s0168-583x(03)00884-xSiwy, Z. S. (2006). Ion-Current Rectification in Nanopores and Nanotubes with Broken Symmetry. Advanced Functional Materials, 16(6), 735-746. doi:10.1002/adfm.200500471Apel, P. Y., Korchev, Y. ., Siwy, Z., Spohr, R., & Yoshida, M. (2001). Diode-like single-ion track membrane prepared by electro-stopping. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 184(3), 337-346. doi:10.1016/s0168-583x(01)00722-4Siwy, Z., Trofin, L., Kohli, P., Baker, L. A., Trautmann, C., & Martin, C. R. (2005). Protein Biosensors Based on Biofunctionalized Conical Gold Nanotubes. Journal of the American Chemical Society, 127(14), 5000-5001. doi:10.1021/ja043910fHan, C., Hou, X., Zhang, H., Guo, W., Li, H., & Jiang, L. (2011). Enantioselective Recognition in Biomimetic Single Artificial Nanochannels. Journal of the American Chemical Society, 133(20), 7644-7647. doi:10.1021/ja2004939Liu, Q., Xiao, K., Wen, L., Lu, H., Liu, Y., Kong, X.-Y., … Jiang, L. (2015). Engineered Ionic Gates for Ion Conduction Based on Sodium and Potassium Activated Nanochannels. Journal of the American Chemical Society, 137(37), 11976-11983. doi:10.1021/jacs.5b04911Han, C., Su, H., Sun, Z., Wen, L., Tian, D., Xu, K., … Jiang, L. (2013). Biomimetic Ion Nanochannels as a Highly Selective Sequential Sensor for Zinc Ions Followed by Phosphate Anions. Chemistry - A European Journal, 19(28), 9388-9395. doi:10.1002/chem.201300200Pérez-Mitta, G., Albesa, A. G., Knoll, W., Trautmann, C., Toimil-Molares, M. E., & Azzaroni, O. (2015). Host–guest supramolecular chemistry in solid-state nanopores: potassium-driven modulation of ionic transport in nanofluidic diodes. Nanoscale, 7(38), 15594-15598. doi:10.1039/c5nr04645aTian, Y., Hou, X., Wen, L., Guo, W., Song, Y., Sun, H., … Zhu, D. (2010). A biomimetic zinc activated ion channel. Chemical Communications, 46(10), 1682. doi:10.1039/b918006kShang, Y., Zhang, Y., Li, P., Lai, J., Kong, X.-Y., Liu, W., … Jiang, L. (2015). DNAzyme tunable lead(ii) gating based on ion-track etched conical nanochannels. Chemical Communications, 51(27), 5979-5981. doi:10.1039/c5cc00288eLiu, Q., Xiao, K., Wen, L., Dong, Y., Xie, G., Zhang, Z., … Jiang, L. (2014). A Fluoride-Driven Ionic Gate Based on a 4-Aminophenylboronic Acid-Functionalized Asymmetric Single Nanochannel. ACS Nano, 8(12), 12292-12299. doi:10.1021/nn506257cXie, G., Xiao, K., Zhang, Z., Kong, X.-Y., Liu, Q., Li, P., … Jiang, L. (2015). A Bioinspired Switchable and Tunable Carbonate-Activated Nanofluidic Diode Based on a Single Nanochannel. Angewandte Chemie International Edition, 54(46), 13664-13668. doi:10.1002/anie.201505269Ngo, H. T., Liu, X., & Jolliffe, K. A. (2012). Anion recognition and sensing with Zn(ii)–dipicolylamine complexes. Chemical Society Reviews, 41(14), 4928. doi:10.1039/c2cs35087dLee, S., Yuen, K. K. Y., Jolliffe, K. A., & Yoon, J. (2015). Fluorescent and colorimetric chemosensors for pyrophosphate. Chemical Society Reviews, 44(7), 1749-1762. doi:10.1039/c4cs00353eKim, S. K., Lee, D. H., Hong, J.-I., & Yoon, J. (2009). Chemosensors for Pyrophosphate. Accounts of Chemical Research, 42(1), 23-31. doi:10.1021/ar800003fHargrove, A. E., Nieto, S., Zhang, T., Sessler, J. L., & Anslyn, E. V. (2011). Artificial Receptors for the Recognition of Phosphorylated Molecules. Chemical Reviews, 111(11), 6603-6782. doi:10.1021/cr100242sHeinonen, J. K. (2001). Biological Role of Inorganic Pyrophosphate. doi:10.1007/978-1-4615-1433-6Timms, A. E. (2002). Genetic studies of disorders of calcium crystal deposition. Rheumatology, 41(7), 