ABSTRACT
Diabetic retinopathy (DR), one of the common complications of diabetes, is the main cause of blindness. Due to the limitations of the existing clinical treatment methods, it is urgent to develop new targets or/and new therapeutic drugs. This review summarizes the clinical trials of anti-DR drugs in recent years, and we note that gene therapy is a potential direction for DR treatment development. Due to the characteristics of ocular structure, including small size, a relatively independent organ, immune privilege and the opportunity for local administration, gene therapy could well be advantageous in the treatment of DR. Furthermore, the long-term therapeutic effects of gene therapy also improve compliance by DR patients. All these indicate that gene therapy is likely a future direction for development of DR therapies.
ABSTRACT
The study investigates the mechanism by which Peganum harmala L. (Luotuopeng, LTP) inhibits tube formation in retinal vascular endothelial cells. Tube formation was induced by treatment of retinal vascular endothelial cells with glucose. The cells were divided into a normal group, model group, and an LTP group. The total length of tube formation was measured. The active components, targets, and pathway by which LTP acts in the treatment of diabetic retinopathy was explored by network pharmacology. The mRNA expression levels of targets [extracellular signal-regulated kinase 2 (ERK2), phosphoinositide 3 kinase catalytic alpha polypeptide (PIK3CA), serine/threonine-protein kinase 1 (AKT1)] related to the mitogen-activated protein kinase (MAPK) signaling pathway and vascular endothelial growth factor (VEGF) signaling pathway was measured by real-time PCR. The results of tube formation indicated that compared with the normal group, the total tube length increased in the model group (P < 0.01); after the treatment with LTP, the total tube length decreased compared with the model group (P < 0.01). Network pharmacology revealed that the targets of LTP included PIK3CA, AKT1, and ERK2, and the pathways involved the MAPK signaling pathway and the VEGF signaling pathway. Real-time PCR indicated that compared with the normal group, the mRNA expression levels of ERK2, PIK3CA and AKT1 were elevated in the model group (P < 0.05); after treatment with LTP, the mRNA expression levels of ERK2, PIK3CA and AKT1 decreased compared with the model group (P < 0.05). LTP may inhibit retinal vascular endothelial cell tube formation by regulating the MAPK signaling pathway and the VEGF signaling pathway. This study confirms the multi-targets and multi-pathways of LTP and provides a basis for its use in the treatment of diabetic retinopathy．