Increase of glycosaminoglycans and metalloproteinases 2 and 9 in liver extracellular matrix on early stages of extrahepatic cholestasis

Chondroitin Sulfate Protects the Liver in an Experimental Model of Extra-Hepatic Cholestasis Induced by Common Bile Duct Ligation

During liver fibrogenesis, there is an imbalance between regeneration and wound healing. The current treatment is the withdrawal of the causing agent; thus, investigation of new and effective treatments is important. Studies have highlighted the action of chondroitin sulfate (CS) in different cells; thus, our aim was to analyze its effect on an experimental model of bile duct ligation (BDL). Adult Wistar rats were subjected to BDL and treated with CS for 7, 14, 21, or 28 days intraperitoneally. We performed histomorphometric analyses on Picrosirius-stained liver sections. Cell death was analyzed according to caspase-3 and cathepsin B activity and using a TUNEL assay. Regeneration was evaluated using PCNA immunohistochemistry. BDL led to increased collagen content with corresponding decreased liver parenchyma. CS treatment reduced total collagen and increased parenchyma content after 21 and 28 days. The treatment also promoted changes in the hepatic collagen type III/I ratio. Furthermore, it was observed that CS treatment reduced caspase-3 activity and the percentage of TUNEL-positive cells after 14 days and cathepsin B activity only after 28 days. The regeneration increased after 14, 21, and 28 days of CS treatment. In conclusion, our study showed a promising hepatoprotective action of CS in fibrogenesis induced by BDL.

SP1 and UTE1 Decoy ODNs inhibit activation and proliferation of hepatic stellate cells by targeting tissue inhibitors of metalloproteinase 1

Background

The excessive accumulation of extracellular matrix of hepatic fibrosis is positively correlated with tissue inhibitors of metalloproteinase 1 (TIMP1). Here we aimed to investigate whether TIMP1 may be down-regulated by Decoy ODNs strategy to capture transcriptional factor upstream TIMP1 element 1 (UTE1) and specificity protein 1(SP1).

Results

By luciferase reporter assays, we confirmed that these Decoy ODNs could influence the promoter activation of TIMP-1, α-SMA and Collagen Iα2 (COLΙα2) genes as well as the enhancer activation of TRE in HSC-T6 cells, and the combination tended to be more effective than SP1 or UTE1 Decoy ODN alone. Western blot analysis also demonstrated down-regulation of the expression of those target genes except for TGF-β. Furthermore, we observed that the viability of HSC-T6 cells at 72 h was significantly in decline in combination group.

Conclusion

The combination of SP1 and UTE1 Decoy ODNs treatments inhibit the activation and proliferation of HSCs more effectively than one of the Decoy ODNs through co-regulation of TIMP1 and TGF-β signal pathway but not the expression of TGF-β itself.

Glycosaminoglycan remodeling during diabetes and the role of dietary factors in their modulation

Glycosaminoglycans (GAGs) play a significant role in various aspects of cell physiology. These are complex polymeric molecules characterized by disaccharides comprising of uronic acid and amino sugar. Compounded to the heterogeneity, these are variously sulfated and epimerized depending on the class of GAG. Among the various classes of GAG, namely, chondroitin/dermatan sulfate, heparin/heparan sulfate, keratan sulfate and hyaluronic acid (HA), only HA is non-sulfated. GAGs are known to undergo remodeling in various tissues during various pathophysiological conditions, diabetes mellitus being one among them. These changes will likely affect their structure thereby impinging on their functionality. Till date, diabetes has been shown to affect GAGs in organs such as kidney, liver, aorta, skin, erythrocytes, etc. to name a few, with deleterious consequences. One of the mainstays in the treatment of diabetes is though dietary means. Various dietary factors are known to play a significant role in regulating glucose homeostasis. Furthermore, in recent years, there has been a keen interest to decipher the role of dietary factors on GAG metabolism. This review focuses on the remodeling of GAGs in various organs during diabetes and their modulation by dietary factors. While effect of diabetes on GAG metabolism has been worked out quite a bit, studies on the role of dietary factors in their modulation has been few and far between. We have tried our best to give the latest reports available on this subject.