title: High glucose-induced hyperosmolarity contributes to COX-2 expression and angiogenesis: implications for diabetic retinopathy.
abstract: BACKGROUND
  We tested the hypothesis that glucose-induced hyperosmolarity, occurring in diabetic hyperglycemia, promotes retinal angiogenesis, and that interference with osmolarity signaling ameliorates excessive angiogenesis and retinopathy in vitro and in vivo.
  
  
  RESULTS
  We incubated human aortic (HAECs) and dermal microvascular endothelial cells (HMVECs) with glucose or mannitol for 24 h and tested them for protein levels and in vitro angiogenesis. We used the Ins2 Akita mice as a model of type 1 diabetes to test the in vivo relevance of in vitro observations. Compared to incubations with normal (5 mmol/L) glucose concentrations, cells exposed to both high glucose and high mannitol (at 30.5 or 50.5 mmol/L) increased expression of the water channel aquaporin-1 (AQP1) and cyclooxygenase (COX)-2. This was preceded by increased activity of the osmolarity-sensitive transcription factor Tonicity enhancer binding protein (TonEBP), and enhanced endothelial migration and tubulization in Matrigel, reverted by treatment with AQP1 and TonEBP siRNA. Retinas of Ins2 Akita mice showed increased levels of AQP1 and COX-2, as well as angiogenesis, all reverted by AQP1 siRNA intravitreal injections.
  
  
  CONCLUSIONS
  Glucose-related hyperosmolarity seems to be able to promote angiogenesis and retinopathy through activation of TonEBP and possibly increasing expression of AQP1 and COX-2. Osmolarity signaling may be a target for therapy.
authors.affiliation: Laboratory of Experimental Cardiology, Center of Excellence on Aging, Institute of Cardiology, "G. d'Annunzio" University, C/o Ospedale SS. Annunziata, Via dei Vestini, 31, 66013, Chieti, Italy. rmadonna@unich.it.|The University of Texas Health Science Center at Houston and the Texas Heart Institute, Houston, TX, USA. rmadonna@unich.it.
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Madonna
authors.affiliation: Department of Neurosciences and Imaging, "G. d'Annunzio" University, Chieti, Italy. gaiagiovannelli@libero.it.
authors.forename: Gaia
authors.initials: G
authors.lastname: Giovannelli
authors.affiliation: Laboratory of Experimental Cardiology, Center of Excellence on Aging, Institute of Cardiology, "G. d'Annunzio" University, C/o Ospedale SS. Annunziata, Via dei Vestini, 31, 66013, Chieti, Italy. pamelaausten@libero.it.
authors.forename: Pamela
authors.initials: P
authors.lastname: Confalone
authors.affiliation: Laboratory of Experimental Cardiology, Center of Excellence on Aging, Institute of Cardiology, "G. d'Annunzio" University, C/o Ospedale SS. Annunziata, Via dei Vestini, 31, 66013, Chieti, Italy. fv.renna@libero.it.
authors.forename: Francesca Vera
authors.initials: FV
authors.lastname: Renna
authors.affiliation: The University of Texas Health Science Center at Houston and the Texas Heart Institute, Houston, TX, USA. yong-jian.geng@uth.tmc.edu.
authors.forename: Yong-Jian
authors.initials: YJ
authors.lastname: Geng
authors.affiliation: Laboratory of Experimental Cardiology, Center of Excellence on Aging, Institute of Cardiology, "G. d'Annunzio" University, C/o Ospedale SS. Annunziata, Via dei Vestini, 31, 66013, Chieti, Italy. rdecater@unich.it.
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Caterina
mesh_terms: D000818:Animals; D051398:Aquaporin 1 / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1; D003930:Diabetic Retinopathy / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D005947:Glucose / Q000378:metabolism* / Q000633:toxicity; D006801:Humans; D008297:Male; D008353:Mannitol / Q000633:toxicity; D008810:Mice, Inbred C57BL; D009389:Neovascularization, Pathologic; D009994:Osmolar Concentration; D034622:RNA Interference; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: C496020:AQP1 protein, human; C496021:Aqp1 protein, mouse; C118125:NFAT5 protein, human; D014157:Transcription Factors; D051398:Aquaporin 1; D008353:Mannitol; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D005947:Glucose
references.citation: J Cell Sci. 2006 Jul 15;119(Pt 14):2985-94
references.pmid: 16803872
references.citation: Biochim Biophys Acta. 2014 Nov;1842(11):2266-75
references.pmid: 25108283
references.citation: J Biol Chem. 2005 Apr 8;280(14):13503-11
references.pmid: 15705589
references.citation: Surgery. 2000 Aug;128(2):198-205
references.pmid: 10922992
