Limits...
Potent inhibition of cicatricial contraction in proliferative vitreoretinal diseases by statins.

Kawahara S, Hata Y, Kita T, Arita R, Miura M, Nakao S, Mochizuki Y, Enaida H, Kagimoto T, Goto Y, Hafezi-Moghadam A, Ishibashi T - Diabetes (2008)

Bottom Line: In the current study, we investigated the inhibitory effects of statins on the progression of PVDs.Human vitreous concentrations of TGF-beta2 were significantly higher in the samples from patients with PVD compared with those without PVD.Statins might have therapeutic potential in the prevention of PVDs.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-Ku, Fukuoka, Japan.

ABSTRACT

Objective: Despite tremendous progress in vitreoretinal surgery, certain postsurgical complications limit the success in the treatment of proliferative vitreoretinal diseases (PVDs), such as proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). One of the most significant complications is the cicatricial contraction of proliferative membranes, resulting in tractional retinal detachment and severe vision loss. Novel pharmaceutical approaches are thus urgently needed for the management of these vision-threatening diseases. In the current study, we investigated the inhibitory effects of statins on the progression of PVDs.

Research design and methods: Human vitreous concentrations of transforming growth factor-beta2 (TGF-beta2) were measured by enzyme-linked immunosorbent assay. TGF-beta2-and vitreous-dependent phosphorylation of myosin light chain (MLC), a downstream mediator of Rho-kinase pathway, and collagen gel contraction simulating cicatrical contraction were analyzed using cultured hyalocytes. Inhibitory effects of simvastatin on cicatrical contraction were assessed both in vitro and in vivo.

Results: Human vitreous concentrations of TGF-beta2 were significantly higher in the samples from patients with PVD compared with those without PVD. Simvastatin inhibited TGF-beta2-dependent MLC phosphorylation and gel contraction in a dose- and time-dependent manner and was capable of inhibiting translocation of Rho protein to the plasma membrane in the presence of TGF-beta2. Vitreous samples from patients with PVD enhanced MLC phosphorylation and gel contraction, whereas simvastatin almost completely inhibited these phenomena. Finally, intravitreal injection of simvastatin dose-dependently prevented the progression of diseased states in an in vivo model of PVR.

Conclusions: Statins might have therapeutic potential in the prevention of PVDs.

Show MeSH

Related in: MedlinePlus

Comparison of inhibitory effects of simvastatin, fluvastatin, and pravastatin on TGF-β2–dependent MLC phosphorylation and collagen gel contraction. A: Starved hyalocytes were pretreated with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 30 min and subsequently treated with or without 3 ng/ml TGF-β2 for 24 h. Total cell lysates were subjected to Western blot analysis with an antibody against p-MLC. Lane loading differences were normalized by reblotting the membranes with an antibody against MLC. B: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of intensity ratio of vehicle alone. *P < 0.05. C: Hyalocytes were embedded in type I collagen gels (n = 4). After starvation and pretreatment with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 24 h, the collagen gels were stimulated with 3 ng/ml TGF-β2. Five days after the stimulation, the gels were photographed. D: The diameter of the collagen gels was measured and expressed as percentage of the average diameter of control group. **P < 0.01, *P < 0.05; NS, not significant. E: The viable cell number in the collagen gels was counted to exclude the effect of cell growth or cytotoxicity on the collagen gel contraction or its inhibition. Five days after the treatment, the collagen gels were dissolved, and the cell suspension was collected. The viable cell number was counted with hemocytometer after trypan blue staining (n = 4; NS, not significant compared with control).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2551690&req=5

f5: Comparison of inhibitory effects of simvastatin, fluvastatin, and pravastatin on TGF-β2–dependent MLC phosphorylation and collagen gel contraction. A: Starved hyalocytes were pretreated with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 30 min and subsequently treated with or without 3 ng/ml TGF-β2 for 24 h. Total cell lysates were subjected to Western blot analysis with an antibody against p-MLC. Lane loading differences were normalized by reblotting the membranes with an antibody against MLC. B: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of intensity ratio of vehicle alone. *P < 0.05. C: Hyalocytes were embedded in type I collagen gels (n = 4). After starvation and pretreatment with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 24 h, the collagen gels were stimulated with 3 ng/ml TGF-β2. Five days after the stimulation, the gels were photographed. D: The diameter of the collagen gels was measured and expressed as percentage of the average diameter of control group. **P < 0.01, *P < 0.05; NS, not significant. E: The viable cell number in the collagen gels was counted to exclude the effect of cell growth or cytotoxicity on the collagen gel contraction or its inhibition. Five days after the treatment, the collagen gels were dissolved, and the cell suspension was collected. The viable cell number was counted with hemocytometer after trypan blue staining (n = 4; NS, not significant compared with control).

Mentions: Simvastatin and fluvastatin significantly suppressed TGF-β2–dependent MLC phosphorylation by hyalocytes, whereas pravastatin did not show an effect (Fig. 5A and B). In addition, simvastatin significantly suppressed MLC phosphorylation compared with fluvastatin (P < 0.05). Next, we compared the inhibitory effect of statins on the contraction of hyalocyte-containing collagen gels. Simvastatin and fluvastatin significantly suppressed TGF-β2–dependent contraction of collagen gel, whereas pravastatin did not show an effect (Fig. 5C and D). In addition, the inhibitory effect of simvastatin (100% vs. control) was significantly higher than that by fluvastatin (94% vs. control) (P < 0.05). To test whether cytokine and/or statin treatment affected the growth and/or viability of the cells in our experiments, we treated the collagen gels with collagenase and counted the number of viable cells. Both TGF-β2 and statins showed no significant effects on cell number in the three-dimensional collagen gels (Fig. 5E).


