Induction of autophagy and apoptosis by miR-148a through the sonic hedgehog signaling pathway in hepatic stellate cells.

Autophagy is an evolutionarily conserved biological process that is activated in response to stress. Increasing evidence indicate that dysregulated miRNAs significantly contribute to autophagy and are thus implicated in various pathological conditions, including hepatic fibrosis. MiR-148a, a member of the miR-148/152 family, has been found to be downregulated in hepatic fibrosis and human hepatocellular carcinoma. However, the role of miR-148a in the development of hepatic fibrosis remains largely unknown. In this study, we describe the epigenetic regulation of miR-148a and its impact on autophagy in hepatic stellate cells (HSCs), exploring new targets of miR-148a. We found that miR-148a expression was significantly increased under starvation-induced conditions in LX-2 and T-6 cells. In addition, dual-luciferase reporter assays showed that miR-148a suppressed target gene expression by directly interacting with the 3'-untranslated regions (3'-UTRs) of growth arrest-specific gene 1 (Gas1) transcripts. Intriguingly, Gas1, which encodes a Hedgehog surface binding receptor and facilitates the Hedgehog (Hh) signaling pathway, inhibited autophagosome synthesis. Furthermore, we demonstrated a novel function for miR-148a as a potent inducer of autophagy in HSCs. Overexpressing of miR-148a increased autophagic activity, which inhibited proliferation and promoted apoptosis in HSCs. In conclusion, these data support a novel role for miR-148a as a key regulator of autophagy through the Hh signaling pathway, making miR-148a a potential candidate for the development of novel therapeutic strategies.

Resveratrol ameliorates high glucose-induced oxidative stress injury in human umbilical vein endothelial cells by activating AMPK.

AIMS: To investigate the effects of resveratrol on high glucose (HG)-induced vascular injury, and to establish the mechanism(s) underlying these effects. MAIN METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with glucose, and then incubated with resveratrol in the presence or absence of Compound C, an AMP-activated protein kinase (AMPK) inhibitor. Cell viability was determined using the Cell Counting Kit-8 (CCK-8) method. Reactive oxygen species, malondialdehyde, and superoxide dismutase were detected by flow cytometry, thiobarbituric acid reaction, and the nitroblue tetrazolium method, respectively. Protein levels of total and phosphorylated AMPKα and acetyl-CoA carboxylase were detected by immunoblotting. KEY FINDINGS: Resveratrol significantly ameliorated HG-induced decreases in cell viability and superoxide dismutase levels and increases in reactive oxygen species and MDA levels. Moreover, resveratrol significantly reversed HG-induced dephosphorylation of AMPKα and acetyl-CoA carboxylase. However, treatment with Compound C curtailed the beneficial effects of resveratrol on HG-treated HUVECs. SIGNIFICANCE: Resveratrol ameliorates HG-induced injury in HUVECs by activation of AMPKα, leading to increased cellular reductive reactions and decreased oxidative stress. These results provide further evidence for resveratrol-mediated activation of AMPKα.

Diversity of methanogens in the hindgut of captive white rhinoceroses, Ceratotherium simum.

BACKGROUND: The white rhinoceros is on the verge of extinction with less than 20,200 animals remaining in the wild. In order to better protect these endangered animals, it is necessary to better understand their digestive physiology and nutritional requirements. The gut microbiota is nutritionally important for herbivorous animals. However, little is known about the microbial diversity in the gastrointestinal tract (GIT) of the white rhinoceros. Methanogen diversity in the GIT may be host species-specific and, or, function-dependent. To assess methanogen diversity in the hindgut of white rhinoceroses, an archaeal 16S rRNA gene clone library was constructed from pooled PCR products obtained from the feces of seven adult animals. RESULTS: Sequence analysis of 153 archaeal 16S rRNA sequences revealed 47 unique phylotypes, which were assigned to seven operational taxonomic units (OTUs 1 to 7). Sequences assigned to OTU-7 (64 out of 153 total sequencs - 42%) and OTU-5 (18%, 27/153) had 96.2% and 95.5% identity to Methanocorpusculum labreanum, respectively, making Methanocorpusculum labreanum the predominant phylotype in these white rhynoceroses. Sequences belonging to OTU-6 (27%, 42/153) were related (97.6%) to Methanobrevibacter smithii. Only 4% of the total sequences (6/153) were assigned to Methanosphaera stadtmanae (OTU-1). Sequences belonging to OTU-2 (4%, 6/153), OTU-3 (3%, 5/153) and OTU-4 (2%, 3/153) were distantly related (87.5 to 88,4%) to Methanomassiliicoccus luminyensis and were considered to be novel species or strains that have yet-to-be cultivated and characterized. CONCLUSION: Phylogenetic analysis indicated that the methanogen species in the hindgut of white rhinoceroses were more similar to those in the hindgut of horses. Our findings may help develop studies on improving the digestibility of forage for sustainable management and better health of these endangered animals.

Protective effect of tetramethylpyrazine isolated from Ligusticum chuanxiong on nephropathy in rats with streptozotocin-induced diabetes.

