AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studi...AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco's Modified Eagle's Medium(DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30 b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30 b on autophagy to promote hepatic IRI. The expression of miR-30 b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nickend labeling(TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene(Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.RESULTS: miR-30 b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30 b could promote hepatic IRI. Furthermore, we found that miR-30 b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30 b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30 b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.CONCLUSION: miR-30 b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.展开更多
AIM To investigate autophagy-related genes, particularly ATG12, in apoptosis and cell cycle in hepatitis B virus(HBV)-associated hepatocellular carcinoma(HCC) and non-HBV-HCC cell lines.METHODS The expression of autop...AIM To investigate autophagy-related genes, particularly ATG12, in apoptosis and cell cycle in hepatitis B virus(HBV)-associated hepatocellular carcinoma(HCC) and non-HBV-HCC cell lines.METHODS The expression of autophagy-related genes in HBVassociated hepatocellular carcinoma and non-HBV-HCC cell lines and human liver tissues was examined by quantitative real-time reverse transcriptase-polymerase chain reaction(q RT-PCR) and western blotting. The silencing of target genes was used to examine the function of various genes in apoptosis and cell cycle progression. RESULTS The expression of autophagy related genes ATG5, ATG12, ATG9 A and ATG4 B expression was analyzed in Hep G2.2.15 cells and compared with Hep G2 and THLE cells. We found that ATG5 and ATG12 m RNA expression was significantly increased in Hep G2.2.15 cells compared to HepG 2 cells(P < 0.005). Moreover, ATG5-ATG12 protein levels were increased in tumor liver tissues compared to adjacent non-tumor tissues mainly from HCC patients with HBV infection. We also analyzed the function of ATG12 in cell apoptosis and cell cycle progression. The percentage of apoptotic cells increased by 11.4% in ATG12-silenced Hep G2.2.15 cells(P < 0.005) but did not change in ATG12-silenced HepG 2 cells under starvation with Earle's balanced salt solution. However, the combination blockade of Notch signaling and ATG12 decreased the apoptotic rate of HepG 2.2.15 cells from 55.6% to 50.4%(P < 0.05). CONCLUSION ATG12 is important for HBV-associated apoptosis and a potential drug target for HBV-HCC. Combination inhibition of ATG12/Notch signaling had no additional effect on HepG 2.2.15 apoptosis.展开更多
基金Supported by National High Technology Research and Development Program(863)of China,No.2012AA021001National Natural Science Foundation of China,No.81270554+1 种基金Special Fund for Health Research in the Public Interest of China,No.201302009National Key Specialty Construction of Clinical Projects,No.201354409
文摘AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco's Modified Eagle's Medium(DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30 b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30 b on autophagy to promote hepatic IRI. The expression of miR-30 b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nickend labeling(TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene(Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.RESULTS: miR-30 b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30 b could promote hepatic IRI. Furthermore, we found that miR-30 b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30 b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30 b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.CONCLUSION: miR-30 b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.
基金Supported by National Research Council of Thailand 2013 and the Ratchadaphiseksomphot Matching Fund from the Faculty of Medicine,Chulalongkorn UniversityInternational Research Integration,Chula Research Scholar,Ratchadaphiseksomphot Endowment FundCenter of Excellence in Immunology and Immune-mediated Diseases and the Rachadapisaek Sompote Post-Doctoral Fund,Chulalongkorn University
文摘AIM To investigate autophagy-related genes, particularly ATG12, in apoptosis and cell cycle in hepatitis B virus(HBV)-associated hepatocellular carcinoma(HCC) and non-HBV-HCC cell lines.METHODS The expression of autophagy-related genes in HBVassociated hepatocellular carcinoma and non-HBV-HCC cell lines and human liver tissues was examined by quantitative real-time reverse transcriptase-polymerase chain reaction(q RT-PCR) and western blotting. The silencing of target genes was used to examine the function of various genes in apoptosis and cell cycle progression. RESULTS The expression of autophagy related genes ATG5, ATG12, ATG9 A and ATG4 B expression was analyzed in Hep G2.2.15 cells and compared with Hep G2 and THLE cells. We found that ATG5 and ATG12 m RNA expression was significantly increased in Hep G2.2.15 cells compared to HepG 2 cells(P < 0.005). Moreover, ATG5-ATG12 protein levels were increased in tumor liver tissues compared to adjacent non-tumor tissues mainly from HCC patients with HBV infection. We also analyzed the function of ATG12 in cell apoptosis and cell cycle progression. The percentage of apoptotic cells increased by 11.4% in ATG12-silenced Hep G2.2.15 cells(P < 0.005) but did not change in ATG12-silenced HepG 2 cells under starvation with Earle's balanced salt solution. However, the combination blockade of Notch signaling and ATG12 decreased the apoptotic rate of HepG 2.2.15 cells from 55.6% to 50.4%(P < 0.05). CONCLUSION ATG12 is important for HBV-associated apoptosis and a potential drug target for HBV-HCC. Combination inhibition of ATG12/Notch signaling had no additional effect on HepG 2.2.15 apoptosis.
