title: Chondrogenesis in scleral stem/progenitor cells and its association with form-deprived myopia in mice.
abstract: OBJECTIVE
  Previously, we demonstrated that scleral stem/progenitor cells (SSPCs) from mice have a chondrogenic differentiation potential, which is stimulated by transforming growth factor-β (TGF-β). In the present study, we hypothesized that chondrogenesis in the sclera could be a possible mechanism in myopia development. Therefore, we investigated the association of form-deprivation myopia (FDM) with expressions in mice sclera representing the chondrogenic phenotype: collagen type II (Col2) and α-smooth muscle actin (α-SMA).
  
  
  METHODS
  The mRNA levels of α-SMA and Col2 in cultured murine SSPCs during chondrogenesis stimulated by TGF-β2 were determined by real-time quantitative RT-PCR (qRT-PCR). The expression patterns of α-SMA and Col2 were assessed by immunohistochemistry in a three dimensional pellet culture. In an FDM mouse model, a western blot analysis and immunofluorescence study were used to detect the changes in the α-SMA and Col2 protein expressions in the sclera. In the RPE-choroid complex, qRT-PCR was used to detect any changes in the TGF-β mRNA expression.
  
  
  RESULTS
  The treatment of SSPCs in vitro with TGF-β2 for 24 h at 1 or 10 ng/ml led to increased levels of both the α-SMA and Col2 expressions. In addition, we observed the formation of cartilage-like pellets from TGF-β2-treated SSPCs. Both α-SMA and Col2 were expressed in the pellet. In an in-vivo study, the α-SMA and Col2 protein expressions were significantly increased in the sclera of FDM eyes in comparison to contralateral control eyes. Similarly, the levels of TGF-β in the RPE-choroid complex of an FDM eye were also significantly elevated.
  
  
  CONCLUSIONS
  Based on the concept of stem cells possessing multipotent differentiation potentials, scleral chondrogenesis induced by SSPCs may play a role in myopia development. The increased expressions of the cartilage-associated proteins Col2 and α-SMA during scleral chondrogenesis may be potential markers for myopia development. In addition, the increased levels of TGF-β mRNA in the RPE-choroid complex might induce the chondrogenic change in the sclera during myopia development.
authors: Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors: Pei-Chang
authors: PC
authors: Wu
authors: Department of Dentistry, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors: Chia-Ling
authors: CL
authors: Tsai
authors: USC Institute for Genetic Medicine, University of Southern California, Los Angeles, CA.
authors: Gabriel M
authors: GM
authors: Gordon
authors: USC Institute for Genetic Medicine, University of Southern California, Los Angeles, CA ; Department of Ophthalmology, University of Southern California, Los Angeles, CA.
authors: Shinwu
authors: S
authors: Jeong
authors: USC Institute for Genetic Medicine, University of Southern California, Los Angeles, CA.
authors: Tatsuo
authors: T
authors: Itakura
authors: USC Institute for Genetic Medicine, University of Southern California, Los Angeles, CA.
authors: Nitin
authors: N
authors: Patel
authors: Department of Anatomy and Cell Biology, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA.
authors: Songtao
authors: S
authors: Shi
authors: USC Institute for Genetic Medicine, University of Southern California, Los Angeles, CA ; Department of Ophthalmology, University of Southern California, Los Angeles, CA ; Department of Cell & Neurobiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA.
authors: M Elizabeth
authors: ME
authors: Fini
mesh_terms: D000199:Actins / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000235:genetics*; D002829:Choroid / Q000378:metabolism / Q000473:pathology*; D024043:Collagen Type II / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D015870:Gene Expression; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009216:Myopia / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D012333:RNA, Messenger / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000473:pathology*; D012590:Sclera / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D016212:Transforming Growth Factor beta / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D053781:Transforming Growth Factor beta2 / Q000494:pharmacology
chemical_list: D000199:Actins; D024043:Collagen Type II; D012333:RNA, Messenger; C509042:Tgfb2 protein, mouse; D016212:Transforming Growth Factor beta; D053781:Transforming Growth Factor beta2; C544013:alpha-smooth muscle actin, mouse