Silencing tissue inhibitors of metalloproteinases (TIMPs) with short interfering RNA reveals a role for TIMP-1 in hepatic stellate cell proliferation

Journal Article · Fri Apr 08 04:00:00 EDT 2011 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2011.02.009· OSTI ID:22204872

Collins, Jane E.; Duncombe, Dale R.; Pickering, Judith A. ^[1]; Rosenberg, William M.C. ^[2]; Benyon, R. Christopher ^[1]

---

1. Liver and Pancreas Group, University of Southampton, Division of Infection, Inflammation and Immunity, Southampton General Hospital, Southampton (United Kingdom)
2. Centre for Hepatology, Division of Medicine, University College London, London (United Kingdom)

Research highlights: {yields} Myofibroblastic, activated hepatic stellate cells (HSC) play a pivotal role in the development of liver fibrosis. {yields} We used short interfering RNA (siRNA) to investigate the effects of autocrine TIMP-1 and -2 on HSC proliferation. {yields} Specific silencing of TIMP-1, but not TIMP-2, significantly reduces HSC proliferation and is associated with reduced Akt phosphorylation. {yields} TIMP-1 is localised in part to the HSC nucleus. {yields} TIMP-1 might promote liver fibrosis by means other than its previously described anti-apoptotic effect on HSC. -- Abstract: Myofibroblastic, activated hepatic stellate cells (HSC) play a pivotal role in the development of liver fibrosis through the secretion of fibrillar collagens and the tissue inhibitors of metalloproteinase (TIMP)-1 and -2. TIMPs are believed to promote hepatic fibrosis by inhibiting both matrix degradation and apoptosis of HSC. In other cell types, there is evidence that TIMP-1 has effects on proliferation, however the role of TIMPs in the regulation of HSC proliferation remains unexplored. Therefore, we have used short interfering RNA (siRNA) to investigate the effects of autocrine TIMP-1 and -2 on HSC proliferation. TIMP-1 and -2 siRNA were highly effective, producing peak target protein knockdown compared to negative control siRNA of 92% and 63%, respectively. Specific silencing of TIMP-1, using siRNA, significantly reduced HSC proliferation. TIMP-1 was localised in part to the HSC nucleus and TIMP-1 siRNA resulted in loss of both cytoplasmic and nuclear TIMP-1. Attenuated proliferation was associated with reduced Akt phosphorylation and was partially rescued by addition of recombinant TIMP-1. We have revealed a novel autocrine mitogenic effect of TIMP-1 on HSC, which may involve Akt-dependent and specific nuclear mechanisms of action. We suggest that TIMP-1 might promote liver fibrosis by means other than its previously described anti-apoptotic effect on HSC. Moreover, these findings, together with our previous reports and the emerging data from in vivo studies of TIMP inhibition, provide strong evidence that TIMP-1 is mechanistically central to liver fibrosis and an important potential therapeutic target.

• OSTI ID: 22204872
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 407; ISSN BBRCA9; ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ANIMAL TISSUES
APOPTOSIS
CELL PROLIFERATION
COLLAGEN
FIBROSIS
IN VIVO
INHIBITION
LIVER
PHOSPHORYLATION
RNA
SECRETION