title: Neovibsanin B increases extracellular matrix proteins in optic nerve head cells via activation of Smad signalling pathway.
abstract: The present study demonstrates the effect of neovibsanin B on the synthesis and deposition of ECM proteins and the signalling pathways used in optic nerve head (ONH) astrocytes and lamina cribrosa (LC) cells. For investigation of the signalling pathway used by neovibsanin B, ONH cells were treated with neovibsanin B. Western blot and immunostaining analyses were used to examine the phosphorylation of proteins involved in Smad and non-Smad signalling pathway. The results revealed that ONH cells on treatment with neovibsanin B showed enhanced synthesis of extracellular matrix (ECM) proteins. Neovibsanin B induced phosphorylation of canonical signalling proteins, Smad2/3. However phosphorylation of non-canonical signalling proteins, extracellular signal-regulated kinases, p38, and c-Jun N-terminal kinases (JNK) 1/2 remained unaffected. There was also increase in co-localization of pSmad2/3 with Co-Smad4 in the nucleus of ONH astrocytes and LC cells indicating activation of the canonical Smad signalling pathway. Treatment of ONH cells with SIS3, inhibitor of Smad3 phosphorylation reversed the neovibsanin B stimulated ECM expression as well as activation of canonical pathway signalling molecules. In addition, inhibition of Smad2 or Smad3 using small interfering RNA (siRNA) also suppressed neovibsanin B stimulated ECM protein synthesis in ONH astrocytes and LC cells. Thus neovibsanin B utilizes the canonical Smad signalling pathway to stimulate ECM synthesis in human ONH cells. The neovibsanin B induced ECM synthesis and activation of the canonical Smad signalling pathway may be due to its effect on transforming growth factor-β2 (TGF-β2). However, further studies are under process to understand the mechanism.
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Ao
authors.initials: A
authors.lastname: Rong
authors.affiliation: Department of Medical, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Xu-Ling
authors.initials: XL
authors.lastname: Qiu
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Qu
authors.affiliation: Department of Ophthalmology, Tongji Hospital, Tongji University School of Medicine Shanghai 200065, China.
authors.forename: Xian-Hai
authors.initials: XH
authors.lastname: Lan
mesh_terms: D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D009898:Optic Disk / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects*; D051899:Smad2 Protein / Q000235:genetics / Q000378:metabolism*; D051900:Smad3 Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014162:Transfection; D015854:Up-Regulation
chemical_list: D004224:Diterpenes; D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D017395:Plasminogen Activator Inhibitor 1; C051321:SERPINE1 protein, human; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; C539540:neovibsanin A
keywords: ECM expression; Smad signalling; glaucoma; phosphorylation; remodelling