references.citation: Exp Eye Res. 2015 Nov;140:124-9
references.pmid: 26297615
references.citation: J Biol Chem. 2005 Mar 11;280(10):8686-93
references.pmid: 15632146
references.citation: Nucleic Acids Res. 2005;33(12):3845-54
references.pmid: 16027109
references.citation: Cardiovasc Res. 2001 Feb 16;49(3):507-21
references.pmid: 11166264
references.citation: J Biol Chem. 1994 Nov 25;269(47):29379-81
references.pmid: 7961914
references.citation: Am J Physiol. 1998 Apr;274(4 Pt 2):F753-61
references.pmid: 9575900
references.citation: Surgeon. 2009 Jun;7(3):174-80
references.pmid: 19580182
references.citation: Semin Oncol. 2004 Apr;31(2 Suppl 7):2-11
references.pmid: 15179620
references.citation: Am J Physiol Renal Physiol. 2003 Aug;285(2):F281-8
references.pmid: 12670830
references.citation: Circulation. 2002 Feb 19;105(7):816-22
references.pmid: 11854121
references.citation: J Am Coll Cardiol. 2004 Dec 21;44(12):2293-300
references.pmid: 15607389
references.citation: Diabetes. 2004 Mar;53(3):795-802
references.pmid: 14988266
references.citation: FASEB J. 1998 Sep;12(12):1063-73
references.pmid: 9737710
references.citation: EMBO J. 2010 Aug 4;29(15):2501-14
references.pmid: 20588253
references.citation: Lancet. 1998 Sep 12;352(9131):854-65
references.pmid: 9742977
references.citation: BMC Ophthalmol. 2010;10:25
references.pmid: 20920307
references.citation: J Immunol. 2010 May 1;184(9):5253-62
references.pmid: 20368270
references.citation: Nature. 2001 Dec 13;414(6865):813-20
references.pmid: 11742414
references.citation: Br J Cancer. 2002 Sep 9;87(6):621-3
references.pmid: 12237771
references.citation: Free Radic Biol Med. 1998 Jul 1;25(1):121-9
references.pmid: 9655530
references.citation: Invest Ophthalmol Vis Sci. 2013 Jan;54(1):574-84
references.pmid: 23221078
references.citation: Endocrine. 2009 Feb;35(1):63-74
references.pmid: 18991026
references.citation: Biochem Pharmacol. 2013 Dec 1;86(11):1603-13
references.pmid: 24076420
references.citation: Cancer Sci. 2009 Dec;100(12):2318-24
references.pmid: 19799610
references.citation: Cardiovasc Diabetol. 2015;14:31
references.pmid: 25848912
references.citation: J Mol Med (Berl). 1998 Jan;76(1):21-31
references.pmid: 9462865
references.citation: Vascul Pharmacol. 2011 Mar-Jun;54(3-6):68-74
references.pmid: 21453786
references.citation: Physiol Rev. 1998 Jan;78(1):247-306
references.pmid: 9457175
references.citation: J Exp Med. 2001 Mar 5;193(5):607-20
references.pmid: 11238591
references.citation: J Biol Chem. 2007 Jul 20;282(29):20933-40
references.pmid: 17522053
references.citation: Trends Endocrinol Metab. 2006 Jan-Feb;17(1):1-2
references.pmid: 16309919
references.citation: Int J Mol Med. 2014 Aug;34(2):533-8
references.pmid: 24888368
references.citation: Int J Immunopathol Pharmacol. 2010 Jul-Sep;23(3):755-65
references.pmid: 20943045
references.citation: Biophys J. 1998 Apr;74(4):2121-8
references.pmid: 9545071
references.citation: Exp Eye Res. 2014 May;122:13-9
references.pmid: 24631337
references.citation: Circulation. 2003 Feb 25;107(7):1017-23
references.pmid: 12600916
references.citation: J Biol Chem. 2006 May 5;281(18):12210-7
references.pmid: 16505480
references.citation: Biochem Pharmacol. 2015 Aug 1;96(3):278-87
references.pmid: 26056075
references.citation: Microvasc Res. 2008 Apr;75(3):297-301
references.pmid: 18275976
references.citation: N Engl J Med. 2008 Oct 9;359(15):1577-89
references.pmid: 18784090
references.citation: Anat Rec. 2002 Oct 1;268(2):85-9
references.pmid: 12221713
references.citation: Cell. 1998 May 29;93(5):705-16
references.pmid: 9630216
references.citation: N Engl J Med. 2004 Jan 1;350(1):48-58
references.pmid: 14702427
references.citation: Nature. 2005 Apr 7;434(7034):786-92
references.pmid: 15815633
references.citation: Invest Ophthalmol Vis Sci. 2005 Jun;46(6):2210-8
references.pmid: 15914643
references.citation: J Cardiovasc Dis Res. 2011 Apr;2(2):96-103
references.pmid: 21814413
references.citation: J Biol Chem. 2003 May 2;278(18):15765-70
references.pmid: 12600999
references.citation: Nat Med. 2003 Jun;9(6):653-60
references.pmid: 12778163
references.citation: Biochem Biophys Res Commun. 2009 Apr 10;381(3):301-5
references.pmid: 19146830
references.citation: PLoS Pathog. 2010 Jan;6(1):e1000733
references.pmid: 20107604
references.citation: Cancer Res. 2000 Mar 1;60(5):1306-11
references.pmid: 10728691
references.citation: Am J Physiol Renal Physiol. 2006 Mar;290(3):F641-9
references.pmid: 16263809