Activation of Sonic hedgehog signaling in ventricular cardiomyocytes exerts DNA protection against hypoxia / 中国药理学通报

Aim To investigate the protective roles of sonic hedgehog( Shh) signaling pathway in hypoxia-in-duced DNA damage with the neonatal rat cardiomyo-cytes. Methods The hypoxia model on neonatal car-diomyocytes was established with one to two days old Sprague Dawley rats by deprivation of oxygen and glu-cose ( OGD) . After pretreated with Shh pathway ago-nist SAG1.3 or antagonist GANT61, the survival rates of cardiomyocytes were assayed by MTT after OGD 6 hours or 12 hours. The protein levels of Shh pathway, phosphorylated histone H2AX at serine 139 (γH2AX), phosphorylated ATM (p-ATM), phospho-rylated p53 ( p-p53 ) , cleaved-caspase-3, Bcl-2 and Bax were detected by Western blot. The γH2AX foci was detected by immunofluorescence. Results Com-pared to control group, the protein expression of γH2AX, p-ATM, cleaved-caspase-3, p-p53 in OGD cardiomyocytes significantly increased, and Bcl-2/Bax ratio proportionally decreased. Particularly, the ex-pression of γH2AX, p-ATM was highest at OGD 6 h, and then gradually declined after OGD 12 h. After SAG1.3 pretreatment, the expression of γH2AX, p-ATM, cleaved-caspase-3 and p-p53 dramatically de-creased and the Bcl2/Bax ratio increased in OGD 6 h or OGD 12 h cardiomyocytes. On the contrary, in GANT61 pretreatment group, the expression of γH2AX, p-ATM, cleaved-caspase-3 and p-p53 signifi-cantly increased and the Bcl-2/Bax ratio decreased compared to the OGD 6 h or OGD 12 h cardiomyo-cytes. Conclusion The activation of Shh pathway protects cardiomyocytes against hypoxia-induced apop-tosis through inhibition of DNA damage.

The role of JNK in apoptosis of renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the signal transduction mechanisms of apoptosis in renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose.</p><p><b>METHODS</b>Healthy SD rats were randomly divided into 3 groups: normal control group (A), stable high blood glucose group (B) and fluctuant high blood glucose group (C). Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg), and the fluctuant high blood glucose animal model was induced by intraperitoneal injection of ordinary insulin and glucose at different time point every day. The superoxide dismutase (SOD) activity and the content of malonaldehyde (MDA) in renal tissue homogenate were detected with colorimetry. The protein expression of Nox4 and JNK were examined by immunohistochemistry and Western blot. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL).</p><p><b>RESULTS</b>After 12 experimental weeks, significantly increased cell apoptosis, up-regulation of Nox4 and P-JNK expression in renal tubular epithelial cells were observed in B and C groups compared with those in A group. The MDA content increased and SOD activity decreased in renal tissue in B and C groups. Above effects were more obviously shown in C group.</p><p><b>CONCLUSION</b>Fluctuant high blood glucose induced more apoptosis of renal tubular epithelial cell than stable high blood glucose in diabetic kidney, which might be related to the activation of JNK signal transduction pathway.</p>

Influence of miR-122 on IFN-α treatment for HCV infection / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the influence of miR-122 on IFN-α treatment for HCV infection.</p><p><b>METHODS</b>Huh7.5.1 cells infected with HCV were treated with miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L) and/or IFN-α (1000 IU/ml). The relative expression of HCV RNA was detected by real-time polymerase chain reaction (PCR). Huh7.5.1 cells were treated with different amounts of HCV (107 copies, 106 copies and 105 copies) and/or IFN-α (1000 IU/ml).</p><p><b>RESULTS</b>IFN-α suppressed the replication of HCV in a time-dependent manner, resulting in a ≊ 83% reduction of HCV at 48 h. MiR-122 mimics facilitated replication of HCV RNA in a dose-dependent manner (P<0.05). The antiviral effect of IFN-α was inverted to levels of miR-122 mimics (20 nmol/L, 100 nmol/L, 400 nmol/L), (73.3% ± 3.5% compared with 84% ± 4.5%, P>0.05; 64.67% ± 5.5% compared with 84% ± 4.5%, P>0.05; 56.33% ± 5.1% compared with 84% ± 4.5%, P<0.05). The antiviral effect of IFN-α was inverted to HCV load (105 copies group compared with 107 copies group, P<0.05).</p><p><b>CONCLUSION</b>MiR-122 facilitates replication of HCV RNA in the cell culture system; and the expression of miR-122 may partly counteract the anti-HCV effect of IFN-α.</p>

Advances in Mechanism of Microbial Degradation of Phenanthrene / 微生物学通报

This review is outlined in terms of the advances in mechanism about microbial degradation of phenanthrene. The degradation pathways of phenanthrene by bacteria and fungus , including aerobic and anaerobic conditions, are discussed respectively. Furthermore, both the enzymes involved in the reactions and the gene clusters encoding for the enzymes are summarized. The application of gene probe is introduced briefly. Based on the preliminary results of our laboratory, it is found that some questions should be taken into more consideration.