Suppression of injury-induced conjunctiva scarring by peroxisome proliferator-activated receptor gamma gene transfer in mice.
OBJECTIVE
To examine the effects of introduction of the adenoviral peroxisome proliferator-activated receptor (PPAR)-gamma gene on postinjury conjunctival scarring in mice. Its effects on fibrogenic reaction of cultured human subconjunctival fibroblasts (hSCFs) were also evaluated.


METHODS
The effects of PPARgamma gene introduction on expression of type I collagen, fibronectin, and connective tissue growth factor (CTGF) in hSCFs were examined. A circumferential incision was made in the equatorial conjunctiva of the right eye of generally anesthetized adult C57BL/6 mice (n = 72). PPARgamma cDNA-expressing adenoviral vector was topically applied; the control eye received nonfunctioning adenoviral vector. At 2, 5, 7, and 14 days (each, n = 18), the eyes were processed for histologic or immunohistochemical examination to evaluate tissue scarring. Expression of type I collagen and growth factors was evaluated by real-time reverse transcription-polymerase chain reaction in 32 eyes from control and treatment groups.


RESULTS
PPARgamma overexpression suppressed type I collagen, fibronectin, and CTGF in cultured hSCFs at the mRNA or protein level. In vivo experiments showed that PPARgamma gene introduction suppressed monocyte/macrophage invasion, generation of myofibroblasts, and mRNA upregulation of cytokines/growth factors and collagen Ialpha2 chain (Col 1A2) in healing conjunctiva.


CONCLUSIONS
PPARgamma gene transfer suppresses the fibrogenic reaction in hSCFs as well as the injury-induced scarring of conjunctival tissue in mice, suggesting the effectiveness of this strategy in preventing excess scarring after filtration surgery. The mechanism may include suppression of activation of fibroblasts and reduction of macrophage invasion.
Yamanaka
Osamu
O
Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan. osa0910@gmail.com
Miyazaki
Ken-ichi
K
Kitano
Ai
A
Saika
Shizuya
S
Nakajima
Yuji
Y
Ikeda
Kazuo
K
D000199:Actins / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D000943:Antigens, Differentiation; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics; D003228:Conjunctiva / Q000293:injuries / Q000378:metabolism*; D003229:Conjunctival Diseases / Q000517:prevention & control*; D055513:Connective Tissue Growth Factor / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism; D005353:Fibronectins / Q000235:genetics; D005786:Gene Expression Regulation / Q000502:physiology*; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D047495:PPAR gamma / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014945:Wound Healing
D000199:Actins; D000943:Antigens, Differentiation; C526317:CCN2 protein, human; D024042:Collagen Type I; D005353:Fibronectins; D047495:PPAR gamma; D012333:RNA, Messenger; C036763:monocyte-macrophage differentiation antigen; D055513:Connective Tissue Growth Factor