Get access

Plasmin plays a key role in the regulation of profibrogenic molecules in hepatic stellate cells

Authors

  • Abril Martínez-Rizo,

    1. Department of Molecular Biology and Genomics, CUCS, Institute for Molecular Biology in Medicine and Gene Therapy, University of Guadalajara, Guadalajara, Jalisco, Mexico
    Search for more papers by this author
  • Miriam Bueno-Topete,

    1. Department of Molecular Biology and Genomics, CUCS, Institute for Molecular Biology in Medicine and Gene Therapy, University of Guadalajara, Guadalajara, Jalisco, Mexico
    Search for more papers by this author
  • Jaime González-Cuevas,

    1. Department of Molecular Biology and Genomics, CUCS, Institute for Molecular Biology in Medicine and Gene Therapy, University of Guadalajara, Guadalajara, Jalisco, Mexico
    Search for more papers by this author
  • Juan Armendáriz-Borunda

    1. Department of Molecular Biology and Genomics, CUCS, Institute for Molecular Biology in Medicine and Gene Therapy, University of Guadalajara, Guadalajara, Jalisco, Mexico
    2. OPD Hospital Civil de Guadalajara, University of Guadalajara, Guadalajara, Jalisco, Mexico
    Search for more papers by this author

Correspondence
Dr Juan Armendáriz-Borunda, Department of Molecular Biology and Genomics, Institute for Molecular Biology in Medicine and Gene Therapy, University of Guadalajara, CUCS, U de G, Apdo. Postal 2-123, Guadalajara, Jalisco, México 44281
Tel: +52 33 10 58 53 17
Fax: 52 33 10 58 53 18
e-mail: armdbo@gmail.com

Abstract

Background: Plasmin role in transforming growth factor-β (TGF-β)-responsive gene regulation remains to be elucidated. Also, plasmin action on co-repressor Ski-related novel protein N (SnoN) and differential activation of matrix metalloproteinases (MMPs) are unknown. Thus, the role of plasmin on profibrogenic molecule expression, SnoN transcriptional kinetics and gelatinase activation was investigated.

Methods: Hepatic stellate cells (HSC) were transduced with adenovirus-mediated human urokinase plasminogen activator (Ad-huPA) (4 × 109 viral particles/ml). Overexpression of urokinase plasminogen activator and therefore of plasmin, was blocked by tranexamic acid (TA) in transduced HSC. Gene expression was monitored by reverse transcriptase polymerase chain reaction. HSC-free supernatants were used to evaluate MMP-2 and MMP-9 by zymography. SnoN, TGF-β and tissue inhibitor of metalloproteinase (TIMP)-1 were analysed by Western blot. Plasmin and SnoN expression kinetics were evaluated in bile duct-ligated (BDL) rats.

Results: Plasmin overexpression in Ad-huPA-transduced HSC significantly decreased gene expression of profibrogenic molecules [α1(I)collagen 66%, TIMP-1 59%, α-smooth muscle actin 90% and TGF-β 55%]. Interestingly, both SnoN gene and protein expression increased prominently. Plasmin inhibition by TA upregulated the profibrogenic genes, which respond to TGF-β-intracellular signalling. In contrast, SnoN mRNA and protein dropped importantly. Plasmin-activated MMP-9 and MMP-2 in HSC supernatants. Taken together, these findings indicate that MMP-9 activation is totally plasmin dependent. SnoN levels significantly decreased in cholestatic-BDL rats (82%) as compared with control animals. Interestingly, hepatic plasmin levels dropped 46% in BDL rats as compared with control.

Conclusion: Plasmin plays a key role in regulating TGF-β-responding genes. In particular, regulation of TGF-β-co-repressor (SnoN) is greatly affected, which suggests SnoN as a cardinal player in cholestasis-induced fibrogenesis.

Ancillary