Endoplasmic reticulum stress and protein degradation in chronic liver disease.

Endoplasmic reticulum (ER) stress is easily observed in chronic liver disease, which often causes accumulation of unfolded or misfolded proteins in the ER, leading to unfolded protein response (UPR). Regulating protein degradation is an integral part of UPR to relieve ER stress. The major protein degradation system includes the ubiquitin-proteasome system (UPS) and autophagy. All three arms of UPR triggered in response to ER stress can regulate UPS and autophagy. Accumulated misfolded proteins could activate these arms, and then generate various transcription factors to regulate the expression of UPS-related and autophagy-related genes. The protein degradation process regulated by UPR has great significance in many chronic liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), viral hepatitis, liver fibrosis, and hepatocellular carcinoma(HCC). In most instances, the degradation of excessive proteins protects cells with ER stress survival from apoptosis. According to the specific functions of protein degradation in chronic liver disease, choosing to promote or inhibit this process is promising as a potential method for treating chronic liver disease.

LncRNA-H19 induces hepatic stellate cell activation via upregulating alcohol dehydrogenase III-mediated retinoic acid signals.

Activation of hepatic stellate cells (HSCs) is a pivotal event in liver fibrosis, characterized by enhanced retinoic acid signals. Although up-regulated retinoic acid signal responds further to maintain HSC activation, the underlying molecular mechanisms are largely unknown. In this study, we sought to investigate the role of lncRNA-H19 in regulation of retinoic acid signals, and to further examine the underlying mechanism in this molecular context. We found that lncRNA-H19 upregulation could enhance retinoic acid signals to induce HSC activation, whereas lncRNA-H19 knockdown completely disturbed retinoic acid signals. Moreover, the activation of retinoic acid signals impaired the lncRNA-H19 knockdown mediated HSC inactivation. Interestingly, we also found that enhanced retinoic acid signals by lncRNA-H19 was associated with a coordinate increase in retinol metabolism during HSC activation. Increased retinol metabolism contributed to obvious lipid droplet consumption. Importantly, we identified that alcohol dehydrogenase III (ADH3) was essential for lncRNA-H19 to enhance retinoic acid signals. The inhibition of ADH3 completely abrogated the lncRNA-H19 mediated retinoic acid signals and HSC activation. Of note, we identified dihydroartemisinin (DHA) as a natural inhibitor for lncRNA-H19. Treatment with DHA significantly decreased the expression of lncRNA-H19, reduced the expression of ADH3, blocked retinoic acid signals, and in turn, inhibited HSC activation. Overall, these results provided novel implications to reveal the molecular mechanism of increased retinoic acid signals during HSC activation, and identify lncRNA-H19/ADH3 pathway as a potential target for the treatment of liver fibrosis.

Effects of Chinese herbal cataplasm Xiaozhang Tie on cirrhotic ascites.

BACKGROUND: Conventional methods of treating cirrhotic ascites are inadequate. We sought to identify a novel, effective approach to relieve the suffering of patients with cirrhotic ascites. AIM OF THE STUDY: To investigate the efficacy of Xiaozhang Tie, a traditional Chinese herbal cataplasm composed of dahuang (Rheum palmatum L.), laifuzi (Raphanus sativus L.), concocted gansui (Euphorbia kansui T.N. Liou ex T.P. Wang), chenxiang [Aquilaria sinensis (Lour.) Gilg], dingxiang (Eugenia caryophyllata Thunb.), bingpian (Borneolum syntheticum) and shexiang (artificial Moschus), as an adjuvant in treating cirrhotic ascites. MATERIALS AND METHODS: A multicenter, randomized, placebo-controlled trial was conducted. One hundred patients with cirrhotic ascites were divided into two groups of equal size. The test group took an umbilical compress with Xiaozhang Tie for 30 days while the control group was administered an umbilical compress with placebo, in addition to primary therapy. Efficacy was evaluated according to the criteria including ascites volume, urine 24-h volume, abdominal circumference, body weight, abdominal distention, appetite, flatus and defecation. RESULTS: Ninety-two patients completed the study, 7 were withdrawn and 1 was excluded. The effective rate of grades I and II was 63.3% for the test group (n=49) and 38.0% for the control one (n=50). Both groups showed decreased body weight and abdominal circumference, increased urine volume and improved symptoms after treatment. However, the differences between pre-treatment and post-treatment in body weight, abdominal circumference and urine volume were 8.7±5.8 kg, 12.4±8.3 cm and 683±644 ml respectively in the test group, noticeably higher than those in the control group, which were 5.3±4.6 kg, 8.0±6.5 cm and 372±697 ml, respectively. The ranking orders of the symptoms of the test group were significantly lower than those of the control group after treatment. No severe adverse reactions were seen. CONCLUSION: Xiaozhang Tie as an adjuvant to primary therapy of cirrhotic ascites is safe and shows a remarkable efficacy on relieving abdominal distention.

