Adenoviral Gene Transfer of Active Human Transforming Growth Factor-beta 2 Elevates Intraocular Pressure and Reduces Outflow Facility in Rodent Eyes

PURPOSE. Glaucoma is a leading cause worldwide of blindness and visual impairment. Transforming growth factor-beta 2 (TGF beta 2) has been implicated in the pathogenesis of primary open-angle glaucoma (POAG) based on elevated levels in glaucomatous aqueous humor and its ability to induce extracellular matrix (ECM) remodeling in the trabecular meshwork (TM). The goal of this study was to generate a rodent model of POAG using viral gene transfer of human TGF beta 2. METHODS. Latent (hTGF beta 2(WT)) or active (C226S, C228S; hTGF beta 2(226/228)) TGF beta 2-encoding cDNA was cloned into the pac.Ad5.CMV.K-N.pA shuttle vector for generation of replication-deficient adenovirus. Empty adenovirus (Ad5.CMV.K-N.pA) was used as a control. Adenoviral expression of active and total TGF beta 2 was assayed in vitro by the transduction of Chinese hamster ovary and trabecular meshwork cells. BALB/cJ mice or Wistar rats were injected either intracamerally or intravitreally with the adenovectors and assessed for changes in intraocular pressure (IOP) using the rebound tonometer. At peak IOP, aqueous outflow facility and total TGF beta 2 levels in aqueous humor were measured. Mouse eye morphology was assessed by hematoxylin and eosin staining. RESULTS. Adenoviral gene transfer of hTGF beta 2(226/228), but not hTGF beta 2(WT), to the rodent eye elevated IOP in rat (43%, P < 0.001) and mouse (110%, P < 0.001) and reduced aqueous humor outflow facility in the mouse. The TGF beta 2-induced ocular hypertension correlated with anterior segment TGF beta 2 expression levels (P < 0.0001). CONCLUSIONS. The adenoviral TGF beta 2 rodent model displays the glaucoma risk factors of elevated IOP and decreased aqueous outflow facility and may potentially serve as a model for studying glaucoma. (Invest Ophthalmol Vis Sci. 2010; 51: 2067-2076) DOI:10.1167/iovs.09-4567