725-729. doi:10.1093/rheumatology/41.7.725Doherty, M., Belcher, C., Regan, M., Jones, A., & Ledingham, J. (1996). Association between synovial fluid levels of inorganic pyrophosphate and short term radiographic outcome of knee osteoarthritis. Annals of the Rheumatic Diseases, 55(7), 432-436. doi:10.1136/ard.55.7.432Lomashvili, K. A., Khawandi, W., & O’Neill, W. C. (2005). Reduced Plasma Pyrophosphate Levels in Hemodialysis Patients. Journal of the American Society of Nephrology, 16(8), 2495-2500. doi:10.1681/asn.2004080694Ronaghi, M., Karamohamed, S., Pettersson, B., Uhlén, M., & Nyrén, P. (1996). Real-Time DNA Sequencing Using Detection of Pyrophosphate Release. Analytical Biochemistry, 242(1), 84-89. doi:10.1006/abio.1996.0432Yang, S., Feng, G., & Williams, N. H. (2012). Highly selective colorimetric sensing pyrophosphate in water by a NBD-phenoxo-bridged dinuclear Zn(ii) complex. Organic & Biomolecular Chemistry, 10(29), 5606. doi:10.1039/c2ob25617gLiu, D. J., Credo, G. M., Su, X., Wu, K., Lim, H. C., Elibol, O. H., … Varma, M. (2011). Surface immobilizable chelator for label-free electrical detection of pyrophosphate. Chemical Communications, 47(29), 8310. doi:10.1039/c1cc12073eCredo, G. M., Su, X., Wu, K., Elibol, O. H., Liu, D. J., Reddy, B., … Varma, M. (2012). Label-free electrical detection of pyrophosphate generated from DNA polymerase reactions on field-effect devices. The Analyst, 137(6), 1351. doi:10.1039/c2an15930aAli, M., Bayer, V., Schiedt, B., Neumann, R., & Ensinger, W. (2008). Fabrication and functionalization of single asymmetric nanochannels for electrostatic/hydrophobic association of protein molecules. Nanotechnology, 19(48), 485711. doi:10.1088/0957-4484/19/48/485711Xue, L., Wang, H.-H., Wang, X.-J., & Jiang, H. (2008). Modulating Affinities of Di-2-picolylamine (DPA)-Substituted Quinoline Sensors for Zinc Ions by Varying Pendant Ligands. Inorganic Chemistry, 47(10), 4310-4318. doi:10.1021/ic702393zCervera, J., Schiedt, B., Neumann, R., Mafé, S., & Ramírez, P. (2006). Ionic conduction, rectification, and selectivity in single conical nanopores. The Journal of Chemical Physics, 124(10), 104706. doi:10.1063/1.2179797Ramírez, P., Apel, P. Y., Cervera, J., & Mafé, S. (2008). Pore structure and function of synthetic nanopores with fixed charges: tip shape and rectification properties. Nanotechnology, 19(31), 315707. doi:10.1088/0957-4484/19/31/315707Ali, M., Ramirez, P., Mafé, S., Neumann, R., & Ensinger, W. (2009). A pH-Tunable Nanofluidic Diode with a Broad Range of Rectifying Properties. ACS Nano, 3(3), 603-608. doi:10.1021/nn900039fCervera, J., Alcaraz, A., Schiedt, B., Neumann, R., & Ramírez, P. (2007). Asymmetric Selectivity of Synthetic Conical Nanopores Probed by Reversal Potential Measurements. The Journal of Physical Chemistry C, 111(33), 12265-12273. doi:10.1021/jp071884cVan der Heyden, F. H. J., Bonthuis, D. J., Stein, D., Meyer, C., & Dekker, C. (2007). Power Generation by Pressure-Driven Transport of Ions in Nanofluidic Channels. Nano Letters, 7(4), 1022-1025. doi:10.1021/nl070194hAlcaraz, A., Ramírez, P., García-Giménez, E., López, M. L., Andrio, A., & Aguilella, V. M. (2006). A pH-Tunable Nanofluidic Diode:  Electrochemical Rectification in a Reconstituted Single Ion Channel. The Journal of Physical Chemistry B, 110(42), 21205-21209. doi:10.1021/jp063204wAli, M., Nasir, S., Ramirez, P., Cervera, J., Mafe, S., & Ensinger, W. (2012). Calcium Binding and Ionic Conduction in Single Conical Nanopores with Polyacid Chains: Model and Experiments. ACS Nano, 6(10), 9247-9257. doi:10.1021/nn303669

