The pathogenesis of polypoidal choroidal vasculopathy (PCV) is still controversial. More evidence of clinical and basic research is needed to distinguish PCV from an independent disease to a subtype of age-related macular degeneration. Not only that, there are also many puzzles in the diagnosis, treatment options and prognosis of PCV. In addition to these common problems, we also face a large population with risk factors, a large number of PCV patients with multiple and complex challenges in China. There is a long way to go to reduce the damage effects of PCV on visual function. To fulfil this goal, we need make full use of the huge resources of PCV patients and turn these challenges into opportunities, and contribute the improvement of diagnosis and better understanding of PCV pathogenesis.
Objective To investigate the modulating effect of transforming growth factor beta;2 (TGFbeta;2) and extracellular matrix (ECM) on the transdifferentiation of human fetal RPE (hfRPE) cells into myofibroblast-like cells , and to determine the mechanism of signal transduction. Methods hfRPE cells were cultured on ECM coated or uncoated petri dish with or witho ut TGFbeta;2 in the medium. The expression of alpha;-smooth muscle actin (alpha;-SMA) were detected by immunocytochemistry examination, flow cytometry and Western blotting via calphostin C, genistein, PD98059, and Wortmannin. Results After cultured on ECM coated petri dish with TGFbeta;2 in the medium,there were obvious morphological changes of hfRPE cells including cellular elongating and appearing of actin microfilaments. The results of flow cytometry and immunocytochemistry examination showed that expression of alpha;-SMA obviously increased after TGFbeta;2 was added in the medium in a dose-dependent manner. Compared with which of hfRPE cells cultured on the uncoated surface of culture plates, the total mean fluore scence intensity (TMFI) of hfRPE cells cultured on FN-coated surface increased (38.01plusmn;1.14)% when the stimulation concentration of TGFbeta;2 was 50ng/ml(Plt;0.05). Western blotting further confirmed the effects. The changes mentioned above could be inhibited mostly by protein kinase C (PKC) and calphostin C (10 nmol/L)(Plt;0.01). Conclusion TGFbeta;2 may induce the transdifferentiation of hfRPE cells into myofibroblast-like cells in a dose dependent manner, which could be intensified by FN. These mediated effects of TGFbeta;2 and ECM may act via the PKC signal transduction pathway. (Chin J Ocul Fundus Dis, 2006, 22: 328-332)
Polypoidal choroidal vasculopathy (PCV) is a fundus disease characterized by choroidal anomalous branch vascular network and terminal polypoidal dilatation. According to its fundus feature, lesion location, imaging feature and disease progression, PCV can be divided into different types or stages. It can be divided into hemorrhage and exudation PCV according to the fundus features, into macular, peripapillary, periphery and mixed types according to the lesion locations. It can also be divided into type 1 and 2 according to the ICGA (indocyanine green angiography) manifestations, and can be classified as early stage and late stage according to disease progression. There were different correlations between different types of PCV and some risk genetic loci, such as ARMS2 (age-related macular degeneration factor 2)/ HTRA1 (high temperature essential protein A1) , C2, complement factor B, complement factor H, and elastin genes. The response to therapy and prognosis are also different between different types. It is important to further study the clinical classification of PCV, to explore the genetic characteristics, influencing factors and treatment or prognosis features of different types of PCV. The results will improve the differential diagnosis of PCV, and the effectiveness of individualized treatment.