Abstract
Purpose: :
Previously we demonstrated that scleral stem/progenitor cells (SSPC) having chondrogenic differentiation potential, which is stimulated by transforming growth factor-β (TGF-β). In the present study, we hypothesized that the up-regulation of alpha- smooth muscle actin (α-SMA) by TGF-β could be the possible mechanism for myopia development. Therefore, we investigated the association between the chondrogenesis and deprivation myopia in mice.
Methods: :
The levels of α-SMA and collagen type II in murine SSPCs during chondrogenesis through stimulation by TGF-β were estimated by real-time quantitative RT-PCR (qRT-PCR) in cell culture. The expressions of α-SMA and collagen type II were investigated by immunohistochemistry in the three dimensional pellet culture. In form-deprivation myopia (FDM) mouse model, qRT-PCR was used to detect any changes in TGF-β mRNA expression in the choroid. Western blot analysis is used to detect the changes in α-SMA and collagen type II in the sclera.
Results: :
The stimulation of SSCPs with TGF-β for 24 hrs at 10 or 1 ng/ml, led to increased levels of both of α-SMA and collagen type II increased. In addition, we observed the formation of cartilage-like pellet with TGF-β treated SSPCs. More importantly, the levels of of TGF-β in the choroid were significantly elevated in mouse with FDM, compared with control mice. Also, α-SMA and collagen type II were significantly increased in the sclera.
Conclusions: :
TGF-β has the potential to induce chondrogenic differentiation of scleral stem/progenitor cells. The increased levels of TGF-β in choroid and the increased cartilage protein in sclera could play an important role in myopia development.
Keywords: myopia • sclera