Exploiting novel valve interstitial cell lines to study calcific aortic valve disease

Calcific aortic valve disease (CAVD) involves progressive valve leaflet thickening and severe calcification, impairing leaflet motion. The in vitro calcification of primary rat, human, porcine and bovine aortic valve interstitial cells (VICs) is commonly employed to investigate CAVD mechanisms. However, to date, no published studies have utilised cell lines to investigate this process. The present study has therefore generated and evaluated the calcification potential of immortalized cell lines derived from sheep and rat VICs. Immortalised sheep (SAVIC) and rat (RAVIC) cell lines were produced by transduction with a recombinant lentivirus encoding the Simian virus (SV40) large and small T antigens (sheep), or large T antigen only (rat), which expressed markers of VICs (vimentin and -smooth muscle actin). Calcification was induced in the presence of calcium (Ca; 2.7 mM) in SAVICs (1.9 fold;

Ablation of the androgen receptor from vascular smooth muscle cells demonstrates a role for testosterone in vascular calcification

Vascular calcification powerfully predicts mortality and morbidity from cardiovascular disease. Men have a greater risk of cardiovascular disease, compared to women of a similar age. These gender disparities suggest an influence of sex hormones. Testosterone is the primary and most well-recognised androgen in men. Therefore, we addressed the hypothesis that exogenous androgen treatment induces vascular calcification. Immunohistochemical analysis revealed expression of androgen receptor (AR) in the calcified media of human femoral artery tissue and calcified human valves. Furthermore, in vitro studies revealed increased phosphate (Pi)-induced mouse vascular smooth muscle cell (VSMC) calcification following either testosterone or dihydrotestosterone (DHT) treatment for 9 days. Testosterone and DHT treatment increased tissue non-specific alkaline phosphatase (Alpl) mRNA expression. Testosterone-induced calcification was blunted in VSMC-specific AR-ablated (SM-ARKO) VSMCs compared to WT. Consistent with these data, SM-ARKO VSMCs showed a reduction in Osterix mRNA expression. However, intriguingly, a counter-intuitive increase in Alpl was observed. These novel data demonstrate that androgens play a role in inducing vascular calcification through the AR. Androgen signalling may represent a novel potential therapeutic target for clinical intervention

The Appearance and Modulation of Osteocyte Marker Expression during Calcification of Vascular Smooth Muscle Cells

Vascular calcification is an indicator of elevated cardiovascular risk. Vascular smooth muscle cells (VSMCs), the predominant cell type involved in medial vascular calcification, can undergo phenotypic transition to both osteoblastic and chondrocytic cells within a calcifying environment.In the present study, using in vitro VSMC calcification studies in conjunction with ex vivo analyses of a mouse model of medial calcification, we show that vascular calcification is also associated with the expression of osteocyte phenotype markers. As controls, the terminal differentiation of murine calvarial osteoblasts into osteocytes was induced in vitro in the presence of calcifying medium (containing ß-glycerophosphate and ascorbic acid), as determined by increased expression of the osteocyte markers DMP-1, E11 and sclerostin. Culture of murine aortic VSMCs under identical conditions confirmed that the calcification of these cells can also be induced in similar calcifying medium. Calcified VSMCs had increased alkaline phosphatase activity and PiT-1 expression, which are recognized markers of vascular calcification. Expression of DMP-1, E11 and sclerostin was up-regulated during VSMC calcification in vitro. Increased protein expression of E11, an early osteocyte marker, and sclerostin, expressed by more mature osteocytes was also observed in the calcified media of Enpp1(-/-) mouse aortic tissue.This study has demonstrated the up-regulation of key osteocytic molecules during the vascular calcification process. A fuller understanding of the functional role of osteocyte formation and specifically sclerostin and E11 expression in the vascular calcification process may identify novel potential therapeutic strategies for clinical intervention