[Effects of Fuzheng Huayu recipe on MMP-2 activity and type IV collagen expression at fibrotic lung].

OBJECTIVE: To study the mechanism of Fuzheng Huayu (FZHY) recipe against pulmonary fibrosis relating to MMP-2 activity and type IV collagen expression at lung tissue. METHOD: The pulmonary fibrosis model was induced by intratracheal instillation with bleomycin once in rats. The models were divided into 3 groups: model control, FZHY recipe treated, and methylprednisolone (Solu-Medrol) treated group, each group was of 14 model rats. Normal control group with 10 rats was intoxicated with the same amount of saline. From the second day of intoxication, FZHY recipe treated group orally took FZHY recipe at the dosage of 4.6 g x kg(-1) rat wt, methylprednisolone treated group received intraperitoneal injection with 15 mg x kg(-1) rat wt of methylprednisolone, while model and normal controls took the same volume of saline, 1 time each day and lasting for 4 weeks. Lung and body weights were weighed and the lung/body ratio was calculated. Collagens deposition was check with Masson stain, and lung hydroxyproline (Hyp) content was assayed with Jamall's method. Protein expressions of MMP-2/9 and type IV collagen at lung tissue were analyzed with Western blot and of MMP-2/9 activities by gelatin zymography. RESULT: Compared to normal rats, the model control rats had a high lung/body ratio, remarkable collagen deposition, increased Hyp content and the expressions of type IV collagen, MMP-2 and MMP-9 protein at lung tissue, increased MMP-2 activity, in particular active MMP-2 activity, but decreased MMP-9 activity. Compared to model control, FZHY recipe and methylprednisolone obviously attenuated pulmonary collagen deposition, decreased lung/body ratio and Hyp content, downregulated MMP-2 protein expression and activity, in particular active MMP-2 activity, and FZHU recipe had some better actions than methylprednisolone on lung/body ratio, type IV collagen expression and active MMP-2 activity. But both drug groups had no influence on MMP-9 protein expression and activity. CONCLUSION: FZHY recipe has a good action against experimental pulmonary fibrosis and its mechanisms are associated with the inhibition of MMP-2 protein and activity, and with the inhibition of over expression of type IV collagen at lung tissue.

[Feature changes of MMP-2/9 activities and TIMP-1/2 protein expressions during the progression of pulmonary fibrosis in rats].

OBJECTIVE: To investigate the dynamic trends of activities of matrix metalloproteinase (MMP)-2/9 and protein expressions of their inhibitors-tissue inhibitor of matrix metalloproteinase (TIMP)-1/2 during the progression of pulmonary fibrosis in rats so as to get insight of the roles played by MMP-2/9 in lung injury and fibrogenesis. METHODS: Forty-eight SD rats were randomly divided into normal control group (n=18) and bleomycin (BLM)-treated group (n=30). The pulmonary fibrosis was induced by intratracheal injection of BLM once. At the consecutive time of 1 day, 3 days, 1 week, 2, 3, and 4 weeks after intoxication, the lung-to-body weight ratio was calculated and the inflammation and collagen deposition in lung tissue were checked by HE and Masson stainings respectively. Meanwhile, the content of hypdroxyproline (Hyp) in lung tissue was assayed with Jamall's method, the protein expressions of MMP-2/9, TIMP-1/2 were examined by Western blotting, and the activities of MMP-2/9 were detected by gelatin zymography. RESULTS: The histopathological changes in lung tissue in the BLM-treated group from 1 day to 2 weeks after intoxication presented local lesions, broadened alveolar wall and septum, infiltration with lots of inflammatory cells and few of fibroblasts inside alveolar space and septum. At this early stage in the BLM-treated group, the lung-to-body weight ratio was increased significantly, the protein expressions and activities of MMP-2/9 were obviously increased especially for activity of active MMP-2, and the protein expressions of TIMP-1/2 were also increased gradually, as compared with those in the normal control group. From 3 to 4 weeks after intoxication in the BLM-treated group, the alveolar structure was damaged, parts of the alveolar space collapsed and replaced by collagens and fibroblasts, and the alveolar wall and septum obviously widened with remarkable fibrotic characteristics, as compared with those in the normal control group. Meanwhile, the lung-to-body weight ratio and the activities of MMP-2/9 were decreased in the BLM-treated group as compared with those in the same group at 2 weeks after intoxication, but the content of Hyp and the protein expressions of TIMP-1/2 were both increased dramatically, especially at 4 weeks after intoxication. CONCLUSIONS: During the lung fibrogenesis induced by BLM in rats, the alveolar inflammation is the most important alteration with enhanced MMP-2/9 activities in the early stage. While in the late stage, the main change is displayed as pulmonary fibrosis, characterized by increased TIMP-1/2 and declined MMP-2/9 activities.