scholarly journals C3a Increases VEGF and Decreases PEDF mRNA Levels in Human Retinal Pigment Epithelial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Qin Long ◽  
Xiaoguang Cao ◽  
Ailing Bian ◽  
Ying Li
Keyword(s):  
Retinal Pigment Epithelial ◽  
Retinal Pigment ◽  
Mrna Level ◽  
Retinal Pigment Epithelial Cells ◽  
Mrna Levels ◽  
Sirna Duplex ◽  
Pigment Epithelial ◽  
Pathological Angiogenesis ◽  
Interfering Rna ◽  
Endothelial Growth Factor

Complement activation, specifically complement 3 (C3) activation and C3a generation, contributes to an imbalance between angiogenic stimulation by vascular endothelial growth factor (VEGF) and angiogenic inhibition by pigment epithelial derived factor (PEDF), leading to pathological angiogenesis. This study aimed to investigate the effects of C3a and small interfering RNA (siRNA) targeting C3 on the levels of VEGF and PEDF mRNAs in human retinal pigment epithelial (RPE) cells. ARPE-19 cells were cultured in the presence of exogenous C3a at 0.1 μM and 0.3 μM C3a for 24, 48, and 72 hours. 0.1 pmol/μL duplexes of siRNA targeting C3 were applied for C3a inhibition by transfecting ARPE-19 cells for 48 hours. RT-PCR was performed to examine the level of VEGF and PEDF mRNA. A random siRNA duplex was set for control siRNA. Results demonstrated that exogenous C3a significantly upregulated VEGF and downregulated PEDF mRNA levels in cultured ARPE-19 cells, and siRNA targeting C3 transfection reversed the above changes, significantly reducing VEGF and enhancing PEDF mRNAs level in ARPE-19 cells compared to the control. The present data provided evidence that reducing C3 activation can decreases VEGF and increase PEDF mRNA level in RPE and may serve as a potential therapy in pathological angiogenesis.

Downregulation of the human taurine transporter by glucose in cultured retinal pigment epithelial cells

1999 ◽  
Vol 277 (4) ◽  
pp. E760-E771 ◽  
Author(s):  
Martin J. Stevens ◽  
Yoshiyuki Hosaka ◽  
Jennifer A. Masterson ◽  
Sandra M. Jones ◽  
Thommey P. Thomas ◽  
...  
Keyword(s):  
High Glucose ◽  
Retinal Pigment Epithelial ◽  
Prolonged Exposure ◽  
Retinal Pigment Epithelial Cell ◽  
Retinal Pigment ◽  
Mrna Abundance ◽  
Retinal Pigment Epithelial Cells ◽  
Mrna Levels ◽  
Pigment Epithelial ◽  
Endogenous Antioxidant

In diabetes, activation of the aldose reductase (AR) pathway and alterations of glucose-sensitive signal transduction pathways have been implicated in depletion of intracellular taurine, an endogenous antioxidant and compatible osmolyte. Cellular taurine accumulation occurs by an osmotically induced, protein kinase C (PKC)-regulated Na+-taurine cotransporter (hTT). The effects of ambient glucose on taurine content, hTT activity, and hTT gene expression were therefore evaluated in low and high AR-expressing human retinal pigment epithelial cell lines. In low AR-expressing cells, 20 mM glucose decreased taurine content, hTT transporter activity, and mRNA levels, and these effects were unaffected by AR inhibition (ARI). In these cells, the inhibitory effects of high glucose on hTT appeared to be posttranscriptionally mediated, because 20 mM glucose decreased hTT mRNA stability without affecting hTT transcriptional rate. Inhibition of PKC overcame the decrease in hTT activity in high glucose-exposed cells. In high AR-expressing cells, prolonged exposure to 20 mM glucose resulted in intracellular taurine depletion, which paralleled sorbitol accumulation and was prevented by ARI. In these cells exposed to 5 mM glucose, hTT mRNA abundance was decreased and declined further in 20 mM glucose but was corrected by ARI. In 5 mM glucose, hTT transcriptional rate was markedly decreased in high AR-expressing cells, did not decline further in 20 mM glucose, but was increased by ARI to levels above those observed in low AR-expressing cells. Therefore, glucose rapidly and specifically decreases taurine content, hTT activity, and mRNA abundance by AR-unrelated and AR-related posttranscriptional and transcriptional mechanisms.

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