title: [Effects of matrix metallopeptidase 9 on the proliferation, apoptosis, type I and III procollagen synthesis of rat dermal fibroblasts].
abstract: OBJECTIVE
  To explore the effects of matrix metallopeptidase 9 (MMP-9) on the proliferation, apoptosis, type I and III procollagen synthesis of rat dermal fibroblasts.
  
  
  METHODS
  Lipopolysaccharide (LPS) at 0.1 and 1.0 µg/ml was used to stimulate fibroblasts to up-regulate the expression of MMP-9 for 18 and 48 h. And then RNA interference was employed to inhibit the high expression of MMP-9. Cell proliferation was tested by CCK-8, cell apoptosis by flow cytometry and type I and III procollagen expressions by quantitative reverse transcriptase PCR (qRT-PCR).
  
  
  RESULTS
  The MMP-9 expression of fibroblasts increased after the stimulation of LPS. And the 1.0 µg/ml LPS stimulation of 48 hours was 14.25 times of mRNA expression and 2.31 times of protein expression versus that of the normal group (both P < 0.05). The RNA interference obviously inhibited the high expression of MMP-9. The mRNA expression was 1/8 and protein expression 1/3 (both P < 0.05) as compared with the control group. Cell proliferation decreased with the rising expression of MMP-9 to some extent [(1.08 ± 0.08) vs (1.18 ± 0.09), P < 0.05] and improved after the inhibition of high expression of MMP-9 [(1.78 ± 0.17) vs (1.53 ± 0.15), P < 0.01]. There was no change of apoptosis accompanied with high expression of MMP-9 (P > 0.05). Apoptosis decreased after the inhibition of high expression of MMP-9 for 48 hours (3.53% ± 0.22% vs 4.47% ± 0.46%, P < 0.05). The synthesis of type I procollagen was the same no matter up-regulation or down-regulation of MMP-9 expression (P > 0.05). As the expression of MMP-9 increased, the synthesis of type III procollagen decreased (P < 0.01), but not increased by 1.02 folds after the inhibited expression of MMP-9 (P > 0.05).
  
  
  CONCLUSIONS
  MMP-9 can affect the biological behaviors of rat dermal fibroblasts.
authors.affiliation: Department of Endocrinology, Sun Yat-set Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.
authors.forename: Diao-Zhu
authors.initials: DZ
authors.lastname: Lin
authors.forename: Chuan
authors.initials: C
authors.lastname: Yang
authors.forename: Li-Hong
authors.initials: LH
authors.lastname: Chen
authors.forename: Meng
authors.initials: M
authors.lastname: Ren
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.forename: Sheng-Neng
authors.initials: SN
authors.lastname: Xue
authors.forename: Li
authors.initials: L
authors.lastname: Yan
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D011347:Procollagen / Q000096:biosynthesis*; D051381:Rats
chemical_list: D011347:Procollagen; D020780:Matrix Metalloproteinase 9