Potent inhibition of cicatricial contraction in proliferative vitreoretinal diseases by statins.

Kawahara S, Hata Y, Kita T, Arita R, Miura M, Nakao S, Mochizuki Y, Enaida H, Kagimoto T, Goto Y, Hafezi-Moghadam A, Ishibashi T - Diabetes (2008)

Comparison of inhibitory effects of simvastatin, fluvastatin, and pravastatin on TGF-β2–dependent MLC phosphorylation and collagen gel contraction. A: Starved hyalocytes were pretreated with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 30 min and subsequently treated with or without 3 ng/ml TGF-β2 for 24 h. Total cell lysates were subjected to Western blot analysis with an antibody against p-MLC. Lane loading differences were normalized by reblotting the membranes with an antibody against MLC. B: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of intensity ratio of vehicle alone. *P < 0.05. C: Hyalocytes were embedded in type I collagen gels (n = 4). After starvation and pretreatment with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 24 h, the collagen gels were stimulated with 3 ng/ml TGF-β2. Five days after the stimulation, the gels were photographed. D: The diameter of the collagen gels was measured and expressed as percentage of the average diameter of control group. **P < 0.01, *P < 0.05; NS, not significant. E: The viable cell number in the collagen gels was counted to exclude the effect of cell growth or cytotoxicity on the collagen gel contraction or its inhibition. Five days after the treatment, the collagen gels were dissolved, and the cell suspension was collected. The viable cell number was counted with hemocytometer after trypan blue staining (n = 4; NS, not significant compared with control).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2551690&req=5

f5: Comparison of inhibitory effects of simvastatin, fluvastatin, and pravastatin on TGF-β2–dependent MLC phosphorylation and collagen gel contraction. A: Starved hyalocytes were pretreated with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 30 min and subsequently treated with or without 3 ng/ml TGF-β2 for 24 h. Total cell lysates were subjected to Western blot analysis with an antibody against p-MLC. Lane loading differences were normalized by reblotting the membranes with an antibody against MLC. B: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of intensity ratio of vehicle alone. *P < 0.05. C: Hyalocytes were embedded in type I collagen gels (n = 4). After starvation and pretreatment with vehicle, 5 μmol/l simvastatin, fluvastatin, or pravastatin for 24 h, the collagen gels were stimulated with 3 ng/ml TGF-β2. Five days after the stimulation, the gels were photographed. D: The diameter of the collagen gels was measured and expressed as percentage of the average diameter of control group. **P < 0.01, *P < 0.05; NS, not significant. E: The viable cell number in the collagen gels was counted to exclude the effect of cell growth or cytotoxicity on the collagen gel contraction or its inhibition. Five days after the treatment, the collagen gels were dissolved, and the cell suspension was collected. The viable cell number was counted with hemocytometer after trypan blue staining (n = 4; NS, not significant compared with control).
Mentions: Simvastatin and fluvastatin significantly suppressed TGF-β2–dependent MLC phosphorylation by hyalocytes, whereas pravastatin did not show an effect (Fig. 5A and B). In addition, simvastatin significantly suppressed MLC phosphorylation compared with fluvastatin (P < 0.05). Next, we compared the inhibitory effect of statins on the contraction of hyalocyte-containing collagen gels. Simvastatin and fluvastatin significantly suppressed TGF-β2–dependent contraction of collagen gel, whereas pravastatin did not show an effect (Fig. 5C and D). In addition, the inhibitory effect of simvastatin (100% vs. control) was significantly higher than that by fluvastatin (94% vs. control) (P < 0.05). To test whether cytokine and/or statin treatment affected the growth and/or viability of the cells in our experiments, we treated the collagen gels with collagenase and counted the number of viable cells. Both TGF-β2 and statins showed no significant effects on cell number in the three-dimensional collagen gels (Fig. 5E).

Bottom Line: In the current study, we investigated the inhibitory effects of statins on the progression of PVDs.Human vitreous concentrations of TGF-beta2 were significantly higher in the samples from patients with PVD compared with those without PVD.Statins might have therapeutic potential in the prevention of PVDs.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Maidashi, Higashi-Ku, Fukuoka, Japan.

ABSTRACT

Objective: Despite tremendous progress in vitreoretinal surgery, certain postsurgical complications limit the success in the treatment of proliferative vitreoretinal diseases (PVDs), such as proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). One of the most significant complications is the cicatricial contraction of proliferative membranes, resulting in tractional retinal detachment and severe vision loss. Novel pharmaceutical approaches are thus urgently needed for the management of these vision-threatening diseases. In the current study, we investigated the inhibitory effects of statins on the progression of PVDs.

Research design and methods: Human vitreous concentrations of transforming growth factor-beta2 (TGF-beta2) were measured by enzyme-linked immunosorbent assay. TGF-beta2-and vitreous-dependent phosphorylation of myosin light chain (MLC), a downstream mediator of Rho-kinase pathway, and collagen gel contraction simulating cicatrical contraction were analyzed using cultured hyalocytes. Inhibitory effects of simvastatin on cicatrical contraction were assessed both in vitro and in vivo.

Results: Human vitreous concentrations of TGF-beta2 were significantly higher in the samples from patients with PVD compared with those without PVD. Simvastatin inhibited TGF-beta2-dependent MLC phosphorylation and gel contraction in a dose- and time-dependent manner and was capable of inhibiting translocation of Rho protein to the plasma membrane in the presence of TGF-beta2. Vitreous samples from patients with PVD enhanced MLC phosphorylation and gel contraction, whereas simvastatin almost completely inhibited these phenomena. Finally, intravitreal injection of simvastatin dose-dependently prevented the progression of diseased states in an in vivo model of PVR.

Conclusions: Statins might have therapeutic potential in the prevention of PVDs.

Show MeSH
Related in: MedlinePlus