title: Transient adenoviral gene transfer of Smad7 prevents injury-induced epithelial-mesenchymal transition of lens epithelium in mice.
abstract: We examined the effect of adenovirus-mediated transient expression of Smad7, an inhibitory Smad in TGFbeta/activin signaling, on injury-induced epithelial-mesenchymal transition (EMT) of lens epithelium in mice. A volume of 3 microl of adenoviral solution was injected into the right lens of adult male C57BL/6 mice (n=56) at the time of capsular injury made using a hypodermic needle under general anesthesia. A mixture of recombinant adenovirus carrying CAG promoter-driven Cre (Cre adv) and mouse Smad7 complementary DNA (Smad7 adv) was administered to induce Smad7 expression, while control lenses were treated with Cre adv alone. After healing intervals of 2, 3, 5, and 10 days, animals were killed 2 h after labeling with bromodeoxyuridine (BrdU) and eyes were processed for histology. During healing, marked expression of Smad7 was observed in lens epithelial cells in the Smad7 adv group with loss of nuclear translocation of Smads2/3, while little Smad7 and abundant nuclear Smads2/3 were seen in cells in the Cre adv group. Lens epithelial cells in the Cre adv control group exhibited a fibroblastic appearance at days 5 and 10 and the capsular break was sealed with fibrous tissue, while Smad7 adv-treated cells around the capsular break retained their epithelial morphology and the break was not sealed. Expression of snail mRNA, and alpha-smooth muscle actin, lumican, and collagen VI proteins, markers of EMT, was observed in control-treated eyes, but not in cells of the Smad7 adv group at day 5 with minimal expression at day 10. Additionally, cell proliferation increased in epithelium infected with Smad7 adv consistent with suppression of injury-induced upregulation of TGFbeta1 in epithelium. We conclude that gene transfer of Smad7 in mice prevents injury-induced EMT of lens epithelial cells and sealing of the capsular break with fibrous tissue.
authors.affiliation: Department Ophthalmology, Wakayama Medical University, Kimiidera, Wakayama, Japan. shizuya@wakayamma-med.ac.jp
authors.forename: Shizuya
authors.initials: S
authors.lastname: Saika
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ikeda
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamanaka
authors.forename: Misako
authors.initials: M
authors.lastname: Sato
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Muragaki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Ohnishi
authors.forename: Akira
authors.initials: A
authors.lastname: Ooshima
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakajima
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Namikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyama
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Flanders
authors.forename: Anita B
authors.initials: AB
authors.lastname: Roberts
mesh_terms: D000199:Actins / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D002455:Cell Division; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D024142:Collagen Type VI / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D005131:Eye Injuries / Q000517:prevention & control*; D005786:Gene Expression Regulation; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D007632:Keratan Sulfate / Q000378:metabolism; D007903:Lens Capsule, Crystalline / Q000293:injuries* / Q000378:metabolism / Q000473:pathology; D007908:Lens, Crystalline / Q000378:metabolism / Q000473:pathology*; D000071234:Lumican; D008297:Male; D008648:Mesoderm / Q000473:pathology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D051906:Smad7 Protein; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014161:Transduction, Genetic; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D014945:Wound Healing
chemical_list: D000199:Actins; D011508:Chondroitin Sulfate Proteoglycans; D024142:Collagen Type VI; D004268:DNA-Binding Proteins; C000604307:Lum protein, mouse; D000071234:Lumican; D012333:RNA, Messenger; D051906:Smad7 Protein; C497807:Smad7 protein, mouse; D015534:Trans-Activators; D016212:Transforming Growth Factor beta; D007632:Keratan Sulfate