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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.

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Related in: MedlinePlus

Inhibitory effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Hyalocytes were starved in Dulbecco's modified Eagle's medium containing 3% calf serum for 24 h. A: Hyalocytes were pretreated for 30 min with or without the indicated concentrations of simvastatin (0.3, 1, 3, and 10 μmol/l) and subsequently treated with 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. C: Hyalocytes were pretreated with or without 5 μmol/l simvastatin for the indicated time (1, 4, 10, and 24 h) and subsequently treated with 3 ng/ml TGF-β2 for 24 h. p-MLC and MLC were also examined in the same way as in Fig. 1A. B and D: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of control intensity ratio. *P < 0.05 compared with TGF-β2 alone.
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f2: Inhibitory effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Hyalocytes were starved in Dulbecco's modified Eagle's medium containing 3% calf serum for 24 h. A: Hyalocytes were pretreated for 30 min with or without the indicated concentrations of simvastatin (0.3, 1, 3, and 10 μmol/l) and subsequently treated with 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. C: Hyalocytes were pretreated with or without 5 μmol/l simvastatin for the indicated time (1, 4, 10, and 24 h) and subsequently treated with 3 ng/ml TGF-β2 for 24 h. p-MLC and MLC were also examined in the same way as in Fig. 1A. B and D: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of control intensity ratio. *P < 0.05 compared with TGF-β2 alone.

Mentions: TGF-β2 enhanced MLC phosphorylation to about two times that seen with control (Fig. 2A and B). TGF-β2–dependent MLC phosphorylation showed a significant reduction at 0.3 μmol/l simvastatin or higher concentrations (up to 10 μmol/l simvastatin) compared with TGF-β2 alone (P < 0.05). The level of MLC phosphorylation at 10 μmol/l simvastatin concentration was lower than in untreated control, suggesting that simvastatin at higher concentrations may block the constitutive level of MLC phosphorylation. Because 3 μmol/l simvastatin was sufficient to reverse the effect of TGF-β2 on MLC phosphorylation, we chose the slightly higher concentration of 5 μmol/l to study the time-dependent effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Treatment of the hyalocytes with 5 μmol/l simvastatin for 1 h or longer (up to 24 h) significantly suppressed the MLC phosphorylation compared with TGF-β2 alone, and treatment with 5 μmol/l simvastatin for 24 h sufficiently suppressed the MLC phosphorylation below that of untreated control (Fig. 2C and D).


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)

Inhibitory effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Hyalocytes were starved in Dulbecco's modified Eagle's medium containing 3% calf serum for 24 h. A: Hyalocytes were pretreated for 30 min with or without the indicated concentrations of simvastatin (0.3, 1, 3, and 10 μmol/l) and subsequently treated with 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. C: Hyalocytes were pretreated with or without 5 μmol/l simvastatin for the indicated time (1, 4, 10, and 24 h) and subsequently treated with 3 ng/ml TGF-β2 for 24 h. p-MLC and MLC were also examined in the same way as in Fig. 1A. B and D: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of control intensity ratio. *P < 0.05 compared with TGF-β2 alone.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2: Inhibitory effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Hyalocytes were starved in Dulbecco's modified Eagle's medium containing 3% calf serum for 24 h. A: Hyalocytes were pretreated for 30 min with or without the indicated concentrations of simvastatin (0.3, 1, 3, and 10 μmol/l) and subsequently treated with 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. C: Hyalocytes were pretreated with or without 5 μmol/l simvastatin for the indicated time (1, 4, 10, and 24 h) and subsequently treated with 3 ng/ml TGF-β2 for 24 h. p-MLC and MLC were also examined in the same way as in Fig. 1A. B and D: Signal intensity ratios (p-MLC to MLC) were expressed as percentage of control intensity ratio. *P < 0.05 compared with TGF-β2 alone.
Mentions: TGF-β2 enhanced MLC phosphorylation to about two times that seen with control (Fig. 2A and B). TGF-β2–dependent MLC phosphorylation showed a significant reduction at 0.3 μmol/l simvastatin or higher concentrations (up to 10 μmol/l simvastatin) compared with TGF-β2 alone (P < 0.05). The level of MLC phosphorylation at 10 μmol/l simvastatin concentration was lower than in untreated control, suggesting that simvastatin at higher concentrations may block the constitutive level of MLC phosphorylation. Because 3 μmol/l simvastatin was sufficient to reverse the effect of TGF-β2 on MLC phosphorylation, we chose the slightly higher concentration of 5 μmol/l to study the time-dependent effect of simvastatin on TGF-β2–dependent MLC phosphorylation. Treatment of the hyalocytes with 5 μmol/l simvastatin for 1 h or longer (up to 24 h) significantly suppressed the MLC phosphorylation compared with TGF-β2 alone, and treatment with 5 μmol/l simvastatin for 24 h sufficiently suppressed the MLC phosphorylation below that of untreated control (Fig. 2C and D).

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