Anti-TIMP2 monoclonal antibody, clone 4I9

Hepatic fibrosis is a result of constant wound-healing response caused by repeated injury in liver. Up to now, there is still no standard treatment for this disease. Tissue inhibitors of metalloproteinase (TIMP) 1/2 have been described to be highly expressed in liver with hepatic fibrosis. However, whether the down-regulation of these two proteins would show protective or curative effect against hepatic fibrosis remains to be defined. In this study, using a shRNA lentiviral system, we investigated the effect of TIMP1/2 down-regulation against hepatic fibrosis on a rat model. Our results showed that specifically knock-down of TIMP1 or TIMP2 could significantly alleviate the severity of hepatic fibrosis. Further study also showed that matrix metalloproteinase (MMP)-1 and MMP-13 were significantly increased in rats with TIMP1/2 knock-down. Signaling pathway analysis by RT-PCR and western blot further revealed that the altered expression of TGF-beta 1-Smad signaling pathway proteins including TGF-beta 1, Smad3 and Smad7 was modulated back to normal levels in TIMP1/2 knock-down rats. Taken together, our study revealed that specifically knocking-down of TIMP1 or TIMP2 by shRNA lentiviral particles could increase the expression of MMP-1 and MMP-13 and alleviate the severity of hepatic fibrosis, probably via TGF-beta 1-Smad signaling pathway. The findings in this study imply a novel treatment strategy against hepatic fibrosis.

Background: Reduced beta(2)-glycoprotein I (reduced beta(2)GP I), which has free sulfhydryl groups, is present in plasma and serum; it can protect vascular endothelial cells from damage due to oxidative stress in vitro. We investigated the effects of reduced beta(2)GP I on the expression of various matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the aortas of diabetic mice. Methods: We provided 120 female 8-week-old Balb/c mice with a high sugar, high fat diet. After 8 weeks they were injected with streptozotocin to induce diabetes. We treated mice in the mono dose groups with beta(2)GP I, reduced beta(2)GP I, or phosphate-buffered saline (PBS) on day 1 and fed them for 3 weeks. The mice in the complex dose groups were treated with beta(2)GP I, reduced beta(2)GP I, or PBS on days 1 and 22 and fed for 6 weeks. Control mice were given a standard chow diet. Blood lipids were measured at the end of 3 or 6 weeks, and aortas removed to observe morphological and molecular biological changes. Results: The low-density lipoprotein cholesterol levels in mice of the reduced beta(2)GP I group were lower than those in the diabetic group. Aortic lipid deposition in the reduced beta(2)GP I group was significantly less than in the diabetic control group. In the aortas, reduced beta(2)GP I decreased MMP2/TIMP2 mRNA and protein expression levels, and MMP9/TIMP1 expression levels compared with those in diabetic controls. Reduced beta(2)GP I down-regulated p38 mitogen-activated protein kinase (p38MAPK) mRNA expression and phosphorylated p38MAPK protein expression compared with those in diabetic controls of the complex dose group. Conclusions: Reduced beta(2)GP I plays a role in diabetic mice related to vascular protection, inhibiting vascular lipid deposition, and plaque formation by reducing MMPs/TIMPs expression through down-regulation of the p38MAPK signaling pathway.