TY - JOUR
T1 - Smad3 is necessary for transforming growth factor-beta2 induced ocular hypertension in mice
AU - McDowell, Colleen M.
AU - Tebow, Holly E.
AU - Wordinger, Robert J.
AU - Clark, Abbot F.
N1 - Funding Information:
Grant support: This work was supported by NEI grants ( R01 EY017374 and R21 EY019977 ).
PY - 2013/11
Y1 - 2013/11
N2 - TGFβ2 induces extracellular matrix (ECM) remodeling and alters the cytoskeleton by both the canonical Smad and non-canonical signaling pathways. TGFβ2 regulates the expression of ECM proteins in trabecular meshwork (TM) cells, increases intraocular pressure (IOP) in an exvivo perfusion organ culture model, and induces ocular hypertension in rodent eyes. A necessary step in the canonical Smad signaling pathway is phosphorylation of receptor protein Smad3 by the TGF-β receptor complex. The purpose of this study was to determine whether TGFβ2 signals invivo through the canonical Smad signaling pathway in the TM using Smad3 knockout (KO) mice. Ad5.hTGFβ2226/228 (2.5×107pfu) was injected intravitreally into one eye of homozygous (WT), heterozygous (HET), and homozygous (KO) 129-Smad3tm1Par/J mice (n=9-10 mice/group), with the uninjected contralateral eye serving as the control. IOP measurements were taken using a rebound tonometer. To test the effect of TGFβ2 signaling on the ECM, fibronectin expression was determined by immunohistochemistry and qPCR analysis. Transduction of the TM with viral vector Ad5.hTGFβ2226/228 caused a statistically significant difference in IOP exposure between Smad3 genotypes: WT, 187.7±23.9mmHg*day (n=9); HET, 95.6±24.5mmHg*day (n=9); KO, 52.8±25.2mmHg*day (n=10); (p<0.05 WT versus HET, p<0.01 WT versus KO). Immunohistochemistry and qPCR analysis showed that Ad5.hTGFβ2226/228 increased fibronectin expression in the TM of WT mice (2.23±0.24 fold) compared to Smad3 KO mice (0.99±0.19 fold), p<0.05. These results demonstrate Smad3 is a necessary signaling protein for TGFβ2-induced ocular hypertension and fibronectin deposition in the TM.
AB - TGFβ2 induces extracellular matrix (ECM) remodeling and alters the cytoskeleton by both the canonical Smad and non-canonical signaling pathways. TGFβ2 regulates the expression of ECM proteins in trabecular meshwork (TM) cells, increases intraocular pressure (IOP) in an exvivo perfusion organ culture model, and induces ocular hypertension in rodent eyes. A necessary step in the canonical Smad signaling pathway is phosphorylation of receptor protein Smad3 by the TGF-β receptor complex. The purpose of this study was to determine whether TGFβ2 signals invivo through the canonical Smad signaling pathway in the TM using Smad3 knockout (KO) mice. Ad5.hTGFβ2226/228 (2.5×107pfu) was injected intravitreally into one eye of homozygous (WT), heterozygous (HET), and homozygous (KO) 129-Smad3tm1Par/J mice (n=9-10 mice/group), with the uninjected contralateral eye serving as the control. IOP measurements were taken using a rebound tonometer. To test the effect of TGFβ2 signaling on the ECM, fibronectin expression was determined by immunohistochemistry and qPCR analysis. Transduction of the TM with viral vector Ad5.hTGFβ2226/228 caused a statistically significant difference in IOP exposure between Smad3 genotypes: WT, 187.7±23.9mmHg*day (n=9); HET, 95.6±24.5mmHg*day (n=9); KO, 52.8±25.2mmHg*day (n=10); (p<0.05 WT versus HET, p<0.01 WT versus KO). Immunohistochemistry and qPCR analysis showed that Ad5.hTGFβ2226/228 increased fibronectin expression in the TM of WT mice (2.23±0.24 fold) compared to Smad3 KO mice (0.99±0.19 fold), p<0.05. These results demonstrate Smad3 is a necessary signaling protein for TGFβ2-induced ocular hypertension and fibronectin deposition in the TM.
KW - Glaucoma
KW - Mouse model
KW - Ocular hypertension
KW - TGFβ2 signaling
KW - Trabecular meshwork
UR - http://www.scopus.com/inward/record.url?scp=84887548100&partnerID=8YFLogxK
U2 - 10.1016/j.exer.2013.10.017
DO - 10.1016/j.exer.2013.10.017
M3 - Article
C2 - 24184030
AN - SCOPUS:84887548100
SN - 0014-4835
VL - 116
SP - 419
EP - 423
JO - Experimental Eye Research
JF - Experimental Eye Research
ER -