PURPOSE: This study was designed to investigate the protective effect of tetramethylpyrazine isolated from Ligusticum chuanxiong, a traditional Chinese medicine, on diabetic nephropathy in a rat model, and to explore the possible mechanism involved in a protective function. MATERIALS: Diabetes was induced in male Sprague-Dawley rats by a single intraperitoneal injection of 70mg/kg of streptozotocin. One week later, 200mg/kg/day of tetramethylpyrazine was administered intragastric gavage daily for 8 weeks. Renal functions and expression of vascular endothelial growth factor were examined at 4 and 8 weeks after tetramethylpyrazine administration. RESULTS: Blood glucose and renal function were significantly improved in the tetramethylpyrazine-treated group compared to the untreated diabetic rats. Diabetic nephropathy resulted in an increase in the expression of vascular endothelial growth factor, while tetramethylpyrazine administration greatly decreased the expression. CONCLUSIONS: Our results suggest that administration of tetramethylpyrazine may reduce kidney damage caused by diabetes. This protective effect may be mediated, in part, by downregulated expression of vascular endothelial growth factor in the kidney.

Percutaneous endoscopic gastrostomy/jejunostomy combined with percutaneous transhepatic biliary drainage in treating malignant biliary obstruction.

OBJECTIVE: To investigate the safety and efficacy of percutaneous endoscopic gastrostomy/jejunostomy (PEG/PEJ) combined with percutaneous transhepatic biliary drainage (PTCD) in treating malignant biliary obstruction. SUBJECTS AND METHODS: Nine patients (6 males and 3 females, average age 71.3 ± 5.5 years) with complete obstruction of the biliary tract were treated with PEG/PEJ after PTCD. The PEG/PEJ and PTCD tubes were linked outside of the abdominal wall to direct the externally drained bile back to the jejunum through the PEG/PEJ intestinal tube. Clinical symptoms and liver function were assessed following the treatment. RESULTS: The operations were successfully completed in the 9 patients within 40 min (average 35 ± 2.9 min). Clinical symptoms such as jaundice, abdominal distension, stomachache and diarrhea appeared but improved within 7 days of the operation. Serum levels of bilirubin, aspartate aminotransferase and alanine aminotransferase were reduced (p < 0.01) 4 weeks following the treatment. There were no procedural complications. CONCLUSIONS: Combined PEG/PEJ and PTCD appeared to be safe and effective in the management of malignant biliary obstruction. Further, larger-scale studies will be needed to verify findings of this report.

A potential regulatory single nucleotide polymorphism in the promoter of the Klotho gene may be associated with essential hypertension in the Chinese Han population.

BACKGROUND: Mice with defects in the Klotho gene exhibit multiple aging phenotypes including arteriosclerosis. We hypothesised that the G-395A polymorphism in the promoter region of the human Klotho gene may contribute to the prevalence of Essential Hypertension (EH). METHODS: We investigate whether the G-395A polymorphism of Klotho is associated with EH in a population consisting of 215 patients with EH and 220 non-hypertensive subjects. We also tested whether a G/A substitution at the G-395A site affected the transcription level in vitro through the dual-luciferase reporter assay. RESULTS: Differences in the genotype distributions of the G-395A polymorphism between the EH and non-hypertension groups are statistically significant (P=0.032). There are differential effects of age, gender and smoking status on the association of the G-395A polymorphism with EH; the G-395A polymorphism is significantly associated with EH in subjects over 60years old, in females and in nonsmokers. A multiple logistic regression analysis indicated that the odds ratio for EH in the -395A allele carriers as compared with the control group was 0.593 (P=0.024) after adjusting for current traditional risk factors. The dual-luciferase reporter assay revealed that the -395A carrier of a 498-bp DNA fragment (containing the G-395A site) upstream of the Klotho gene has higher relative luciferase activity than the -395G carrier. CONCLUSIONS: The G-395A polymorphism of the human Klotho gene is associated with EH and may be a potential regulatory site.

[Ultrastructural changes of duodenal mucosas and their significance in patients with liver cirrhosis].

OBJECTIVE: To investigate the ultrastructural changes of duodenal mucosas and their significance in patients with liver cirrhosis (PLC). METHODS: Endoscopic biopsy duodenal mucosa specimens of 60 PLC and 18 healthy volunteers as controls were obtained. Ultrastructural changes of them were studied with transmission electron microscopy. These PLC were divided into groups A, B and C according to the Child-Pugh classification. The ultrastructural changes in the duodenal mucosas of each group were rated and compared with those of the other groups. PLC with and without ultrastructural changes of duodenal mucosas were divided into a positive group and a negative group. Levels of plasma Alb, TBil, PT, plasma endotoxin, and blood ammonia of the PLC were detected and compared. RESULTS: There were 20 PLC each in groups A, B, and C. Ultrastructural changes of duodenal mucosas were found in 5 PLC of group A, 9 in group B and 17 in group C. Among the 60 PLC, 52% had some changes in their duodenal mucosas. The changes included decrease and rupture of the microvilli; also karyopyknosis, karyorrhexis, widening of the gaps of the tight junction and tumefactions of mitochodrion of duodenal mucosa epithelial cells. No ultrastructural changes of duodenal mucosas were found in the control group. The rate of changes in the three Child-Pugh class groups and in the control group were 25%, 45%, 85%, 0% respectively (P < 0.01). The level of Alb of the positive group was significantly lower than that of the negative group (P < 0.01). Levels of plasma TBil, PT, endotoxin and blood ammonia of the positive group were significantly higher or longer than those of the negative group (P < 0.01). Levels of plasma Alb of the positive and negative groups were significantly lower than those of the control group (P < 0.01). Levels of TBil, PT, plasma endotoxin and blood ammonia of the positive and negative groups were significantly higher or longer than those of the control group (P < 0.01). CONCLUSION: There were ultrastructural changes of duodenal mucosas in PLC, especially in end-stage PLC. Ultrastructural changes of intestinal mucosas in the PLC may have important pathophysiological and clinical significance.